JPS59163070A - Soldering device - Google Patents

Abstract

PURPOSE:To provide a soldering device which can stick throughly a solder melt on a printed circuit board by the constitution in which many rugged liquids formed on the peaks of the solder melt gushing from a jet type solder tank housed disposed in a secondary tank of two successively arranged solder tanks are moved in the direction intersecting with the traveling direction of the printed circuit board. CONSTITUTION:The solder melts 8, 9 in a primary tank 6 and a secondary tank 7 are pressurized respectively by the rotation of impellers 13, 20, and are fed into overflow tanks 11, 18. A plane solder surface 8a is formed in the upper part by the melt 8 entering the tank 11 of a floating type solder tank 10 and is returned by overflowing 12 into the tank 6 so that the melt is circulated 15 into the tank 11. On the other hand, the melt 9 entering the jet tank 18 of a jet type solder tank 17 is run in an arrow B direction through the screw part of a rotating body 24 and is ejected from jet ports 19. Many rugged waves 9b are formed on the peak of the jet wave 9a in the direction intersecting with the traveling direction (arrow A direction) of a printed circuit board 1. On the other hand, the board 1 conveyed into a soldering device 3 is lowered diagonally from an arrow A1 direction to an arrow A2 direction in the tank 10 and is immersed in the surface 8a to solder preliminarily electronic parts 2 and thereafter the circuit board is soldered in the tank 17.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, solder tanks are arranged in two tanks, a primary tank and a secondary tank, sequentially in the running direction of a printed circuit board, and the primary tank has a fuser tank.
- A dip-type soldering bath, in which a jet-type soldering bath is housed in the secondary bath, and a large number of uneven waves are formed on the top surface of the melted solder that is ejected from the jet port provided in the jet-flowing bath of the jet-type soldering bath. This relates to a soldering device in which the soldering device is moved in a direction that intersects with the running direction of the unevenly corrugated printed board.

The printed circuit board material is phenolic resin or.

Synthetic resins such as epoxy resins are used, but as electronic components such as resistors and capacitors have become much smaller, electronic devices that use these electronic components can also be made smaller. It's here.

For this reason, the printed circuit boards on which these electronic components are mounted are required to be small and thin, but conventionally, the above-mentioned synthetic resin printed circuit boards have been made with a certain size and thickness due to individual factors such as strength. I couldn't use it because I needed it. Therefore, ceramic materials have come to be used as materials that meet the above requirements.

By the way, ceramic printed circuit boards require preheating in the same way as synthetic resin printed circuit boards.
Ceramic materials tend to heat sink more easily than synthetic resin materials, so if the difference between the preheating temperature and the soldering temperature suddenly increases, it will give a thermal shock to the printed circuit board and cause cracks. There were drawbacks such as breakage.

Even if you try to heat the ceramic printed circuit board to a predetermined temperature using a conventional preheating device to avoid these drawbacks, the heating time will be extended because the conveyor cinchon that transports the printed circuit board is set at a constant speed. It is impossible to do so. Another method would be to make the preheating device larger, but this would make the entire device larger for soldering, and the longer heating time would be inappropriate for soldering. The drawback is that it takes a long time.

In addition, for ceramic printed circuit boards, it is necessary to reduce the temperature difference between the preheating temperature and the soldering temperature. Therefore, increasing the temperature of the preheating device prevents adhesion to the printed circuit board. Because there was a risk of the flux dissipating and causing a fire, preheating had to be carried out in a short period of time.

Chip-shaped electronic components such as magnets, resistors, and capacitors are temporarily attached using adhesives, etc. (・ indicates when soldering is performed using a jet of melted solder on a printed circuit board that is densely packed with electronic components. The portion behind the chip components with respect to the running direction of the printed circuit board and the portion where each chip component is close to each other are like recessed portions.

Due to the shape of the solder, air and other gases stagnate, preventing the mixed melt from flowing in, resulting in the solder melt not adhering or, even if it does, forming cavities and not adhering completely. . Moreover, if air bubbles are generated during one soldering process, there is a drawback that the air bubbles cannot be removed even if a jet of solder melt is applied for a long time.

This invention was made to solve the above-mentioned drawbacks, and the solder bath is sequentially placed one by one in the running direction of the printed circuit board.
By immersing the printed circuit board in a dipping type soldering bath, the Vc primary tank is arranged in two tanks, a solder tank and a secondary tank, and can be controlled separately. In order to obtain the temperature for final soldering, a jet soldering tank is installed in the secondary tank and the printed circuit board is soldered. A means is provided for forming a large number of concave and convex waves and simultaneously moving the concave and convex waves in a direction intersecting the running direction of the printed circuit board. This invention will be explained below.

