JPH10126049A - Post soldering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post soldering device which makes a post soldering work using a solder iron unnecessary, stabilizes the quality at low cost, and can perform a prompt post soldering. SOLUTION: This post soldering device for soldering a post soldering part 72 to a back face 7b of a substrate 7 on which electronic parts 71 have been mounted on a surface 7a, comprises: a holding stand 6 for supporting the substrate 7 with the surface 7a facing down; a solder nozzle 3 arranged just below the substrate 7, facing the post soldering part 72 mounted on the back face 7b of the substrate 7 in a state where a lead wire 721 is inserted into a through hole 73 of the substrate 7; and a lifting mechanism for lifting the holding stand 6 between the lower end position where the through hole 73 of the substrate 7 is immersed in solder S overflowed from the solder nozzle 3 and the upper end position away from the solder nozzle 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a post-mounting soldering device for mounting a post-mounting component on the back side of a substrate on which electronic components have been mounted on the front side.

[0002]

2. Description of the Related Art As a method of mounting an electronic component on a printed circuit board, a so-called vertical mounting method is widely used, in which a lead wire (including a pin) of the electronic component is inserted into a through hole of the printed circuit board and soldered. It is to be fixed.
At present, in order to make such a mounting process more efficient, electronic components are mounted on the front surface side of the printed circuit board, and the entire back surface of the printed circuit board is immersed in the solder in the automatic soldering tank and all the electronic components are soldered simultaneously. Is becoming more common.

As shown in FIG. 10, an extension connector 72 for connecting an electric circuit on a printed circuit board 7 to the outside.
Are often provided on the back surface 7b side of the printed circuit board 7. In such a case, the extension connector 72
Cannot be soldered and fixed in the solder tank at the same time as the other electronic components 71. In addition, when the electronic component 71 is mounted, then turned over, and the expansion connector 72 is inserted, and the automatic electronic component is passed through the automatic soldering bath, the mounted electronic component 71 is immersed in the soldering bath. Did not. Therefore, conventionally, after all the electronic components 71 are soldered and mounted on the surface 7a side of the printed circuit board 7, the backing components such as the expansion connector 72 are manually attached one by one using a soldering iron. .

[0004]

However, the manual soldering requires a lot of experience in the work, the quality is varied, and the soldering iron may erroneously hit an unnecessary part and the solder may be attached. (Increase in defective products), high running cost due to the use of thread solder,
When the number of pins (the number of lead wires) such as connector pins is large, there are some problems such as an excessively long working time (20 to 30 seconds).

An object of the present invention is to provide a post-installation soldering apparatus which solves the above-mentioned problems, eliminates post-installation work using a soldering iron, is low in cost, has stable quality, and can perform quick soldering. I do.

[0006]

In order to achieve the above object,
The gist of the present invention according to claim 1 is that, using a substrate (7) on which an electronic component (71) has been mounted on a front surface (7a), a retrofit component (72) is mounted on the back surface (7b) of the substrate (7). A mounting table (6) for supporting the substrate (7) with the surface (7a) facing down, and a lead wire (721) in a through hole (73) of the substrate (7). A solder nozzle (3) disposed immediately below the substrate (7) opposed to the retrofit component (72) placed on the back surface (7b) of the substrate (7) in the inserted state; The holding table (6) is moved up and down between a lower end position where the through hole (73) of the substrate (7) is immersed in the solder (S) jetted from 3) and an upper end position away from the solder nozzle (3). And a lifting mechanism (5A, 5B).

According to the first aspect of the present invention, when the substrate on which electronic components have been mounted on the surface is turned down, the substrate is supported on a holding table, and the substrate is lowered to a lower end position by an elevating mechanism. Since all the through holes of the substrate are immersed in the solder jetted from the solder nozzle, all the lead wires can be simply and instantly attached to the solder. Since it is not necessary to use a soldering iron, no work experience is required, and there is no danger that the soldering iron will erroneously hit an unnecessary part and solder will be attached as in the related art. Further, it is possible to avoid running cost increase due to the use of thread solder.

