JPH0726050Y2 - Automatic soldering machine - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention mainly relates to a so-called solder reflow type automatic soldering machine which automatically performs soldering on a printed circuit board. Further, the present invention has made it possible to improve the form of heating for soldering to a printed circuit board, in particular, to allow the heat dissipation in the furnace by the stirring fan of the heater heat source to be performed extremely well without causing temperature unevenness. It is characterized by.

[Prior art]

The conventional automatic soldering machine of this type is configured to carry out a predetermined soldering process by transferring a printed circuit board into a so-called tunnel type furnace through a chain conveyor and bringing it into contact with molten solder. It was a thing. And, the tunnel furnace is of both-end open type,
The chain conveyor for transferring the printed circuit board has an endless shape, and although the forward path part for transferring the printed circuit board passes through the tunnel furnace, the return path part after the substrate transfer is completed,
It was constructed so as to perform a pivotal movement so as to return through the outside of the tunnel furnace.

[Problems to be solved by the device]

In the conventional automatic soldering machine as described above, both end faces of the tunnel furnace are kept open, air is freely flowing, and a chain that returns through the outside of the tunnel furnace is used. When the conveyor is returned, it is cooled by the outside air, and when it is introduced into the furnace again, there arises a problem of lowering the temperature inside the furnace, which inevitably causes uneven temperature inside the furnace and soldering. There was no choice but to cause a problem that the heating form for the product to be attached was inappropriate. Then, specifically, the conventional heating mode for the printed circuit board (temperature rising rate based on heating) is a curve shown by a dotted line in FIG. 7, that is, the heating is gradually performed and the maximum temperature at the time of soldering is The temperature curve is such that the rate of increase in heat is proportional to time. And, after the soldering, a natural heat drop occurs. However, in such a heating mode, the printed circuit board is exposed to a high temperature atmosphere for a long time, and therefore,
The printed circuit board on which electronic components such as ICs were set was inevitably accompanied by the problem that it would be damaged by the adverse effects of high heat. In other words, ideally, the curve as shown by the solid line in FIG. 7, that is, the printed circuit board is preheated to a certain temperature for soldering, and while maintaining the preheating temperature, It is desirable to draw a temperature curve such that the temperature rises instantaneously during the soldering work to complete the soldering process, and then the temperature drops promptly after the soldering process is completed. Made it extremely difficult to take such a temperature curve. The present invention is intended to eliminate the occurrence of temperature unevenness in a new automatic soldering machine which solves the above-mentioned conventional problems.

[Means for solving problems]

The present invention defines a first preparation heating chamber (1), a second preparation heating chamber (2), and a soldering main heating chamber (3) in a tunnel furnace (A), and each heating An automatic soldering machine configured to provide a heating heater and a stirring fan in each chamber to form independent temperature atmospheres, wherein each heating heater and the stirring fan portion are entirely covered with a grid-like surface or The present invention relates to an automatic soldering machine configured so as to be covered with a hot air diffusion cover body formed as a mesh surface. In addition, a refrigerant gas is circulated in a tubular body wound in a coil shape at required portions of the first preparation heating chamber (1), the second preparation heating chamber (2), and the soldering main heating chamber (3) described above. Based on this, it can be configured and implemented by providing a cooling pipe configured to exert a cooling action. Regarding the mounting location of the cooling pipe described above, specifically, the first cooling pipe (15) is provided in the adjacent portion between the first preparation heating chamber (1) and the second preparation heating chamber (2). 2 A second cooling pipe (16) is installed in the center of the preparatory heating chamber (2).
A third cooling pipe (17) is provided near the outlet in the preparation heating chamber (2), and a fourth cooling pipe (17) is provided adjacent to the second preparation heating chamber (2) and the main heating chamber for soldering (3). Pipe (18)
It is desirable to implement each. In addition, a cooling pipe is provided also in the outlet side airtight holding chamber (7) which is connected to the outlet part of the tunnel furnace (A) and is provided with a front door (8) and a rear door (9) which can be opened and closed respectively. Therefore, the product after the soldering process can be configured to be rapidly cooled.

