汽车电子系统中英文对照外文翻译文献

汽车电子系统中英文对照外文翻译文献

汽车电子系统中英文对照外文翻译文献

汽车电子系统中英文对照外文翻译文献

(文档含英文原文和中文翻译)

The Changing Automotive Environment:

High-Temperature Electronics

R. Wayne Johnson, Fellow, IEEE, John L. Evans, Peter Jacobsen, James R. (Rick)

Thompson, and Mark Christopher

Abstract

—

The underhood automotive environment is harsh and current trends

in the automotive electronics industry will be pushing the temperature

envelope for electronic components. The desire to place engine control units

on the engine and transmission control units either on or in the transmission

will push the ambient temperature above 125℃However, extreme cost

125

℃.

pressures,increasing reliability demands (10 year/241 350 km) and the cost

of field failures (recalls, liability, customer loyalty) will make the shift

to higher temperatures occur incrementally. The coolest spots on engine and

in the transmission will be used. These large bodies do provide considerable

heat sinking to reduce temperature rise due to power dissipation in the control

unit. The majority of near term applications will be at 150 ℃ or less and

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these will be worst case temperatures, not nominal. The transition to

X-by-wire technology, replacing mechanical and hydraulic systems with

electromechanical systems will require more power electronics. Integration

of power transistors and smart power devices into the electromechanical

actuator will require power devices to operate at 175 ℃ to 200 ℃ . Hybrid

electric vehicles and fuel cell vehicles will also drive the demand for higher

vehicles, the high temperature will be due to power dissipation. The

alternates to high-temperature devices are thermal management systems which

add weight and cost. Finally, the number of sensors in vehicles is increasing

as more electrically controlled systems are added. Many of these sensors must

work in high-temperature environments. The harshest applications are exhaust

temperature power electronics. In the case of hybrid electric and fuel cell

gas sensors and cylinder pressure or combustion sensors. High-temperature

electronics use in automotive systems will continue to grow, but it will be

gradual as cost and reliability issues are addressed. This paper examines the

motivation for higher temperature operation,the packaging limitations even

at 125 C with newer package styles and concludes with a review of challenge

beyond 125 ℃.

at both the semiconductor device and packaging level as temperatures push

Index Terms

—

Automotive, extreme-environment electronics.

I. INTRODUCTION

I

N

1977, the average automobile contained $110 worth of electronics [1]. By

2003 the electronics content was $1510 per vehicle and is expected to reach

$2285 in 2013 [2].The turning point in automotive electronics was government

TABLE I

MAJOR AUTOMOTIVE ELECTRONIC SYSTEMS

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TABLE II

AUTOMOTIVETEMPERATUREEXTREMES(DELPHIDELCOELECTRONIC SYSTEMS) [3]

regulation in the 1970s mandating emissions control and fuel economy. The complex

fuel control required could not be accomplished using traditional mechanical systems.

These government regulations coupled with increasing semiconductor computing power at

decreasing cost have led to an ever increasing array of automotive electronics. Automotive

electronics can be divided into five major categories as shown in Table I.

The operating temperature of the electronics is a function of location, power dissipation

by the electronics, and the thermal design. The automotive electronics industry defines

high-temperature electronics as electronics operating above 125

℃.

However, the actual

temperature for various electronics mounting locations varies considerably. Delphi Delco

Electronic Systems recently published the typical continuous maximum temperatures as

reproduced in Table II [3]. The corresponding underhood temperatures are shown in Fig. 1.

The authors note that typical junction temperatures for integrated circuits are 10

℃

to15

℃

higher than ambient or baseplate temperature, while power devices can reach 25

℃

higher.

At-engine temperatures of 125

℃

peak can be maintained by placing the electronics on the

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intake manifold.

Fig. 1. Engine compartment thermal profile (Delphi Delco Electronic Systems) [3].

TABLE III

THEAUTOMOTIVEENVIRONMENT(GENERALMOTORS ANDDELPHIDELCO

ELECTRONICSYSTEMS) [4]

TABLE IV

REQUIREDOPERATIONTEMPERATURE FORAUTOMOTIVEELECTRONIC

SYSTEMS(TOYOTAMOTORCORP. [5]

TABLE V

MECHATRONICMAXIMUMTEMPERATURERANGES(DAIMLERCHRYSLER,EATONCORPORA

TION, ANDAUBURNUNIVERSITY) [6]

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Fig. 2. Automotive temperatures and related systems (DaimlerChrysler) [8].

automotive electronic systems [8]. Fig. 3 shows an actual measured

transmission temperature

transmission

temperature profile

temperature

profile during

profile

during normal

during

normal and

normal

and excessive driving

excessive

driving

conditions [8]. Power braking is a commonly used test condition where the

A similar real-world situation would be applying throttle with the emergency

brake applied. Note that when the temperature reached 135℃the over

135

℃,

temperature light came on and at the peak temperature of 145℃the

145

℃,

transmission was beginning to smell of burnt transmission fluid.

brakes are applied and the engine is revved with the transmission in gear.

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TABLE VI

2002

I

NTERNATIONAL

T

ECHNOLOGY

R

OADMAPFOR

S

EMICONDUCTORS

A

MBI

ENTOPERATINGTEMPERATURES FORHARSHENVIRONMENTS (AUTOMOTIVE)

[9]

The 2002 update to the International Technology Roadmap for Semiconductors (ITRS)

did not reflect the need for higher operating temperatures for complex integrated circuits,

but did recognize increasing temperature requirements for power and linear devices as

shown in Table VI [9]. Higher temperature power devices (diodes and transistors) will be

used for the power section of power converters and motor drives for electromechanical

actuators. Higher temperature linear devices will be used for analog control of power

converters and for amplification and some signal processing of sensor outputs prior to

transmission to the control units. It should be noted that at the maximum rated temperature

for a power device, the power handling capability is derated to zero. Thus, a 200

℃

rated

power transistor in a 200

℃

environment would have zero current carrying capability. Thus,

the actual operating environments must be lower than the maximum rating.

In the 2003 edition of the ITRS, the maximum junction temperatures identified for

harsh-environment complex integrated circuits was raised to 150

℃

through 2018 [9]. The

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ambient operating temperature extreme for harsh-environment complex integrated circuits

was defined as 40

℃

to 125

℃

through 2009, increasing to 40

℃

to 150

℃

for 2010 and

beyond. Power/linear devices were not separately listed in 2003.

The ITRS is consistent with the current automotive high-temperature limitations. Delphi

Delco Electronic Systems offers two production engine controllers (one on ceramic and

one on thin laminate) for direct mounting on the engine. These controllers are rated for

operation over the temperature range of 40

℃

to 125

℃

. The ECU must be mounted on the

coolest spot on the engine. The packaging technology is consistent with 140

℃

operation,

but the ECU is limited by semiconductor and capacitor technologies to 125

℃

.

The future projections in the ITRS are not consistent with the desire to place controllers

on-engine or in-transmission. It will not always be possible to use the coolest location for

mounting control units. Delphi Delco Electronics Systems has developed an

in-transmission controller for use in an ambient temperature of 140

℃

[10] using ceramic

substrate technology. DaimlerChrysler is also designing an in-transmission controller for

usewith a maximum ambient temperature of 150

℃

(Figs. 4 and 5) [11].

II. MECHATRONICS

Mechatronics, or the integration of electrical and mechanical systems offers a number

ofadvantages in automotive assembly. Integration of the engine controller with the engine

allows pretest of the engine as a complete system prior to vehicle assembly. Likewise with

the integration of the transmission controller and the transmission, pretesting and tuning to

account for machining variations can be performed at the transmission factory prior to

shipment to the automobile assembly site. In addition, most of the wires connecting to a

transmission controller run to the solenoid pack inside the transmission. Integration of the

controller into the transmission reduces the wiring harness requirements at the automobile

assembly level.

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Fig. 4. Prototype DaimlerChrysler ceramic transmission controller [11]

Fig. 5. DaimlerChrysler in-transmission module [11].

The trend in automotive design is to distribute control with network communications. As

the industry moves to more X-by-wire systems, this trend will continue. Automotivefinal

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assembly plants assemble subsystems and components supplied by numerous vendors to

build the vehicle. Complete mechatronic subsystems simplify the design, integration,

management, inventory control, and assembly of vehicles. As discussed in the previous

section, higher temperature electronics will be required to meet future mechatronic

designs.

III. PACKAGINGCHALLENGES AT125

℃

Trends in electronics packaging, driven by computer and portable products are

resulting in packages which will not meet underhood automotive requirements at

125

℃

. Most notable are leadless and area array packages such as small ball grid

arrays (BGAs) and quadflatpacks no-lead (QFNs). Fig. 6 shows the thermal cycle

test 40

℃

to 125

℃

results for two sizes of QFN from two suppliers [12]. A typical

requirement is for the product to survive 2000

–

2500 thermal cycles with

<1

%

failure for underhood applications. Smaller I/O QFNs have been found to meet the

requirements.

Fig. 7 presents the thermal cycle results for BGAs of various body sizes [13].

