JPH0665433B2 - Carrierless automatic soldering equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrierless automatic soldering apparatus, and more particularly, to carrying a substrate while tilting the substrate in a vertical plane perpendicular to the carrying direction. In addition to transporting so that the position in the horizontal direction gradually rises, the jet type solder bath is arranged so as to be inclined in a non-perpendicular direction in the horizontal plane with respect to the substrate transport direction, and the lower surface of the substrate and the nozzle of the jet type solder bath The present invention relates to a carrierless automatic soldering device in which good soldering is performed so that the distances are substantially equal over the entire length in the longitudinal direction of the nozzle, and the substrate after soldering is returned to the substrate loading section.

2. Description of the Related Art In a conventional carrierless automatic soldering device in which a substrate is returned while being soldered while being transported, the conventional carrierless automatic soldering device transports the substrate while holding it horizontally and in the transport direction of the substrate. A device for ejecting molten solder from a jet type solder tank arranged in a direction perpendicular to the solder is used for soldering. However, according to the conventional device, when the molten solder separates from the lower surface of the substrate, so-called solder breakage occurs. Since the molten solder tends to warp downward, the molten solder separates from the substrate at the central portion in the width direction of the substrate, so that the lead wires of the electronic components arranged near the central portion are soldered together. There are drawbacks that bridging, flicker, and fluttering are likely to occur, so that it is difficult to secure sufficient soldering performance, and the finished substrate may be defective. Especially in the recent high-density mounting board, the pitch between the lead wires is small, and the above-mentioned soldering failure is likely to occur in the board with the minimum pitch, for example, a board with a pitch of about 0.5 mm, which is a serious problem from the reliability of the completed board. was there. In addition, the defective soldering board has to be manually repaired, resulting in a decrease in work efficiency.

In addition, Japanese Patent Publication No. 61-27149 discloses an automatic transfer device for continuous circuit soldering of printed circuit boards. However, the conventional example only discloses a so-called elevator mechanism for carrierless return. Are all oriented at right angles to the direction of travel of the board, and this still fails to eliminate the above-mentioned drawbacks, and it has not been possible to achieve high-speed soldering.

Further, Japanese Laid-Open Patent Publication No. 64-15995 discloses a method for soldering a printed circuit board. In the conventional example, the board is conveyed in a non-perpendicular direction relative to a jet solder bath. It only discloses the soldering method,
It does not disclose a heater arrangement method or a specific shape for preheating the substrate. With such a configuration, it is possible to improve the soldering performance to some extent, but it may be possible to perform soldering at a considerably higher speed than before. However, the present invention is different from the present invention in the configuration and the operation and effect.

OBJECT The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art, and an object of the present invention is to tilt a substrate in a plane vertical to the substrate transfer direction in a carrierless automatic soldering device. It is held in a state of being held, and the substrate is conveyed so that the horizontal position gradually rises as it is conveyed, and at the same time, the jet type solder bath is arranged so as to be inclined in a non-perpendicular direction in the horizontal plane with respect to the substrate conveying direction. By contacting the lower surface of the substrate with the molten solder ejected from the nozzle to solder it,
The distance between the lower surface of the board and the nozzle is made substantially equal over the entire length of the nozzle, and the contact condition of the molten solder on the board is made the same ideal condition over the entire surface of the board. This also improves the soldering performance. It is to let. Another purpose is to perform soldering while causing a flow of molten solder of a component perpendicular to the substrate transport direction so that solder breakage is performed at one end in the direction orthogonal to the direction of travel of the substrate. Is to prevent the defective soldering such as bridges, flicker, and fluttering by concentrating on the center portion in the width direction of the substrate, and to improve the work efficiency by eliminating the repair work of the board. Still another object is to improve work efficiency by allowing one person to carry in and carry out a board at one place by returning the soldered board by a returning device provided below the carrying apparatus. It is to let.

Another object of the present invention is to construct the heater such that the length of the heater is gradually increased at the front end portion and gradually shortened at the rear end portion of the heater according to the inclination of the jet solder bath. While the solder bath is non-perpendicular to the substrate transport direction, the preheating time of the board and the time from the end of heating to the arrival of the solder bath should be equal in all parts of the board. In addition, by this, even if the substrate is transported at a high speed, the temperature of the substrate does not fluctuate, and particularly high-speed soldering is possible.

