SU1230778A1 - Soldering compound - Google Patents

Description

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The invention relates to soldering, in particular, compositions for protecting metallized holes and conductors of printed circuit boards from molten solder during the process of mechanized soldering of products, and can be used in radio engineering, electrical engineering, instrument-making industry in the manufacture of electronic equipment.

The aim of the invention is to reduce. reduction of the labor intensity of the soldering process by reducing the time of formation and removal of the protective film, as well as reducing the corrosivity of the composition

The composition contains components in the following ratio, wt.%:

Polyvinyl acetal or

polyacrylate. 7.6-12.4

Limit monoatomic alcohol 59,5-82,4

Ester

carboxylic acid7, 0-21.1

Dibutyl phthalate

or dibutyl sebacate 0.1-0.4

Triethanolamine titanium 2.9-6.6

The introduction of triethanolamine titanate in combination with dibutyl phthalate or dibutyl sebacate provides a reduction in film formation time while simultaneously increasing its elasticity and flexibility.

At the soldering temperature, the composition polymerizes. The resulting film acquires a structure with low adhesion to the conductors and mounting holes of the printed circuit boards, which reduces the time it takes to remove them after soldering.

The introduction of triethanolamine titanate reduces its corrosiveness, since triethanolamine titanate fulfills the function of a corrosion inhibitor. Polyvinyl acetal or polyacrylate is film-forming. If the content of the film film is less than 7.6%, the integrity of the coating and, consequently, the quality of protection of the metallized holes and conductors of printed circuit boards are not ensured.

When the content of the film-forming more than 12.4% decreases the elasticity

30778

film that crumbles and cracks. The content in the composition of the monohydric alcohol limit below 59.5% increases the coating thickness, 5 which increases the film formation time. The content of the monohydric alcohol limit in an amount above 82.4% does not ensure the integrity of the coating. Reducing the amount of carboxylic acid ester below 7.0% increases the film formation time as the coating thickness increases. Increasing the amount of carboxylic ester above

15 21.1% does not ensure the integrity of the coating.

When the content of triethanolamine titanate is less than 2.9%, a sticky poorly drying film is formed. 20 When the content of triethanolamine titanate is more than 6.6%, the adhesion of the film to the metal during its coating increases and its removal from the printed circuit board is not provided. 25 Table. 1 shows examples of the composition for protecting metallized holes and conductors of printed circuit boards from molten solder.

Comparative characteristics of the properties of this and known compositions are given in table. 2 and 3.

Compounds (1-6) for protecting metallized holes and conductors

 printed circuit boards from the molten solder are prepared as follows.

The film-forming agent (polyvinyl acetal or polyacrylate) is dissolved in a mixture of monohydric alcohol and carboxylic ester in a water bath at 60 + 5 ° C. To control the quality of the preparation of formulations, 11-15% solutions of film-forming to the desired

 viscosity For example, for compounds 1, 3, and 5, an 11–15% solution of polyvinyl butyral of the PP grade or a 9–13% solution of polyvinyl butyral and Marxi PSH were prepared.

 The prepared film-forming solution in the solvent mixture of the specified ratio in the heated state filtered through 1-2 layers of nylon mesh No. 61-73. Controls40

55

The percentage concentration and viscosity of the film-forming agent were measured. The viscosity was checked on a VZH-1 or VZH-2 viscometer at. Viscosity

312307784

Prepared polyvinyl butyral ma- The results of studies of PP and PN measurements should be within whether this compound is designed to protect 8–20 wastewaters .. metallized holes and wires. Before use, the printed circuit board nicknames were added to adhere to the calculated amount of excess pre-5 molten solder. when applying a monohydric alcohol, the dibu on the surface quickly forms shtft phthalate or dibutyl sebacate and a protective film, which is easily removed with triethanol aminotitanate after soldering.

The use of this compound with the help of a brush with a brush. Increases the productivity of the metal and the quality of the fabricated parts and conductors of printed circuit boards. radio equipment.

Table 1

Polyvinyl butyral 7.6 - 10.0

Polyvinyl ethyl ethyl alcohol

Isopropyl alcohol

Amyl Acetate Butylacetate Dib Utilft Ala T Dibutyl Sebacate

Triethanolamine titanate

Prototype 40-50

12,,

7,6

10.0

12.4

82.4

71.0

59.5

82.4-71.0-59.5

-14.0-21.1

7.0-14.0-21.1

-0.3--0.4

0.1-0.30.4

2,94,74,76,66,6

Table 2

120-150

 The value of the peeling force is given as an average of 10-15 measurements.

Alcohol was used as a solvent for the film.

Does not show

Does not show 1-10

Does not show

Continued tabl, 2

Table1: a 3

100-200

3-10

500-1000 6-10

500

8-10

 Corrosion tests were carried out in a humidity chamber for 56 days at 40 ± 2 ° С and humidity 98 + 2%.

The effect of the residual composition on the insulation resistance was determined by the PCB at IStS c and a humidity of 98 + 2%.

Editor L.Povkhan

Compiled by V.Pol Kova

Tehred O. Gortvay Proofreader L. Pilipenko

Order 2481/16 Circulation 1001 Subscription

VNIIPI USSR State Committee

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

. Production and printing company, Uzhgorod Project Project, 4

Continuation of table 3

Claims (2)

COMPOSITION FOR BRAZING, mainly to protect metallized holes and conductors of printed circuit boards from molten solder, containing polyvinyl acetal or polyacrylate, saturated monohydroxy alcohol, carboxylic acid ester, dibutyl phthalate or dibutyl sebacinate, characterized in that, in order to reduce labor, 7.6-12.4 59.5-82.4 7.0-21.1 0.1-0.4 2.9-6.6 bones of the soldering process by reducing the time of formation and removal of the protective film and corrosion activity of the composition, it additionally contains triethanolamine titanate in the following ratio of components, wt.%: Polyvinyl acetal or polyacrylate Carboxylic ester. acid Dibutyl phthalate or dibutyl sebacinate Triethanolamine titanate SU ..., 1230778