This week I read of the lawsuit filed by Quanta Computer Inc. against AMD and its ATI division. The lawsuit alleges that components that they sold Quanta turned out to have heat tolerance related issues that caused the laptops they were used in to fail. It seems a little strange to me that Quanta is the only company with the problem unless they are buying a unique product or batch of products from AMD/ATI. Even so, with a multi-layered testing process the type of problem claimed by Quanta should not happen. The facts of the case will no doubt be revealed if additional claimants come forward and/or the case goes to trial.
Quanta is a Taiwanese contract manufacturer of notebook computers. Since they are a contract manufacturer this means that most of the finished goods they produce are someone else’s brand. They compete on the basis of cost and reliability/quality to get business from the owner of that brand. The damages they are seeking would be from their production losses from needing to repair or scrap finished products and/or subsequent damage to the perception of their own corporate brand.
This case has great relevance to the embedded hardware markets we cover and underscores the importance of a multi-tiered testing process. Therefore, I thought I would share some insights from my 30 year experience in the automatic test industry. I can safely say that despite the perception that testing increases cost, the costs of failure go up significantly at each step of the process between wafer creation and when the finished consumer/industrial product is completed. As one might understand, the absolute worst case is when the manufacturing/design failure occurs in the finished product when it is in the hands of the end customer. How can this be avoided? In this blog, I will look at the manufacturing process for semiconductor devices and, in next week’s follow up, I will look at what happens on the product manufacturing side.
1.) Raw Silicon Wafer: Optical checks are used to look for impurities and surface imperfections before the wafer goes through the extensive chemical/photo process that creates the semiconductor product. This test is very fast and it can save you the cost of chemicals and lost production time.
2.) Wafer Test: The semiconductor devices are still on the round wafer. The wafer is tested by using a probe mechanism that makes temporary contact with all of its contact pads. The tester than makes fairly extensive tests to make sure that the device is worth packaging. Tests can be made at various temperatures as part of this test cycle. In some cases, higher temperatures are used to speed up testing.
3.) Package Device Tests:
- Quick continuity and resistance tests are made to make sure the wire bonding/connecting process between the individual semiconductor dies and the package were good and that the device does not have any major faults.
- More detailed tests are then made to ensure the device works perfectly. Several cycles may be involved with the devices being subjected to high or low heat and less than optimal input voltages. The ultimate goal is to subject to the device to similar conditions to what it will see when it is installed in the finished product.
If the device passes through all of these testing steps, it is then further packaged for safe transport and easy assembly into the circuit board by the company like Quanta.In next week's follow up, we will look at what happens on the product manufacturing side.
Comments