Method for controlling etching solution concentration

Abstract

The invention discloses a method for controlling an etching solution concentration, which comprises the following steps: setting a target concentration value of an etching solution; extracting an etching solution sample; diluting the etching solution sample by using propanediol; measuring the concentration of the etching solution sample to obtain a measured concentration value; and adjusting the concentration of the etching solution to the target concentration value according to a difference value between the target concentration value and the measured concentration value. Without using poisonous substance in an analysis process of the etching solution concentration, the method can reduce the burden on environment in the control process of the etching solution concentration.

Description

technical field [0001] The present invention relates to a concentration control method, in particular to a concentration control method of etching solution. Background technique [0002] The wet etching method using acidic or alkaline solution has become a fairly common manufacturing method in the current manufacturing process of electronic products, which is applied in technical fields including panels, semiconductors, and circuits. Since the etching method must maintain the concentration of the etching solution within a certain range without excessive changes, the stability of the etching rate can be ensured and the quality of the product can be controlled. Indispensable technology. [0003] The conventional concentration control method is to sample the etching solution at a fixed time, conduct concentration analysis, and then add a certain amount of acid-base liquid after comparing the changes in the concentration of the etching solution to keep the concentration of the ...

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Problems solved by technology

The conventional technology can only replenish the concentration of the etching solution to the "last measured concentration" based on the results of the two measurements, but if the concentration measured last time is not the initial proper concentration, then the replenishment can never be replenished to the proper concentration. concentration

(2) Comparing the concentration of the etching solution measured twice before replenishing, so that the replenishment time is longer, the longer the time is, the greater the concentration change is, and it is prone to excessive or insufficient replenishment

(3) When measuring the concentration of the etching solution, it is necessary to sample the etching solution and then dilute it. When measuring the concentration of the etching solution with a non-aqueous titration method, it is necessary to sample the etching solution and then dilute it. Because the conventional non-aqueous diluent either has a toxin or a flash point Quite low, the manufacturing process is relatively less environmentally friendly and requires additional cost to dispose of

Since each measurement requires repeated washing of the diluent and sample from the previous measurement, as the number of measurements increases, more environmental pollutants will be generated during the manufacturing process, which will cost extra to process

[0004] The above-mentioned shortcomings all make the concentration control of the etching solution take a considerable amount of time and cost but fail to improve product quality, which is even more unfavorable for market competition in the current environment full of environmental protection concepts.

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