The die size in the BGA remained constant (8.6 *8.6 mm). As the body size

decreases so does the reliability. Only the 23-mm BGA meets the requirements.

The 15-mm BGA with the 0.56-mm-thick BT substrate nearly meets the minimum

requirements. However, the industry trend is to use thinner BT substrates (0.38

mm) for BGA packages.

One solution to increasing the thermal cycle performance of smaller BGAs is to

use underfill. Capillary underfill was dispensed and cured after reflow assembly of

the BGA. Fig. 8 shows a Weibull plot of the thermal cycle data for the 15-mm

BGAs with four different underfills. Underfill UF1 had no failures after 5500 cycles

and is, therefore, not plotted. Underfill, therefore, provides a viable approach to

meeting underhood automotive requirements with smaller BGAs, but adds process

steps, time, and cost to the electronics assembly process.

Since portable and computer products dominate the electronics market, the

packages developed for these applications are replacing traditional packages such

as QFPs for new devices. The automotive electronics industry will have to

continue

developing assembly approaches such as underfill just to use these new packages

in current underhood applications.

IV. TECHNOLOGY

CHALLENGES

ABOVE125

℃

The technical challenges for high-temperature automotive applications are

interrelated, but can be divided into semiconductors, passives, substrates,

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interconnections, and housings/connectors. Industries such as oil well logging

have successfully fielded high-temperature electronics operating at 200

℃

and

above. However, automotive electronics are further constrained by high-volume

production, low cost, and long-term reliability requirements. The typical operating

life for oil well logging electronics may only be 1000 h, production volumes are in

the range of 10s or 100s and, while cost is a concern, it is not a dominant issue. In

the following paragraphs, the technical challenges for high-temperature

automotive electronics are discussed.

Semiconductors: The maximum rated ambient temperature for most silicon based

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integrated circuits is 85

℃

, which is sufficient for consumer, portable, and computing

product applications. Devices for military and automotive applications are typically rated

to 125

℃

. A few integrated circuits are rated to 150

℃

, particularly for power supply

controllers and a few automotive applications. Finally, many power semiconductor devices

are derated to zero power handling capability at 200

℃

.Nelmset Johnsonet

shown that power insulated-gate bipolar transistors (IGBTs) and metal

–

oxide

–

semiconductorfield-effect transistors (MOSFETs) can be used at 200

℃

[14], [15]. The

primary limitations of these power transistors at the higher temperatures are the packaging

(the glass transition temperature of common molding compounds is in the 180

℃

to

200

℃

range) and the electrical stress on the transistor during hard switching.

A number of factors limit the use of silicon at high temperatures. First, with a bandgap

of 1.12 eV, the silicon p-n junction becomes intrinsic at high temperature (225

℃

to

400

℃

depending on doping levels). The intrinsic carrier concentration is given by (1)

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As the temperature increases, the intrinsic carrier concentration increases. When the

intrinsic carrier concentration nears the doping concentration level, p-n junctions behave as

resistors, not diodes, and transistors lose their switching characteristics. One approach used

in high-temperature integrated circuit design is to increase the doping levels, which

increases the temperature at which the device becomes intrinsic. However, increasing the

doping levels decreases the depletion widths, resulting in higher electricfields within the

device that can lead to breakdown.

A second problem is the increase in leakage current through a reverse-biased p-n junction

with increasing temperature. Reverse-biased p-n junctions are commonly used in IC design

to provide isolation between devices. The saturation current (I,the ideal reverse-bias

current of the junction) is proportional to the square of the intrinsic carrier concentration

where Ego=bandgap energy atT= 0KThe leakage current approximately doubles for each

10

℃

rise in junction temperature. Increased junction leakage currents increase power

dissipation within the device and can lead to latch-up of the parasitic p-n-p-n structure in

complimentary metal

–

oxide

–

semiconductor (CMOS) devices. Epitaxial-CMOS

(epi-CMOS) has been developed to improve latch-up resistance as the device dimensions

are decreased due to scaling and provides improved high-temperature performance

compared to bulk CMOS.

Silicon-on-insulator (SOI) technology replaces reverse-biased p-n junctions with

insulators, typically SiO2 , reducing the leakage currents and extending the operating range

of silicon above 200

℃

. At present, SOI devices are more expensive than conventional p-n

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junction isolated devices. This is in part due to the limited use of SOI technology. With the

continued scaling of device dimensions, SOI is being used in some high-performance

applications and the increasing volume may help to eventually lower the cost.

Other device performance issues at higher temperatures include gate threshold voltage

shifts, decreased noise margin, decreased switching speed, decreased mobility, decreased

gain-bandwidth product, and increased amplifier input

–

offset voltage [16]. Leakage

currents also increase for insulators with increasing temperature. This results in increased

gate leakage currents, and increased leakage of charge stored in memory cells (data loss).

For dynamic memory, the increased leakage currents require faster refresh rates. For

nonvolatile memory, the leakage limits the life of the stored data, a particular issue for

FLASH memory used in microcontrollers and automotive electronics modules.

Beyond the electrical performance of the device, the device reliability must also be

considered. Electromigration of the aluminum metallization is a major concern.

Electromigration is the movement of the metal atoms due to their bombardment by

electrons (current flow). Electromigration results in the formation of hillocks and voids in

the conductor traces. The mean time to failure (MTTF) for electromigration is related to

the current density (J)and temperature(T) as shown in (3)

The exact rate of electromigration and resulting time to failure is a function of the

aluminum microstructure. Addition of copper to the aluminum increases electromigration

resistance. The trend in the industry to replace aluminum with copper will improve the

electromigration resistance by up to three orders of magnitude [17].

Time dependent dielectric breakdown (TDDB) is a second reliability concern. Time to

failure due to TDDB decreases with increasing temperature. Oxide defects, including

pinholes, asperities at the Si

–

SiO2 interface and localized changes in chemical structure

that reduce the barrier height or increase the charge trapping are common sources of early

failure [18]. Breakdown can also occur due to hole trapping (Fowler

–

Nordheim

tunneling). The holes can collect at weak spots in the Si

–

SiO2 interface, increasing the

electricfield locally and leading to breakdown [18]. The temperature dependence of

time-to-breakdown(tBD) can be expressed as [18]

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Values reported for Etbd vary in the literature due to its dependence on the oxidefield

and the oxide quality. Furthermore, the activation energy increases with breakdown time

[18].

With proper high-temperature design, junction isolated silicon integrated circuits can be

used to junction temperatures of 150

℃

to 165

℃

, epi-CMOS can extend the range to

225

℃

to 250

℃

and SOI can be used to 250

℃

to 280

℃

[16, pp. 224]. High-temperature,

nonvolatile memory remains an issue.

For temperatures beyond the limits of silicon, silicon carbidebased semiconductors are

being developed. The bandgap of SiC ranges from 2.75

–

3.1 depending on the polytype.

SiC has lower leakage currents and higher electric field strength than Si. Due to its wider

bandgap, SiC can be used as a semiconductor device at temperatures over 600

℃

. The

primary focus of SiC device research is currently for power devices. SiC power devices

may eventuallyfind application as power devices in braking systems and direct fuel

injection. High-temperature sensors have also been fabricated with SiC. Berget

demonstrated a SiCbased sensor for cylinder pressure in combustion engines [19] at up to

350

℃

and Casadyet al.[20] have shown a SiC-based temperature sensor for use to 500

℃

.

At present, the wafer size, cost, and device yield have made SiC devices too expensive for

general automotive use. Most SiC devices are discrete, as the level of integration achieved

in SiC to date is low.

Passives: Thick and thin-film chip resistors are typically rated to 125

℃

. Naefeet al.[21]

and Salmonet al.[22] have shown that thick-film resistors can be used at temperatures

above 200

℃

if the allowable absolute tolerance is 5% or greater. The resistors studied

were specifically formulated with a higher softening point glass. The minimum resistance

as a

function of temperature was shifted from 25

℃

to 150

℃

to minimize the temperature

coefficient of resistance (TCR) over the temperature range to 300

℃

. TaN and NiCr

thin-film resistors have been shown to have less than 1% drift after 1000 h at 200

℃

[23].

Thus, for tighter tolerance applications, thin-film chip resistors are preferred. Wire wound

resistors provide a high-temperature option for higher power dissipation levels [21].

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High-temperature capacitors present more of a challenge. For low-value capacitors,

negative-positive-zero (NPO) ceramic and MOS capacitors provide low-temperature

coefficient of capacitance (TCC) to 200

℃

. NPO ceramic capacitorshave been

demonstrated to 500

℃

[24]. Higher dielectric constant ceramics (X7R, X8R, X9U), used

to achieve the high volumetric efficiency necessary for larger capacitor values, exhibit a

significant capacitance decrease above the Curie temperature, which is typically between

125

℃

to 150

℃

. As the temperature increases, the leakage current increases, the dissipation

factor increases, and the breakdown strength decreases. Increasing the dielectric tape

thickness to increase breakdown strength reduces the capacitance and is a tradeoff. X7R

ceramic capacitors have been shown to be stable when stored at 200

℃

[23]. X9U chip

capacitors are commercially available for use to 200 C, but there is a significant decrease

in capacitance above 150

℃

.

