[Lab] Laser cutter precision

[jeanmarc.leblanc at gmail.com]

can you elaborate on the bump mask? I am curious. a quick google did not  
reveal any thing.

I am simply experimenting of a cheap way to solder these LGA chips

I forgot to cc the lab

(igoogle does not have a reply all)

On , Michael Ayukawa <mike.ayukawa at gmail.com> wrote:
That is good stuff. Were you planning on using it as an etch mask?


Or are you thinking something completely different? People usually use  
Kapton if they
plan to retain it as a dielectric layer in the stack. So perhaps you are  
using this for
what would be called a "bump mask"?


You really don't need the high temp properties for wet chemical processes.
The interface to the Cu is probably more important (etchant can quickly  
move along the
interface). We used to use special adhesion promoters and bakes to avoid

jeanmarc.leblanc at gmail.com wrote:
I was going to buy this
http://www.ebay.ca/itm/Kapton-Polyimide-100TAB-E-8-x12-3-Sheets-Free-SH-/370109637919?pt=LH_DefaultDomain_0&hash=item562c40e51f
 From what I read, that is the metrial that is recommended for this kind of  
thing and cuts well with lasers
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