According to a second aspect of the present invention, there is provided the post-installation soldering apparatus according to the first aspect, wherein the holding table (6) is provided with the substrate surface (7a).
Mask hole (6) for exposing only the through hole (73) and its surrounding area to the solder nozzle (3).
3) is provided.

According to the second aspect of the present invention, when the mask hole is provided, only the through hole on the surface of the substrate and a necessary portion in the vicinity of the through hole are immersed in the solder jetted from the solder nozzle. Prevent more reliably.

According to a third aspect of the present invention, in accordance with the first or second aspect of the present invention, the holding table (6) is lowered to the lower end position, and after a lapse of a set time, the holding table (6) is moved to the upper end position. And a control circuit (8) for controlling the elevating mechanism (5A, 5B) so as to raise the pressure.

According to the third aspect of the present invention, since the lowering of the substrate, the immersion in the solder for a predetermined time, and the subsequent pulling up from the solder are automatically performed, the quality is stable, and the solder post-attachment process is labor-saving. Will be done.

According to a fourth aspect of the present invention, there is provided the post-installation soldering apparatus according to the first to third aspects, wherein the substrate (7) is a mask that exposes only the through hole (73) and the substrate surface (7a) around the through hole (73). A flux is applied only to the exposed portion using a jig (9) having a hole (91).

According to the fourth aspect of the present invention, since the flux is applied only to the through hole and the surface of the substrate surrounding the through hole, the "wettability" of the solder is increased only in the area where the flux is applied, so that the unnecessary portion can be removed. Avoid solder adhesion and contribute to further quality stability.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a retrofit soldering apparatus according to the present invention will be described below in detail. 1 to 9 show an embodiment of a post-mounting soldering device of the present invention. FIG. 1 is a perspective view of the post-mounting soldering device as viewed from the front, FIG. 2 is a plan view thereof, and FIG. The figure is shown. The post-mounting soldering apparatus has a rectangular casing 1, and a heater for heating solder and a solder tank for storing molten solder are provided in the casing 1 (not shown). A motor 21 is provided in the rear half of the casing 1.
A pump 22 connected to the belt 23 and driven to rotate is provided, and a solder nozzle 3 is provided substantially at the center of the casing 1 by projecting a tip 31 from an upper surface of a solder tank (not shown). Is located. On the other hand, casing 1
On the front surface of the main switch 41, in addition to the main switch 41, a flow switch 45 for raising the solder, an operation knob 42 for setting the solder jet level from the solder nozzle 3, and a temperature integrated with a digital switch for setting the solder temperature Display 4
4 and the like are provided. The temperature of the solder in the solder bath is maintained at a set temperature (for example, 250 ° C.) by a heater, and the solder jet level from the solder nozzle 3 is changed by changing the rotation speed of the pump 32 by the motor 21. Is done. The configuration described above is a known technique.

The left and right side surfaces of the casing 1 are provided with air cylinders 5A and 5B constituting a lifting mechanism. These air cylinders 5A and 5B are directed upward in a vertical posture, and both ends of a holding table 6 provided so as to cross over the casing 1 are connected to the respective air cylinders 5A and 5B.
A and 5B are supported and fixed to the tip of the rod 51. The holding base 6 is formed by combining plate bodies, and the main plate 61 is formed in a substantially U-shape facing forward (downward in the figure), as shown in FIG. 5B
And the center thereof protrudes rearward in a rectangular shape, and the locking plate 6
2 is fixed.

