JP3362351B2 - Automatic soldering method of printed circuit board and automatic soldering apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for automatic soldering of a printed circuit board on which a lead electronic component having a lead to be cut and a surface mount electronic component are mounted on both sides and an automatic soldering apparatus therefor. Belong to

[0002]

2. Description of the Related Art Conventionally, as a technique for soldering a double-sided printed circuit board having a leaded electronic component (lead size of about 30 mm) having a length to be cut, FIG. An example of an attachment device is shown. First, flux is uniformly applied to the back surface (soldered surface) of the printed circuit board using a primary fluxer device. Then 1
In the next soldering device 71, the electronic components with leads are soldered by the static soldering method to fix the electronic components with leads. In this case, in the soldering state of the surface mount electronic component, unsolder and bridges may occur frequently. Then, use the lead cutter device 72 to measure the lead size of the electronic component with leads from the back side of the printed circuit board by several mm.
Cut to the extent. Then, the flux is again applied with the secondary fluxer, and the secondary soldering apparatus 73 solders the surface-mounted electronic components by the jet soldering method. In this case, the jet height of the jet type soldering device is generally about 7 to 8 mm, and it is necessary to cut the lead size to less than that in advance due to mechanical restrictions.

Further, by cutting the lead size of the electronic component with leads into short pieces in advance, a secondary fluxer device,
Although soldering is possible only by the process of the secondary soldering device, there are problems such as an increase in lead cutting man-hours before mounting electronic components with leads and a decrease in mounting efficiency of electronic components with leads on a printed circuit board. Substantially as described above, there is a need for production equipment that performs soldering twice.

[0004]

However, the prior art has the following problems. In order to solder the double-sided printed circuit board on which the electronic components with leads are mounted, as shown in FIG. 9, a fluxer device and a soldering device are required for each two units, which results in a large size or a long size. Not only the consumption of flux and solder,
Since a large amount of waste flux (organic solvent) and waste solder (lead-containing) are also generated, there is a problem of causing environmental pollution.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce the size of an apparatus and to automatically solder a printed circuit board to cope with environmental problems without lowering work efficiency. A point is to provide a method and a technique relating to the automatic soldering apparatus.

[0006]

