This month issue An Independent Journal Dedicated to the Advancement of Chip - Scale Electronics September - October 2000 Email the editor

Paul M. Sakamoto Contributing Editor

One of the really interesting (and sometimes puzzling) differences between component test services is how they select their equipment.

I've been on many sides of this issue since spring 1977 when I hired on at the IBS (Incredibly Big Semiconductor) Corp. I've been an ATE user, buyer, seller and maker.

Having helped decide the fate of a few billion dollars of expensive colored boxes filled with precision electronics, I have become just self-absorbed enough to want to tell others how ATE purchasing decisions are made.

Test Heavyweights

First, you should realize that in almost all cases there are very few people in any given company (even IBS Corp.) who are real semiconductor test heavyweights. In a company with revenues under $1 billion, there may be only one or two.

What is an expert? You want to see about 10 or more years of direct experience in the areas of test that are under question.

You want to have that experience divided between a lot of tough, hands-on work and different levels of management.

You want some business savvy.

You want to see someone who has made a mistake or two, has recovered and learned. And you want to see someone who is going to stick with the test issue forever, because they are hooked on it.

You also want someone who has done (or can) do whatever it takes with no funds, despite shifting political winds. Remember, the top executives are spending time and money on design, marketing and the fab-never on test.

At this point, the merely technically savvy have dropped out. And, at last, you've found the surly, Rambo-like individual (or two), who is ready, qualified and able to decide what tester or testers your company will select.

He or she is the real force in your company's selection process. Let's call this person the "tester selection troll" (TST). All subsequent efforts to select the test platform are mere window dressing over the decisions of the TST.

Most large companies have a committee to select test equipment. At many firms, the appearance of a thorough due diligence period and overwhelming consensus is deemed vital.

These tester selection committees (TSCs) are granted the task of checking off both the due diligence and the consensus boxes. Therefore, the TSCs appear to be important. In truth, however, they are important only in the length of time they take to run their course and allow the TST to push his/ her already completed decision forward.

That's right, before the whole committee is even notified that it is a TSC, the TST has already made the choice.

The best TSCs come up with perfect and rational choices in a few months. A TST, however, will come up with an 80-100% decent choice instantly, since the TST is always thinking about the issues and always has a choice in mind.

Typical Scenarios

Now let's look at some typical scenarios:

• The TSC takes six months to converge on the TST's choice and then goes on to meet for another three months to argue over deployment. Total time, six months.

• The TSC takes one month to confirm the TST's choice and then just deploys according to the TST's decision. The company gets results and the appearance of consensus much faster than the former option.

• The TST kills and eats half of the committee members at the first meeting. The survivors of the TSC complete the TST's deployment plan, and the company gets to market very quickly.

I have witnessed all three outcomes and their many subvariants.

What is strange to many is that the last method works so well, especially in "boom" times. So the lesson to be learned is when it comes to tester selection, we are all just pawns of the Tester Selection Troll.

Mr. Sakamoto is vice president of the Memory Products Division at Credence Systems Corp., Fremont, Calif. He advises that none of the statements here refer to people who are currently employed at Credence Systems, or at any of Mr. Sakamoto's former employers. [paul_sakamoto@credence.com]