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Date: | Mon, 5 Mar 2018 17:02:14 -0500 |
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if it is mission critical part, there is always solder foil (flux
build in or flux sticky on both side), you can order at volume - (not
cost effective - however, you can cut on your own if you only make
less than 30ish) - for either prototype, or low volume extremely
pricy stuff. you can minimize the voids for sure.
On Mar 5, 2018, at 4:51 PM, Wayne Showers wrote:
> Dave et al,
> You can add me to the list of companies that will provide voiding
> data. I am data mining variations of the print pattern to reduce
> voiding and I am in the process of marrying up stencil design to
> void and fill percentages.
>
> I can echo the voiding request from Blackberry. The original
> request was 90% coverage and no more than 3 voids with no single
> void greater than 5%. Even to get to the 70%, I ended up using a
> custom solder slug and still had voiding due to via in pad.
>
> I would like to see a standard that reflects something similar to
> the following:
> Class 1: Undefined
> Class 2: Shall be 50% coverage with no single void exceeding X% or
> as defined by customer or part manufacturer.
> Class 3: Shall be 70% coverage with no single void exceeding X% or
> as defined by customer or part manufacturer.
> Note 1: Customer Requirements supersede
> Note 2: Manufacturer Recommendations/Requirements supersede
> Note 3: VIA in Pad and other design factors shall be considered and
> evaluated if criteria cannot be met.
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