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Acid copper PCB board to resolve instances of fog
Last Updated : 2011/5/5

Acid copper circuit board factory instance fog solution

       Old copper tank fog, MU and B can exclude the possibility of overdose, the situation is much better after a large, but made two days the phenomenon of fog can not cover off bright nickel, nickel-plated and the longer the more the fog Obviously, once a good-plated piece of copper in the wash on the potassium dichromate, nickel plating the activated white mist in the go out of low areas can be coated on cover, but not bright, no light, the film hit the lower zone Cao Hall severe fog and poor high-brightness area, the high temperature effect is not obvious, and the whole coating the light is slow.

       Discussing the solution:

       1, light dose offset,Imbalance may be the agents of light, what with the small amount of activated carbon adsorption, or you continue to do two specimens without light agent, general agent A consumption to be bigger, hit the third time in the specimen to see, is that which less and more, plus hydrogen peroxide, activated carbon filter to clean and bath, plus temperature to 70 degrees, electrolysis a few hours, until the time of the coating even after electrolysis, electrolysis, alternating current when the size and proportion of the normal complement of light agent. Generally low chloride bright color will be darker.
        2, oil Gaga SDS stir, add a clean filter cartridge
        3, is well known, MN-based bright acid copper plating bath to be used include chlorine ion, including five to six kinds of brightener. The proper ratio, the coating of bright, excellent leveling, high-temperature properties of the bath is better; but serious imbalance, its treatment requires some experience and simulation analysis tools.

        There are three factory about 1200L of MN-type copper trough, the light is poor due to low areas and the emergence of sand and Ma Ma, technology staff, has added a sulfuric acid and copper sulfate supplement to improve much; plus hydrogen peroxide, the active carbon filtration, without a heat treatment, supplemented with the original self-brightener with a good result, coating does not shine, hemp sand even more serious.

        I made the Hall bath experimental tank were adjusted individually to add several brightener, the effect is acceptable but add in a large tank or two tank plating normal soon after the anesthesia was sandy. The analysis was based less than the amount of activated carbon treatment, causing serious imbalance selective adsorption, and after adding hydrogen peroxide to remove residual material is not heated, so that additional additives has been partially destroyed. By conventional methods, should be combined with hydrogen peroxide, heat, total destruction of additives with large doses of activated carbon adsorption, and then cooled again by additional brightener formula, but requires 3 to 4 days to complete (no refrigeration equipment, cooling than heating difficulties, nor the filter.) The rush to complete the urgent processing plant, the time allowed, only to find another way.

        According to oxidant properties, take 1 L bath test: measurement of potassium permanganate oxidation of hydrogen peroxide added, stirring constantly oxygen bubbles. When no oxygen to be generated, then add about 0.2 g / L potassium permanganate and continue stirring 10min, the remaining oxide brightener. Do not filter, take the solution for the Hull Cell test, known brightener has basically been destroyed; the best ratio by adding a new re-mixed with brightener, and then the Hull Cell test, the light of the basic recovery. With a high power magnifying glass can be seen, there is still a small amount of very fine specimen Ma sand, additional SP invalid, suspected of chloride ion concentration is not enough, then 0.0001 ml / L by adding concentrated hydrochloric acid, hemp sand all but disappeared, light is also increased, but still slight protuberance, like crystal rough. Analyze the reasons may be caused by excessive copper sulfate. Remove the three tenths of the bath, and a small amount of additional distilled water mixed brightener, leveling the light works well: After sanding, 500 fine specimens of copper, in the Hall stirred tank plating 5 to 2 A min, addition of about 1cm lower area of ​​somewhat less bright, the other is to achieve the full brightness of the mirror effect, high-power magnifying glass, no pit points and protruding objects. Plating bath for three separate tests to determine the dosage of potassium permanganate of the tank, according to test results after treatment, take fluid re-examination, and further fine-tune the ratio of brightener, bath completely back to normal, and the former than the failure better leveling effect of light. Bath adjusted by the test more than ten hours, that is well into urgent processing.

        After the troubleshooting, I have the following experience:
        (1) appears plating failure symptoms should be carefully observed (the plant that the failure to deposit the rough, in fact, fine linen, sand), can be high-powered magnifying glass coating (I previously encountered too much saccharine in bright nickel plating produced by fine pitting, the naked eye as hair spray and hair spray manufacturers by examples of the reasons for treatment not effective). On the bright copper, the whole difference and the brightness level is low, can be subtle pit point processes may be subtle, if not observed accurately, its approach is difficult to determine. The failure was mainly due to higher self-made supplementary brightener M, resulting from the accumulation of sand and fine linen, plus SP can be solved, and as judge allowed improper treatment of the plant's production.

        (2) If the bright acid copper plating bath brightener difficult to adjust the imbalance, should be thoroughly treated, add enough hydrogen peroxide, activated carbon and heated to remove residual hydrogen peroxide. If after adding hydrogen peroxide to make activated carbon treatment is not heating, bath would be more serious disorders.

        (3) bath treatment failure, we must have practical experience, should have a certain chemical basis can handy. Such information has not been reported for treatment of acid copper plating bath with potassium permanganate, according to the principle of chemical, potassium permanganate oxidation in acid than the hydrogen peroxide under the conditions of strong heating after the entry without residual hydrogen peroxide oxidation can be oxidized and thus lost destruction of brightener, without activated carbon adsorption, filtration, that is a good emergency treatment bath (of course, the added amount should be after careful testing to determine), to meet the production need.

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