Monday, August 6, 2007

One Cranky Otter

I work in a production facility. We process parts in the form of wafers. Every so often something goes wrong and I or another engineer has to look into it and look at the wafers and make a disposition. Some problems are "routine" and have prescribed solutions. The engineering techs can disposition these just fine. With the non-routine problems, particularly with visual defects, it helps to have one set of eyes to evaluate problems because what one person might write up as a "stain" someone else will call an "overetch" and someone else might call "corrosion". They might all be right, they might all be wrong. But if one person does the evaluation, they can at least tell if this "stain" is the same as that "corrosion" and start to build a consistent picture of the problem.

We had a lot pass through with a visual defect of the type I've been trying to get the process techs to hold for me, and me specifically, to look at. I'm not sure why people are so reluctant to hold things for me, but it was from night shift and I can think they didn't want the lot sitting for 10 hours waiting on me. So they wrote up the disposition (mask out that section of wafer as scrap) and sent the wafers on. But the description of the problem was new and unusual. I have no idea what they mean. Since I'm on a team looking into defects at this step, I need to know what they mean. So I tracked the wafers down after and got them put on hold. But they didn't get on hold until well into friday night. This was so the lot could get to a point where I could only hold my few wafers and send the unaffected wafers on without being held all weekend.

The wafers were tracked down and held by the shift supervisor. They held through the shift change at night shift. The held through the new day shift that comes in sunday. Then, inexplicably, this morning they were let off hold. This is the same shift that works sunday. I could understand if they let them go yesterday. But I checked this morning and they were on hold. I had to deal with a down tool, then I went and called up to find out where the wafers were and were told they were sent on. GAH!!!! When sent on, they go to a step where I can no longer inspect them. What part of hold for ME to evaluate means "let the shift technician evaluate them and send them on"? And it was a supervisor who released the hold! WTF!?! Did anyone call me to ask if it was ok? No. Did anyone call to say they were being let go? No. Why do I even put my name on a hold if it can just be blown off?

It's not a case, this time, of letting bad parts get to customers, but of me adding to my inventory of issues at a certain step. But what happens if they let something go that shouldn't go out? What if I miss a developing or evolving problem because my wafers are just let go to get moves? I need some special code that says "no one but this exact person or their specified representative is allowed to move these wafers beyond this point". Maybe I should just write "Hold for me and only me" next time, instead of merely specifying "hold for me."

As you can tell, I needed to rant. This is driving me crazy. It's happened way too many times now, too. And I need to not be a raving lunatic that is going to choke the daylights out of my colleagues when I go over to try and evaluate these wafers at a stage where I probably won't be able to see through the mounting film to my defect. Gah!

No comments: