Before washing, look. The surface of the IC chip is covered with silver hardening ink, and the black part on the same side as the gold finger is solder resist ink.

Place the IC wafer at 80°C in hardened ink cleaners ACHM04-A, ACHM04-H1 and PTC13 for 10 minutes.

Take it out and rinse with water. After cleaning, it was found that none of the three agents could effectively remove the silver ink. Among them, although PTC13 can remove the ink, but PTC13 is an alkaline ink cleaning agent. Once the ink is removed, PTC13 will corrode the exposed wafer and cause damage to the chip.

Heat hardened ink cleaner ACHM04-A to 140°C and soak for 20 minutes. It was found that although the hardened silver ink had been moistened, it could be removed by wiping. But the black glue on the edge package has been damaged, exposing the copper wire.

Test Hardened Ink Cleaner ACHM01-GG. ACHM01-GG was found to be effective in removing silver hardened inks. However, ACHM01-GG is a gel formulation, which is highly corrosive and is only suitable for wiping. The chip is small in size and not easy to fix and wipe.

Test Hardened Ink Cleaner ACHM01. It was found that heating the hardened ink cleaner ACHM01 to 140°C and soaking for 1 minute can effectively remove the silver hardened ink.

Repeat the test. It was found that heating the hardening ink cleaner ACHM01 to 140°C and soaking for 3 minutes can effectively remove the silver hardening ink, and the surface is cleaner.

Repeat the test, taking the IC wafer whose surface is covered with black ink. It was found that heating the hardened ink cleaner ACHM01 to 140°C and soaking for 3 minutes can also effectively remove the black hardened ink.

Suggestions and discussions:

9.1 From the results of this experiment, the hardening ink cleaning agent ACHM01 is a more effective cleaning agent. The recommended cleaning conditions are: heat to 140°C, soak for 3 minutes, take it out and rinse with warm water.
9.2 This cleaning test only involves simple heating and soaking. Will the effect be better if it is cleaned with an ultrasonic wave or a cloth brush? It needs to cooperate with the equipment manufacturer for further testing.

Exterior before washing. The outer surface of the gold finger of the IC chip is covered with green hardening ink, and the black part on the other side is encapsulation vinyl, with laser engraved marking on it. On the far right of the green paint (pictured below), there is a line cut out by a laser, and there are copper contacts that are not completely exposed below (see the position indicated by the arrow). The purpose of this test is to find out the appropriate agent that can remove the green paint on the copper joints and expose the copper joints.

Place the IC chip in 140°C, hardened ink cleaning agent ACHM01, soak for 3 minutes. Take it out and rinse it with clean water. It was found that the green paint had completely peeled off. And the copper wire under the green paint has been completely exposed. But observing the line cut out by the laser, the copper contact is still not exposed.

Before Cleansing

After soaking the left side in 110℃ ACHM01 cleaning agent for 5 minutes, take it out and rinse it with clean water immediately. After soaking the right side in ACHM01 cleaning agent at 120°C for 7 minutes, take it out and rinse it with clean water immediately.

left after cleaning

right after cleaning

Before Cleansing

After soaking in ACHM01 cleaning agent at 120℃ for 5 minutes, take it out.

Rinse off with water under the tap. Blow dry with Air. (Using a water jet machine with resin sand can clean it more quickly and conveniently, and the effect is better.)

After Cleansing

Compare

5.1 Epoxy black glue, there is no significant difference in color and hardness before and after washing.
5.2 Copper sheet, the oxidized part has been obviously removed after cleaning.
5.3 Marking, the hardened Marking has been obviously removed after cleaning.

Sample before cleaning

Use Xiwei TM Hardening Ink Cleaner ACHM01, heat to 120~140°C, soak for 5 minutes, take it out, wipe it with a non-woven cloth, and wash it under the tap.

After cleaning.

Sample before cleaning

zoom in

Placed on a black polarizing plate, the overflowing EPOXY resin in the black frame can be seen clearly.

Magnify with a microscope.

The EPOXY hardening ink cleaners ACHM01 and ACHM04 developed by our company (Chang Xinsheng Industrial Co., Ltd.), the Epoxy paint stripper AHLR03 for aluminum alloys, and the high-temperature hardening polyimide remover PIC06 were used for cleaning tests.

Test Results:
5.1 EPOXY hardening ink cleaning agent ACHM04 is invalid for cleaning at room temperature. Heating at 60°C for 10min, 30min, and 1hr is ineffective.

5.2 The special Epoxy paint stripper AHLR03 for aluminum alloy is invalid for cleaning at room temperature. Heating at 120°C for 10min, 30min, and 1hr is ineffective.
Magnify with a microscope.

5.3 High temperature hardening polyimide remover PIC06 is not effective for cleaning at room temperature. Heating at 120°C for 10 minutes is invalid. After heating at 120°C for 30 minutes, it was found that it can be easily removed with a PE spatula. It is recommended to run the waterjet (mixed resin sand) process, which should be effectively removed.

5.4 EPOXY hardened ink cleaning agent ACHM01 is invalid for cleaning at room temperature. Heating at 120°C for 30 minutes and washing with water can effectively remove it.

Magnify with a microscope.

Repeat the experiment to verify the cleaning effect of EPOXY hardening ink cleaning agent ACHM01.

Comparison: Put the workpieces that are not clean with the special Epoxy paint stripper AHLR03 for aluminum alloys into the EPOXY hardened ink cleaner ACHM01, at 120 degrees C, for 30 minutes.

Attention!! When cleaning with EPOXY Hardening Ink Cleaner ACHM01, the brown TRM Tape at the back should be torn off first. Because I found that ACHM01 will dissolve the silica glue on the TRM Tape, if it is not torn off first, it will cause sticking back, which is not good.