JPH10303545A - Double-sided mounting board manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a double-sided mounting board wherein soldering efficiency is improved, unsoldering and solder bridge are eliminated, and soldering reliability is remarkably improved. SOLUTION: On the rear B1 of a double-sided mounting board B cream solder is printed in the step 1, and adhesive agent is spread in the step 2. A back mount component C1 is mounted in the step 3 and soldered by reflow in the step 4. On the board surface B2, cream solder is printed, and a surface mount component C2 is mounted and soldered by reflow. A manual insertion component C3 is inserted in the board surface. The board is made to pass an automatic solder vessel in the step 6 wherein primary jet is stopped and secondary jet only is operated, and the rear side of the board is subjected to flow soldering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a double-sided mounting board, and more particularly to a method for manufacturing a double-sided mounting board with improved soldering reliability when mounting both sides of a surface-mounted electronic component on a printed circuit board.

[0002]

2. Description of the Related Art As a method of mounting components on a printed wiring board, it is required to mount a large number of electronic components in a limited space at a high density. Have been done. As a conventional method for manufacturing a double-sided mounting board, there are two-sided reflow + manual insertion board shown in FIG. 2 and one-sided reflow +
Flow (automatic solder tank) + manual insertion board.

In the case of the double-sided reflow + manual insertion board shown in FIG. 2, first, the cream solder printing is performed on the board back face B1 through the cream solder printing apparatus 1 with the board back face B1 of the raw board B up, and then the chip component mounter is mounted. 3, a chip component C1, which is a back surface mounted component, is mounted on the back surface B1 of the substrate,
Reflow soldering is performed in the reflow furnace 4, and the substrate back surface B1
Of the chip component C1 is completed.

[0004] Next, with the substrate surface B2 of the raw substrate B facing upward, cream solder printing is performed on the substrate surface B2 through the cream solder printing apparatus 1, and a chip component C2, which is a surface mount component, is mounted on the substrate surface B2 through the chip component mounter 3. The chip component C2 on the board surface B2 is soldered by mounting and reflow soldering in the reflow furnace 4.

Further, after the manual insertion step 5 of inserting the manually inserted component C3 into the substrate surface B2 with the substrate surface B2 facing upward, the foot of the manually inserted component C3 that has come out on the substrate back surface B1 is subjected to a manual soldering step 7. Solder to complete the double-sided mounting board. Next, in the case of single-sided reflow + flow (automatic solder tank) + manually inserted substrate shown in FIG. 3, first, the substrate surface B2 of the raw substrate B
After the cream solder printing on the board surface B2 through the cream solder printing apparatus 1, the chip component C2 is mounted on the board surface B2 through the chip component mounter 3, and reflow soldering is performed in the reflow furnace 4 to fix the board surface B2. The chip component C2 is soldered, the adhesive is applied to the substrate back surface B1 through the adhesive application device 2 with the substrate back surface B1 of the raw substrate B facing upward, and the chip component is mounted on the substrate back surface B1 through the chip component mounter 3. C1 is mounted, and the chip component C1 is temporarily fixed to the substrate back surface B1 in the curing furnace 8.

Further, after a manual insertion step 5 of inserting the manually inserted component C3 into the substrate surface B2 with the substrate surface B2 facing upward, the substrate back surface B1 side where the foot of the manually inserted component C3 has protruded is placed in the automatic solder tank 6. Dip to complete the double-sided mounting board.

[0007]

By the way, since the conventional manufacturing method is configured as described above, FIG.
In the case of the double-sided reflow + manual insertion board, the chip component C1 on the back surface B1 of the board is merely fixed with cream solder, and thus the foot of the manual insertion component C3 has come out after the manual insertion step 5 for inserting the manual insertion component C3. If the back surface B1 of the substrate is immersed in the automatic solder bath 6 and soldered, the chip component C1 on the back surface B1 of the substrate falls off, so that the automatic solder bath 6 cannot be used, and the manually inserted component C3 is soldered by the manual soldering process 7. There was a drawback that it had to be very time-consuming.

In the case of a single-sided reflow + manual insertion board shown in FIG. 3, the chip component C1 on the back surface B1 of the board is only temporarily fixed with an adhesive such as a bond. After mounting the component C3, the back surface B1 of the board with the foot of the manually inserted component C3 is immersed in the automatic solder bath 6, and the chip component C1 on the back surface of the board B1 and the foot of the manually inserted component C3 are simultaneously flow soldered. At this time, since the chip components C1 on the substrate back surface B1 are dense and the land of the chip component C1 is small, if the chip components C1 are immersed in the automatic solder tank 6 and soldered, unsolder is generated due to the generation of bubbles, and the solder is further applied. The soldering flux of the manually inserted component C3 is washed away by the primary jet for soldering the chip component C1, and many solder bridges are generated. was there.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and has been made to improve the soldering efficiency, eliminate unsoldered and solder bridges, and greatly improve the soldering reliability. It is an object to provide a method for manufacturing a substrate.