According to the present invention, there is provided an automatic soldering method for a printed circuit board in which a lead electronic component having a lead to be cut and a surface mount electronic component are mounted on a front surface and a back surface. Then, the carry-in shutter provided in the chamber that hermetically seals the inert gas is opened to open the carry-in entrance of the printed circuit board, and the printed circuit board gripped by the carrier having a pair of left and right carrier chains By moving the carry-in port to a position vertically above a stationary jet tank provided in the chamber and in the molten solder bath, and closing the carry-in port shutter to fill the inert gas with the molten solder bath. In the static soldering method using the static jet tank to which the molten solder is supplied from, the solder on the soldered surface of the leaded electronic component in which the leads protrude vertically downward The molten solder is supplied from the molten solder tank to the jet tank for high jet provided inside the chamber and in the molten solder tank so as to be aligned in the horizontal direction of the jet tank for stationary, and the high jet flow By a high jet soldering method in which the molten solder is pushed out from the nozzle opening of the nozzle provided in the jet tank and jetted upward, and the liquid surface of the molten solder that keeps the jet is in contact with the soldering surface of the printed circuit board. , Soldering the surface mount electronic components,
An automatic soldering method for a printed circuit board, characterized in that the carry-out port shutter provided in the chamber is opened, and the printed circuit board gripped by the carrier is carried out from the carry-out port. Generates a flow in the molten solder by the rotation of a fan accompanying the rotation of a motor, collects the molten solder in a duct and pushes it toward the opening of the stationary jet tank, and applies a predetermined pressure by the rotation of the fan to the duct. By holding the liquid surface of the molten solder in a static state, lowering the carrier included in the carrier chain in the atmosphere of the inert gas, gripping the carrier, and holding the print in a substantially horizontal state. The soldering surface of the board is brought into contact with the liquid surface of the molten solder to solder the electronic components with leads, and An automatic soldering method of a printed circuit board for carrying the printed circuit board is obtained by elevating one of the standing transfer chains to separate the printed circuit board from the liquid surface of the molten solder and raising the other transfer chain. To be The high jet soldering method generates a flow in the molten solder by the rotation of a fan accompanying the rotation of a motor, collects the molten solder in a duct and pushes it into the jet tank for high jet, and a predetermined amount by the rotation of the fan. By applying pressure to the duct, the molten solder is jetted upward from the nozzle opening of the jet tank for high jet,
Moving the carrier chain at a predetermined speed to carry the printed circuit board held by the carrier while keeping the printed circuit board on a substantially horizontal surface, and bringing the liquid surface of the molten solder holding a jet flow into contact with the soldering surface of the printed circuit board. Then, the surface-mounted electronic component temporarily fixed may be soldered. The nozzle opening of the nozzle has a substantially band-shaped hole, and the molten solder is jetted in a curtain shape at a predetermined height exceeding the length of the lead projecting vertically downward from the soldering surface kept on a substantially horizontal surface. Then, the molten solder may be brought into contact with the soldering surface. In the high jet soldering method, all the soldering surfaces are melted by transporting the printed circuit board while maintaining a substantially horizontal surface in a direction perpendicular to the width direction of the molten solder in which a jet is maintained in a substantially curtain shape. It may be one that is brought into contact with the solder. According to the present invention, there is also provided an automatic soldering device for a double-sided mounting printed circuit board, in which a leaded electronic component having a lead to be cut and a surface mounting electronic component are mounted on a front surface and a back surface,
By pushing the molten solder collected in the duct with a predetermined pressure, the stationary jet tank that keeps the liquid surface of the molten solder stationary at the opening, and upward from the nozzle by pushing the molten solder with a predetermined pressure A jet tank for a high jet to be jetted into, a stationary jet tank and a molten solder bath for supplying the molten solder to the high jet jet tank, wherein the stationary jet tank and the high jet jet tank are , Are arranged in the molten solder bath so as to be horizontally aligned with each other, and further lower the printed circuit board during the soldering process in the stationary jet bath than in the soldering process in the high jet bath An automatic soldering device for a printed circuit board is obtained, which is provided with a means for making it possible. The nozzle is held by a carrier having a pair of left and right carrier chains, and exceeds the length of the lead projecting vertically downward from the soldering surface of the printed circuit board held on a substantially horizontal plane, and also upward. In order to jet the molten solder to a predetermined height and maintain a substantially curtain shape, a nozzle opening having a substantially band-shaped hole may be provided.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. As shown in FIG. 1, the main part of the automatic soldering apparatus for a printed circuit board according to the present embodiment is roughly configured by a molten solder tank HS, a motor 1, a stationary jet tank 2, and a high jet jet tank 3. The stationary jet tank 2 is provided with an opening 24, and the high jet jet tank 3 is provided with a nozzle 6 provided with a nozzle port 23.
It is supplied from one molten solder tank HS to the stationary jet tank 2 and the high jet tank 3.

FIG. 2 is a sectional view of a main part of the automatic soldering apparatus for a printed circuit board shown in FIG. FIG. 3 is a diagram showing each operation of the automatic soldering device according to the present embodiment. Hereinafter, each component will be described with reference to FIGS. 1, 2, and 3. The heater 5 melts solid solder. Fan 4
Generates a flow in the molten solder H contained in the molten solder bath HS. The motor 1 is a rotation drive source of the fan 4. The duct 7 collects the flow of the molten solder H and receives a predetermined pressure from the fan 4. The stationary jet tank 2 keeps the focused molten solder H in a stationary state by the pressure from the fan 4. The jet tank 3 for high jets and the nozzle 6 jet the collected molten solder H upward in a substantially curtain shape by the pressure from the fan 4. The chamber 12 is filled with an inert gas G,
The liquid surface of the molten solder H is covered. The carrier 18 holds and conveys the printed circuit board 8. A pair of left and right transport chains 19 that move independently transport the carrier 18. The carry-in cylinder 16 opens the carry-in shutter 14, and the carry-out cylinder 17 opens the carry-out shutter 15.