Consideration must also be given to the capacitor electrodes and terminations. Ni is now

being substituted for Ag and PdAg to lower capacitor cost. The impact of this change on

hightemperature reliability must be evaluated. The surface finish for ceramic capacitor

terminations is typically Sn. The melting point of the Sn (232

℃

) and its interaction with

potential solders/brazes must also be considered. Alternate surfacefinishes may be

required.

For higher value, low-voltage requirements, wet tantalum capacitors show reasonable

behavior at 200

℃

if the hermetic seal does not lose integrity [23]. Aluminum electrolytics

are also available for use to 150

℃

. Mica paper (260

℃

) and Teflonfilm (200

℃

) capacitors

can provide higher voltage capability, but are large and bulky [25]. High-temperature

capacitors are relatively expensive. Volumetrically efficient, high-voltage, highcapacitance,

capacitors are relatively expensive. V

olumetrically efficient, high-voltage, highcapacitance,

high-temperature and low-cost capacitors are still needed.

Standard transformers and inductor cores with copper wire and teflon insulation are

suitable for operation to 200

℃

. For higher temperature operation, the magnetic core, the

conductor metal (Ni instead of Cu) and insulator must be selected to be compatible with

the higher temperatures [16, pp. 651

–

652] Specially designed transformers can be used to

450

℃

to 500

℃

, however, they are limited in operating frequency.

Crystals are required for clock frequency generation for microcontrollers. Crystals with

acceptable frequency shift over the temperature range from 55

℃

to 200

℃

have been

demonstrated [22]. However, the selection of packaging materials and assembly process

for the crystal are key to high-temperature performance and reliability. For example,

epoxies used in assembly must be compatible with 200

℃

operation.

Substrates: Thick-film substrates with gold metallization have been used in circuits to

500

℃

[21], [23]. Palladium silver, platinum silver, and silver conductors are more

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commonly used in automotive hybrids for reduced cost. Silver migration has been

observed with an unpassivated PdAg thick-film conductor under bias at 300

℃

[21]. The

time-to-failure needs to be examined as a function of temperature and bias voltage with

and without passivation. Low-temperature cofired ceramic (LTCC) and high-temperature

cofired ceramic (HTCC) are also suitable for high-temperature automotive applications.

Embedded resistors are standard to thick-film hybrids, LTCC, and some HTCC

technologies. As previously mentioned, thick-film resistors have been demonstrated at

temperatures 200

℃

. Dielectric tapes for embedded capacitors have also been developed

for LTCC and HTCC. However, these embedded capacitors have not been characterized

for high-temperature use.

High-Tg laminates are also available for fabrication of hightemperature printed wiring

boards. Cyanate esters [Tg=250

℃

by differential scanning calorimetry (DSC)], polyimide

(260

℃

by DSC), and liquid crystal polymers(Tm>280

℃）

provide options for use to 200

℃

.

Cyanate ester boards have been used successfully in test vehicles at 175

℃

, but failed when

exposed to 250

℃

[26]. The higher coefficient of thermal expansion (CTE) of the laminate

substrates compared to the ceramics must be considered in the selection of component

attachment materials. The temperature limits of the laminates with respect to assembly

temperatures must also be carefully considered. Work is ongoing to develop and implement

embedded resistor and capacitor technology for laminate substrates for conventional

temperature ranges. This technology has not been extended to high-temperature

applications.

One method many manufacturers are using to address the higher temperatures while

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maintaining lower cost is the use of laminate substrates attached to metal. The typical

design involves the use of higher Tg( +140

℃

and above) laminate substrates attached to an

aluminum plate (approximately 2.54-mm thick) using a sheet or liquid adhesive. To assist

in thermal performance, the laminate substrate is often thinner (0.76 mm) than traditional

automotive substrates for under-the-hood applications. While this design provides

improved thermal performance, the attachment of the laminate to aluminum increases the

CTE for the overall substrates. The resultant CTE is very dependent on the ability of the

attachment material to decouple the CTE between the laminate substrate and the metal

backing. However, regardless of the attachment material used, the combination of the

laminate and metal will increase the CTE of the overall substrate above that of a

stand-alone laminate substrate. This impact can be quite significant in the reliability

performance for components with low CTE values (such as ceramic chip resistors). Fig. 9

illustrates the impact of two laminate-to-metal attachment options compared to standard

laminate substrates [27], [28]. The reliability data presented is for 2512 ceramic chip

resistors attached to a 0.79-mm-thick laminate substrate attached to aluminum using two

attachment materials. Notice that while one material significantly outperforms the other,

both are less reliable than the same chip resistor attached to laminate without metal

backing.

This decrease in reliability is also exhibited on small ball grid array (BGA) packages.

Fig. 10 shows the reliability of a 15-mm BGA package attached to laminate compared to

the same package attached to a laminate substrate with metal backing [27], [28]. The

attachment material used for the metal-backed substrate was the best material selected

from previous testing. Notice again that the metal-backed substrate deteriorates the

reliability. This reliability deterioration is of particular concern since many IC packages

used for automotive applications are ball grid array packages and the packaging trend is for

reduced packaging size. These packaging trends make the use of metal-backed substrates

difficult for next generation products.

One potential solution to the above reliability concern is the use of encapsulants and

underfills. Fig. 11 illustrates how conformal coating can improve component reliability for

surface mount chip resistors [27], [28]. Notice that the reliability varies greatly depending

on material composition. However, for components which meet a marginal level of

reliability, conformal coatings may assist the design in meeting the target reliability

requirements. The same scenario can be found for BGA underfills. Typical underfill

materials may extend the component life by a factor of two or more. For marginal IC

packages, this enhancement may provide enough reliability improvement toall the designs

to meet under-the-hood requirements. Unfortunately, the improvements provided by

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encapsulants and underfills increase the material cost and adds one or more manufacturing

processes for material dispense and cure.

Interconnections: Methods of mechanical and electrical interconnection of the active and

passive components to the board include chip and wire,flip-chip, and soldering of

packaged parts. In chip and wire assembly, epoxy die-attach materials can be

used to 165

℃

[29]. Polyimide and silicone die-attach materials can be used to 200

℃

. For

higher temperatures, SnPb ( >90Pb), AuGe, AuSi, AuSn, and AuIn have been used.

However,with the exception of SnPb, these are hard brazes and with increasing die size,

CTE mismatches between the die and the substrate will lead to cracking with thermal

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cycling. Ag

–

glass die attach has also been used with Si die, but the die stresses are high

[30]. The processing temperatures (330

℃

to 425

℃

) required for the hard brazes and the

Ag-glass are not compatible with the laminate-based substrates.

Small-diameter Au and Pt wire bonding can be used to 500

℃

on thick-film Au with Au

pads on the SiC die [22].However, most Si die have aluminum metallization and the use of

Au wire is limited to 180

℃

to 200

℃

due to Au

–

Al intermetallic formation and

Kirkendall voiding. Use of Al wire creates a monometallic bond at the die interface.

Pd-doped thick-film Au conductors have been developed for compatibility with

small-diameter Al wire to 300

℃

[31]. While Al wire can be bonded to silver bearing

thick-film conductors, the primary concern is corrosion due to the galvanic potential

between Al and Ag [32]. Chlorine contamination in the presence of moisture is the primary

corrosion mechanism. Increasing the Pd content of the PdAg conductor, extreme care in

the cleanliness of the assembly and potting in silicone gel can be used to reduce the risk of

corrosion. Au wire can be bonded to pure Ag thick films, but the Ag migrates along the

surface of the gold wire at elevated temperatures [33].

On laminate substrates, Ni/Aufinishes over the copper are compatible with Au wire

(thick Aufinish) and with Al wire (thin Aufinish). In the case of Al wire, the Au layer must

be thin so the Al wire bonds to the underlying Ni. Intermetallic formation and voiding will

occur if the Au layer is too thick. If a phosphorus containing Ni is used, the phosphorus

content should be limited to 6

–

8 .Al

–

Ni bonds are potentially reliable to 300

℃

, but

further study is required [32].

For wire bonding to power devices, large-diameter Al wire bonding is used. In some

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cases the Al wire is bonded directly to the thick-film PdAg conductors (the potential for Al

–

Ag corrosions exists) or to Ni-plated slugs soldered to the metallization.

For solder assembly of passives,flip-chip die and packaged semiconductors, alternate

solders are required above 135

℃

to 140

℃

to replace eutectic SnPb. High-lead solders can

be used if the substrate and component can withstand the assembly temperature. At

intermediate temperatures, lead-free solders are being considered. The SnAgCu eutectic

alloy has been selected by the general electronics industry to replace eutectic

r, the performance of this alloy with 2512 chip resistors and 1206 chip

resistors arrays on high- laminate over the 40

℃

to 150

℃

thermal cycle range is

significantly worse compared to eutectic SnPb (Figs. 12 and 13) [34]. As seen in Fig. 12,

fourth-element additions such as Bi to the SnCuAg alloy improve the thermal cycle

performance.

