JP2002252453A - Automatic soldering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic soldering device which can solve the problem raised by a conventional soldering device that the device is very efficient at the time of continuously producing many printed boards, but it uselessly consumes electric power, solder, etc., in each process, due to an idle time in treatment in each process at the time of producing a small number of printed boards. SOLUTION: After a printed board 1 is set at the carrying-in port of a transporting mechanism section 6, the transportation of the board 1 is started and a jet of a flux is started at the timing of coating the board 1 with the flux by means of a flux coating section 2. After the board 1 is coated with the flux, the jet of the flux is stopped and, at the same time, a jet of solder from a solder bath is started at the timing of performing soldering by means of a soldering section 4. After the completion of soldering, the jet of the solder is stopped and the printed board 1 is returned to the carrying-in port by reversely transporting the board 1 through the transporting mechanism section 6. In addition, a filtration system using a filter is adopted for treating gas generated at the time of performing the soldering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic soldering apparatus, and more particularly, to an automatic soldering apparatus suitable for small-scale production.

[0002]

2. Description of the Related Art FIG. 3 shows a main part of a conventional automatic soldering apparatus. Printed circuit board 1 on which electronic components are mounted
(Hereinafter referred to as the printed circuit board)
With the soldering surface (hereinafter referred to as a soldering surface) facing down, it is held by the claws of the transport mechanism 6 and transported in the direction A at a constant speed. Then, the wafers are sequentially processed in each processing unit while being transported, and the printed circuit board is soldered.

[0003] The printed circuit board is first conveyed to a flux application section indicated by 2, and the flux is applied to the solder surface. Next, the printed circuit board is conveyed to a preheating unit indicated by 3 and preheated to a predetermined temperature to reduce a thermal stress generated at the time of soldering.

[0004] Next, it is conveyed to a soldering portion indicated by 4 and soldered. In this soldering part, molten solder at about 250 ° C is contained in the solder tank, and the built-in propeller rotates to blow up the molten solder upward from the nozzle, and the solder jet surface becomes convex. It is formed. Then, the printed circuit board is soldered by being conveyed while being immersed in the convex solder jet surface.

[0005] The soldered printed circuit board is conveyed to a cooling section indicated by 5, cooled and returned to room temperature. In this way, the printed circuit board is transported to each part and processed by each part to perform soldering.

[0006] In the transport mechanism, claws for holding the printed circuit board are continuously provided in a loop shape, and the loops are provided on both sides of the printed circuit board. Is transported to each processing unit. Therefore, the printed circuit boards to be soldered are sequentially placed on the claws with a time interval from the carry-in entrance, and the mounted printed circuit boards are transported to the respective processing units and processed, so that the soldering of the printed circuit boards is continuously performed. Is processed. Therefore, it is suitable for soldering a large number of printed circuit boards.

[0007]

Consumer trends in recent years have become diversified, and products on which printed circuit boards are mounted are also in the direction of high-mix low-volume production. From such a background, production is being performed in which one worker is responsible for mounting components on a printed board, soldering the printed board, and inspecting. In the conventional soldering apparatus, since the printed circuit board is transported linearly, the carry-in port of the printed circuit board is separated from the carry-out port for taking out the soldered printed circuit board. For this reason, for example, if an operator is working around the entrance, it is necessary to take the soldered printed circuit board to the exit.

[0008] Further, since there are few printed boards to be soldered and they cannot be continuously mounted on the transport mechanism, there arises a problem. In the flux application part, the flux jet surface is always formed to apply the flux to the printed board, but it is necessary to manage the viscosity so that the flux becomes an appropriate amount when applied to the printed board,
Volatile solvents are supplied for this purpose. This volatile solvent is wasted when the production amount of the printed circuit board is small.

In the soldering section, a solder jet surface is always formed in a solder tank. However, if the jet surface is in contact with air, the solder is oxidized and the oxidized solder cannot be used. If the production amount of the printed circuit board to be attached is small, the proportion of time during which the soldering is not performed increases, and wasteful solder is consumed due to oxidation.

Further, since the conventional soldering apparatus is large in size, a duct is provided for exhausting gas generated at the time of soldering. However, when a production layout is changed, a large-scale change is required, and time is required. Costly and costly.

[0011]

The present invention is configured as follows to solve the above-mentioned conventional problems.

