JPH0625612A - Anaerobic adhesive for forming electronic circuit and method for forming electronic circuit - Google Patents

Abstract

PURPOSE:To obtain an anaerobic adhesive which can be cured by low-temp. heating and is suitable for producing an excellent circuit board allowing no movement of electronic parts by compounding a methacrylic ester, a peroxide, chlorinated paraffin, an inorg. filler, and an org. pigment. CONSTITUTION:This adhesive consists mainly of a methacrylic ester, a peroxide, chlorinated paraffin, an inorg. filler, and an org. pigment. The adhesive is used for forming an electronic circuit by applying the adhesive 3 to a space between board electrodes 2 of a board 1 with an adhesive applicator, mounting an electronic part 4 with a part-mounting machine, curing the adhesive 3 at room temp. in an atmosphere contg. about 10-10,000ppm oxygen to convert it into a cured layer 5, applying a flux 6 to the board 1, and dipping the board 1 in a molten solder to form the bonding of a solder alloy 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anaerobic adhesive for forming an electronic circuit and an electronic circuit forming method for fixing an electronic component to form an electronic circuit on a substrate.

[0002]

2. Description of the Related Art In recent years, as an electronic circuit forming method, a thermosetting adhesive is applied on a substrate, electronic parts are mounted, the adhesive is heat-cured in a high temperature furnace, flux is applied, and then immersed in molten solder. Either method 1 in which solder bonding is performed and then cream solder is printed on a substrate, electronic parts are mounted, and solder is melted in a high temperature furnace to perform solder bonding is widely used.

[0003]

However, the conventional electronic circuit forming method 1 as described above cannot be applied to electronic parts having poor heat resistance because the adhesive must be hardened at high temperature for a long time. I had a problem.

Further, in the conventional electronic circuit forming method 2, since the cream solder cannot be heated at a high temperature before melting due to the characteristics of the cream solder, a thermosetting type component fixing adhesive cannot be used, and the heat resistance of the adhesive is insufficient. Then, there was a problem that parts move.

The present invention solves the above-mentioned conventional problems, and provides an anaerobic adhesive for forming an electronic circuit and a circuit forming method for manufacturing a circuit board of excellent quality which has a low heating temperature and does not move parts. The purpose is.

[0006]

In order to achieve this object, the present invention is to cure an anaerobic adhesive based on a methacrylic acid compound in a room temperature low oxygen concentration atmosphere to temporarily fix a component, It is designed to be soldered.

[0007]

[Function] Since the anaerobic adhesive having the above structure is used to cure the anaerobic adhesive in a low oxygen concentration atmosphere at room temperature, soldering of electronic parts having low heat resistance becomes possible. It is also possible to solder the electronic components with high accuracy.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

(Example 1) 1.5 g of butyl methacrylate
Butyl peroxybenzoate 0.2g as a curing agent
And 0.1 g of Carmine 6B (trade name, manufactured by Dainippon Ink and Chemicals) as an organic pigment and stirred at room temperature for 1 hour, and then 628 g of butyl methacrylate and 60 g of Empara (trade name, manufactured by Ajinomoto Co.) as chlorinated paraffin. 317 g of calcium carbonate was added as an inorganic filler, and the mixture was stirred at room temperature for 2 hours and then degassed by centrifugation to obtain an anaerobic adhesive for forming an electronic circuit.

(Example 2) 1.5 g of butyl methacrylate
Butylperoxybenzole 0.2g and Carmine 6
0.1 g of B (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) was added and stirred at room temperature for 1 hour, then 37 g of butyl methacrylate and 60 g of phosphoric acid ester were added and stirred for 1 hour, and then 568 g of methacrylate ester and inorganic filler were added. After adding 317 g of calcium silicate as a material and stirring at room temperature for 2 hours, pressure filtration and centrifugal defoaming were performed to obtain an anaerobic adhesive for forming an electronic circuit.

In Examples 1 and 2, butyl methacrylate was used as an example, but a methacrylic ester formed by an alkyl group having an alkyl group having 1 to 10 carbon atoms may be used.

(Embodiment 3) FIGS. 1 (a) to 1 (e) show an electronic circuit forming process by an electronic circuit forming method using the adhesive produced in the embodiment 1, and FIG.
Shown in. As shown in FIGS. 1A to 1E, a substrate electrode 2 is formed on the substrate 1, and the substrate 1 between the substrate electrodes 2 is formed.
The adhesive 3 produced in Example 1 is applied to the surface of the. When the electronic component 4 is inserted into the hole of the substrate electrode, the substrate 1 and the electronic component 4 are bonded by the adhesive 3 with a non-hardened adhesive. The solder 7 is applied to the lower surface of the substrate 1 via the flux 6 and fused.

