Visual Inspection Standard Specification for Thick Film Hybrid Substrates

[davekellerman]

Hello--
I am very new to blogging, and this is my first experience, but here goes:
I am working for a client that needs to impose a quality requirement on his incoming thick film hybrid parts.
Specifically he needs better print quality control; line width and spacing uniformity within the part, part to part and manufacturing lot to manufacturing lot.
So far I have determined that Mil-std-883 method 2032 is a good start. It only seems to address defects, however, not manufacturing consistency and/or control.
I am sure there must be an automotive specification for hybrid microcircuits, but I have been unable to unearth that avenue. I remember DuPont citing that their pastes, once processed (of course) meet rigorous automotive standards, but I have not been able to find the reference...
Can anyone help? Is there a universal standard such as this one that covers industrial applications (this is not a military part, but its electrical performance sensitivity is such that better control over substrate features seems to be required.
Many thanks
Dave

[Stijloor]

Originally Posted by davekellerman

Can anyone help? Is there a universal standard such as this one that covers industrial applications (this is not a military part, but its electrical performance sensitivity is such that better control over substrate features seems to be required.
Many thanks
Dave

Hello Dave,

Have you looked here? There may be something that would apply to you. I will search some more.

Stijloor.

[davekellerman]

Yes, I DID Google this, but your keywords brought out some results that I had not yet seen.
Most address defects, but do not address the specific issue of print quality and consistency. Us thick filmers have been studying that for a long time especially when it comes out to obtaining nice consistent resistor values over the entire surface of the substrate!
One that I also found was 60748-23-1,2,3,... The issue with that one is to get a copy you have to be ready to shell out $300++ !! Granted the big guys would not have too much issue with that, but us tiny guys do, so would that not be prohibitive to universal adoption?
Thanks for the help!
Dave

[ralphsulser]

I have been involved in primer paint of fiberglass body parts we molded for Ford, GM, and Chrysler. They had specs for min film thickness and the method to use. Everyone in the similar industry used a "Took" gage (cost was about $140.00 then), which basically scratches the paint down to the substrate with an angled blade. Then you look through the scope and the grid lines to determine the actual thickness. This was in the 70's and the spec was 1.0 mil min if I remenber correctly.