(1) An automatic soldering apparatus including a transport mechanism for transporting a printed circuit board, a flux application section, a preheating section, and a soldering section, wherein the printed circuit board is set at a carry-in entrance of the transport mechanism section. Thereafter, the conveyance is started, the processing is performed in each section, and after the completion of the soldering, the conveyance direction is changed to the reverse direction, and the conveyance is returned to the entrance.

(2) In the automatic soldering apparatus according to the item (1), a jet of the flux is started at a timing when the printed board is conveyed to the flux application section, and after the printed board is conveyed and applied, the jet is stopped. The jet of the solder is started at the timing when the printed circuit board is conveyed to the soldering section, and after the soldering is completed, the jet is stopped.

(3) In the automatic soldering apparatus described in (1) or (2), a cooling unit is arranged near a carry-in entrance of the transport mechanism to cool after soldering.

(4) In the automatic soldering apparatus according to any one of (1) to (3), a processing apparatus employing a filter filtration method as a processing method of gas generated at the time of soldering is incorporated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic soldering apparatus according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a block diagram for explaining a main part of the automatic soldering apparatus. 1 is a printed circuit board before soldering on a printed circuit board on which components are mounted, 2 is a flux application section, 3 is a preheating section,
4 is a soldering section, 5 is a cooling section, and 6 is a transport mechanism section. The arrangement of each part is different from the conventional one in that the cooling part 5 is conventionally disposed on the right side as a post-process of the soldering part 4, but in the present embodiment, the cooling part 5 is disposed at a place where the printed board is carried in.
The reason for this arrangement will be described later.

Each unit has a drive unit. The cooling unit 5 is provided with a drive unit 7 for rotating a cooling fan. The flux application unit 2 blows out a flux from a nozzle (blow-out port), and the flux is applied to the solder surface. The preheating unit 3 is provided with a driving unit 9 for heating the printed circuit board to a predetermined temperature, and the soldering unit 4 is provided with a solder in a molten state. Each of the driving units 10 is provided to maintain the temperature of the solder at a predetermined temperature and to form a solder jet surface.

Four timers are provided for processing each part while synchronizing each other or for making the processing a predetermined time. The first timer is timer 11
Therefore, it takes a predetermined time for the flux to blow out from the nozzle and stabilize, so that when the printed circuit board is transported, it is necessary to transport the printed circuit board with a delay. It is a timer that creates that time. The second timer is a timer for setting a preheating time by the timer 12. The third timer is a driving start time of the driving unit 10 such that when the printed circuit board is preheated to a predetermined temperature by the timer 13 and transferred to the soldering unit, the temperature of the solder bath is set to the predetermined temperature and the solder jet surface is formed. Is a timer for setting. The fourth timer is a timer for setting the cooling time by the timer 14.

This device has three sensors,
Each is a position detection sensor for detecting at which position of the transport mechanism the printed circuit board is being transported. The first sensor 17 is a position detection sensor that outputs a signal when the printed circuit board has been soldered at the soldering section, conveyed in the opposite direction, and returned to the entrance. The second sensor 15 is a position detection sensor that outputs a signal when the printed circuit board reaches a predetermined position for preheating. A third sensor 16 is a position detection sensor that outputs a signal after the soldering of the printed circuit board is completed.

Reference numeral 19 denotes a transport drive unit, which controls the transport direction of the printed circuit board and whether the transport is performed or stopped. Therefore, three types of input signals of forward transport, reverse transport, and transport stop are input to the transport driver. Forward direction transport signal is 19a terminal (FRONT)
And the printed circuit board is transported in the forward direction. The reverse transport signal is input to the 19b terminal (BACK), and the printed circuit board is transported in the reverse direction. And the transport stop signal is 1
The signal is input to the terminal 9c (STOP) and the conveyance is stopped.

The apparatus is provided with a start switch 18 for starting a soldering operation. When the start switch 18 is turned on, the operation starts. Reference numerals 20 and 21 denote OR gates.

Next, the operation of the present apparatus will be described step by step with reference to FIGS. In the following description, "on" means that the signal level is "1", and "off" means that the signal level is "0".

The printed circuit board 1 on which the components are mounted is set at the entrance of the transport mechanism. Next, start switch 18
Is turned on, a start pulse signal is output, and one of the signals is input to the driving unit 8 for applying the flux, and the signal causes the flux to blow out from the nozzle,
A jet surface is formed so that a flux can be applied to the solder surface when the printed circuit board is transported.

