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US 12,503,775 B2Granted
Copper etching solution
AssigneeC. Uyemura & Co., Ltd.
InventorsTakuya Komeda, Tetsuji Ishida, Hisamitsu Yamamoto, Kazunari Kato, Ryoyu Shimizu
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Abstract
A copper etching solution contains an oxidizing agent and an amine compound. The oxidizing agent is one or more selected from the group consisting of a perchlorate, a chlorate, a chlorite, a hypochlorite, hydrogen peroxide, and a perborate, and the amine compound has one or more primary amino groups or secondary amino groups.
Claims10
A circuit board processing method comprising etching a copper portion on a circuit board in connection to a dissimilar metal by using a copper etching solution, wherein the copper etching solution comprises:
- one or more oxidizing agents selected from the group consisting of a perchlorate, a chlorate, a chlorite, a hypochlorite, and a perborate;
- and
- an amine compound having one or more primary amino groups or secondary amino groups,
- the dissimilar metal is stainless steel, silver, and/or gold, and
- the dissimilar metal is in contact with a surface portion of the circuit board conducted to the copper portion and is in contact with the copper etching solution,
- wherein an etching rate of the copper is from 0.0208 μm/min to less than 0.2 um/min, the etching rate is represented by a formula of etching amount (μm)/immersion time (min).
3 more elements
Dependencies are inferred from the claim text.