Hi Edward, You are correct in that you must take the cost of engineering and test materials before making the decision to go ahead with a new process. And that isn't always easy to determine up front. Perhaps the best way of looking at this is on a case by case basis. By that I mean, if you are going to install an additional finish, say for example immersion tin (a relatively new product on the market) there are certain parameters and "output" criteria it has to meet. It must allow for some measure of storage and still maintain its solderability, it must allow for so many thermal cycles and still maintain solderability, etc. Once it is determined what those parameters are it's a matter of running through numerous mental exercises and models in order to project a cost of test materials, time, engineering and other shop labor costs, outside test costs, etc. It's a good idea to have a formal program that forces you to address ALL these issues and more such as cost of sending back chemicals that this new stuff may be replacing, discarding old tanks and supplies, training new operators, writing SOP's, among other things. Now looking at something on the order of direct plate the picture gets fuzzier. For several reasons. First, unlike the example above, direct plate has no means for measuring "output". Immersion tin does. You can put systems in place to test the product right off the line - tests that prove with no doubt how the process is performing. Direct plate doesn't allow for that. Sure, you can measure resistance with an Ohm meter - and that really doeasn't prove squat. Ask any direct plate supplier and they'll tell you the same thing - resistivity readings are "indicitave" only. Or maybe you can panel plate (flash) test panels and perform backlights - better but still takes an hour or so. But even that requires you to produce panels similar to the boards you are actually producing. Testing double sided coupons when you're building 10 layer blind/buried vias with liquid dielectric doesn't cut it. The coupons must be similar to product you're building. So, installing something that has no sure method of measuring output is quite hard and should be heavily engineered at the start. You know, look around your shop for processes you can measure output performance on. Drill, copper, soldermask, legend, dry film, lamination, oxide, Ni/Au, etch - all of these areas are easily measured. There are systems you can put in place that lets you determine with no doubt the quality of the product off the line. Now, look for areas that arean't so easy - like desmear, oxide replacements, direct plate. There are no good ways of measuring performance off these lines. There are indication methods. There are ways of measuring process parameters, sure. But you need to measure OUTPUT. So, engineering these processes are quite difficult. Edward, to some degree you must trust your supplier. It would be nice to put all you faith in them but of course you can not. The case study I told about in my report was a good example of trusting too much. You know, had this place survived there would likely have been a lawsuit against the supplier or else large refunds made by the supplier. Win, lose or draw there are arguments for both sides. The supplier has dozens of installations and most of them have no problems. But we did. On certain product EVERYONE will. There was no data to alert any of us to the potential problem. We learned the hard way. Bottom line? Try to put processs in that have a fool proof method of measuring OUTPUT. When a vendor walks in and tries to sell you a process that doesn't have such a method be scared - very, very scared. You know, there are dozens of installations of oxide alternatives and many more going in as you read this. It's the new wave of "replacements". You know how we measure performance? We LOOK at the panels for color or hue. We measure etch rate. We might laminate coupons daily and do peel strength. What's the problem then? This stuff works by not only etching, but it also applies an "adhesion promoter". Can't measure that - can't measure its weight gain - can't measure its effectiveness. Etch rate doesn't tell the whole picture - the window for weight loss is HUGE. And even if it weren't, etch loss is not the mechanism that allows it to work. Laminating coupons takes several hours. And many shops have stopped baking product as it exits, like you once did with oxide. So, now there are millions of boards being built that employ this new technology and we've stopped moisture baking (cause the suppliers have dozens of installations that don't - AND IT WORKS). In my mind that's scary - very scary. I expect to get dozens of responses here telling me all about how this new technology works well and how you've come up with a way that's foolproof. Have at it - I'm all ears. Edward, good luck in future engineering endeavors. Make your shop "engineering" oriented rather than "production" oriented. If you do you might manage to avoid costly errors. Sincerely, Mark Mazzoli ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################