1 and 2 show an embodiment of the present invention, with FIG. 1 being a side sectional view and FIG. 2 being a partially cutaway front view showing an enlarged main part. In the figure, reference numeral 1 denotes a ceramic printed circuit board, which is attached to a carrier (not shown) or a holding claw of a conveyance unit. 2 is a resistor tjc which is temporarily attached to the printed circuit board 1 with an adhesive or the like; 3 is a chimney-shaped electronic component such as a capacitor; 3 is a soldered device; and 3 is the entire device.

Reference numeral 4 denotes a solder tank body, which is formed into two tanks by a partition wall 5 provided at the center of 5. Reference numerals 6 and 1 denote a primary tank and a secondary tank of the solder tank main body 4, which are arranged sequentially in the running direction of the printed circuit board 1 (in the direction of the arrow). 8.9 is the primary tank 6
, the solder melt 9 in the secondary tank 7 is held at a higher temperature than the solder melt 8 in the primary tank 6. 6 is a flow dip type soldering tank installed inside tt, 11 is an overflow tank, 12 is an overflow port, 13 is an impeller that pressurizes the solder melt 8 and forcibly circulates it. Due to the drive, it rotates in a fixed direction. 15 is a flow tube, and 16 is a reflux port, which constitute the flow dip type solder bath 10.

17 is a jet type solder tank installed in the secondary tank 7, 18 is a jet tank, 19 is a jet port, 20 is an impeller that pressurizes the solder melt 9 and forcibly circulates it. motor 2
1, it rotates in a certain direction. 22 is a flow pipe, 23 is a return port, and these are the jet type solder tank 1.
7 is composed. Reference numeral 24 denotes a wah-ohm-shaped rotating body provided at the jet port 19 of the jet-type solder bath 17, the main part of which is connected to the second
As shown in the figure. 25 is a threaded portion of the rotating body 24, which is connected to the jet port 1;
The convex portion 26.
It is formed by a recess 27. 28 is the rotating body 24
The rotating shaft is rotatably supported in the jet tank 18.
The motor 29 allows rotation in forward and reverse directions. The motors 14, 21, and 29 are provided apart from the running direction so as not to interfere with the running of the printed circuit board 1.

Next, the operation will be explained.

The solder melts 8 and 9 in the primary tank 6 and secondary tank 7 are pressurized when the impellers 13 and 20 are rotated by the drive of the motor 14.21, respectively, and flow through the flow pipe 15.22 to the overflow tank. 11
．． Enter the jet tanks 1 and 8.

Next, the solder melt 8 that has entered the overflow tank 11 of the flow dip type solder tank 10 forms a planar overflow solder surface 8a above the overflow tank 11, and further overflows from the overflow port 12. The water returns to the primary tank 6-, and flows from the reflux port 16 into the flow pipe 15.

Next, the solder melt 9 that has entered the jet tank 18 of the jet solder tank 17 flows in the direction of arrow B in FIG. At the concave portion 27 of the rotating body 24, a large amount of solder melt 9 is spouted out at a high height, and at the convex portion 26, a small amount of solder melt 9 is spouted out. The height of the jet wave 9a decreases, and a large number of uneven waves 9b are formed on the top surface of the jet wave 9a in a direction intersecting the running direction of the printed circuit board 1 (direction of arrow A in FIG. 1).

On the other hand, the motor 29 is also driven at the same time as the motor 21 is driven,
Since the rotating body 24 rotates in the direction indicated by the arrow, the threaded portion 25 apparently moves in the direction of the upward arrow C (direction perpendicular to the direction of the arrow A, which is the running direction of the printed circuit board 10 shown in FIG. 1). Therefore, when the solder melt 9 passes through the concave portion 27 in the direction of the arrow B, the side surface 26a of the convex portion 26 of the solder melt 9 apparently moves upward in the direction of the arrow C, so that the top surface of the jet wave 9a The uneven waves 9b also move in the direction of arrow C. Next, when the motor 29 is driven in the reverse direction, the rotating body 24 rotates in the opposite direction to the arrow direction, and therefore the uneven wave 9b on the top surface also moves in the opposite direction to the arrow C direction 2.

By repeating forward and reverse rotation of the motor 29 in this way,
The large number of uneven waves 9b repeats movement alternately in the direction of arrow C and in the opposite direction.

Note that the motor 29 does not necessarily need to rotate in the forward and reverse directions, but may rotate in one direction.

The solder melt 9 spouted from the jet port 19 returns to the secondary tank 7 and flows into the flow pipe 22 from the reflux port 23 . In addition, the temperature of the solder melt 8 in the primary tank 6 is lower than the temperature of the solder melt 9 in the secondary tank 7, so in the primary tank 6, the conventional preheating is performed at the same time as the pre-soldering. Preheating is performed at a temperature higher than the preheating temperature in the final stage of the apparatus (usually heating is performed in several stages).

