The figure below provides customers with the stoppers used for PVD sputtering in the semiconductor industry to be cleaned. The base material of this part is aluminum, the bottom surface is anodized, and there is a QRcode number engraved by laser on the bottom surface. The surface of the part has been covered by about 50 layers of coatings containing copper and titanium. The customer requires that the surface coating be removed so as not to damage the QRcode.

Since the agent will affect the anodic treatment, the QRcode is protected with glue before the experiment. After dehydration and curing, the beaker is filled with an appropriate amount of SCE01, and the parts are put into the agent. Micro bubbles appear after the surface coating of the part starts to react. After 10 minutes, the coating Already started to fall off.

After 4 hours, the surface coating of the part began to fall off layer by layer, and the color of the agent became darker and darker. When the part was picked up with tweezers, it was found that the surface coating had not completely fallen off due to too many layers.

Continue to soak for 4 hours until the surface of the parts is completely peeled off. At this time, the surface of the aluminum material has been oxidized. After confirming with the customer, this degree of oxidation will not affect the customer's use

Put the sample into a beaker filled with an appropriate amount of glue remover, heat it to 70-90°C, soak for about 40 minutes, check that the glue at the bottom has been removed, and the QRcode is not damaged

Conclusion: SEC01 selective copper etchant can be used to strip the SUS+copper coating on the surface of the part. Before stripping, the QRcode needs to be protected with glue. After the coating is stripped off, the glue can be removed.

Suggestion: Before immersing in the agent, add more glue to the bottom QRcode to prevent the QRcode from being peeled off due to too little glue.

The picture below provides customers with equipment parts to be cleaned. The base material of this spare part is anodized black nickel on the aluminum surface, and there is a QRcode number engraved by laser on the bottom surface.

Fill the beaker with an appropriate amount of SCE01, put the parts into the medicine, micro bubbles appear after the coating on the surface of the parts reacts, after 10 minutes the coating has begun to fall off, and the medicine turns slightly green.

After 4 hours, the surface coating of the part began to fall off layer by layer, and the color of the agent became darker and darker. When the part was picked up with tweezers, it was found that the black nickel plating layer had also fallen off, but the surface coating had not completely fallen off due to too many layers.

Continue to soak for 4 hours until the surface of the part falls off completely, at this time the surface of the aluminum material has oxidized and turned white

Continue to soak for 12 hours overnight to see if the solution will continue to erode the aluminum. The second day inspection shows that the solution has no obvious erosive effect on the aluminum, but the black nickel on the anode has been removed, and the QR code has also disappeared.

Conclusion: Using SEC01 selective copper etchant can remove the coating on the surface of this part, but at the same time it will also strip off the black nickel coating, and the lack of color difference on the bottom will cause the QRcode to be unreadable.

suggestion:

(1) Before immersing in the chemical, apply glue on the side of the QRcode at the bottom or use other methods for protection to prevent chemical erosion.
(2) Or after all the coatings of the parts are stripped off, the parts are re-plated with nickel and marked with QRcode.