JPS6184894A - Solder printing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solder printing method for printing solder on a printed pattern on a board, and the size and shape of the printed pattern on the board, as well as the amount of solder on the board after solder printing. The present invention relates to a solder printing method that allows an appropriate amount of solder to be printed on the same substrate in one process using the same mask depending on the size and shape of the chip components to be mounted on the board.

Conventional configuration and its problems Conventional solder printing will be explained with reference to FIGS. 1 to 4.

FIG. 1 is a process diagram from solder printing to chip component mounting and soldering (reflow) 1.

Solder printing method Use the spatula called squeegee 1 with the arrow
direction, the solder 2 is pushed out through the hole 4 which is the printed part of the mask 3, and printed on the printed pattern e on the printed circuit board (hereinafter referred to as the board) 6. Next, in the chip component mounting step B, the chip suction nozzle 7 of the chip mounting machine is lowered in the direction of arrow Y to mount the chip component 8 onto the printed pattern 6 on the substrate 6. Finally, in the chip component soldering step C (reflow step), the solder 2 is reflowed by the lamp 9 and the chip component 80 is soldered.

As shown in FIG. 2, the hole 4 of the conventional mask 3 is
It has the same shape as the printed pattern 6 above, and the thickness of the mask 3 is 10
Since the amount of solder printed was determined by
Chip parts 8, 11 and 12 with different thicknesses as shown in the figure
When mounted and soldered on the same board 6, a normal soldering state, a state B in which the amount of solder 2 is relatively small, or a state C in which the amount of solder 2 is relatively large will occur. Further, as shown in FIG. 4, they are adjacent to each other on the substrate 6. When solder 2 was printed on printed patterns 13 and 14, chip components 16 were mounted, and soldered, a short circuit (bridge) 16 occurred, resulting in poor soldering.

To solve this problem, each printing mask was required depending on the size, shape, and mounting of the printed pattern on the board, and the size and shape of the chip components to be soldered, and the printing process involved multiple steps. .

OBJECT OF THE INVENTION The present invention solves the above-mentioned problems, and it is possible to print the same mask on the same substrate in one process according to the size, shape and mounting of the printed pattern, and the size and shape of the chip components to be soldered. The purpose of this is to print an appropriate amount of solder.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is a method for adjusting the amount of solder to be printed by making the holes in a printing mask larger or smaller than the printed pattern on the substrate. This makes it possible to print an appropriate amount of solder on the same substrate in one process using the same mask according to different printing patterns and chip components.

Description of examples An embodiment of the method of the present invention will be described below with reference to FIG.

This figure shows how the mask is constructed in accordance with the size and shape of the printed pattern and the size and shape of the chip component in the solder printing process.

In order to print on adjacent printing patterns 1a on the substrate 5, it is necessary to prevent bridging (see FIG. 4-16). Therefore, if the holes in the mask 3 are made like the hole 1B which is smaller than the printed pattern 17, bridging can be prevented since the solder spreads over the entire printed pattern 17 due to the wettability of the solder and becomes thinner at the pre-filling stage 70. This also enables preliminary soldering.

next. In order to print the appropriate amount of solder when attaching and soldering chip parts with different sizes and thicknesses to the printed patterns 19 and 20 on the board 6, it is necessary to remove the mask 1 for thin chip parts in the chip parts storage. Make the holes smaller than the printed pattern 19 like punch holes 21 to reduce the amount of solder and prevent excess solder (see Figure 3 - ○). Also, for thick chip parts warehouses, make the holes smaller than the printed pattern 19. As shown in 22, the print pattern is made larger than 2o and the amount of solder is increased to avoid insufficient solder amount (
(see Figure 3-B).

Effects of the Invention As described above, according to the method of the present invention, the conventional method of printing by adjusting the amount of solder only by adjusting the thickness of the printing mask is different from the conventional method of printing by adjusting the amount of solder only by adjusting the thickness of the printing mask. Printing masks were required for each chip component to be soldered, depending on its size and shape, and the printing process involved multiple steps. However, in the method of the present invention, the holes in the printing mask can be made from the printed pattern on the board. Since the amount of solder can be adjusted by making it larger or smaller, the same mask can be used on the same board in one process depending on the size, shape and mounting of the printed pattern, and the size and shape of the chip components to be soldered. It is possible to print the appropriate amount of solder.

[Brief explanation of drawings]

Figure 1 is a process diagram showing the process from solder printing to chip component mounting and soldering (reflow), Figure 2 is a sketch showing the structure of a conventional mask, and Figure 3 is a cross section showing the state printed by the conventional printing method. FIG. 4 shows a state in which adjacent printed patterns on a substrate are printed by a conventional printing method. FIG. 5a is a side view, and FIG. 5a is a plan view showing the configuration of an embodiment of a mask incorporating the method of the present invention, and FIG. 5A is a sectional view thereof. 2... Solder, 3... Mask, 5 Old...
・Circuit printed board, 18, 21, 22...holes. Name of agent Patent attorney Toshio Nakao and 1 other personb Figure 3 Figure 5 Figure 17 IU/'1

Claims (2)

[Claims] (1) A solder printing method in which solder is printed on a printed circuit board using a printing mask consisting of a non-printed part and a printed part, in which the area of the printed part of the mask is determined by the part to be mounted. A solder printing method that performs solder printing using a mask that changes the size of the round of the printed circuit depending on the shape of the circuit, the pattern shape of the printed circuit, and the adjacent pitch. (2) Among the printed portions provided on the mask, for a printed portion corresponding to a round to which preliminary soldering is applied, the area of the printed portion is made smaller than the size of the round. The solder printing method described in Section 1.