For printed circuit boards, the electronic components 2 are temporarily attached with a mounting agent, etc., then dried, then subjected to flux treatment, preheated in a preheating device, and transferred to the device 3 for soldering.

Then, the printed circuit board 1 is soldered in a flow dip type solder bath 1.
Or in the direction of arrow A1 at o?

The electronic component 2 is pre-soldered at the same time as the electronic component 2 is lowered diagonally while maintaining the horizontal position in the direction of the arrow A2, and is immersed and heated in the overflow solder surface 8aK. Next, the printed circuit board 1 maintains a horizontal position on the overflow solder surface 8a and advances in the direction of arrow A3 to reach the jet solder bath 17.

Next, in the jet solder tank 17, the printed circuit board 1 moves in the direction of arrow A4 at an upward angle θ with respect to the horizontal line. The jet waves 9a of the solder melt 9 cause soldering, and the printed circuit board 1 is moved by a large number of concave and convex waves 9b that alternately move across the direction of travel of the printed circuit board 1 A4. Air bubbles adhering to the rear part of the electronic components 2 and the concave-shaped areas where the electronic components 2 are close to each other in the direction are removed, so that the electronic components 2 are not densely mounted on the printed circuit board 1. The solder melt 9 adheres well to the electronic components 2 and lead wires, and complete soldering is achieved.

It should be noted that the soldering apparatus of the present invention is not limited to the printed circuit board 1 made of ceramic, but can of course be used for printed circuit boards made of synthetic resin such as phenol resin or epoxy resin.

As explained above, the present invention has two solder tanks, a primary tank and a secondary tank, which are sequentially formed in the running direction of the printed circuit board, an overflow tank is provided in the primary tank, and the solder tank is connected to the overflow tank. A flow-dip soldering bath is provided for heating printed circuit boards on which electronic components are mounted, and a jet bath is provided as a secondary bath, and jet waves eject from this jet bath to solder the heated printed circuit boards. By providing a type soldering tank and a means for forming a large number of concave and convex waves on the top surface of the jet wave in a direction intersecting the running direction of the printed circuit board, the preheating temperature and soldering temperature for the ceramic printed circuit board can be adjusted. Since the printed circuit board is not heated rapidly during soldering, there is no damage due to cracks, etc. (Also, there is no risk of heat sinking, so soldering It is possible to solder at a temperature close to that of the solder melt, and since it is heated by being immersed in the solder melt, it is possible to prevent ignition caused by the volatile components of the flux. By moving in a direction that intersects with the running direction of the printed circuit board, the part behind or on both sides of the electronic component with respect to the running direction of the printed circuit board, or the part where the electronic component is close to each other and has a recess-like shape, Furthermore, it has the advantage of being able to completely adhere the solder melt by removing bubbles or gas stagnation in areas where lead wires are densely packed.4.
.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention; Figure 1 is a partially cutaway side view, and Figure 2 is a partially cutaway front view showing an enlarged main part of Figure 1. It is. In the figure, 1 is a printed circuit board, 2 is an electronic component, 3 is a soldering device, 4 is a soldering tank body, 5 is a partition wall 6 is a primary tank, 7
is the secondary tank, 8 and 9 are the solder melt, 8a is the overflowing solder surface,
9a is a jet wave, 9b is an uneven wave, 10 is a flow dip type soldering tank, 11 is an overflow tank, 12 is an overflow port, 13.20 is an impeller, 14° 21.29 is a motor, 15.22 is a flow Pipe, 16° 23 is reflux port, 17 is jet solder bath, 18
19 is a jet tank, 19 is a jet port, 24 is a rotating body, 25 is a threaded portion, 26 is a convex portion, 27 is a recessed portion, and 28 is a rotating shaft.

Claims (1)

[Claims] A solder tank containing a solder melt is formed into two tanks, a primary tank and a secondary tank, arranged in sequence in the running direction of the printed circuit board, and the primary tank is pressurized by an impeller for the solder melt. An overflow tank is installed above which the flow is forcibly circulated, and a flow dip type is installed above the overflow tank in which a printed circuit board with electronic components is immersed in the overflow solder surface that overflows from a constant temperature flow port and heated. A solder bath is housed, and the secondary tank is provided with a jet tank in which the solder melt is pressurized by one impeller and forced to circulate, and the jet wave ejected from the jet port provided above the jet tank , a jet-type solder a for soldering is placed on a heated printed circuit board, and a large number of uneven waves are applied to the top surface of the jet wave in a direction intersecting the running direction of the printed circuit board, and the printed circuit board is run. A soldering device characterized by being provided with means for moving in a direction crossing the soldering direction.