FIG. 4 is a diagram showing a printed circuit board used in an automatic soldering apparatus. In the figure, a printed circuit board 8, an electronic component 9 with leads, a surface mount electronic component 10, and a soldering surface 22 are shown.
And indicates. FIG. 5 is a view showing the stationary jet tank of FIG.
In the figure, the molten solder H, the molten solder bath HS, the stationary jet bath 2, the opening 24 thereof, the printed board 8 and the electronic component 9 with leads are shown. FIG. 6 is a view showing the operation of the jet tank 3 for high jet shown in FIG. In the figure, the molten solder H, the molten solder bath HS, the nozzle 6, the printed circuit board 8, and the leaded electronic component 9 are shown.
And the nozzle port 23 are shown.

Next, the operation of the automatic soldering apparatus for printed boards according to the present embodiment will be described with reference to FIG. The carrier 1 holding the printed circuit board 8 by driving the transporting motor 20 (not shown) with the loading port shutter 16 opened by the loading port cylinder 16 and the loading port opened.
8 is carried by the carrying chain 19 from the carry-in port to just above the stationary jet tank 2. This operation is shown in FIG.

Next, referring to FIG. The loading port shutter is closed and the inert gas G is filled from the inert gas nozzle. Wait until the inert gas G is sufficiently filled in the chamber.

Next, the soldering operation in the stationary jet tank 2 will be described with reference to FIG. The fan 4 rotates with the rotation of the motor 1 to generate a flow in the molten solder H. The flowed molten solder H is collected in the duct 7 and pushed into the opening 24 of the stationary jet tank 2, and the liquid level of the molten solder H is increased by the pressure from the fan 4 to the opening 2 of the stationary jet tank 2.
At 4 it becomes stationary.

Referring to FIG. In the inert gas atmosphere, the transport chain 1 is moved by the transport unit vertical cylinder 21.
Lower 9 As a result, the carrier 18 descends, and the printed circuit board 8 gripped by the carrier 18 is brought into contact with the liquid surface of the molten solder H kept stationary. The transport chains 19 are independent from each other on the right and left sides, one side of which is raised by the transport unit vertical cylinder 21 and the contact surface of the printed circuit board 8 is separated from the liquid surface of the molten solder H, and the other is raised by the transport unit vertical cylinder 21. Then, the printed circuit board 8 is kept substantially horizontal.
By the above operation, the electronic component with leads is soldered. This operation is shown in Figure 3c.

Next, the soldering operation in the jet tank for high jet will be described with reference to FIGS. 1 and 2. The molten solder H that has generated a flow in the same manner as described above is collected in the duct 7 and jetted in a substantially curtain shape from the nozzle 6 provided in the jet jet tank 3 for high jet by the pressure from the fan 4. The molten solder H forms a jet flow having a height exceeding about 30 mm from a substantially strip-shaped nozzle opening 23 provided in the nozzle 6. This jet flow is formed upward with a height exceeding the length of the lead protruding from the soldering surface 22 of the printed circuit board 8 shown in FIG. The shape of this jet is shown by molten solder H in FIG.

Referring to FIG. 3d. In the state where the jet flow formed in the substantially curtain shape is held, the carrier chain is driven to carry the carrier at a constant speed. As a result, the liquid surface of the molten solder comes into contact with the soldering surface of the printed circuit board held by the carrier in a substantially horizontal plane, and the surface-mounted electronic component temporarily fixed with an adhesive or the like is soldered.

Finally, please refer to FIG. With the transport motor driven, the carry-out port cylinder opens the carry-out port shutter to carry out the carrier from the carry-out port.

FIG. 7 is a diagram showing the operation configuration of FIG.
In the figure, the printed circuit board 8, the carrier 18, and the carrier chain 1
9, a transport motor 20, and a transport unit up / down cylinder 21 are shown.