The NCMS report on lead-free, high-temperature, fatigue-resistant solder recommends

Sn3.35Ag1Cu3.3Bi and Sn4.6Ag1.6Cu1Sb1Bi for 55

℃

to 160

℃

applications[35]. The

performance of the NCMS-selected solders over the range from 55

℃

to 160

℃

is still less

than the reliability of SnPb over the 55

℃

to 125

℃

range. Thus, extending the temperature

range with these alloys will be less reliable than the current SnPb assemblies at 125

℃

With

the push in the automotive industry to 150 000 mile/10 year design goals, this will pose an

issue for high-temperature electronics acceptance. Amagai et al. have evaluated the effect

of Ag and Cu percent composition as well as the addition of various fourth elements on

reliability with a goal of optimizing thermal cycle and mechanical shock performance [36].

Nowottnicket proposed using liquid solders for high-temperature applications [37].

In this approach, Sn

–

Bi solders are used. At elevated operating temperatures, the solder

alloys melt, but maintain electrical contact. A polymer encapsulant is used to maintain

mechanical integrity when the solder is molten. Work continues tofind better

high-temperature soldering solutions or automotive applications.

Flip-chip assembly on thick-film ceramic substrates with high Pb-containing solders has

been used for many years. With increasing die size and thermal cycle range, underfills will

be required to improve the thermal cycle reliability on ceramic. Underfill is definitely

required on laminate substrates. Most commercial underfills have a less than 150

℃

and are

not suitable. Higher underfills are being developed for higher temperature automotive

applications on both ceramic and laminate Substrates.

20

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Electromigration and underbump metallurgy diffusion at elevated temperature are also

issues withflip-chip solder bumps. Electromigration can contribute to consumption of the

underbump metallurgy and joint failure. The allowable current density (current/area of

passivation opening) decreases with increasing temperature. Elenius [38] and Zhou [39]

have reported that Au surfacefinishes on the substrate are detrimental to the SnPb eutectic

solder bumps and underbump metallurgy. Zhou recommends Ag as an alternate PWB

surfacefinish. The SnAgCu eutectic alloy is reported to be less prone to failure due to

electromigration and underbump metallurgy (UBM) diffusion than eutectic SnPb [38].

Housings/Connectors: If chip and wire assembly is used, mechanical and environmental

protection of the assembly must be provided. In automotive applications, this is commonly

achieved using a molded plastic housing, silicone gel, and a cover. Lead inserts are molded

into the housing to provide an electrical I/O. Silicone gels are available rated to 260

℃

. The

temperature limit is established by the selection of material used in the molded housing.

With laminate-based surface mount technology (SMT) andflip-chip assemblies, a cast

aluminum housing is commonly used. Sealed hermetic packages commonly used in

military applications are considered too expensive for automotive modules.

High-temperature issues with connectors include thermal limits of the housing polymer,

and the base metal and platingn finish of the connector contacts. The spring force exerted

by the receptacle on the contact pin must be maintained over the temperature range. This is

particularly true for on-engine and in-transmission applications where vibration levels are

higher,increasing the potential for fretting corrosion. This impacts the selection of base

metals. BeCu and BeNi can be used for higher temperature applications. Gold can provide

a nonoxidizing and corrosion resistant pinfinish, but is more expensive.

21

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V. SUMMARY:AUTOMOTIVEHIGH-TEMPERATURE

CHALLENGES

The challenges for high-temperature automotive electronics are significant. First is

volume. With one engine controller per vehicle and approximately 55 million vehicles sold

in the world per year, if all engine controllers were high-temperature, the volume is still not

high. In terms of microcontrollers, this volume might be significant if all of the

manufacturers used a common microcontroller

—

they do not. In terms of passive

components, the volume is very small compared to applications such as cell phones.

The lack of an industry-wide definition for

“

high temperature

”

limits the ability of the

supplier base to address the needs. Each application is unique

—

mounting location, vehicle

model, thermal management, and power dissipation. Thus, the temperature requirements

from Delphi Delco, DaimlerChrysler, and Toyota vary as discussed in the introduction. A

second question from the component suppliers is

“

How long will the device see the

maximum temperature?

”

Assuming an average speed of 72.4 km/h, 241 350 km is 3334 h.

Does this mean the component has to function for 3334 h at the maximum temperature or

is there a temperature profile: A hours at , B hours at 10

℃

, C hours at 20

℃

, and so on. As

shown in Fig. 3, the nominal transmission temperature was 110

℃

with a peak to 143

℃

for

a worst case situation. This would require a transmission controller that would function in

a 143

℃

environment, but how many hours would it need to operate in a 143

℃

environment? Clearly, it would operate at 110

℃

most of the 3334 h. The requirements on

the semiconductor manufacturer are significantly different for 50 h at 143

℃

compared to

3334 h at 143

℃

.

Cost is a driving factor in automotive electronics. The industry works under the

paradigm that with time electronics be-come less expensive or have increasing

functionality at the same price. In general, consumers are unwilling to pay for increased

fuel economy or lower emissions. Thus, it becomes difficult to pass increased costs to the

consumer. Silicon-on-insulator technology exists for fabricating high-temperature

semiconductor devices, but is too expensive to be considered.

Reliability is a significant concern. Reliability impacts safety, customer loyalty, recalls,

and litigation. Increased temperature decreases the time to failure for many failure

mechanisms, such as time dependent dielectric breakdown of gate oxides and

electromigration of metals such as aluminum interconnect lines. An increased thermal

cycling range, decreases the number of cycles to failure for solder joints due to fatigue and

creep. The trend in the automotive electronics industry is toward 10 year/150 000

mile designs. Thus, more robust designs will be required to achieve improved reliability

22

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with high-temperature operation

不断变化的汽车使用环境：高温电子

R

·韦恩·约翰逊，院士，

IEEE

，约翰·

L

·埃文斯，彼得·雅各布森，詹姆斯河

（里克）汤普森，和克里斯托弗·马克

（里克）汤普森，和克里斯托弗·马克

摘要：在汽车发动机罩下恶劣环境和当前的趋势，在汽车电子产业将力推温度包络

电子元件。把发动机控制单元对发动机和变速器控制单元无论是在或在传输的方面将

10

推动环境温度高于

125

℃ 。然而，极端的成本压力，提高了可靠性的需求（

year/241 350

公里）和现场故障成本（召回，负债，客户忠诚度）将转移到更高的温

度递增的。在发动机和变速装置中的最冷点将会被使用。这些大装置也会提供相当大

的散热片来降低温度的上升，由于在控制单元的功耗。大多数短期应用将是在

150

℃

或以下的，这将是最坏的情况下，不会是有名无实的。过渡到的

X

线传技术，机电

系统取代机械和液压系统将需要更多的电力电子产品。集成功率晶体管和智能功率器

件进入机电制动器将要求功率器件在

175

℃至

200

℃这个环境进行操作。混合动力

电动汽车和燃料电池汽车也将推动对更高温度功率电子产品的需求。在混合动力和燃

料电池汽车的情况下，高温会引起功耗。

料电池汽车的情况下，

高温会引起功耗。该候补高温器件的热管理系统，

高温会引起功耗。

该候补高温器件的热管理系统，增加重量和

该候补高温器件的热管理系统，

增加重量和

成本。最后，

成本。

最后，伴随更多的电控系统被添加在车辆传感器的数量将会增加。

最后，

伴随更多的电控系统被添加在车辆传感器的数量将会增加。许多这些传

伴随更多的电控系统被添加在车辆传感器的数量将会增加。

许多这些传

感器必须工作在高温环境下。最恶劣的应用是排气体传感器和气缸压力燃烧传感器。

在汽车系统高温电子产品的使用将继续增长，但在渐进的成本和可靠性问题得到解

决。本文考察了动机较高的温度操作，使用较新的封装形式的封装的限制，即使在

125

℃和总结了同时在半导体器件和推动下超越

125

℃的包装水平的挑战。

℃的包装水平的挑战。

关键词：汽车，极端环境的电子产品

关键词：汽车，极端环境的电子产品

I

引言

引言

1977

年，汽车平均包含

110

美元价值的电子产品

[1]

。到

2003

年电子含量为

1510

美元每车，预计在

2013

年将达到

2285

美元

[2]

。汽车电子的转折点是在政府 。

。汽车电子的转折点是在政府

表一主要汽车电子系统

表一主要汽车电子系统

23

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表二

表二

汽车温度的极限（

DELPHI

德科电子系统）

[3]

调控在

20

世纪

70

年代强制排放的控制和燃油的经济性。所需要的复杂的燃料控

制无法通过传统的机械系统来实现。再加上越来越多的半导体运算能力在降低成本，

这些政府法规导致了汽车电子的不断增加的数组。汽车电子可以分为五个主要的类

别，如表

I

。

电子设备的工作温度的位置，通过电子设备的功耗和热设计的函数来确定。汽车电

子行业定义的高温电子为经营超过

125

℃电子。然而，实际温度的各种电子设备的安

装位置变化相当大。德尔福的

Delco

电子系统最近公布的典型的连续最高气温转载于

1

，作者指出，典型的结温为集成电路表二

[3]