The other is input to the timer 11, and the timer is turned on for a predetermined time. The output of the timer is OR gate 20
Is input to the terminal 19a (FRONT) of the transport drive unit via the. The transport driver does not operate when the timer 11 is turned on, but operates when the timer 11 is turned off from on, and the printed circuit board is transported in the forward direction as described above.

Then, the printed circuit board placed on the transport claws of the transport mechanism is transported to the flux applying section 2, and the flux is applied to the entire solder surface. The printed circuit board is further transported in the forward direction, and reaches the next preheating unit 3. When the printed circuit board reaches a predetermined position where preheating can be performed, a pulse signal is output from the position detection sensor 15. The output signal is input to the drive unit 8 and the flux jet stops. Further, the signal is input to the terminal 19c (STOP) of the transport driving unit 19 via the OR gate 21, and the transport is stopped.

The output signal is input to a timer 12 and a timer 13, and both timers are turned on. The output signal of the timer 12 is input to the drive unit 9 and the output causes a current to flow through the pre-heater, so that the printed circuit board starts to be heated. When the temperature reaches a predetermined temperature, the timer 12 is turned off and the heating is stopped.

The output signal from the timer 13 is
Although 0 is input, the soldering section 4 does not operate at all. When the timer set time elapses and the timer 13 is turned off from on, the output signal drives the driving unit 10,
An electric current flows through a heater disposed inside the solder tank, and after the solder is in a molten state, the propeller rotates to form a solder jet surface.

During the time set by the timer 13, the printed circuit board is heated to a predetermined temperature in the preheating section, and when the printed circuit board is conveyed to the soldering section, the solder in the solder bath is melted and maintained at the predetermined temperature. The time is set such that a solder jet surface is formed.

Therefore, when the pre-heated printed circuit board is conveyed to the soldering section, the solder in the solder bath is in a molten state at a predetermined temperature, a solder jet surface is formed, and the solder can be soldered at any time. ing. Therefore, when the printed board is transported to the solder bath, the printed board is transported while being immersed in the molten solder, and soldering is performed.

When the entire solder surface is soldered, a position detection signal is output from the position detection sensor 16, and one of the output signals is input to the drive unit 10, the heater current of the solder tank is cut off, and the The rotation of the propeller also stops.
The other is input to the 19b terminal (BACK) of the transport drive unit, and the printed circuit board is transported in the opposite direction (in the direction of the entrance). In the time chart of FIG. 2, the forward direction is displayed on the upper side and the reverse direction is displayed on the lower side with respect to the direction of the transport drive unit (19).

When the printed circuit board reaches the entrance position, an output signal is output from the position detection sensor 17, and
The output signal is input to the timer 14, and the timer 14
Turns on for a predetermined time. The drive unit 7 is driven by the ON output of the timer 14, the fan rotates, and the printed circuit board is cooled. Then, after a predetermined time, the timer is turned off, and the rotation of the cooling fan is stopped. Further, the output signal is sent to the 19c terminal (STO) of the transport drive unit 19 via the OR gate 21.
Is input to P), and the conveyance is stopped.

In the above description, when the printed circuit board has been conveyed to the predetermined position of the preheating unit, the conveyance is stopped, a current is supplied to the heating heater, the printed circuit board is heated, and when the predetermined temperature is reached, the printed circuit board is heated. Although the description has been given of the case where the current of the heater is interrupted, the heater may be constantly heated when it takes a long time to start up the heater. At that time, the drive unit 8 is always turned on.

When it takes a long time for the heater of the solder bath to reach the predetermined temperature, a current is always supplied to the heater to maintain the temperature of the molten solder at the predetermined temperature. When the drive signal is input, the solder of the soldering portion is jetted to form a solder jet surface, and when the drive signal is lost, the jet may be stopped.

Further, in the present apparatus, the printed circuit board on which soldering has been completed is returned to the carry-in port, and a cooling section is provided near the carry-in port, so that the high-temperature printed circuit board on which soldering has been completed is returned to the carry-in port. Since it is cooled in the process of being cooled, it has been cooled to some extent when transported to the cooling unit,
The cooling amount is small, and the cooling time is short. In addition, since the cooling unit is provided at the lower part of the carry-in port, the entire apparatus becomes small.

In this apparatus, a paper-type filter is used to exhaust gas generated during soldering. Since the filter can be mounted inside the apparatus, when a production layout is changed with a conventional apparatus, a large-scale operation such as movement of an exhaust duct is required, but such an operation is not required.

