Posted by Donnie: Sat Mar 25, 2006 7:35 am    Post subject: Silicon dust contamination

Mga Sir's and Ma'ams,
May I ask for your help about our current problem in wafer
saw. I'm just new in the process, can you please give me some pointers??

thanks.
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PACLANDER

Posted by FARel Engr: Tue Mar 28, 2006 3:30 pm    Post subject:

Hi Donnie,

Welcome to the forum. We don't know what you already know, which is why it's difficult to answer your question. Anyway, just to start things off, here are my tips to you.

1. Understand your sawing process well. By optimizing your wafer saw process, you can minimize the amount of particles generated during sawing. Try to check for the history of your process. Is this the first time you had a silicon dust issue? if not, what do the previous engg reports tell you? Dig these up and learn from these reports.

2. How do you clean your wafers during and after saw? Does it involve vacuuming or wet cleaning? Is static charge, which makes the particles stick to the wafers, being addressed?

I'm not an Assembly guy as you can see from my alias, but hopefully with these simple tips the Assembly guys will come out with more sophisticated answers. Until they do, you need to do a lot of research on the internet on how wafer saw is done in the industry to minimize saw dust.

BTW, have you tried consulting with the 'senior' engineers in your org?

Good luck to you!

FARel Engr

Posted by Donnie: Tue Mar 28, 2006 10:44 pm    Post subject:

Dear Sir,
It's kind'a funny Sir, because my Senior Engineer has only
1 year experience in wafer saw (local Engineer) that's why I'm
on my own. Anyway, about your questions Sir:

1. Yeah, this is the first time this case happened here because our
assembly is only 6 months old.

2. We use wet cleaning Sir, high pressured water spray.

Thank you for your reply Sir, I very much appreciated it.
I just hope the Experts can add more deeper answers.
_________________
PACLANDER

Posted by FARel Engr: Thu Mar 30, 2006 9:21 am    Post subject:

Donnie,

Given that your assembly is just 6 months old, you really need to go through the birth pains that all established assembly houses have gone through. Be prepared to do tons and tons of evaluations to optimize your process. I've seen our assembly guys doing all sorts of evaluations just to get things 'right', and this is a continual process.

Anyway, I suggest that you : 1) conduct evaluations to optimize your saw parameters so that the generation of dust particles is minimized; and 2) conduct evaluations to optimize your cleaning process. Before you design your evaluations, do a lot of research on what parameters are important and how such evaluations are done. Surf the net extensively, download as many papers as you can, and even buy documents that you think will be useful to you. Soon you'll have tons of ideas on how to attack your line problems.

Posted by FARel Engr: Thu Mar 30, 2006 9:27 am    Post subject:

One more thing - before you optimize your process, make sure first that your process is IN CONTROL. Look at your data first and ensure that your output parameters are consistently meeting their specs. If your process output is jumping all over the place, then your first order of the day is to 're-establish' your process and bring it first under control. After that can you only optimize your process further.

Posted Donnie: Fri Mar 31, 2006 7:27 am    Post subject:

Thank you again Sir for your advice. yeah, I think I really have to do
a lot of research and experiments.

thanks again!!!
_________________
PACLANDER