Configuration In summary, the present invention, as the substrate is sandwiched and conveyed between a pair of chain conveyors arranged in parallel, the horizontal position of the substrate is gradually raised and the substrate is moved in the substrate conveyance direction. A transport device that transports the substrate by inclining it in a vertical plane of the orthogonal direction, and the substrate is mounted on the substrate transport terminal side of the transport device and lowered by the conveyor disposed below the transport device. A returning device that conveys the substrate in a direction opposite to the conveying direction and then raises the substrate to the substrate conveyance start end side of the conveying device, and a heater that is arranged below the conveying device and preheats the substrate,
A jet-type solder bath for ejecting molten solder is provided downstream of the heater in the substrate transport direction in a non-perpendicular direction in a horizontal plane with respect to the substrate transport direction, and the substrate is continuously transported. Then, the distance between the lower surface of the substrate transported by the transport device and the upper surface of the nozzle of the jet solder bath is substantially equal over the entire length in the longitudinal direction of the nozzle, and the heater is The heater is characterized in that the length of the heater is gradually increased at the front end thereof and is gradually reduced at the rear end thereof in accordance with the inclination of the jet solder bath.

The present invention will be described below based on the embodiments shown in the drawings. First
1 and 2, a carrierless automatic soldering device 1 includes a carrier device 2, a returning device 3, a heater 4, and a jet solder bath 5.

The transfer device 2 transfers the substrate 6 in the direction of arrow B, and has two sets of chain conveyors 8 arranged in parallel. The chain conveyor 8 is wound around a sprocket 9 driven by a motor (not shown), and is arranged with an inclination of an angle α so as to rise with respect to the horizontal line in the carrying direction of the substrate 6 (direction of arrow B). It is set up.
A large number of holding claws (not shown) are fixed to the chain conveyor 8, and the substrate 6 is held between the two holding claws of the chain conveyor 8 and the substrate 6 is conveyed in the arrow B direction without using a carrier. Is configured. On the extension lines of the two sets of chain conveyors 8, belt conveyors 11 that receive the substrates 6 from the chain conveyors 8 and convey them to the lifting platform 10A are respectively arranged. In the belt conveyor, a belt 13 is wound around a plurality of guide pulleys 12, and a first bevel gear 14 integrally fixed to one guide pulley 12 is attached to a pulley 15 integrally fixed to a sprocket 9. The second bevel gear 18 whose rotational movement is transmitted via the belt 16 is meshed with the belt conveyor 13 so that the belt 13 travels at the same speed as the chain conveyor 8 to convey the substrate 6.

The return device 3 conveys the board 6 on which the soldering is completed to the transfer device 2.
Of the conveying device 2 are fitted to two guide rods 19 at the starting end side 2a and the terminating end side 2b of the conveying device 2, respectively, and guided by the guide rods 19 in the vertical direction (directions of arrows C and E). ) Is provided with movable elevators 10A and 10B, and two arms 10a and 10b are formed in a bifurcated shape at the tip of the elevator, and each arm has a plurality of guide pulleys 20.
A belt 22 that is wound around and is driven by a motor 21 is attached. The belt 22 is configured to run at the same speed as the belt conveyor 11 and receive the substrate 6 from the belt conveyor or a conveyor 25 described later.

A conveyor belt 25 wound around a pulley 24 driven by a motor 23 is disposed below the transport device 2 between the two elevators 10A and 10B, and the substrate 6 is moved from the lowered elevator 10A. It is configured to receive and convey in the direction of arrow D.

The fluxer 26 disposed below the transport device 2 is disposed below the substrate 6 to be transported and applies flux so that the solder easily attaches to the soldering points of the substrate 6, Is inclined at an angle of about 45 ° in the horizontal plane with respect to the conveying direction (direction of arrow B).

The heater 4 causes the substrate 6 to have a predetermined temperature (for example, about 110 ° C.).
It is preheated up to 1 m, and an electric heater 28 is arranged over a length of about 1 m. In this embodiment, the jet solder bath 5 is used.
The length of the heater is gradually increased at the front end portion 4a of the heater 4 in accordance with the inclination of and the time for preheating is made the same over the entire surface of the substrate 6 by making the heater gradually shorter on the rear end side 4b. It is designed to heat uniformly.

The jet-type solder bath 5 is composed of a primary solder bath 29 and a secondary solder bath 30, and molten solder (not shown) melted by a heater (not shown) is stored in each of the solder baths 29 and 30, and each of them is used as a motor. Molten solder is jetted from the nozzles 36 and 38 by an impeller 35 that is driven via 31, a pulley 32, a belt 33, and a pulley 34 so that the molten solder is brought into contact with the lower surface of the substrate 6 to be soldered. There is.