。对应的发动机罩下的温度示于图。

。对应的发动机罩下的温度示于图。

比环境温度或底板温度

10

℃至

15

℃以上，而功率器件可以达到

25

℃以上。在发动机

的温度为

125

℃的峰值可以通过放置在电子上的进气歧管进行维护。

℃的峰值可以通过放置在电子上的进气歧管进行维护。

24

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图。

1

，发动机舱的温度曲线（德尔福德尔科电子系统）

[3]

。

表三 汽车环境（

GENERAL MOTORS

和

Delphi

德科 电子系统）

[4]

表三

德科

表四 所需的操作温度用于汽车电子 系统（

TOYOTA MOTORCORP[5]

。

表四

所需的操作温度用于汽车电子

表

V MECHATRONIC

最大温度范围（戴姆勒克莱斯勒， 伊顿公司和奥本大学）

[6]

最大温度范围（戴姆勒克莱斯勒，

25

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外文资料翻译

图。

2

，汽车的温度和相关系统（戴姆勒

-

克莱斯勒公司）

[8]

。

，汽车的温度和相关系统（戴姆勒

汽车电子系统

[8]

。图。图

3

示出在正常的和过大的驱动条件下的实际测量的传输温

度分布

[8]

。动力制动，其中施加制动和发动机加快转速与齿轮传动常用的测试条件。

一个类似真实世界的情况将会运用油门施加紧急制动。请注意，当温度达到

135

℃时，

超温光来了，并在

145

℃的峰值温度，传输已经开始闻到烧焦的油液的味道。

℃的峰值温度，传输已经开始闻到烧焦的油液的味道。

26

外文资料翻译

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图。

3

，在正常和过度的行驶条件下测得的传输温度。 （戴姆勒克莱斯勒）

[8]

。

，在正常和过度的行驶条件下测得的传输温度。

2002

年国际半导体技术蓝图

AMBIENT

适用于恶劣环境工作温度（汽车）

[9]

表六

表六

2002

年更新的国际半导体技术蓝图（

ITRS

）没有反映需要较高的操作温度为复杂

的集成电路，但没有认识到，如表六，提高温度要求，功率和线性器件

[9]

。更高温

度的功率器件（二极管和晶体管），将用于功率转换器和电机驱动器的机电致动器的

电源部分。较高的温度线性器件将用于功率转换器的模拟控制和用于放大和传感器输

出之前传输到控制单元的一些信号处理。但应注意的是，在最大额定温度为功率器件，

功率处理能力会下降到零。因此，在

200

℃的环境下

200

℃额定功率晶体管将具有零

电流承载能力。因此，在实际操作环境中必须比最大额定值更低。

电流承载能力。因此，在实际操作环境中必须比最大额定值更低。

在

ITRS

的

2003

年版，确定适用于恶劣环境复杂的集成电路的最大结温到

2018

年

提高到

150

℃

[9]

。工作环境温度为极端恶劣环境下的复杂的集成电路被定义为

40

℃

到

125

℃，到

2009

年，上升到

40

℃至

150

℃

2010

年及以后。

2003

年电源

/

线性器件均

没有单独列出。

没有单独列出。

ITRS

的是与当前汽车工业的高温度限制是一致的。德尔福的

Delco

电子系统提供

了两种生产引擎控制器（一个在陶瓷，一个在薄层压板）直接安装在发动机上。这些

控制器的额定工作在

40

℃至

125

℃的温度范围内。在

ECU

必须安装在发动机上的最

冷点。包装技术与

冷点。

包装技术与

140

℃的操作一致，但

℃的操作一致，

但

ECU

是由半导体和电容技术，以

是由半导体和电容技术，

以

125

℃的限

制。

制。

27

外文资料翻译

外文资料翻译

在

ITRS

对未来的预测是不把控制器上的发动机或传输的愿望是一致的。它并不总

是可能使用最冷的位置，用于安装控制单元。德尔福海德科电子系统公司采用陶瓷基

-

克莱斯勒公司板技术开发了一个传输控制器，用于在

140

℃

[10]

环境温度。戴姆勒

环境温度。戴姆勒

还设计一个在传输控制器，用于使用具有

150

℃的最大环境温度（图

4

和

5

）

[11]

。

二．机电一体化

二．机电一体化

机电或电气和机械系统的集成提供了在汽车装配具有许多优点。发动机控制装置与

发动机的集成允许所述发动机的预测试车辆组装前的一个完整系统。同样与传输控制

器的集成和传输，预试和调试，以占机械性的差异可以在变速器工厂在发货前对汽车

组装现场进行。此外，大部分的导线连接到变速器控制器运行到发送内部的电磁线圈

组件。集成控制器到传输减少了在汽车装配水平线束的要求。

组件。集成控制器到传输减少了在汽车装配水平线束的要求。

-

克莱斯勒原型陶瓷传输控制器

[11]

图。

4

，戴姆勒

，戴姆勒

-

克莱斯勒的传输模块

[11]

。 图。

5

，戴姆勒

，戴姆勒

在汽车设计发展趋势是分配网络通信控制。随着行业移动到更多的

X-

线控系统，这一趋势将继

续下去。汽车总装厂组装由众多供应商提供建立车辆子系统和组件。完整的机电一体化子系统简

28

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化设计，集成，管理，库存控制，以及车辆的装配。正如上一节所讨论的，较高温度的电子将被

要求满足未来的机电一体化设计的需求。

要求满足未来的机电一体化设计的需求。

IIII

。封装挑战

125

℃

电子产品包装的趋势，由计算机和便携式产品驱动导致其不能满足发动机罩下汽车需求在

125

℃。最值得注意的是无铅和区域阵列封装，如小球栅阵列

最值得注意的是无铅和区域阵列封装，

如小球栅阵列（

BGA

）和四扁平封装无引线（

QFN

封装）。图

6

显示了热循环试验

40

℃至

125

℃的结果从两个供应商

[12]

两种尺寸

QFN

封装的。一

个典型的要求是产品生存

2000-2500

热循环与

<1

％的失败的发动机罩的应用。较小的

I / O QFN

封装已发现符合要求。

封装已发现符合要求。

图

7

给出了热循环的结果为各种体型

[13]

的

BGA

。在

BGA

芯片尺寸保持不变（。

芯片尺寸保持不变

（

8.6* 8.6

毫米）

15

毫米的

BGA

用

0.56

由于机身尺寸的减小也是如此的可靠性。只有

23

毫米的

BGA

符合要求。

毫米厚的

BT

基板几乎满足最低要求。然而，该行业的发展趋势是使用较薄的

BT

基板（

0.38

毫

米），用于

BGA

封装。

封装。

一种解决方案，是以提高小球栅阵列的热循环性能使用底部填充。毛细填充物分散并固化在

BGA

8

显示了热循环的数据为

15

毫米的

BGA

有四种不同的底部填充胶的威布的回流焊组装后。图

的回流焊组装后。图

尔制图。底部填充

UF1

没有失败后

5500

周期的，因此，未标出。底部填充胶，因此，提供了一

种可行的方法来满足更小的

BGA

发动机罩下的汽车的需求，但增加了工艺步骤，时间和成本的

电子组装过程。

电子组装过程。

由于便携式和电脑产品占领电子市场，为这些应用开发的软件包取代传统的软件包，

如

QFP

的新设备。汽车电子行业将不得不继续开发装配方法，如底部填充只是在目

前的引擎盖应用程序中使用这些新的软件包。

四。超过

125

℃技术的挑战

用于高温汽车应用的技术挑战是相互关联的，但可以分为半导体，无源器件，基板，

布线，和外壳

/

连接器。行业，如石油测井已成功派出耐高温电子在

200

℃以上运行。

然而，汽车电子被进一步通过大批量生产，成本低，并且长期可靠性的要求的制约。

典型的工作寿命为油井测井电子可能只有

1000

小时，产量在

10

秒或

100

秒的范围

内，虽然成本是一个问题，它不是决定性的因素。在下面的段落中，对用于高温汽车

电子的技术挑战进行了讨论。

29

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外文资料翻译

半导体：根据最高额定环境温度对大多数硅集成电路是

85

℃，这足以满足消费产

品，便携，计算和产品应用。设备用于军事和汽车应用通常是额定

125

℃。一些集成

电路的额定

150

℃，特别是对电源控制器和一些汽车应用。最后，许多功率半导体器

件的降额至零功率处理能力在

200

℃。内尔姆斯等和约翰等人。已经表明，功率绝缘

栅双极晶体管（

IGBT

）和金属氧化物半导体场效应晶体管（

MOSFET

）可以用于在

200

℃

[14]

，

[15]