FIG. 8 is a diagram showing an example of an apparatus arrangement in the soldering process using FIG. This means that the soldering by the automatic soldering device for the printed circuit board is performed after the processing by the fluxer device, and then the printed circuit board is carried out.

In the present embodiment, the present invention is not limited to this, and can be applied to an automatic soldering method of a printed circuit board and an automatic soldering apparatus thereof suitable for applying the present invention.

Further, the number, position, shape, etc. of the above-mentioned constituent members are not limited to those in the above-mentioned embodiment, and the number, position, shape, etc. suitable for carrying out the present invention can be adopted.

In each figure, the same constituent elements are designated by the same reference numerals.

[0022]

Since the present invention is configured as described above, it has the following effects. By mounting the static soldering method and the high-jet soldering method together in the same molten solder bath in an inert gas atmosphere, the electronic components with leads are mounted on the front surface of the printed circuit board, and the back surface is also mounted. Since it is possible to solder a double-sided mounting printed circuit board on which surface mounting electronic components are mounted (temporarily fixed with an adhesive), it is possible to reduce the number of work steps without requiring pre-processing for lead cutting. In addition, the automatic soldering machine can be downsized (space-saving), so the amount of solder and flux consumed can be suppressed, resulting in a large amount of waste solder (leaded) and waste flux (organic solvent). It is possible to reduce it to be environmentally effective.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a main part in an automatic soldering apparatus for a printed circuit board according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the automatic soldering device for a printed circuit board shown in FIG.

FIG. 3 is a diagram showing each operation of the automatic soldering apparatus for a printed circuit board according to the present embodiment.

FIG. 4 is a diagram showing a printed circuit board used in FIG.

5 is a diagram showing the stationary jet tank of FIG. 1. FIG.

FIG. 6 is a view showing the operation of the jet tank for high jet of FIG. 1.

FIG. 7 is a diagram showing the operation configuration of FIG. 3;

FIG. 8 is a diagram showing an example of an apparatus arrangement in a soldering process using FIG.

FIG. 9 is a diagram showing an example of an automatic soldering device for a double-sided printed circuit board according to a conventional technique.

[Explanation of symbols] G inert gas H molten solder HS molten solder bath 1 motor 2 Static jet tank 3 Jet tank for high jet 4 fans 5 heater 6 nozzles 7 ducts 8 printed circuit boards 9 Electronic components with leads 10 Surface mount electronic components 12 chambers 13 Inert gas nozzle 14 Transport entrance shutter 15 Transport exit shutter 16 Inlet cylinder 17 Carry-out cylinder 18 career 19 Transport chain 20 Transport motor 21 Transport unit vertical cylinder 22 Soldering surface 23 Nozzle mouth 24 opening 71 Primary soldering equipment 72 Lead cutter device 73 Secondary Soldering Equipment

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshihiro Saito 2 Raijin, Yoshioka, Yamato-cho, Kurokawa-gun, Miyagi Miyagi NEC Corporation (72) Rikio Kumagai Raijin, Raijin, Yoshioka, Yamato-cho, Kurokawa-gun, Miyagi (56) Reference JP-A-11-135932 (JP, A) JP-A-58-58795 (JP, A) JP-A-60-184464 (JP, A) JP-A-61-82968 (JP, A) Actual development Sho 62-169762 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05K 3/34 B23K 1/08

Claims (6)

