Automotive ICs to control almost everything under the hood have become one of the fastest growing applications over the past few years. Chip Scale Review recently interviewed a trio of experts at Delphi Delco Electronics Systems, Kokomo, Ind., one of the leading suppliers of automotive electronics, and, until 1999, an operating unit of General Motors. The company now counts 38 of the 54 automobile manufacturers worldwide as customers.
Q What are the principal trends in automotive ICs? A We see two trends. We're heavily involved in flip chip, and we do a lot of that (Delco Delphi was formerly co-owner of Flip Chip Technologies, which is now Kulicke & Soffa's Flip Chip Division.). For a lot of ICs, we're also moving from fine-pitch QFPs to BGAs for several reasons. As you move to higher pin counts, QFPs reach a natural limitation. Also, board assembly yields deteriorate when the lead pitch of QFPs is less than 20 mils. BGAs also provide improved lead pitch and better assembly yields. Q Are you doing much IC assembly at Delco? A Yes, we have sites around the world and also here, in Kokomo. We assemble components on laminate and ceramic substrates for the automotive electronics industry. Among the products manufactured in Kokomo are radios, air bag electronics and heating, ventilation and air conditioning controls. Q In moving from QPFs to BGAs do you have specific cost goals? A Less expensive packaging is what we're ultimately trying to accomplish-not only in terms of the component price, but for the overall assembly costs of the product, as well. While we want to reduce costs, we also want to ensure that we can maintain or improve product reliability when we use new packages.
Q Where are ICs now being used in automobiles? A Products are usually located either in the passenger compartment or under the hood. For engine management systems, they're usually under the hood. Some of the engine management systems are mounted either on or near the engine. Additionally, nearly every product that we make contains a microprocessor. Q How fast is the use of ICs under the hood growing? A The use of ICs for automotive applications is a common practice. The amount of electronics that is being employed in vehicles is increasing every year. The growth is related to new products, an increase in features and functions for current products, and a need to reduce the size of products due to limited space in the vehicle. In conjunction with the introduction of new models, many of our customers want to add new products. They also like adding functions and features and/or reducing the size of electronics of current products being used in the vehicle. Q What are the principal considerations for ICs that will be placed under the hood? A Thermal cycle fatigue of the solder joints is a key issue. As a result, solder joint fatigue is a major focus of much of our testing. Thermal management of devices is also a major issue. Thermal issues are taken into account during the design of our products. We've demonstrated that BGAs mounted to laminate substrates possess very good solder joint fatigue in under-hood applications. The solder joint fatigue life of BGAs is comparable to other devices and to underfilled flip chips mounted on laminates. So far, nearly all the CSPs we've tested need to be underfilled to survive thermal cycling for under-hood uses. Q Are you using CSPs in your designs? A No, but we expect to incorporate them in future designs. There are currently no CSPs in design that are mounted under the hood. We expect CSPs to be included in future products that will be mounted under the hood. They could start showing up in products as soon as the 2005 model year, which will be the Fall of 2004. Q What type of reliability testing do you perform? A Resistance to fluid penetration, vibration, power temperature cycling and high temperature storage are a subset of the testing that we perform on our products. Our under-hood products are expected to operate between -40°C to +125°C for their useful life. i |
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