。这些功率晶体管在较高温度下的主要限制是在包装（普通模塑料的

玻璃化转变温度是在

180

℃至

200

℃范围内），在硬开关的晶体管上的电应力。

，在硬开关的晶体管上的电应力。

有许多因素限制了在高温下使用的硅。首先，用

1.12 eV

的带隙，硅

pn

结在高温

（

225

℃至

400

℃取决于掺杂水平）变为内在的。本征载流子浓度是由（

1

）给出

）给出

30

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随着温度的升高，本征载流子浓度增加而增加。当本征载流子浓度接近的掺杂浓度

的水平，

pn

结表现为电阻器，而不是二极管和晶体管失去它们的开关特性。在高温

集成电路设计中使用的一种方法是增加掺杂水平，从而增加了在该设备成为固有的温

度。然而，增加掺杂浓度减小的耗尽宽度，导致可能导致故障的设备内较高的电场。

第二个问题是通过一个反向偏置的

pn

结随温度升高而增加的漏电流。反向偏置的

pn

结中常用的

IC

设计，以提供器件之间的隔离。饱和电流（

设计，

以提供器件之间的隔离。饱和电流（

I

，结的理想反向偏置电

流）成正比的征载流子浓度的平方。

流）成正比的征载流子浓度的平方。

Ego=

带隙能量在

T=0K

的漏电流大约增加一倍，每

10

℃结温上升。增大结漏

其中

其中

电流增加的功耗的装置内，并可能导致在互补金属氧化物半导体（

CMOS

）器件闭锁

的寄生

PNPN

结构。外延

CMOS

（外延

CMOS

）已开发，以改善锁定电阻作为器件

31

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尺寸减少由于结垢而相比传统

CMOS

提供改进的高温性能。

提供改进的高温性能。

-

绝缘体（

SOI

）技术取代反向偏置的

pn

结与绝缘子，典型的二氧化硅，减少 硅

-

绝缘体器件比传统的了泄漏电流和延伸的硅的操作范围在

200

℃以上。目前，硅

℃以上。目前，硅

pn

结隔离的设备更为昂贵。这部分是由于有限的使用硅

-

绝缘体技术。随着器件尺

结隔离的设备更为昂贵。这部分是由于有限的使用硅

-

绝缘体正被用于一些高性能应用和量增加可能有助于最终降低寸的不断扩展，硅

寸的不断扩展，硅

成本。

成本。

在较高温度下其它设备的性能问题包括：栅极阈值电压的变化，

在较高温度下其它设备的性能问题包括：

栅极阈值电压的变化，降低噪声容限，

栅极阈值电压的变化，

降低噪声容限，降

降低噪声容限，

降

低开关速度快，流动性下降，下降增益带宽积，并增加放大器的输入失调电压

[16]

。

漏电流也增加绝缘子随着温度的升高。这导致增加的栅极泄漏电流，并且电荷存储在

存储单元（数据丢失）的泄漏量增加。对于动态内存，增加了漏电流要求更快的刷新

率。对于非易失性存储器，泄漏限制了存储数据的生命，在微控制器和汽车电子模块，

用于

FLASH

存储器的特定问题。

存储器的特定问题。

超出了器件的电性能，器件的可靠性也必须考虑。铝金属的电迁移是一个主要问题。

电迁移是由于它们轰击的电子（电流）

电迁移是由于它们轰击的电子

（电流）的金属原子的运动。

（电流）

的金属原子的运动。电迁移导致小丘和空穴中

的金属原子的运动。

电迁移导致小丘和空穴中

的导体图案的形成。平均无故障时间（

MTTF

）为电迁移是与电流密度（

J

）和温度（

T

），

如图（

3

）

电迁移和产生故障时间的准确率是铝微观结构的函数。除了铜与铝增加抗电迁移

性。在行业的发展趋势，以铜代替铝将以数量级

[17]

至三个数量提高抗电迁移性。

至三个数量提高抗电迁移性。

时间取决于介质击穿（

TDDB

）是第二可靠性问题。随着温度的升高无故障时间，

由于

TDDB

下降。氧化缺陷，包括针孔，凹凸在硅

-

二氧化硅界面和在化学结构，可

以降低势垒高度或增加的电荷俘获是早期失效

[18]

共同来源局部变化。击穿也可以是

-

北海姆隧道）发生。这些孔可以收集在硅

-

二氧化硅界面的薄由于空穴俘获（福勒

由于空穴俘获（福勒

弱点，增加当地的电场，并导致破裂

[18]

。温度的时间到击穿（

TBD

）的依赖可以表

示为

[18]

32

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外文资料翻译

报道

Etbd

值，由于其上的氧化字段依赖性和氧化物的质量变化在文献中。此外，

活化能随分解时间

[18]

。

EPI-CMOS

有了适当的高温设计，结隔离硅集成电路可用于

150

℃至

165

℃的结温，

可以扩大范围到

225

℃〜

250

℃，

SOI

，可用于

250

℃至

280

℃

[16

，页

224]

。高温，非

易失性存储器仍然是一个问题。

易失性存储器仍然是一个问题。

SiC

的能带隙范围从

2.75-3 .1

当温度超过硅的极限，正在开发的碳化硅基半导体。

SiC

具有较低的泄漏电流和较高的电场强度比硅。由于其较宽的取决于多种类型。

取决于多种类型。

带隙，碳化硅可被用作在温度超过

600

℃的半导体装置。碳化硅器件研究的主要焦点

是目前功率器件。

SiC

功率器件最终可能会发现应用程序作为功率器件的制动系统和

燃油直喷技术。高温型传感器也已制作与碳化硅。比格特等人对

.

高达

350

℃表现出的

SiC

基传感器，用于内燃机

[19]

气缸压力和卡萨特等人

[20]

都表现出了基于

SiC

温度传

感器用于

500

℃。目前，晶片的尺寸，成本和设备产量已使

SiC

器件一般的汽车使用。

SiC

器件是离散的，如集成在碳化硅迄今取得的电平为低。

器件是离散的，如集成在碳化硅迄今取得的电平为低。

Naefeet[21]

和

Salmonet[22]

表 无源产品：厚和薄膜片式电阻器通常是额定

125

℃。

℃。

明，厚膜电阻可以用来在温度高于

200

℃，如果允许的绝对容差为

5

％或更高。研究

了电阻器具有更高的软化点的玻璃进行了专门配制。最小电阻作为温度的函数是从

25

℃转移至

150

℃，以在温度范围为

300

℃最小化电阻的温度系数（

TCR

）。氮化钽和

镍铬薄膜电阻已经显示出，在

200

℃

[23]

后

1000

小时具有小于

1

％的漂移。因此，以

获取更高精度的应用，薄膜芯片电阻是首选。线绕电阻器更高的功耗水平

[21]

提供高

温选项。

温选项。

-

正

-

零（

NPO

）陶瓷和 高温电容器呈现一个更大的挑战。对于低价值电容，负

高温电容器呈现一个更大的挑战。对于低价值电容，负

MOS

电容，

NPO

陶瓷电容器已被证明是

500

℃以

200

℃为电容（

TCC

）的低温度系数。

[24]

。高介电常数陶瓷（

X7R

，

X8R

，

X9U

），用于实现所需的更大的电容值的容积效

率高，表现出显著电容减小居里温度以上，通常是在

125

℃至

150

℃。随着温度的增

加，漏电流增大，耗散因子增大，击穿强度降低。增加介电带材的厚度，以提高击穿

X7R

陶瓷电容器已被证明是稳定的存储，强度降低了电容，并是一个折衷。 在

200

℃

[23]

时。

X9U

片状电容器是商业上可使用至

200

℃，但有一个显著下降在电容

150

℃

时。

以上。

以上。

考虑也必须考虑到电容器电极和终端。倪现在被替换为银和

PDAG

降低电容器的

成本。这种变化对

hightemperature

可靠性的影响必须进行评估。陶瓷电容器端子表面

光洁度通常锡。锡（

232

℃），其与潜在的焊料

/

铜焊相互作用的熔点也必须加以考虑。

备用

surfacefinishes

可能需要。

可能需要。

对于更高的价值，低电压的要求，液体钽电容器在

200

℃表明合理的行为，如果密

封不输完整性

[23]

。铝电解也可使用至

150

℃。云母纸（

260

℃）和聚四氟乙烯薄膜

（

200

℃）的电容可以提供更高的电压能力，但大而笨重的

[25]

。高温电容器是相对

昂贵的。容积效率，高电压，高电容，高温和低成本电容器仍然需要。

昂贵的。容积效率，高电压，高电容，高温和低成本电容器仍然需要。

33

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标准的变压器和铜线和聚四氟乙烯绝缘电感磁芯适用于操作

200

℃。对于较高温度

的操作，该磁芯中，导体金属（镍代替铜）和绝缘体必须被选择为具有较高的温度下

相容的

[16

，第

651-652]

特别设计的变压器可以用于

450

℃〜

500

℃，但是，它们在有

限的工作频率。 晶体所需要的时钟频率产生的微控制器。晶体的可接受的频率偏移

限的工作频率。

在温度范围从

55

℃到

200

℃已被证实

[22]