[Action]

When using the automatic soldering machine shown in the drawings as an example, the inside of the tunnel furnace A is kept in a nitrogen gas atmosphere. Then, in the inlet side airtight holding chamber 4 continuously provided on the inlet side of the tunnel furnace A, the front door 5 is opened and the rear door 6 is closed. On the other hand, the outlet side airtight holding chamber 7 connected to the outlet side of the tunnel furnace A has its front door 8 opened and its rear door 9 closed. In the above state, the endless chain conveyor for carry-in
The soldering target product M (mainly a printed circuit board) carried in through 10 is received by the feeding endless chain conveyor 11 which is housed in the inlet side airtight holding chamber 4. Through the carry-in endless chain conveyor 10, the product M to be soldered is fed into the endless chain conveyor 11
After moving to the upper side, the front door 5 of the inlet side airtight holding chamber 4 is closed, the completion of the closing is waited, and the rear door 6 is opened this time, and the inlet side airtight holding chamber 4 and the tunnel furnace A are connected. To establish communication. As a result, the nitrogen gas filling the tunnel furnace A is blocked by the front door 5 of the inlet-side airtight holding chamber 4, and therefore,
The soldering target product M is housed in the tunnel furnace A.
It is achieved without leakage of nitrogen gas to the outside. In this state, the endless chain conveyor for feeding
Turn 11 to turn the soldering target product M into the tunnel furnace A
It is transferred onto the endless chain conveyor 12 for movement which is rotating inside. After the completion of the transfer, closing the rear door 6 and then opening the front door 5 prepares for the above-described feeding operation for a new soldering target product. On the other hand, the soldering target product M introduced into the tunnel furnace A
Will be moved in the furnace by the moving endless chain conveyor 12. Therefore, the product M to be soldered is the first
After being heated in the preparation heating chamber 1 and the second preparation heating chamber 2, it is introduced into the main heating chamber 3 and a predetermined soldering operation is performed. At this time, the first cooling pipe 15, the second cooling pipe 16, and the third cooling pipe 17, which are provided at required portions in the tunnel furnace A,
Based on each cooling action of the fourth cooling pipe 18, the temperature rise in the tunnel furnace A is suppressed, and the heating mode for the soldering target product M exhibits the temperature rise as shown by the solid line in FIG. Adjustments are made. That is, the main heating chamber 3
Therefore, before the rapid heating suitable for soldering is reached, by keeping a gentle temperature, the continuation of high temperature heating that adversely affects the soldering target product M itself is cut off. The stirring fans 1c, 2c, 3c provided in each heating chamber described above.
Of rotation, and by the hot air diffusion cover body 1d, 2d, 3d,
The heat uniformity is improved. In addition, the endless chain conveyor 12 for moving is the tunnel furnace A
The inside of the furnace is based on cooling of the conveyor, which occurs when the return path of the conveyor is configured to return through the outside of the tunnel furnace A, for example, because it is rotated while being accommodated in its entirety. Partial reduction of temperature or non-uniformity is prevented. After the soldering work is completed, the product is transferred to the takeout endless chain conveyor 13 housed in the outlet side airtight holding chamber 7 via the endless chain conveyor 12 for transfer. At this time,
The front door 8 of the outlet side airtight holding chamber 7 is opened, and the rear door 9 is closed. Then, after the product after the soldering work is completed is transferred to the takeout endless chain conveyor 13, the front door 8 is closed, and the rear door 9 is opened after waiting for the complete closing. As a result, the takeout endless chain conveyor 13
After the soldering work is completed, the product is transferred to the endless chain conveyor 14 for unloading, and then the rear door 9 is closed and the front door 8 is opened to fill the tunnel furnace A. The nitrogen gas is blocked by the front door 5 of the outlet side airtight holding chamber 7, and therefore the product removal from the tunnel furnace A is achieved without leaking the nitrogen gas filling the tunnel furnace A to the outside. Then, the fifth cooling pipe 19 provided in the outlet side airtight holding chamber 7 exerts a quenching action on the product after the soldering process, and eliminates the deterioration of the product due to the high temperature residual heat due to the soldering process. To do. Where, the above-mentioned carry-in endless chain conveyor 10, feed-in endless chain conveyor 11, moving endless chain conveyor 12, take-out endless chain conveyor 13,
Although each endless chain conveyor of the endless chain conveyor 14 for carry-out, since each of them is independent, it does not hinder the transfer of the soldering target product to each room as described above, and each room as described above. The airtight opening and closing by the door of the can not be hindered. And, the transfer of the soldering target product M by each of the above endless chain conveyors is as shown in FIG. 5 and FIG.
As shown in the figure, the opposing first and second endless chains a
And a soldering target product mounting projection c provided on the
And d and transfer. When the product M to be soldered is accidentally dropped during the transfer, it is received by the receiving pieces e and f provided on the first and second endless chains a and b and separated from the endless chain conveyor. Is prevented. Then, the existence of the holding pieces g and h provided on the receiving pieces e and f prevents the receiving pieces e and f from sliding down. Eventually, the soldering target product M is prevented from falling off the endless chain conveyor and leaving the endless chain conveyor in the room where the endless chain conveyor is housed.