In the apparatus of the present invention, the conveying speed for passing through each step can be freely set, so that the apparatus can be made much smaller than the conventional apparatus. For example, the size of the solder tank is large if the heat capacity is large, and small if the heat capacity is small.However, when soldering many printed boards in a certain time as in the past, much heat in the solder tank is taken by the printed boards. In other words, if the heat capacity is not large, the temperature of the solder bath decreases, and soldering failure occurs. Therefore it had just become a solder bath of large large heat capacity, for a small amount in device production of the invention, less amount of heat removed from the solder bath can be miniaturized greatly it is possible to make heat capacity small.
Further, since the pre-heating unit and the cooling unit heat or cool in a stationary state, the amount of heating or cooling can be reduced, and the size can be reduced. In addition, the flux application section can be miniaturized by being conveyed at a low speed.

[0037]

As described above, the conventional soldering process can be used in the case where a part is mounted on a printed circuit board, a step of soldering the printed circuit board, and a step of inspecting are carried out by a single person near the entrance. Since the printed circuit board is transported linearly in the soldering apparatus, the operator has to take the printed circuit board after soldering to the exit, but in the automatic soldering apparatus of the present invention, the printed circuit board has a flux. After being processed in the coating process and preheating process, it is soldered in the soldering process.After the soldering is completed, the printed circuit board is transported in the reverse direction and returned to the entrance, so it is transported for inspection. There is no need to go to the exit.

In the flux application section, the conventional apparatus always forms a jet surface of the flux in order to apply the flux to the printed circuit board. Although an appropriate amount of volatile solvent is supplied to make the viscosity of the flux a predetermined viscosity, the solvent is wasted because the number of printed circuit boards to be applied is small. In the above, the flux jet surface is formed at the timing when the printed circuit board is conveyed, the flux is applied, and the jet is stopped when the flux is finished, so that useless solvent is not consumed.

Further, in the soldering section, the conventional apparatus forms the solder jet surface even during the time when the device is not soldered to the printed circuit board, so that the solder is oxidized at that time, and wasteful solder is consumed. However, in the apparatus of the present invention, the solder jet surface is formed at the timing when the printed board is conveyed, and the jet is stopped when the soldering is completed, so that wasteful consumption of solder is eliminated.

Further, since the conventional soldering apparatus is large, a duct is provided for exhausting gas generated at the time of soldering. Therefore, when a production layout is changed, a large-scale change is required, and time is required. However, the apparatus of the present invention employs a method of filtering using paper, so that the apparatus can be easily incorporated into the apparatus, and the production layout can be easily and easily performed. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram of an automatic soldering apparatus according to the present invention.

FIG. 2 is a time chart of the automatic soldering apparatus of the present invention.

FIG. 3 is an explanatory view of a main part of a conventional automatic soldering apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed board 2 Flux application part 3 Preheating part 4 Soldering part 5 Cooling part 6 Conveying mechanism part 7-10 Driving part 11-14 Timer 15-17 Position detection sensor 18 Start switch 19 Transport driving part 21, 22 OR gate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B23K 1/08 B23K 1/08 C 320 320Z // B23K 101: 42 101: 42 (72) Inventor Michiaki Suzuki 2-9-13 Nakameguro, Meguro-ku, Tokyo F-term (reference) in Stanley Electric Co., Ltd. 4E080 AA01 AB03 DA01 DC05 5E319 AC01 CC24 CD22 CD35 GG15

Claims (4)

[Claims] An automatic soldering apparatus including a transport mechanism for transporting a printed circuit board, a flux application section, a preheating section, and a soldering section, wherein the printed circuit board is set at a carry-in entrance of the transport mechanism section. , Transport is started, processed in each part,
An automatic soldering apparatus, wherein after the completion of the soldering, the transport direction is changed to the reverse direction and returns to the entrance. 2. A timing in which a flux jet is started at a timing when the printed circuit board is conveyed to the flux application section, and after the printed circuit board is conveyed and applied, the jet flow is stopped, and a timing when the printed circuit board is conveyed to the soldering section. 2. The automatic soldering apparatus according to claim 1, wherein the jetting of the solder is started at the step (c), and after the soldering is completed, the jetting is stopped. 3. The automatic soldering apparatus according to claim 1, wherein a cooling unit is arranged near a carry-in entrance of the transfer mechanism unit to perform cooling after soldering. 4. The automatic soldering apparatus according to claim 1, wherein a processing apparatus employing a filter filtration method is used as a processing method for gas generated during soldering, and the processing apparatus is incorporated therein.