SU1207692A2 - Flux for soldering and tinning - Google Patents

Description

The invention relates to the soldering and tinning of fusible solders of electronic equipment, as well as to the melting of galvanically applied fusible coatings on printed circuit boards.

The purpose of the invention is to increase the activity of the flux and to preserve a small corrosive effect on the melted material.

Flux contains components in the following ratio, wt.%:

Rosin

Tatrabromid

dipentene Lemon or tartaric acid Surface-active substance Ethyl alcohol

20-50 0.05-0.2 5-6

0.01-5 Else

The greater activity of the proposed flux is obtained due to the fact that citric and tartaric acids are more active than dairy or block. The positive effect is also due to the fact that in the flux an increased concentration of activating components is obtained with the same rate of action: the first component is citric acid or tartaric acid; the second is hydrobromic acid; the third component is formed from the first two components at the temperature of the soldering. 3-Bromo-pentantriic acid -1s3s5 is obtained by using citric acid, and - 5-dibromo-succinic acid is obtained by using tartaric acid. Combining citric or tartaric acid and tetrabromide dipentene, the active component is obtained, which leads to a new structure of the flux and to an increase in its activity while maintaining the same level of insulation resistance of products,

To obtain flux, crushed rosin is dissolved in alcohol. To the resulting solution was added a 5% solution of tetrabromide dipentene in ethyl acetate and stirred. Then citric sludge is added: both tartaric acid and surfactant top.

the society. Then mix thoroughly.

Specific examples of the proposed flux are given in table. one,

;; The flux is used at soldering temperatures of 200 to 290 s. Removal of residual fluxes after soldering is performed in an alcohol-freon mixture or alcohol-gasoline and subsequent

10 rinse in water at 50 ± 5 ° C. Efficient removal of flux residues can also be carried out in alkaline washes such as an electrician on jet installations.

15 The products sealed using the proposed flux meet the requirements of specifications and are of high quality and reliability. The effect of flux residues at temperature and relative humidity of 95 ± 3% on the electrical characteristics of the product (printed circuit board) is presented in Table. 2

The table shows that the proposed

25, the composition of the flux has a higher activity than the known flux, while the insulation resistance of the printed circuit board is within the limits specified by GOST.

thirty

Table

Rosin

Tetrabromide

dipentene

Lemon or

winna

acid

Ethanol

Surface-active substance

203550

0,050,120,2

55.56

74,9456,8738, J

0,012,55

Known (on malic acid)

Composition 1 on citric acid Composition 1 on tartaric acid

Editor S. Lisin

Compiled by L. Abrosimova

Tehred A. Kikemezey Proofreader O, Lugova

Order 127/15

Circulation 1000

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

table 2

1.2 2.0 1.8

ten

ten

ten

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Claims (1)

Flux for soldering and tinning, containing rosin, dipentene tetrabromide, ethyl alcohol, a surfactant, characterized in that, for the purpose. increase the activity of Flux and maintain a small corrosion effect, it additionally contains citric or tartaric acid in the following ratios of components, wt.%: Rosin Tetrabromide dipentene Lemon or 20-50 0.05-0.2 tartaric acid 5-6 Surface-active substance Ethanol 0.01-5 Rest