Workpiece description: The IC chip is covered with black hardened ink, and the ink is a wafer. There are exposed gold fingers on the other side of the IC chip, and the black part on the same side as the gold fingers is solder resist ink. The purpose of this cleaning test is to remove the black hardened ink, but the black solder resist ink on the same side as the golden finger cannot be damaged.
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Before washing, look. The surface of the IC chip is covered with black hardening ink, and the black part on the same side as the golden finger is solder resist ink.
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Place the IC chip in 130°C, hardened ink cleaning agent ACHM01-i, soak for 2 minutes.
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Take it out and rinse with water. After cleaning, it was found that ACHM01-i can quickly dissolve the black hardening ink, and it will not harm the black solder resist ink, and the font on the black solder resist ink has not changed. But the dissolved black hardening ink will contaminate and adhere to the surface of the wafer.
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Take another brand-new hardening ink cleaning agent ACHM04-i and heat it to 130°C, and put the IC chip whose surface is contaminated by dissolved resin into it again for 2 minutes. After taking it out, wash it with clean water. It was found that the dirt on the surface of the wafer can be removed. And the black solder mask didn't hurt either, and the font on the black solder mask didn't change either.
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Conclusion: 2~3 tanks of agents are needed to remove black hardened ink with hardened ink cleaner ACHM04-i. The first tank dissolves 99% of the ink. The second tank cleans up the residual ink. The 3rd slot is used as Guarantee. Each tank was heated to 130°C and rinsed for 2 minutes.
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Adjust the formula so that the black hardening ink resin does not dissolve in the agent, but peels off, and develops: hardening ink cleaning agent ACHM01-j. Place the IC chip in 160°C, hardened ink cleaning agent ACHM01-j, soak for 2 minutes. It was found that the black hardening ink had completely fallen off, but the color of the font on the black solder resist ink on the same side as the golden finger became duller.
The wafer on the left is using ACHM01-i, and the wafer on the right is using ACHM01-j, a 160°C hardening ink cleaner.
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Repeat the test. Place the IC chip in 130°C, hardened ink cleaning agent ACHM01-j, soak for 2 minutes.
It was found that the black hardened ink had been completely peeled off, and the black solder resist ink was not damaged, and the font on the black solder resist ink had not changed. However, there are some attachments on the wafer surface, which seem to have not been completely removed.
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discuss:
8.1 If it is wise to use the hardening ink cleaner ACHM01-j, and then use the hardening ink cleaner ACHM04-i to rinse, is it a better choice?