Liquid and method to clean metal masks for surface mounting technology

United States Patent

[19]

Kim et al.

US005916858A [ii] Patent Number: [45] Date of Patent:

5,916,858 Jun. 29,1999

[54] LIQUID AND METHOD TO CLEAN METAL MASKS FOR SURFACE MOUNTING TECHNOLOGY

[75] Inventors: Choul-Su Kim; Woo-Sig Kim;

Masaharu Tsukue, all of Suwon, Rep. of Korea

[73] Assignee: SamSung Electronics Co., Ltd.,

Suwon, Rep. of Korea

[21] Appl. No.: 08/864,119

[22] Filed: May 28, 1997

[30] Foreign Application Priority Data

Jul. 19, 1996 [KR] Rep. of Korea 96 29277

[51] Int. CI.6 CUD 3/43; C23G 5/02

[52] U.S. CI 510/175; 510/176; 510/407;

510/412; 510/413; 134/1.3; 134/26

[58] Field of Search 510/175, 176,

510/407, 412, 413, 414; 134/1.3, 34.2, 26, 38, 40, 42

[56] References Cited

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OTHER PUBLICATIONS

McCutcheon's, vol. 1: Emulsifiers & Detergents, North American Edition, p. 83, #-97.

Sharovarnikov, A.F., et al., "Surface activity of fluorinecontaining surfactants in polar solvents and water-organic mixtures", Kolloidn. Zh., 53(5), 949-954, #-91. Shah, Khalid M., et al., "Change your surfactant formula and use etch baths for a week", Semicond. Int., 11(11), 132-134, #-88.

# Month not available.

Primary Examiner—Mark Kopec

Assistant Examiner—Gregory E. Webb

Attorney, Agent, or Firm—Robert E. Bushnell, Esq.

A method for washing metal masks using a cleaning liquid includes the steps of washing the metal masks before a solder printing process on printed circuit boards, washing the metal masks at least once during the solder printing process and washing the metal masks after completing the last solder printing process. The washing liquid has a composition consisting of from 1 to 5% by weight of a ffuorine43ased surfactant and from 95 to 99% by weight of isopropyl alcohol, the some of the constituents being 100% by weight. More preferably, the cleaning liquid is a composition consisting of 2% by weight of the ffuorine43ased surfactant and 98% by weight of isopropyl alcohol, the some of the constituents being 100% by weight.

4 Claims, 4 Drawing Sheets