(57) [Claims] 1. An automatic soldering method for a printed circuit board, wherein a leaded electronic component having a lead to be cut and a surface-mounted electronic component are mounted on a front surface and a back surface, the method comprising a chamber for sealing an inert gas. Open the carry-in port shutter provided to open the carry-in port of the printed circuit board, and move the carry chain to move the printed circuit board held by a carrier having a pair of left and right carrier chains into the chamber from the carry-in port. And transported to a position vertically above the stationary jet tank provided in the molten solder tank, closed the inlet shutter, filled with an inert gas,
In the static soldering method using the stationary jet tank in which molten solder is supplied from the molten solder tank, the leads of the electronic components with leads are soldered on the soldering surface protruding vertically downward, The molten solder from the molten solder bath in the chamber
And in the molten solder bath, in the horizontal direction of the stationary jet bath
It is supplied to a jet tank for high jets arranged side by side, and the molten solder is forced to flow upward from a nozzle opening of a nozzle provided in the high jet jet tank, and jetted upward to the soldered surface of the printed circuit board. With a high jet soldering method of contacting the liquid surface of the molten solder to keep the jet flow,
An automatic soldering method for a printed circuit board, comprising: soldering the surface-mounted electronic component, opening a carry-out port shutter provided in the chamber, and carrying out the printed circuit board held by the carrier from the carry-out port.
In the static soldering method, the melted solder is generated by the rotation of the fan accompanying the rotation of the motor.
Flow is generated, the molten solder is collected in a duct, and the stationary jet tank is opened.
Drift to the mouth and apply a predetermined pressure to the duct by the rotation of the fan
By keeping the liquid surface of the molten solder stationary by
The carrier chain is provided in the atmosphere of the inert gas.
The carrier is lowered , grasped by the carrier, and held in a substantially horizontal state.
The attached surface solder of printed circuit boards to the liquid surface of the molten solder
Contact and solder the electronic component with the lead,
Lift one side of the transport chain
The printed circuit board from the liquid surface of the molten solder.
Then raise the other carrier chain to
An automated soldering method for printed circuit boards, characterized by transporting the board . 2. The high jet soldering method comprises: generating a flow in the molten solder by the rotation of a fan accompanying the rotation of a motor, collecting the molten solder in a duct, and pushing the molten solder into the jet tank for high jet; By applying a predetermined pressure to the duct by the rotation of, the molten solder is jetted upward from the nozzle port of the jet tank for high jet flow, and the carrier chain is moved at a predetermined speed to be held by the carrier. Carrying the printed circuit board while keeping the printed circuit board substantially horizontal, and contacting the liquid surface of the molten solder that maintains the jet flow with the soldering surface of the printed circuit board, soldering the temporarily mounted surface-mounted electronic components is performed. The method for automatically soldering a printed circuit board according to claim 1, wherein: 3. A nozzle opening of the nozzle has a substantially band-shaped hole, and the molten solder has a predetermined height exceeding the length of the lead projecting vertically downward from the soldering surface maintained on a substantially horizontal surface. The method for automatically soldering a printed circuit board according to claim 1 or 2 , wherein the molten solder is brought into contact with the soldering surface. 4. The soldering method according to claim 1, wherein the high-jet soldering method is performed by transporting the printed circuit board while maintaining a substantially horizontal surface in a direction perpendicular to a width direction of the molten solder in which a jet is maintained in a substantially curtain shape. The method for automatically soldering a printed circuit board according to any one of claims 1 to 3 , wherein the entire surface is brought into contact with the molten solder. 5. An automatic soldering device for a double-sided mounting printed circuit board, wherein a leaded electronic component having a lead to be cut and a surface-mounted electronic component are mounted on a front surface and a back surface, and the molten solder is collected in a duct. A stationary jet tank that keeps the liquid surface of the molten solder stationary at the opening by pushing the solder with a predetermined pressure, and a high jet for jetting the molten solder upward from the nozzle by pushing the molten solder at a predetermined pressure A jet tank, and a molten solder tank for supplying the molten solder to the stationary jet tank and the high jet jet tank , wherein the stationary jet tank and the high jet jet tank are
It is provided so as to be horizontally aligned with each other in the molten solder tank, and further, during the soldering process in the stationary jet tank,
Print base more than during soldering process in jet tank for high jet
An automatic soldering device for a printed circuit board, comprising means for lowering the board downward . 6. The nozzle is held by a carrier having a pair of left and right carrier chains, and exceeds the length of the lead projecting vertically downward from the soldering surface of the printed circuit board, which is held on a substantially horizontal plane, Further, in order to jet the molten solder to a predetermined height in the upward direction to maintain a substantially curtain shape, a nozzle opening having a substantially band-shaped hole is provided.
5. The printed circuit board automatic soldering device according to item 5 .