。然而，包装材料和用于晶体组装过程的选

择是关键的高温性能和可靠性。例如，在组件中使用的环氧树脂必须是具有

200

℃的

操作兼容。

操作兼容。

基材：厚膜基板与镀金已被用于电路

500

℃

[21]

，

[23]

。钯银，铂银，银导体更常用

于汽车混合动力汽车的成本降低。银迁移已被观察到与偏置电压下的未钝化

PDAG

厚膜导体在

300

℃

[21]

。的时间到故障需要检查温度和偏置电压与一个函数并没有钝

化。低温共烧陶瓷（

LTCC

）和高温共烧陶瓷（

HTCC

）也适合用于高温汽车应用。

嵌入式电阻标准厚膜混合动力汽车，

LTCC

和

HTCC

的一些技术。如前所述，厚膜电

阻器已被证明在温度

200

℃。也被开发用于

LTCC

和

HTCC

介质磁带嵌入式电容器。

然而，这些嵌入式电容器还没有被表征为高温度下使用。

然而，这些嵌入式电容器还没有被表征为高温度下使用。

高

Tg

的层压板也可用于高温的印刷电路板的制造。氰酸酯

[Tg

为

250

℃用差示扫描

量热法（

DSC

）

]

，聚酰亚胺（

260

℃通过

DSC

测量）和液晶聚合物（

TM>280

℃）为

使用

200

℃的选项。氰酸酯板已被成功地用于测试车辆在

175

℃，但是当暴露在

250

℃

[26]

失败。相比，陶瓷层压基板的热膨胀系数（

CTE

）的系数较高，必须在零件安装

材料的选择来考虑。的温度限制层压板相对于装配温度也必须仔细考虑。工作正在进

行制定和实施嵌入式电阻和电容技术层压基板的常规温度范围。这项技术尚未推广到

高温应用。

高温应用。

许多制造商正在使用，解决了更高的温度，同时保持较低的成本的一种方法是使用

34

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附着于金属叠层衬底。典型的设计涉及到使用片或液体粘接剂的使用较高的

Tg

140

℃以上）连接到铝板（约

2.54

毫米厚）的层压板的基材。为了帮助散热性能，（

层压基板往往是较薄（

0.76

毫米） ，比传统汽车底物下的发动机应用。虽然这种设

毫米）

计可提供改进的热性能，叠层与铝的附着增加了热膨胀系数的整体基材。所得到的热

膨胀系数是非常依赖于该附件材料的去耦的

CTE

叠层基板和金属背衬之间的能力。

但是，无论所使用的附接材料，该层压材料和金属的结合将增加超过了一个独立的层

叠基板的整个基片的热膨胀系数。这种影响可以在与低

CTE

值（如陶瓷贴片电阻）

[28] 2

层压到元件的可靠性性能相当显著。图。图

9

示出相对于标准层压基板

[27]

，

金属附件选择的影响。呈现的可靠性数据是用于连接到使用两个连接材料附着到铝

0.79

毫米厚的层压衬底

2512

的陶瓷片式电阻器。请注意，当一种材料显著优于其他

的，都是比同芯片电阻连接不带金属衬层压不太可靠。

的，都是比同芯片电阻连接不带金属衬层压不太可靠。

BGA

）封装。图。图

10

示出安装到层压 这减少了可靠性也表现出对小球栅阵列（

这减少了可靠性也表现出对小球栅阵列（

[28]

的层叠基板相同的封装的可有

15

毫米的

BGA

封装相比，附着到金属背衬

[27]

，

靠性。用于金属支持基片的附着材料是从以前的测试中选择的最佳材料。再次请注意，

金属背基板恶化的可靠性。这种可靠性恶化尤为令人担忧，因为用于汽车应用的许多

IC

封装球栅阵列封装和包装趋势是减少包装大小。这些包装趋势使得使用金属背底

物难以下一代产品。

物难以下一代产品。

11

一个潜在的解决了上述的可靠性值得关注的是使用密封剂和底部填充的。图

说明了保形涂料如何提高元件的可靠性表面贴装片式电阻器

[27] [ 28 ]

。请注意，可

靠性有很大关系的材料组成。然而，

靠性有很大关系的材料组成。

然而，对于满足可靠性的边际级组件，

然而，

对于满足可靠性的边际级组件，保形涂料可协助

对于满足可靠性的边际级组件，

保形涂料可协助

设计在满足目标可靠性要求。相同的情况下，可以发现

BGA

底部填充。典型的底部

填充材料可以由两种或更多种的一个因素延长部件寿命。对于边际

IC

封装，这种增

强可以提供足够的可靠性的设计，以满足在引擎罩的要求。

强可以提供足够的可靠性的设计，

以满足在引擎罩的要求。不幸的是，

以满足在引擎罩的要求。

不幸的是，由密封剂和底

不幸的是，

由密封剂和底

层填料提供的改进增加了材料成本和材料分配和固化将一个或多个制造过

层填料提供的改进增加了材料成本和材料分配和固化将一个或多个制造过

35

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互连：的有源和无源器件到电路板的机械和电气互连的方法包括芯片和引线，倒装芯片和封装

器件的焊接。在芯片和导线组件，环氧管芯附着材料可以是 用

165

℃

[29]

。聚酰亚胺和聚硅氧烷

器件的焊接。在芯片和导线组件，环氧管芯附着材料可以是

模片连接材料可用于

200

℃左右。对于更高的温度，锡铅（

>90Pb

），金戈，金硅，金锡，和金铝

在已被使用。然而，除锡铅，这些是硬钎焊和随着芯片尺寸，芯片和基板之间热膨胀系数的不匹

-

玻璃芯片附着也被用来与硅管芯，但模具的压力是高的

[30]

。的加配会导致与热循环开裂。银

配会导致与热循环开裂。银

-

玻璃不与层叠体为基础的底物相容。 工温度（

330

℃至

425

℃）所需的硬钎焊和银

℃）所需的硬钎焊和银

玻璃不与层叠体为基础的底物相容。

36

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小直径金和

Pt

丝焊可用于

500

℃的厚膜金与金片上的碳化硅死亡

[22]

。然而，大

200

℃

-

铝金多数硅电路小片有铝金属化和使用金丝的限制为

180

℃〜 ，由于金

，由于金

属间化合物的形成和

Kirkendall

空洞。使用铝导线产生在模具接口单金属键。钯掺杂

300

℃

[31]

。而铝导线可键合到厚膜金导体已被开发用于小直径铝导线的兼容性，

厚膜金导体已被开发用于小直径铝导线的兼容性，

[32]

之间的电势。在水分存在的氯含银厚膜导体，主要关注的是腐蚀是由于铝和银

含银厚膜导体，主要关注的是腐蚀是由于铝和银

污染是主要的腐蚀机理。增加了

Pd

含量的

PDAG

导体，特别小心在硅凝胶的组装和

Au

线可粘接到纯银厚膜，但银迁移沿着金封装的洁净度，可用于减少腐蚀的风险。

封装的洁净度，可用于减少腐蚀的风险。

线可粘接到纯银厚膜，

但银迁移沿着金

线的表面在升高的温度

[33]

。

在层压基板，镍

/

金完成了铜与金线（厚铜层），并与铝丝（细凹完成）兼容。在

铝电线的情况下，铜层必须是薄的，以便在铝引线键合到底层的

Ni

。如果铜层过厚

的金属间化合物和排尿会发生。如果使用含有镍一磷，磷的含量应限制在

6-8

。铝镍

债券是潜在的可靠至

300

℃，但需要进一步的研究

[32]

。

对于引线键合到功率器件，大口径铝引线键合使用。在某些情况下，铝导线直接

-

银腐蚀电位）或焊接到金属化镀镍的蛞蝓。 结合到厚膜导体

PDAG

（存在于铝

（存在于铝

银腐蚀电位）或焊接到金属化镀镍的蛞蝓。

对于无源器件的焊接组装，倒装芯片和封装半导体，替代焊料需要高于

135

℃至

140

℃，以取代共晶锡铅。高铅焊料可以使用，如果在基板和元件能够承受组件的温

度。在中间温度下，

度。

在中间温度下，无铅焊料正在考虑中。

在中间温度下，

无铅焊料正在考虑中。在锡银铜的共晶合金已被选定的通用电子

无铅焊料正在考虑中。

在锡银铜的共晶合金已被选定的通用电子

工业，取代的共晶锡铅。然而，相较于共晶锡铅（图

12

和

13

）

[34]

这种合金与

2512

贴片电阻和

1206

片式电阻在高层压板阵列在

40

℃至

150

℃的热循环范围的性能显著

恶化。正如图。

12

，第四个元素的增加，如碧的锡银铜合金改进热循环性能。

，第四个元素的增加，如碧的锡银铜合金改进热循环性能。

新型无铅报告建议

Sn3.35Ag1Cu3.3BiSn4.6Ag1.6Cu1Sb1Bi

高温焊料为

55

到

160

摄

氏度的应用程序

[35]

。

NCMS-selected

焊料的性能范围从

55

到

160

摄氏度仍不到的可

37

外文资料翻译

外文资料翻译

靠性

SnPb

的

55

到

125

摄氏度的范围内。因此，扩展这些合金的温度范围将不可靠比当

前

Sn Pb

总成

125 c

与推动在汽车行业

150000

英里

/ 10

年设计耐高温电子产品的目标，

这将构成一个问题接受。

Amagai

等人已经评估

Ag

的影响和铜组成百分比以及添加

不同第四个元素优化热可靠性的目标周期和机械冲击性能

[36]

。

Nowottnick

等人提出

了对高温使用液态焊料应用

[37]

。在这种方法中，

Sn-Bi

焊料。在操作温度升高

,

焊料

合金熔化

,

但是保持电接触。用于聚合物密封剂当焊料熔化保持机械完整性，需要继

续寻找更好的高温焊接解决方案汽车应用。

倒装含有铅的焊料已经使用了许多年。随着

-

压痕模的尺寸和热循环范围内，底部

填充胶将重新改善陶瓷的热循环可靠性，肯定是需要在层压基板。大多数

COM-

商用

底部填充有低于

150

℃，而且很不适合。更高底部填充胶正在开发更高

TEM-

在陶瓷

和层压温度汽车应用基材。

和层压温度汽车应用基材。

图

13.

