Difference between revisions of "Photographs of corrosion and surface defects"

Revision as of 09:13, 30 March 2009

Photographs of flaws in the Allflex films were taken when the boards arrived in September '08 and again in March '09 after being stored in a dry Nitrogen environment. The first two photographs below show that there was already evidence for corrosion or poor quality of the copper surface on one of the 5 micron boards when they arrived from the manufacturer, but it is not clear that this problem became worse over time.

figure 1a: Photograph of 5micron/Left#2 flaw taken 09/08.

figure 1b: Photograph of 5micron/Left#2 flaw taken 03/09.

There are marks on one of the 5 micron center boards that from a distance look like fingerprints but actually turn out to be scuff/scratch marks:

figure 2a: Photograph of 5micron/Center#2 flaws taken 09/08.

figure 2b: Photograph of 5micron/Center#2 flaws taken 03/09.

There is evidence for degradation of 2 traces on the same 5 micron center board that I was not able to verify already existed when the board came from the manufacturer:

figure 3: Photograph of 5micron/Center#2 bad traces taken 03/09.

Below are before and after photographs for one of the central 2 micron boards. There is evidence for either oxidation of the copper or left-over photo-resist material present upon arrival of the boards from the manufacturer. Again, it does not appear that these flaws got worse over time.

figure 4a: Photograph of 2micron/Center#2 flaws taken 09/08.

figure 4b: Photograph of 2micron/Center#2 flaws taken 03/09.

figure 5a: Photograph of 2micron/Center#2 flaws taken 09/08.

figure 5b: Photograph of 2micron/Center#2 flaws taken 03/09.

Almost all of the 2 micron boards have regular marks indicating possible left-over contamination from rollers:

figure 6a: Photograph of roller marks on 2 micron board.

figure 6b: Photograph of roller marks on 2 micron board