If the scratches are superficial and not exposing metal they are not rejectable. The bridging refers to exposing adjacent conductors because of a scratch down to metal. If there is soldermask still at the bottom of a scratch it is not rejectable.
Sent from my iPhone
> On Jun 10, 2018, at 9:07 PM, Willis Tam <[log in to unmask]> wrote:
>
> Hi All,
>
> Any comments and suggestion will be highly appreciated.
>
> B.R.
> WT
>
> -----邮件原件-----
> 发件人: TechNet [mailto:[log in to unmask]] 代表 Willis Tam
> 发送时间: 2018年6月5日 10:23
> 收件人: [log in to unmask]
> 主题: [TN] 答复: Interpretation of IPC standard for Solder Mask Scratches on PCBA
>
>
> Hi Technet,
>
>
> We have some arguments with one of our customers on the interpretation of IPC standard for Solder Mask Scratches on PCBA.
>
> According to IPC-A-610F §10.7.2. Solder Mask Coating-Voids, Blisters, Scratches.
> Acceptable- Class 1,2,3.
> Blister, Scratches, Voids that do not expose conductors and do not bridge adjacent conductors, conductor surface or create a hazardous condition which would allow loose mask particles to become enmeshed in moving parts or lodged between two electronically conductive mating surfaces.
>
>
> Customer's product specification defined the PCBA to be compliance to IPC-A-610F standard Glass 3.
> Customer found some scratches on solder mask surface on some of the PCBAs, the scratches are minor scratches, not deep/heavy scratches, not expose conductors(copper traces under solder mask), but go across the adjacent conductors;
> We considered those scratches acceptable according to IPC-A-610F §10.7.2, but customer said not acceptable.
>
> The main argument is: customer considered any scratch which go across adjacent conductors as rejection, (Bridge adjacent conductors = go across), even not expose conductor.
> This is an 5mil/5mil(width/space) board, not accept scratches which go across adjacent conductors means not accept scratch of 10mil (0.25mm) length.
>
> I would like to seek clarification from IPC guru so that we move forward
>
>
> Best Regards
> Willis Tam
>
>
>
>
|