Weibull

分布图的热循环的数据（﹣

40

℃到

+150

℃）

1206

片式电阻阵列

[34]

电迁移和凸起下方冶金扩散在

EL

温度也与倒装芯片焊料凸点的产生问题。 随

温度也与倒装芯片焊料凸点的产生问题。

着允许的密度（钝化开口电流

/

地区）的增加而减小温度。

Elenius

[38]

等人

[39]

报道了金

在基板上表面光洁度都有损于锡铅

EU-

包晶焊料凸点和凸起下方冶金。周推荐 择友

包晶焊料凸点和凸起下方冶金。周推荐

银作为备用电路板的表面光洁度。在锡银铜

EU-

包晶合金据报道，不易发生故障，由

于

ELEC

和凸起下方金属层（

UBM

）的扩散比共晶锡铅

[38]

。

外壳

/

连接器：如果芯片和引线装配时，机械和环保大会必须的来提供。在汽车

应用中，这是常见的实现使用一个模制的塑料外壳，

应用中，

这是常见的实现使用一个模制的塑料外壳，硅胶和一个盖。

这是常见的实现使用一个模制的塑料外壳，

硅胶和一个盖。引线插入模制到

硅胶和一个盖。

引线插入模制到

外壳，以提供一个电气

I / O

。有机硅凝胶可额定值为

260

℃。温度限制是由材料的选

择确定。在模制的外壳使用。与层压板基面贴装技术（

SMT

）和倒装芯片装配，铸造

铝

-

最小离壳体是常用的。密封的密封封装常用于军事应用中使用过于考虑昂贵的汽

38

外文资料翻译

外文资料翻译

车模块。

车模块。

高温问题与连接器包括热壳体聚合物的极限，并且在基体金属和镀完成连接器的

接触。通过施加的弹簧力在接触销的插座必须保持在温度范围。这是对发动机特别真

实，在传输应用中的振动水平较高，

实，

在传输应用中的振动水平较高，增加对摩擦腐蚀的可能性。

在传输应用中的振动水平较高，

增加对摩擦腐蚀的可能性。这会影响选择基本金

增加对摩擦腐蚀的可能性。

这会影响选择基本金

属。铍铜和贝尼可用于更高温度的应用。

属。

铍铜和贝尼可用于更高温度的应用。金可以提供非氧化性和耐腐蚀针完成，

铍铜和贝尼可用于更高温度的应用。

金可以提供非氧化性和耐腐蚀针完成，但是

金可以提供非氧化性和耐腐蚀针完成，

但是

比较昂贵。

比较昂贵。

总结：汽车高温的挑战

总结：汽车高温的挑战

用于高温的汽车电子面临的挑战是显著。首先是体积。一台发动机控制器每辆

汽车，并在售出大约

55

万辆汽车每年的世界，如果所有的引擎控制器是高温，成交

量依然不高。在微控制器而言，这音量可能会显著如果所有的厂家使用一个普通的单

片机，他们不这样做。在被动条款组件，相比于应用程序的体积非常小 ，如手机。

片机，他们不这样做。在被动条款组件，相比于应用程序的体积非常小

，如手机。

对高温度业界广泛的定义缺乏

TURE

，限制了供应商以解决需求的能力。每个

应用程序都是独一无二的安装位置，车辆模型，热管理和功耗。因此，德尔福德科，

-

克莱斯勒和

ATURE

要求丰田有所不同，在引言中已经讨论。第二个疑问，戴姆勒

戴姆勒

从元件供应商是“有多长的装置看到的最高温度？”假设的平均速度

72.4

公里每小

时，

241350

公里是

3334

小时。这是否意味着康波，

NENT

具有的功能为

3334

小时，

最高温度或者是有一个温度曲线：一小时时，

B

小时

10 C

，

C

在小时

20

℃，等等。

如所示图

3

，峰值到

143

℃为最坏的情况发生。这将需要一个

143 Ç

环境转换，但有

多少时间将它需要在

143

℃操作环境？显然，这将在操作

110

℃的最在

3334

小时。在

半导体的制造要求，制造商有显著的不同在

143

℃相比

50

小时在

143

℃

3334

ħ

中。

成本是汽车电子的驱动因素。在工厂里，随着时间的电子来不太昂贵或有增加的

函数而精湛在相同的模式下工作价格。一般情况下，消费者是不愿意支付增加燃油经

济性和降低排放。因此，

济性和降低排放。

因此，变得难以通过成本增加给消费者。硅绝缘体上技存在制造高

变得难以通过成本增加给消费者。

硅绝缘体上技存在制造高

温半导体设备，但太昂贵加以考虑。

温半导体设备，但太昂贵加以考虑。

可靠性是一个显著影响安全的因素，客户忠诚度，

可靠性是一个显著影响安全的因素，

客户忠诚度，召回和诉讼。

客户忠诚度，

召回和诉讼。温度升高降低了

召回和诉讼。

温度升高降低了

失效时间为许多失败机制，例如栅氧化物和

ELEC-

时间取决于介质击穿金属如铝互连

线。一个增加的热循环范围，

线。

一个增加的热循环范围，减小的周期数失败对于因疲劳和蠕变焊点。

一个增加的热循环范围，

减小的周期数失败对于因疲劳和蠕变焊点。在趋势汽车

减小的周期数失败对于因疲劳和蠕变焊点。

在趋势汽车

电子行业正向着

10 year/150000

英里的设计。因此，更稳定的设计将需要实现与高温

作业提高了可靠性。

作业提高了可靠性。

参考文献

参考文献

[1] G. Leen and D. Heffernan,“Expanding automotive electronic systems,”IEEE Computer,

[1] G

. Leen and D. Heffernan,“Expanding automotive electronic systems,”IEEE Computer,

no. 1, pp. 88–

no. 1, pp. 88

–93, Jan. 2002.

[2] OEM Automotive Electronics in North America, The Freedonia Group,Inc., Cleveland,

OH, 2004.

39

外文资料翻译

外文资料翻译

[3] M. R. Fairchild, R. B. Snyder, C. W. Berlin, and D. H. R. Sarma,

“

Emerging substrate

technologies for harsh-environment

harsh-

environment automotiveelectronics applications,”, SAE Technical

Paper Series 2002-01-1052.

[4] D. S. Eddy and D. R. Sparks, “Applications of MEMS technologyin automotive sensors

and actuators,”Proc. IEEE, vol. 86, no. 8, pp.1747–1755, Aug. 1998.

and actuators,”Proc. IEEE, vol. 86, no. 8, pp.1747–

1755, Aug. 1998.

[5] M. Hattori, “Needs and applications of high-temperature LSIs for automotive electronic

[5] M. Hattori, “Needs and applications of high

-temperature LSIs for automotive electronic

systems,”in Proc. HITEN High-Temperature Electronics Conf., 1999, pp. 37

systems,”in Proc. HITEN High

-Temperature Electronics Conf., 1999, pp. 37–43.

[6] R. W. Johnson, J. L. Evans, P. Jacobsen, and R. Thompson,“High-temperature

Thompson,“High

-temperature

automotive electronics,”in Proc. Int. Conf. Advanced Packaging and Systems, Reno, NV,

s, Reno, NV

,

Mar. 10–

Mar. 10

–13, 2002, pp. 77–

13, 2002, pp. 77

–87.

[7] “Personal Communications with DaimlerChrysler,”unpublished, Jun.2002.

[8] R. Thompson,Proc. SMTA/CAVE Workshop Harsh Environment Electronics, Dearborn,

[8] R. Thompson,Proc. SMTA/CA

VE Workshop Harsh Environment Electronics, Dearborn,

MI, Jun. 24–

MI, Jun. 24

–25, 2003.

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