Seems like a great resource... thanks!
Ed Popielarski
Engineering Manager
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Oak Harbor, Wa. 98277
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-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo
Sent: Wednesday, April 26, 2017 10:14 AM
To: [log in to unmask]
Subject: Re: [TN] PCB delamination at area with ground-plane cutout
http://www.circuits-expert.com/art/thick-copper-layers-in-printed-circuit-boards-application-and-design-13
> a bit tough if pressure is low... and time is short. imho.
>> The copper is 1.5-oz. on the outer layers, and 1-oz. on inner layers.
>>
>>
>> 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] http://cipherengineering.com
>>
>>
>> -----Original Message-----
>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo
>> Sent: Wednesday, April 26, 2017 7:48 AM
>> To: [log in to unmask]
>> Subject: Re: [TN] PCB delamination at area with ground-plane cutout
>>
>> what is the copper thickness?
>>> I have to wonder why the plane was pulled back. Looks like a DB9,
>>> so I'm thinking, low speed signals, possible RS232. But it could be
>>> some high impedance circuit where capacitive loading is a big problem.
>>> Perhaps not.
>>> Perhaps the pullback was done not to limit capacitive effects on
>>> the traces on that DB9, just a pullback to prevent coupling, as a
>>> plane wasn't required. Just guessing, so as to not impact circuit
>>> performance.
>>>
>>> If low capacitance is required, it might be a bit more work than
>>> just adding a split plane or thieving, as it couldn't be added under
>>> the traces--but it could be brought "near" for the desired effect.
>>> But if it was just a "we don't need a plane here, just remove it"
>>> then a split plane should be easy enough to use, with a full or
>>> crosshatched pour.
>>>
>>> Shawn Upton
>>> Section Head, Test Engineering
>>> Sensors Business Unit
>>> Allegro MicroSystems, LLC
>>> [log in to unmask]
>>> 603.626.2429/fax: 603.641.5336
>>>
>>>
>>> -----Original Message-----
>>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Carl Van Wormer
>>> Sent: Wednesday, April 26, 2017 9:51 AM
>>> To: [log in to unmask]
>>> Subject: [TN] PCB delamination at area with ground-plane cutout
>>>
>>> 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_missin
>>> g_
>>> ground_plane__1_.jpg
>>> http://stevezeva.homestead.com/Delamination_-_is_it_caused_by_missin
>>> g_
>>> 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/>
>>>
>>> This message may contain confidential and/or proprietary
>>> information, and is intended for the person/entity to whom it was
>>> originally addressed. Any use by others is strictly prohibited. If
>>> I sent this to you by mistake, please be nice and delete it, and
>>> then tell me of my mistake so I can send it to the right person.
>>>
>>>
>>>
>>
>
>
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