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Electronic design automation technology leader MentorGraphics (mentor graphics) recently released a titled "PCB reliability is of vital importance to the application in automobile research.

1. The authors of the report is introduced

The writer Mentor is Market development department director JohnIsaac

Market development department director Mr JohnIsaac in electronic design automation industry has more than 40 years of experience, specializing in PCB and IC technology. At the beginning of the career, he worked for IBM, is mainly responsible for use on the inside IBM high-end IC and PCB design for the development of electronic design automation system. After joining Ming, Mr Isaac in PCB and IC products division multiple marketing position. Now he is mainly responsible for the company system design department of global market development work.

2. Introduction, background

Automotive electronics is not totally different from other complex electronic products: multiple CPU, network, real-time data collection, and extremely complex PCB. The design pressure of the auto industry is similar to other types of electronic products: design time short, intense market competition. The automotive electronics and high-end entertainment products such as some electronic between what's the difference? Big difference! If PCB failure occurs in the entertainment products, people's life is not threatened; But if the failure occurs in the car, people's life is at stake. Therefore, automotive electronic components reliability design is the design process of a major aspect to consider.

3. The full text key points and outline is as follows:

A. time and cost pressure

And the design time and development costs under pressure all of the products, auto parts, is no exception. A development practice can give electronics company provides great help satisfy the basic business objectives, it is the use of virtual prototype to analyze the design, and do not need to cost and time to build a variety of physical prototype, test the model and make incremental changes according to the results of the test. In addition, a number of factors that affect product reliability need after weeks, months or years of physical damage. So in these cases the physical prototype is not a feasible way. Even in experimental cabin, you also can't be accurate to copy several years of physics oscillation, thermal environment, vibration and temperature cycling.

B. the simulation is the key

Simulation, or virtual prototype, has become more and more important steps in the design process. As Ming guide electronic ExpeditionEnterprise, a complex system of PCB design solutions contain a variety of forms of virtual prototype function.

C. thermal control

The key point that influence the reliability of (here in terms of performance) is hot. Integrated circuit (IC) overheating will appear over time, car environment will become very heartless. Overheating, for example, the parts in the engine compartment, or driving through from Michigan winter until the summer climate in Arizona. Since IC assembly, PCB, until the operating conditions of complete products, both should be able to control the heat.

Has brought great changes in the heat.

In the field of PCB design and mechanical design using complex thermal analysis can lead to better thermal management and reliability, and don't need to build and test a variety of physical prototype. This saves a lot of time and cost. In addition, there are closely integrated with design system is convenient and easy to use software, designers can quickly use a variety of "hypothesis" scene experiment, and obtain a better solution.

D. high accelerated life test

Another reason for vehicle reliability problem is continuous vibration of PCB and subsequent fault component lead and accessories. Generally by building a prototype and place them in accelerating chamber, vibration and temperature cycling test in the PCB, to detect fault occurs. With the progress of the design, this method need to build several prototypes, and often take weeks or months to complete in accelerating chamber simulation of automobile parts in life expectancy. This is a very time consuming and high cost of process, so the reliability enhancement testing may not be complete and comprehensive.

Is there software can carry out the same test in virtual prototype model. Designers can use this software for defining the PCB and easy to carry out the simulation experiment. The software can be finished in a few hours of complex analysis, and points out possible failure

In the design of electronic products, power integrity is a more complex problems.

Space and the possible long-term printed circuit board failure

Space is narrow and can lead to serious reliability problem, and this problem may be in a few years to emerge. High current can make the space temperature rise, leading to PCB like fuse burned or plate. Now, but in the software to analyze the distribution network, and can determine the virtual prototype and high current density of space. Designers can then to expand space or create parallel current path in adjacent layers, and in maintaining the IC supply sufficient current at the same time to solve this problem.

In the test room by using the physical prototype testing the problems of the current density is not practical, because it may be in a few years can lead to failure. The problem may never emerge, leading to subsequent failure in this regard.

4. The study conclusion

Reliability is very important in the automotive electronics, now given pressure from product time to market and cost reduction, take in the virtual prototype software environment compared with the test indoor, the paper analyses the physical prototype method appears increasingly necessary. At present because of the existence of the software, so that the electronic and mechanical design personnel can be more simulation scheme.