[0010]

A method of manufacturing a double-sided mounting board according to the present invention comprises the steps of: printing cream solder and applying an adhesive on the backside of the double-sided mounting board; mounting the backside mounting parts; soldering by reflow; After cream solder printing, mount the surface mount components and solder by reflow,
A manually inserted component is inserted into the surface of the substrate, and the primary jet is stopped, and the secondary jet is passed through an automatic solder bath, and flow soldering is performed on the rear surface of the substrate.

[0011] Reflow soldering by double-sided cream solder printing eliminates unsoldered solder, and automatic soldering on the back surface of the substrate using only the secondary jet suppresses the outflow of flux and eliminates solder bridges, greatly improving the reliability of soldering.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a double-sided mounting board according to the present invention will be described below in detail with reference to the drawings. The double-sided mounting board manufacturing method according to the present invention is a double-sided mounting board manufacturing method in which surface-mounted electronic components C1 and C2 and a manually inserted component C3 are surface-mounted and inserted and mounted on both sides B1 and B2 of a printed wiring board B. As shown in FIG. 1, first, the raw substrate B with the substrate back surface B1 facing upward is passed through a cream solder printing device 1 to print cream solder on the substrate back surface B1, and then an adhesive is applied to the substrate back surface B1 through an adhesive application device 2. Then, the chip component 1, which is a back surface mounted component, is mounted on the substrate back surface B1 through the chip component mounter 3, and reflow soldering of the chip component C1 to the substrate back surface B1 is performed in the reflow furnace 4, thereby completing the soldering of the substrate back surface B1. .

Next, after the cream solder printing is performed on the board surface B2 through the cream solder printing apparatus 1 with the board surface B2 of the raw board B facing upward, a chip component C2, which is a surface mount component, is mounted on the board surface B2 through the chip component mounter 3. The chip component C2 is mounted on the substrate surface B2 in the reflow furnace 4 and reflow soldering is performed. Further, the substrate surface B
After the manual insertion step 5 of inserting the manually inserted component C3 into the substrate surface B2 with the 2 up, the flow soldering is performed on the substrate back surface B1 side through which the foot of the manually inserted component C3 protrudes through the automatic solder tank 6. To complete the double-sided mounting board. At this time, since an adhesive is applied to the back surface B1 of the substrate and reflow soldering is performed, the soldering of the chip component C2 is not performed in the automatic solder tank 6, and only the feet of the manually inserted component C3 are soldered. The primary jet in which the solder flow is blown to the chip component is stopped, and only the secondary jet in which the foot of the manually inserted component C3 is attached to the solder tank is used.

As described above, in the method for manufacturing a double-sided mounting board according to the present invention, the rear-surface-mounted component C2 is soldered by an adhesive and a rear-surface reflow, the surface-mounted component C1 is surface-reflowed, and the manually inserted component C3 is soldered by a flow method. In fixing the insert part C3, when passing through the automatic solder bath 6, the primary jet is stopped and soldering can be performed only by the secondary jet, so that the chip part C
No influence is exerted on the cream soldered portion 2 and no solder is generated due to the generation of air bubbles, and a solder bridge is not generated due to the outflow of the flux, so that the reliability of the soldering is remarkably improved.

[0015]

As described above, according to the present invention, both the cream solder and the adhesive are used to fix the back surface mounting component to the back surface of the double-side mounting substrate, so that soldering is performed only by reflow. And the reliability of soldering is extremely improved. In addition, since the hand-inserted component can be flow-soldered with only the secondary jet after reflow, the flux can be suppressed from flowing out and soldering without a solder bridge can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for manufacturing a double-sided mounting board according to the present invention.

FIG. 2 is a diagram illustrating a conventional method for manufacturing a double-sided mounting board.

FIG. 3 is a diagram illustrating a conventional method for manufacturing a double-sided mounting board.

[Explanation of symbols]

 B ‥ Double-sided mounting board B1 ‥ Backside of the board B2 ‥ Board surface C1 ‥ Backside mounting part C2 ‥ Surface mounting part C3 ‥ Hand-inserted part 1 ‥ Cream solder printer 2 ‥ Adhesive applicator 3 ピ Chipper part mounter 4 ‥ Reflow furnace 5 ‥ Manual insertion process 6 ‥ Automatic solder tank

Claims (1)

[Claims] After the cream solder printing (1) and the application of an adhesive (2) on the back surface (B1) of the double-sided mounting substrate (B), the back mounting component (C1) is mounted (3) and reflow (4). After solder cream printing on the substrate surface (B2), the surface mount component (C2) is mounted and soldered by reflow, and the manually inserted component (C3) is inserted into the substrate surface (5), 1 A method for manufacturing a double-sided mounting board, characterized in that the next jet is stopped, and is passed through an automatic solder tank (6) in which only a secondary jet is formed, and flow soldering is performed on the back surface of the board.