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Date: | Wed, 20 Feb 2013 15:22:30 +0100 |
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Hi Ramakrishnan,
I've had rather much to do with 5880 as a microwave guy. First, this
material is unique with its very high Z CTE = 237 ppm/C, in fact double
FR-4. Therefore, be aware of keeping a good balance in the overall copper,
as equal as possible per square all over the board.
Second, selective Hot Air levelling is recommended, which means that you
coat with molten solder (Tin/Lead) horizontally, and only sites for solder
mount of components. All other copper shall be remaining the mask. The
finish shall be maximum 20 micrometers and minimum 5 micrometers.
5880 has very good heat resistance and stands well after std 10 sec/ 265
Centigrades testing.
Alternatives: Fused Tin/Lead, electroplated soft gold for MCMs,
electroless immersion Tin. When I worked for Ericsson, our division for
Radiolink production made over two millions large double sided boards with
practically no reported warpage. You mentioned warpage, how much?
On 20 February 2013 13:00, Ramakrishnan Saravanan <[log in to unmask]>wrote:
> We have been using Rogers 5880 material for realizing Micro Strip PCBs.
>
> The final finish is HASL The thickness is 0.8mm & 1.6mm.
>
> We found warping is more after HASL.
>
> Is it recommended to do HASL on Rogers 5880 ?.
>
> If not what are the alternative finishes suitable for this material.(We
> are making High reliability PCBs).
>
> R.Saravanan
>
>
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