The locking plate 62 has an inverted L-shaped cross-section (see FIG. 3) in which a locking groove 621 is formed in the lower half, and extends in the left-right direction. A hole 63 is provided. The mask hole 63 has a shape that exposes only a portion requiring post-soldering to the solder nozzle 3 and surrounds the vicinity of a connector pin 721 which is a lead wire of an expansion connector 72 which is a post-installed component described later. In the present embodiment, as shown in FIG. 2, two rows of symmetric elongated holes 631 and 632 in which the positions of the tooth profiles at both ends are shifted are provided. The tip end 31 of the solder nozzle 3 having a shape slightly larger than the mask hole 63 is opened immediately below the mask hole 63 (FIG. 3). A long plate-shaped receiving plate 64 is located below the concave portion 61a of the main plate 61 so as to cover the concave portion 61a. The left and right ends of the receiving plate 64 are fixed to the main plate 61 via a spacer plate 65 having a predetermined thickness. I have. Further, rectangular guide plates 66 are provided on the main plate 61 along the left and right short sides of the recess 61a.

The printed circuit board 7 is placed on the holding table 6 as shown by a chain line in FIG. The enlarged view is shown in FIG.
The printed board 7 has its front edge (right edge in the drawing) inserted into the groove 621 of the locking plate 62 with the front surface 7a side on which the electronic components 71 already soldered are placed facing down. Then, the unsoldered connector pins 721 of the extension connector 72 placed on the back surface 7b side of the printed circuit board 7 are inserted into the through holes 73 of the printed circuit board 7 and positioned in the mask holes 63 of the main plate 61. ing. The printed circuit board 7 is stably held by the load of the electronic component 71 on the lower surface of the rear half portion and the front edge thereof is pressed against the upper and lower surfaces of the locking groove 621. The printed circuit board 7 is not shifted laterally by the guide plate 66. Further, the electronic component 71 provided at the intermediate portion of the printed circuit board 7 is supported by the receiving plate 64 to prevent the printed circuit board 7 from being excessively curved.

FIG. 5 is a circuit diagram of the air cylinder control circuit 8. In the figure, reference numeral 81 denotes a foot switch, and a timer 82 is connected between the foot switch and a power supply line in series. The timer 82 has a timer contact 821
A relay 83 is connected in parallel through the relay switch. One of the relay contacts 831 is connected in parallel to the foot switch 81 to form a self-holding circuit. The other relay contact 832 is connected in series to the solenoid valve coil 85. Have been. FIG. 6 is a diagram showing a piping system to the air cylinders 5A and 5B.
4 is provided, and the inlet port 841 is connected to a compressed air pipe. Each outlet port 84 of the solenoid valve 84
Reference numerals 2 and 843 denote pressure chambers 5 of the air cylinders 5A and 5B via variable throttles (speakons) 86 and 87 on the way.
2,53. In the illustrated state in which the solenoid valve coil 85 is not energized, compressed air is supplied to each air cylinder 5.
The rod 51 is supplied to the pressure chambers 53 of A and 5B, and the rod 51 is raised, so that the holding table 6 is disposed at the rising end (up position). When the solenoid valve coil 85 is energized, the ports 841, 842, 84
3 is switched, the compressed air is supplied to the pressure chambers 52 of the air cylinders 5A and 5B, the rod 51 descends, and the holding table 6 reaches the lower end (lower end position). When in the lower end position, the through-hole portion 73 of the printed circuit board 7 related to the connector pin 721 is immersed in the solder S jetted from the solder nozzle 3. Each air cylinder 5A, 5A
The speed at which B rises and falls can be appropriately adjusted by the speed controllers 86 and 87. If the ascending speed and the descending speed are too fast or too slow, a problem such as a solder bridge or a solder pinhole will occur. . Reference numeral 43 denotes a timer knob (can be set between 0 and 60 seconds) for setting a solder immersion (dip) time under a condition where the rod 51 of the air cylinder is lowered.

