Some might say in many cases "delam" is standard for RF boards with low pressure areas as well. ;^)
Pays my mortgage... /heh/
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of haviv gendelis
Sent: Wednesday, April 26, 2017 8:06 AM
To: [log in to unmask]
Subject: Re: [TN] PCB delamination at area with ground-plane cutout
There os nothing to do with the design. Standard for RF boards.
Possible reasons
1. Material should be min tg 170c
2. Poor board manufacturing contamination, prepreg, lamination process 3. Water absorption 4. Assembly profile
The delamination could
appear in other areas but is hard to detect because of the Cooper shadow.
Haviv
On Apr 26, 2017 4:52 PM, "Carl Van Wormer" <[log in to unmask]>
wrote:
> We received pictures from our contract manufacturer, marked to show
> delamination occurring in 2 areas on our 6-layer boards. The
> delamination areas were at the electrically isolated communication
> interfaces that were made with no copper on the power and ground
> planes to reduce capacitive coupling. The response from the PCB manufacturer is:
>
> 1)defect reason: we used our stock boards to run the thermal
> shock test, we see the de-lam is only taking place in the two areas
> without copper (pic 1.jpg),
> There is insufficient glue in this area that happened during
> lamination and that is why the de-lam is happening when the customer
> is assembling under the high temp, 2)correction action: if the
> customer needs us to remake, we suggest to modify the design a little,
> pls see pic 2.jpg, we will fill the marked area with solid copper .
> Please confirm if a remake is needed, we will arrange right away.
>
> Steve Gregory has posted the pictures at:
> http://stevezeva.homestead.com/Carl1.jpg (board cut open for
> evaluation at board house)
>
> http://stevezeva.homestead.com/Carl2.jpg (picture showing where they
> want to add copper)
>
> (and 2 pictures of the delaminated areas)
> http://stevezeva.homestead.com/Delamination_-_is_it_
> caused_by_missing_ground_plane__1_.jpg
> http://stevezeva.homestead.com/Delamination_-_is_it_
> caused_by_missing_ground_plane__2_.jpg
>
>
> Question to the group: Will adding copper on the electrically
> isolated open areas eliminate this type of delamination? We could add
> the copper, but not connect it to the system ground.
>
> Thanks,
> Carl
>
>
>
>
>
>
> Carl B. Van Wormer, P.E., AE7GD
> Senior Hardware Engineer
> Cipher Engineering LLC
> 21195 NW Evergreen Pkwy Ste 209
> Hillsboro, OR 97124-7167
> 503-617-7447x303
> [log in to unmask]<mailto:[log in to unmask]>
> http://cipherengineering.com<http://cipherengineering.com/>
>
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