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PCB Delamination

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#53486

PCB Delamination | 31 January, 2008

Since the implementation of the ROHS process in our Company with the higher temp requirements, we had observed an increase in problems related to delamination in the PCB's. Actually we are using FR408 and Gracescore materials and are changing to a Ventec47 and Taiwan Union laminate materials. Tg on these materials are between 170-180 degrees C. The humidity absorbsion for FR408 and Gracescore is between 0.45-0.35% and in the Ventec47 and Taiwan Union is between 0.18 and 0.20. What are tendencies of laminates used in the Industry that have less probability of delamination? How can I minimize/eliminated the delamination problem. Besides the laminate material there is any other concerned factors that we need to consider?

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#53501

PCB Delamination | 31 January, 2008

Hi Felix,

First thing to verify is that your supplier is actually suppling you with the correct material. China is known for not keeping with the requested materials and will substitute if not controlled.

I would recomend ITEQ, TUC or Nan ya for offshore laminate and Nelco 4000-11, -29 and Isola 370 for State side.

Most Rohs laminates have a higher Absorbsion rate than standard laminate and need to be better controlled for moisture.

Shelf life of Rohs Pre-preg is also shorter than standard Pre-preg material, 3mos vs 6mos. Make sure your suppliers is using a first in first out system.

Some of the CM's I work with also Pre-back before assembling , so many hrs at 125c. You would know more about this than I do.

The olny laminate our Customer base has decided not to use is Isola IS410.

Hope your Delam issues clears up.

Regards,

Mike

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#53504

PCB Delamination | 31 January, 2008

It's not as simple as specifying tg in a leadfree world. You need to better understand delamination temperature - td. To start, search the fine SMtnet Archives on td. For instance: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=50312

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aj

#53510

PCB Delamination | 1 February, 2008

we have also seen this issue but seems to be on boards whee there is a open space and no copper hatching.

We bake these boards out for 4-6 hrs @ 125oC.

aj...

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#53518

PCB Delamination | 1 February, 2008

our company has beed experiencing some delamination on our circuit boards, we have been lead free for a while and haven't been adjusting temperatures, Found out that the board house was doing something wrong in there process, finally was able to prove it by showing them the beginning of delamination before I had even built the board (bare panel). now they pay us for everyone of these boards that goes through the process that is scrapped as a result. so make sure your board house isn't to blame!!!!.

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#54632

PCB Delamination | 6 May, 2008

Could you tell me how to detect PCB delamination issue? through cross section, SAM or others?

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#57360

PCB Delamination | 20 November, 2008

Calling out materials by name locks you into laminates by brand. If these are typically phenolic materials it can lead to moisture absorption, less mechanical strength and more prone to delamination during assembly.

It is more effective to refer to IPC callouts. Our recent webinar demonstrates the benefits of mid-grade materials as opposed to the high Tg and Td materials.

Here's the link: http://saturnelectronics.com/leadfree.htm

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#57413

PCB Delamination | 25 November, 2008

Listen, I conqure with with wAyne on this one as your board house is always gonna the first person y a blame if you haven't adjusted any process paarameters in a while and see board related issues that can be traced to the board house. I once thought we had an board house issue with a board once only to find out it was do to bad repair. My brother likes to crank up th eheat on his soldering gun to make quick reapairs even faster only to lift traces and pads and stuff but it wasn't the board houses falt. I think he does it on purpose some times cause i run the wave and he repairs the boards frorm wave. We some times argu for hours on the line so Thats when I bring out the Big Gun!!!

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