When the extension connector 72 is to be retrofitted with the above-described retrofit soldering device, the soldering is performed by the jig 9 shown in FIGS. 7 and 8 before the printed circuit board 7 is mounted on the holding table 6. A flux is applied to the through hole 73 to be provided and the printed circuit board surface 7a around the through hole 73. The jig 9 is obtained by cutting a plate into a predetermined shape, and has a mask hole 91 formed in the center of the plate surface, the mask hole 63 having a shape substantially inverted from the mask hole 63 of the holding table 6 when viewed from above.
Positioning bolts are provided on the lower surface of the plate body of the jig 9 by inserting and fixing spacers 92 to the bolts at both ends of the mask hole 91, and the bolt head 93 is fitted into the positioning hole 74 of the printed circuit board 7. The positioning hole 74 utilizes a mounting hole for mounting the mounted printed circuit board product to the device. Thus, the jig 9 is positioned slightly above the surface 7 a of the printed circuit board 7, and is passed through the mask hole 91 to connect the connector pin 72 of the extension connector 72.
Only the through-hole 73 into which 1 is inserted and the vicinity of the through-hole 73 are exposed upward (FIG. 7). In this state, a flux is applied to the tip of the brush W, and the flux is applied only through the mask hole 91 to the through hole 73 on the printed circuit board surface 7a and the vicinity thereof. Fix the jig 9 to the printed circuit board surface 7
The defect that the flux is a little apart from a is that the flux is mainly composed of alcohol, and if the flux is provided so as to be in contact with the printed circuit board surface 7a, the applied flux penetrates between the jig 9 and the printed circuit board surface 7a due to a capillary phenomenon and spreads. This is because

The printed circuit board 7 having the surface 7a coated with flux has connector pins 721 in through holes 73.
And the extension connector 72 is attached to the back surface 7b, and is mounted on the holding base 6 as described above with the front surface 7a facing down (FIG. 4). In this state, the foot switch 81
, The switch contact is closed and the relay 83 is energized and excited, and the relay contacts 831 and 832 are closed,
While the solenoid valve coil 85 is energized, the foot switch 81 is held by itself. When the solenoid valve coil 85 is energized, the communication between the ports of the solenoid valve 84 is switched, the rods 51 of the air cylinders 5A and 5B are lowered, and the holding table 6 reaches the lower end. As a result, the through hole 73 on the printed circuit board surface 7 a and the surrounding area thereof are immersed in the solder S jetted from the tip 31 of the solder nozzle 3 via the mask hole 63.

The time set by the timer knob 43 (3 to
10 seconds), the timer contact 821 opens,
The relay 83 is de-energized, and the relay contacts 831 and 832
Is opened, the self-holding of the foot switch 81 is cancelled, and the power supply to the solenoid valve coil 85 is stopped. As a result, the rod 51 of each of the air cylinders 5A and 5B rises, the holder 6 moves to the initial upper end position again, and the through hole 73 on the printed circuit board surface 7a escapes from the inside of the solder S. The enlarged cross section of the through hole 73 at this time is shown in FIG.
Shown in The solder S has an increased wettability due to the applied flux, and the connector pins 721 and the through holes 7
It adheres well to the electrode part (not shown) in and around 3 and electrically connects between them. The holding table 6 and the printed circuit board 7 are in contact with each other. Solder S is different from flux,
Outside the range where the flux is applied, the surface tension is large,
Providing a gap between the holding table 6 and the printed board 7
On the contrary, it promotes the penetration of solder and causes a defect.

In the post-mounting soldering apparatus configured as described above, the printed circuit board 7 on which the flux is applied and the expansion connector 72 is mounted is set on the holding table 6 and the foot switch 8 is set.
1 automatically presses all the connector pins 721 of the expansion connector 72 at the same time and instantaneously, so that it is very significant to attach the expansion connector 72 to the back side after mounting the electronic components on the front side. Become. ADVANTAGE OF THE INVENTION The post-installation soldering apparatus of the present invention can easily and quickly perform post-installation soldering work while ensuring quality, regardless of experience through mechanization and automation. Since the post-processing of the connector pins 72 is performed in a short time (3 to 10 seconds), the productivity is greatly improved. In addition, since the mask hole 63 is provided, unnecessary portions are not soldered, the finish of soldering is good, and stable high quality can be maintained. Furthermore, since the finish is clear, visual inspection of the product is also facilitated. In addition, the bar solder used in the present invention is cheaper than thread solder, and contributes to not only labor costs but also consumables costs. Thus, the quality variation due to the conventional skill of the worker, the increase of mistakes due to the manual work (for example, the solder adheres to the contact portion, the connector insertion portion,
In addition, the present invention solves all problems such as the occurrence of pinholes in soldering and the increase in running costs due to the consumption of thread solder and soldering iron.

