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The SH-5000, which was MCT’s 4th generation strip test handler, is being replaced with the SH-5300, our 5th generation machine. The main difference is that the SH-5300 has had some parts of it re-designed so that it can handle the new ultra high-density lead frames (XDLF) now being produced. These new XDLF lead frames are 100mm x 300mm in size and are being introduced to help drive down assembly costs. The SH-5000 could only accommodate a maximum lead frame size of 100mm x 275mm. The SH-5000 will continue to be available thru mid-2015.
Other than the minor changes to the strip handling mechanisms, the new SH-5300 is identical to the SH-5000. This means that the SH-5300 will enjoy the same high reliability and high uptime as the SH-5000, thus avoiding the problems associated with an entirely new design.
As a point of reference, change kits that were designed and used on the SH-5000 will still work on the SH-5300 with the addition of some new parts. However, SH-5300 change kits are not backwards compatible with the SH-5000.
It depends what you define as high volume! If you only have enough volume to keep one (1) 4-up gravity handler busy then it is probably more economical to stay with singulated testing. However, if volumes begin to ramp so that additional gravity test cells would be needed, you will soon reach a volume point where the Capex required to add more singulated cells (another handler + another tester for each test cell) may well exceed the cost to put in a single strip test cell. As a general guideline, once you need two (2) 4-up gravity handlers to meet volume requirements, it’s time to take a serious look at doing the testing with a strip test handler. You will save money on Capex plus lower your test cost per unit plus have additional burst capacity available on very short notice with the strip test cell.
Here is a simple example to illustrate the point more clearly. For an 8L SOIC digital product with a 2 second test time in a 6×28 matrix lead frame (192 total parts), it’s well within the capability of a strip test handler to contact all 192 parts in a single plunge.
This would require a tester with approximately 1600 digital pins, which is well within the capabilities of today’s digital testers. The SH-5300 strip handler, at a 2 second device test time, is capable of testing 10.9 million parts per week, assuming 80% utilization, or just over 125K per hour. A typical 4-up gravity handler might be capable of testing around 850,000 units per week at a UPH of approximately 6,200 and an OEE (Operating Equipment Efficiency) of 80%.
With this type of information, we can determine the best way to proceed. For example, if you really do need 10M parts per week, the math will tell you that you will need twelve (12) separate gravity cells (a handler + a tester) to produce that many parts per week. In that case, the Capex required to purchase 12 gravity handlers and 12 low pin count digital testers will far exceed the cost of a single strip handler and a 1600 pin digital tester. If you factor in the additional costs of the gravity cells in terms of floor space, maintenance, operators and power consumption, the cost advantage of strip test becomes even greater. On the other hand, if you only need 850K parts per week, the economics will clearly favor a single gravity cell. The crossover point where strip test becomes a more cost effective solution is somewhere in between 850K/week and 10M/week because you also need to account for the other process steps that are required for strip testing such as the process for lead isolation.
MCT can help you analyze your operation and find where the volume trade-off point exists for your particular product.
This is a very relevant question and one that deserves a serious look at the reasons. First of all, more and more IDM’s and Subcons are doing strip testing because they have figured out that it is one of the best solutions available to help them reduce their overall cost of test.
But one of the main reasons why some customers still have not adopted strip testing is due in large part to the way that the semiconductor test industry works. The simple example below will help illustrate this key point.
At most companies, a marketing team is responsible for forecasting the sales for a new product. If they are un-certain about the demand, the initial forecasts may be low and conservative. Management will want to get those parts assembled and tested for the lowest possible cost. For very low volumes, the best way to approach the problem is probably with standard singulated test using either a gravity, turret, or in some cases a pick-and-place handler with a small (i.e. low cost) tester, meaning one with just enough resources to handle the small degree of parallelism that can be achieved with one of the fore mentioned handlers.
The problems start when the product becomes popular and starts to ramp. At that point, everyone is under pressure to ship more parts and to do it quickly. The easiest way to get more output at test is to simply replicate the test cell that is already in place and qualified. That means buying more gravity, turret or PnP handlers and more small testers until there is enough equipment to meet the capacity requirements.
Three things happen as a result: 1)… more capex is spent than should have been and 2)… the test cost per unit is 2X-10X higher than it should be (as compared to a strip test cell) and 3).… it doesn’t take long before a significant area of the test floor is filled with multiple singulated test cells, thus increasing the costs for extra floor space, extra technicians needed to maintain the equipment, extra operators to run it, extra maintenance costs and extra expenses for all the additional power those multiple cells will consume.
MCT can help you analyze where the trade-off occurs so that you can achieve the lowest possible cost of test.