Nozzles 36 and 3 of the primary solder bath 29 and the secondary solder bath 30
The reference numeral 8 is arranged so as to be inclined by about 45 ° in the horizontal plane with respect to the transfer direction of the substrate 6 (direction of arrow B), and the parallel rotation plate is provided in the nozzle 36 of the primary solder bath 29 along the longitudinal direction of the nozzle. Three
9 is provided, and is configured to generate a pulse wave in the molten solder ejected from the nozzle 36 by rotating the motor 40.

Further, a cooling fan 41 for cooling the soldered and high temperature substrate 6 is provided on the downstream side of the jet solder bath 5, and a gas, smoke, etc. generated during the soldering are discharged to the upper portion of the main body cover 42. An exhaust fan 43 is provided.

Action The present invention is configured as described above, and its action will be described below. In FIGS. 1 and 2, the solder in the solder baths 29 and 30 is heated and melted by energizing a heater (not shown), and the motor 31 rotates the impeller 35 via the belt 33 to melt the solder. The solder is ejected upward from the respective nozzles 36 and 38. A parallel rotating plate 39 which is driven by a motor 40 and rotates in the molten solder acts on the molten solder ejected from the nozzle 36 to generate a pulse wave in the jet solder, and a guide plate (see FIG. (Not shown) is arranged, and a flat portion is formed on the wave front of the molten solder which is guided by this and jets from the nozzle 38.

When a motor (not shown) is energized, the motor starts to rotate, and the rotational movement is transmitted to the sprocket 9, and the chain conveyor 8 wound around the sprocket runs. Here, when the substrate 6 is carried in in the direction of arrow A, a large number of claws fixed to the chain conveyor 8 cause left ends 6a and right ends 6 of the substrate 6 in the traveling direction.
The substrate b is clamped and conveyed in the direction of arrow B.

The board 6 transferred by the transfer device 2 is transferred to the upper side of the fluxer 26 so that the fluxer 2 is transferred to a portion of the board 6 to be soldered.
The flux spouted from 6 is applied. Flaxer 26
Is placed at an angle of about 45 ° in the horizontal plane with respect to the substrate transfer direction, so the actual flux application opening area is about 1.4 times larger than the actual opening area, and flux is applied efficiently. Is done.

The substrate 6 processed by the flexor 26 is further preheated to about 110 ° C. while being conveyed above the heater 4. Since the front end portion 4a and the rear end side 4b of the heater 4 are inclined substantially 45 ° in the horizontal plane in parallel with the jet solder bath 5,
The preheating time of the substrate and the time from the completion of heating to the time of reaching the jet type solder bath 5 are equal in all parts of the substrate 6, so that there is no variation in temperature of the substrate 6.

When the substrate 6 is conveyed to the primary solder bath 29, it is primary-soldered, but since the pulsed wave is generated in the molten solder ejected from the nozzle 36 as described above, the flux is heated. The generated gas is efficiently removed from the lower surface of the substrate 6 by the pulse wave, and the substrate 6 is uniformly wetted with the molten solder. Next, the substrate 6 has a wave front of the molten solder in the flat portion 2
In the next solder bath 30, soldering is performed by contacting the molten solder for about 3 seconds which is an ideal soldering time. Jet type solder bath 5
Is inclined by approximately 45 ° in the horizontal plane with respect to the transfer direction of the substrate 6 (direction of arrow B), the flow of the molten solder ejected from the nozzles 36 and 38 is relative to the substrate 6 Soldering is performed while generating a component flow in a direction substantially perpendicular to the direction of arrow B), and the solder breakage starts from the left end 6a of the substrate 6 in FIG. 1 and ends at the right end 6b.
Therefore, the molten solder is not concentrated on the central portion of the substrate 6 in the width direction, and the occurrence of defective soldering such as bridge, flicker, and fluttering is prevented.