It should be noted that the present invention is not limited to the embodiment described above, but can be variously modified within the scope of the present invention depending on the purpose and application. The shape, size, and the like of the solder nozzle 3, the holding table 6, the printed circuit board 7, the jig 9, and the like can be appropriately selected according to the application. The lifting mechanism is not limited to the air cylinders 5A and 5B, but may be a hydraulic actuator, an electric actuator (for example, an electromagnetic solenoid), or the like. In the present embodiment, the extension connector 72 has been described as an example of a retrofit component, but the present invention can be applied to a retrofit of a liquid crystal display, an IC, or the like. The retrofitting of these electronic components is not limited to one and can be applied to a plurality.

[0024]

As described above, the post-installation soldering apparatus of the present invention eliminates the post-installation work using a soldering iron, and is not only low in cost and stable in quality, but also capable of performing quick solder post-installation. It works.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a post-installed soldering apparatus.

FIG. 2 is an overall plan view of a post-installed soldering device.

FIG. 3 is an overall side view of the post-mounting soldering apparatus.

FIG. 4 is an enlarged cross-sectional view taken along the arrow A in FIG. 3;

FIG. 5 is a drive circuit diagram of the air cylinder.

FIG. 6 is a piping system diagram of an air cylinder.

FIG. 7 is a front view of a jig during flux application.

FIG. 8 is a side view of a jig when a flux is applied.

FIG. 9 is an enlarged sectional view of a connector pin portion of the extension connector after soldering.

FIG. 10 is an overall side view of a printed circuit board provided with electronic components and extension connectors.

[Explanation of symbols]

 3 Solder Nozzle 5A, 5B Air Cylinder 6 Holder 63 Mask Hole 7 Printed Circuit Board 7a Surface 7b Back 71 Electronic Component 72 Expansion Connector 721 Connector Pin 73 Through Hole 8 Control Circuit 9 Jig 91 Mask Hole S Solder

Claims (4)

[Claims] 1. Using a board (7) on which an electronic component (71) has been mounted on a front surface (7a), using a post-installation soldering device for mounting a post-installation component (72) on the back surface (7b) of the board (7). A support (6) supporting the substrate (7) with the surface (7a) facing down; and a lead wire (7) in a through hole (73) of the substrate (7).
21) With the inserted state, the back surface (7b) of the substrate (7)
A solder nozzle (3) disposed immediately below the board (7) facing the retrofit component (72) mounted thereon; and the solder (S) jetted from the solder nozzle (3). )), A post-mounting solder (5A, 5B) for raising and lowering the holding table (6) between a lower end position where the through hole (73) is immersed and an upper end position away from the solder nozzle (3). apparatus. 2. The method according to claim 1, wherein the holding table is provided on the substrate surface.
2. The post-mounting soldering device according to claim 1, wherein a mask hole (63) for exposing only the through hole (73) of FIG. 3. A control circuit for lowering the holding table (6) to the lower end position and controlling the elevating mechanism (5A, 5B) to elevate the holding table (6) to the upper end position after a lapse of a set time. 3. The retrofit soldering device according to claim 1, wherein (8) is provided. 4. The substrate (7) is exposed by using a jig (9) having a mask hole (91) for exposing only the through hole (73) and the substrate surface (7a) around the through hole (73). 4. The post-installation soldering device according to claim 1, wherein the flux is applied only to the portion.