JP2762866B2 - Soldering equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used for soldering a printed wiring board and a flexible wiring board in a process of assembling a liquid crystal display panel. The present invention relates to a soldering apparatus that can prevent a terminal from being cut in a soldering step.

[0002]

2. Description of the Related Art Conventionally, soldering of a printed wiring board and a flexible wiring board in assembling a liquid crystal display panel is performed in a circuit for inputting a video signal for displaying an image on the liquid crystal display panel to the liquid crystal display panel. Generally, a printed wiring board is used on the input side of a video signal, and a flexible wiring board is used on the liquid crystal display panel side.

FIG. 2 is a perspective view showing a positional relationship between a liquid crystal display panel, a flexible wiring board, and a printed wiring board.
FIG. 3 is a sectional view illustrating soldering using a heating head.

A plurality of external connection terminals 1 of the liquid crystal display panel 1
a is connected to a plurality of flexible wiring boards 2, a plurality of terminals 2 a are provided in parallel and linearly at one end of the flexible wiring board 2, and tin plating 2 b is applied to the surface of the terminals 2 a . The terminals 3a provided on the printed wiring board 3 are arranged in the same manner as the terminals 2a of the flexible wiring board 2, and solder 3b is previously attached to the surface thereof.

In the soldering operation, first, the position of the printed wiring board 3 is set such that the terminals 2a of the flexible wiring board 2 and the terminals 3a of the printed wiring board 3 overlap with each other while watching or enlarging the television screen from the upper surface of the flexible wiring board 2. Adjust back and forth and left and right. Next, after a thin coating of the flash 12 is applied to the entire surface of the terminal 2a, the aligned terminal 2a is placed under the vertically movable heating head 4, and the heating head 4 is brought into contact with the upper surface of the terminal 2a. . Since the heating head is not heated except during soldering, terminals 2
After contact with a, it is heated.

In order to shorten the heating time, a large current is supplied to the heating head 4 to heat it with Joule heat. In addition, the length of the heating head 4 is 50 to
It is processed to a length of 100 mm, and the terminals 2a of the plurality of flexible wiring boards 2 are simultaneously soldered.

In soldering, first, the heating head 4 is
C. to 260.degree. C. for 2 to 3 seconds, and then stop heating and cool air or nitrogen gas from before and after the heating head 4 to cool the heating head 4, the flexible wiring board 2, and the printed wiring board 3. It is sprayed from a nozzle 11 provided on a pipe 10.

This is performed because if the heating head 4 is separated from the terminal 2a in a state where the temperature of the terminal 2a is heated to the melting point of the solder or higher, a positional shift occurs. After cooling the temperature of the heating head 4 and the terminals 2a to the melting point of the solder or lower, the heating head 4 is moved upward.

[0009]

By cooling the temperature of the heating head and the terminals with compressed air or nitrogen gas, it is possible to prevent displacement of the soldered terminals. And the number of external connection terminals is increasing, and the terminal width and terminal pitch of the terminals to be soldered are 0.3 m each.
m and 0.6 mm or less. The flexible wiring board has an insulator film thickness of 70 to 105 μm.
And the thickness of the conductor serving as the terminal is also about 35 μm. Therefore, such miniaturization reduces the mechanical strength, and the terminal is cut off with a small force.

[0010] In the conventional soldering method, the temperature of the heating head, the terminal and the flash is lowered because the solder is melted and then cooled. However, the flux is solidified by cooling and the heating head and the terminal are connected to each other. When the heating head is moved above the terminals after cooling, the force of pulling the terminals of the flexible wiring board acts to cut the terminals.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide an apparatus capable of preventing the cutting of a miniaturized terminal caused by a soldering operation.

[0012]

According to the present invention, there is provided a soldering apparatus provided with a heating head in which a heater is inscribed, and terminals of two wiring boards are fixed by soldering and connected to each other. A base plate vertically held and vertically moved so that a heating surface faces downward, a sliding pin slidably inserted through the base plate so as to be parallel to an axis of the heating head, and a heater are provided therein. A pressing plate fixed to the lower end of the sliding pin, and a pressing plate fixed to the lower end of the sliding pin, and interposed between the base plate and the pressing plate. A spring for urging the presser plate, wherein the temperature of the heater of the presser plate is higher than the softening point of the flux and lower than the melting point of the solder.

[0013]

When the terminal of the flexible wiring board is superimposed on the terminal of the pre-soldered printed wiring board, and the holding plate on which the heater is mounted and the base plate holding the heater are lowered, the position of the lower end surface of the heating head is changed. Also, the spring is compressed upward until the lower end surface of the holding plate located 3 to 5 mm below comes into contact with the upper surface of the flexible wiring board, and the lower end surface of the heating head comes into contact with the upper surface of the flux-coated terminal of the flexible wiring board. Go to Even if the heating operation is completed and the base plate rises and the heating head starts to separate from the terminals of the flexible wiring board, the pressing plate is pressed by the spring and abuts on the flexible wiring board until the heating head moves away from the terminal by 3 to 5 mm. To make the flux molten.