The soldered substrate 6 is cooled by the cooling fan 41, and is further transported, loaded on the belt 13 traveling at the same speed as the chain conveyor 8 and transported, and further transferred to the belt 22. Are transported and placed on the lift 10A. When the substrate 6 is placed on the lift table 10A, the movement of the belt 22 stops, and the lift table 10A is lowered (in the direction of arrow C) while being guided by the guide rod 19 so that the height of the belt 22 and the belt 25 of the returning device 3 is substantially the same. Stop at equal positions.
Then, the motor 21 rotates in a direction opposite to the direction in which the substrate 6 is received and sends out the substrate 6 (direction of arrow D) to place the substrate on the belt 25. Belt 2 driven by motor 23
5 is a platform 10 that conveys a substrate 6 in the direction of arrow D and is in a lowered position and a belt 22 is driven by a motor 21.
The substrate 6 is sent to B. When the substrate 6 is placed on the lift table 10B, the motor 21 stops, and the lift table rises along the guide rod 19 in the arrow E direction and stops. And the operator is the substrate 6
The soldering is completed by carrying out the board 6 in the direction of arrow F at a position substantially the same as the position where the board is carried in in the direction of arrow A.

Advantageous Effects of Invention According to the present invention, in the carrierless automatic soldering device as described above, the substrate is held in a state of being inclined in a plane vertical to the substrate transport direction, and the horizontal position is gradually raised as the substrate is transported. And the lower surface of the substrate is brought into contact with the molten solder ejected from the nozzle of the jet-type solder bath which is inclined in a non-perpendicular direction in the horizontal plane with respect to the substrate conveying direction for soldering. Therefore, there is an effect that the distance between the lower surface of the substrate and the nozzle can be made substantially equal over the entire length in the longitudinal direction of the nozzle, and the contact condition between the substrate and the molten solder can be the same ideal condition over the entire surface of the substrate. As a result, there is an effect that the soldering performance can be improved. Furthermore, since the solder is soldered while causing the flow of the molten solder in the direction perpendicular to the board transport direction, the solder is cut at one end in the direction perpendicular to the direction of travel of the board so that the width of the board is wide. Since it is possible to prevent concentration in the central part of the direction, there is an effect that it is possible to prevent soldering defects such as bridges, flicker, and fluttering, and as a result, there is an effect that work efficiency can be improved by eliminating the work of modifying the board. . Further, since the soldered board is returned, one person can carry in and carry out the board at one place, which has the effect of improving work efficiency.

Further, the heater is configured such that the length at the front end portion of the heater is gradually increased and the length at the rear end portion thereof is gradually shortened in accordance with the inclination of the jet solder bath. Although not perpendicular to the direction, the preheating time of the board and the time from the end of heating to the solder bath can be made equal in all parts of the board, resulting in high speed. Since there is no temperature variation in the substrate even when the substrate is transported by, there is an effect that particularly high-speed soldering can be performed.

[Brief description of drawings]

1 is a plan view showing an entire carrierless automatic soldering device, and FIG. 2 is a side view of the same. 1 is a carrierless automatic soldering device, 2 is a carrier device, 2
a is the start end side, 2b is the end side, 3 is a returning device, 4 is a heater, 4a is a front end part, 4b is a rear end part, 5 is a jet solder bath,
6 is a substrate, 8 is a chain conveyor, 25 is a belt, 3
Reference numerals 6 and 38 are nozzles.

Claims (2)

[Claims] 1. As the substrate is sandwiched and conveyed between a pair of chain conveyors arranged in parallel, the horizontal position of the substrate is gradually raised and the substrate is orthogonal to the substrate conveying direction. A conveying device that inclines and conveys the substrate in a vertical plane of the direction in which the substrate is conveyed, and the substrate is conveyed by a conveyor disposed below the conveying device on which the conveyed substrate is mounted and descends. A returning device that conveys the substrate in a direction opposite to the direction and then raises the substrate to the substrate conveyance start end side of the conveying device, a heater that is disposed below the conveying device and preheats the substrate, and a heater of the heater. A jet-type solder bath for jetting molten solder is provided on the downstream side of the substrate transport direction inclining in a non-perpendicular direction in a horizontal plane with respect to the substrate transport direction, and the substrate is continuously transported to solder. Attach The distance between the lower surface of the substrate carried by the carrying device and the upper surface of the nozzle of the jet solder bath is substantially equal over the entire length in the longitudinal direction of the nozzle, and the heater is the jet solder. A carrierless automatic soldering device, characterized in that the length of the heater is gradually increased at the front end and gradually decreased at the rear end of the heater in accordance with the inclination of the bath. 2. The carrierless automatic soldering device according to claim 1, wherein an inclination angle of the jet solder bath in the horizontal plane with respect to the substrate transport direction is approximately 45 °.