The electronic circuit forming process will be specifically described below. First, as shown in FIG. 1A, the substrate electrode 2 of the substrate 1
In the meantime, the adhesive 3 is applied by an adhesive applicator. Next, as shown in FIG. 1B, the electronic component 4 is mounted by the component mounting machine. Next, as shown in FIG. 1C, the adhesive 3 is cured in an atmosphere having an oxygen concentration of 10 to 10000 ppm at room temperature to change into a cured product 5. Next, as shown in FIG. 1D, the flux 6 is applied to the substrate 1. Next in FIG.
As shown in (e), the substrate 1 is dipped in the molten solder to obtain the solder alloy 7 joint.

In this embodiment, the electronic component 4 is described as a leaded component, but the same effect can be obtained by using a chip component.

(Embodiment 4) FIG. 3 shows an electronic circuit forming process using the adhesive and the chip type electronic component produced in Embodiment 2.
4 (a) to (e) show a flowchart of the same process in FIG. In the figure, 11 is a substrate on which a chip-type electronic component is mounted, 12 is a substrate electrode for electrically connecting electronic components, 13
Is a solder paste for soldering electronic components to a board, 14
Is a mounting material produced in Example 2, 15 is a chip-type electronic component, 16 is a cured product of the adhesive 14, and 17 is a solder alloy after fusion bonding.

The electronic circuit forming process using the chip parts will be specifically described below. First, as shown in FIG. 3A, cream solder 13 is printed on the substrate electrode 12 on the substrate 11. Next, as shown in FIG. 3B, an adhesive 14 is applied to the side of the two substrate electrodes 12 on the substrate 11 by an adhesive applicator. Next, as shown in FIG. 3C, the electronic component 15 is mounted by the component mounting machine. Next, as shown in FIG. 3D, the mounting agent 14 is cured at room temperature in an atmosphere having an oxygen concentration of 10 to 10,000 ppm to be changed into an adhesive cured product 16. Next, as shown in FIG.
It is heated in a high temperature furnace to melt the cream solder 13 into a solder alloy 17 and complete soldering.

According to the present embodiment, the anaerobic thermosetting adhesive is used for thermosetting at a low temperature in a non-oxidizing atmosphere, so that electronic components having low heat resistance can be mounted with good yield using cream solder. You can

[0018]

As is apparent from the above description of the embodiments, according to the present invention, the adhesive is cured at room temperature in a low oxygen concentration atmosphere to fix the electronic component, so that the electronic component is displaced. Instead, the electronic components having low heat resistance can be joined by the immersion soldering method. Further, it is possible to print the cream solder, temporarily fix the electronic component, and perform solder joining to melt the solder.

[Brief description of drawings]

FIG. 1 is a sectional view showing an electronic circuit forming process according to a third embodiment of the present invention.

FIG. 2 is a flowchart showing an electronic circuit forming method according to the third embodiment.

FIG. 3 is a cross-sectional view showing the electronic circuit forming process of the fourth embodiment.

FIG. 4 is a flowchart showing an electronic circuit forming method according to the fourth embodiment.

[Explanation of symbols]

 1 Substrate 2 Substrate Electrode 3 Adhesive 4 Electronic Component 5 Adhesive Cured Product 6 Flux 7 Solder Alloy

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichiro Suetsugu 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A methacrylic acid ester and a peroxide,
An anaerobic adhesive for forming an electronic circuit, which is mainly composed of chlorinated paraffin, an inorganic filler and an organic pigment. 2. A methacrylic acid ester and a peroxide,
An anaerobic adhesive for forming an electronic circuit, which mainly comprises a phosphoric acid compound, an inorganic filler and an organic pigment. 3. An anaerobic adhesive for forming an electronic circuit according to claim 1, which is applied on a substrate, and parts are mounted on the adhesive.
An electronic circuit forming method in which the adhesive is cured in a low oxygen concentration atmosphere at room temperature, flux is applied to the substrate, and the substrate is immersed in molten solder to perform solder joining. 4. A cream solder is printed on a substrate, the anaerobic adhesive for forming an electronic circuit according to claim 2 is applied on the substrate, parts are mounted on the adhesive, and the adhesive is kept at room temperature. The method for forming an electronic circuit, wherein the solder is bonded by hardening in a low oxygen concentration atmosphere and melting the cream solder at a high temperature.