Thus, the heating head can be prevented from sticking to the terminal due to the flux, and the terminal can be prevented from being cut when the heating head is detached.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing a positional relationship among a liquid crystal display panel, a flexible wiring board, and a printed wiring board used in the embodiment of the present invention and a conventional example.

In the embodiment of the present invention, the heater 5a is inscribed,
A heating head 4 for fixing the flexible wiring board 2 and the terminals 2a and 2b of the printed wiring board 3 to each other by soldering and connecting the terminals to each other is further provided. A base plate 6 which is vertically held and moves up and down, a sliding pin 8 slidably inserted through the base plate 6 so as to be parallel to the axis of the heating head 4, and a heater 5b are provided therein. A pressing plate 9 having a surface in contact with the flexible wiring board 2 and fixed to a lower end portion of the sliding pin 8, inserted between the sliding pins 8, and interposed between the base plate 6 and the pressing plate 9. And a spring 7 for urging the holding plate 9.

When the pressing plate 9 is urged by the spring 7, the lower end surface thereof is more than the lower end surface of the heating head 4.
５5 mm below, the heater 5b of the holding plate, the temperature is higher than the softening point of the flux,
It is controlled below the melting point of the solder.

Next, the soldering operation by the apparatus according to the present invention configured as described above will be described step by step.

First, the terminals 2a of the flexible wiring board 2
And the terminals 3a of the printed wiring board 3 are adjusted and fixed so as to overlap each other, and a flux 12 is thinly applied to the entire terminal surface in order to improve solderability. Next, the terminals 2a and 3a are placed under the heating head 4, and the heating head 4 is brought into contact with the terminals 2a and 3a. The heating head 4 is constantly controlled by a heater 5a and a temperature controller (not shown).
It is controlled to be 0 to 260 ° C.

A base plate 6 on which the heating head 4 is mounted
Similarly to the heating head 4, a holding plate 9 provided at the tip of a sliding pin 8 which is slid up and down and constantly urged downward by a spring 7 is also 80 to 110 by a heater 5b and a temperature controller. ℃. Presser plate 9
Is usually 3 to 5 m below the lower end of the heating head 4.
m.

When the heating head 4 is lowered to bring the holding plate 9 into contact with the flexible wiring board 2 and the heating head 4 is further lowered, the pressing force is increased by the sliding pins 8 and the springs 7. Since the heating head 4 has already been heated to the soldering temperature, the solder is melted by being applied to the terminal 2a for a few seconds.

After the solder is melted, when the heating head 4 is moved upward, the solder is in a molten state, but the pressing plate 9 is pressed by the spring 7 to press the flexible wiring board 2. Therefore, the terminal 2a does not shift. When the heating head 4 moves further upward, the holding plate 9
Pressure decreases. The upward moving speed of the heating head 4 is set to about 2 to 3 seconds, which is the time required for the molten solder to solidify before the pressing plate 9 leaves the flexible wiring board 2.

When the holding plate 9 separates from the flexible wiring board 2, the flux 12 adhering to the holding plate 9 is still in a softened state because it is still heated, and the holding plate 9 loses its adhesiveness and is pressed. The terminal 2a is separated without applying stress.

[0024]

As described above, according to the present invention, the holding plate heated above the softening point of the flux used at the time of soldering is attached to the vicinity of the heating head for soldering, and the flux is softened to improve the adhesiveness. By eliminating the heating head and the holding plate from being attached and pulled up to the terminal when detached from the flexible wiring board, and
Since the heating head can be constantly heated to the soldering temperature, there is an effect that the heating time and the cooling time can be shortened and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing a positional relationship between a liquid crystal display panel, a flexible wiring board, and a printed wiring board used in the embodiment of the present invention and the conventional example.

FIG. 3 is a side view showing a configuration of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 1a External connection terminal 2 Flexible wiring board 2a, 3a terminal 2b Tin plating layer 3 Printed wiring board 3b Solder 4 Heating head 5a Heater for heating head 5b Heater for holding plate 6 Base plate 7 Spring 8 Sliding pin 9 Holding Plate 10 Pipe 11 Nozzle 12 Flux

Claims (1)

(57) [Claims] 1. A soldering apparatus provided with a heating head in which a heater is inscribed and which connects the terminals of two wiring boards with each other by fixing them by soldering, wherein the heating head is placed so that a heating surface thereof faces downward. A base plate that is held vertically and moves up and down; a sliding pin slidably inserted through the base plate so as to be parallel to the axis of the heating head; A pressing plate having a contacting surface and fixed to a lower end portion of the sliding pin; being inserted through the sliding pin, biasing the pressing plate interposed between the base plate and the pressing plate; Wherein the temperature of the heater of the holding plate is equal to or higher than the softening point of the flux and equal to or lower than the melting point of the solder.