【Example】

The structure of the present invention will be described in detail with reference to the embodiments shown in the drawings. In the drawing, A is a tunnel furnace, and inside thereof, a first preparation heating chamber 1, a second preparation heating chamber 2, and a soldering main heating chamber 3 are respectively defined. Then, in the first preparatory heating chamber 1, a first preparatory heating heater 1a, in the second preparative heating chamber 2, second preparatory heating heaters 2a and 2b, and a soldering book. Main heating heaters 3a are housed in the heating chambers 3, respectively. The inside of the first preparation heating chamber 1 and the inside of the second preparation heating chamber 2 are configured to be heated at about 140 ° C to 180 ° C, and in the main heating chamber 3, 200 ° C to 250 ° C. It is constructed so that the heating is carried out at about ° C. The tunnel furnace A forms the desired temperature rise (heating) with respect to the soldering target product M (mainly the printed circuit board) without being affected by other heating chambers by forming the heating chambers as described above. It is configured to be performed. Here, the tunnel furnace A described above is configured so that the inside thereof is constantly filled with nitrogen gas, and heating and soldering operations are performed in the nitrogen atmosphere. Although not shown in the drawings, a solder reflow type soldering mechanism is provided in the main soldering heating chamber 3. 1c is a stirring fan provided in the first preparation heating chamber 1, 2c is a second
An agitation fan 3c provided in the preparatory heating chamber 2 and an agitation fan 3c provided in the main heating chamber 3 for soldering are for uniformizing hot air in each chamber. Reference numeral 1d denotes a hot-air-dissipating cover body for covering the first preparatory heating heater 1a and the stirring fan 1c provided in the first preparatory heating chamber 1, and the hot air emitted by the first preparatory heating heater 1a. It is intended to stabilize the temperature of the. Reference numerals 2d and 2d denote hot air diffusion cover bodies for covering the second preparation heating heaters 2a and 2b and the stirring fan 2c provided in the second preparation heating chamber 1, and the second preparation heating heaters 2a and 2b. This is for the purpose of stabilizing the temperature of the hot air generated by. 3d is a heater for main heating provided in the main heating chamber 3 for soldering
A cover body for hot air diffusion for covering the 3a and the stirring fan 3c, for the purpose of stabilizing the temperature of the hot air generated by the main heating heater 3a. The hot air radiating cover bodies described above are configured so that the surface portion is a fine grid-like surface in the embodiment shown in the drawings. However, if the hot air sent by the stirring fan can be dissipated without uneven temperature,
For example, an appropriate shape such as a mesh shape is acceptable. It is desirable that each of the hot air diffusion cover bodies is formed of a material having a high thermal conductivity, for example, a metal material such as iron or stainless steel. Reference numeral 4 denotes an inlet-side airtight holding chamber that is connected to the inlet of the tunnel furnace A, and front and rear doors 5 and 6 are openably and closably provided on both front and rear surfaces thereof. Further, the front door 5 and the rear door 6 are configured to perform opening / closing operations opposite to each other such that when one is opened, the other is closed. Then, the inlet side airtight holding chamber 4 is configured to communicate with the inside of the tunnel furnace A by sequentially opening the respective doors. 5a is an air cylinder for controlling the opening and closing of the front door, and 6a is an air cylinder for controlling the opening and closing of the rear door. Reference numeral 7 denotes an outlet-side airtight holding chamber that is connected to the outlet of the tunnel furnace A, and front and rear doors 8 and 9 are openably and closably provided on both front and rear mouth surfaces thereof. Further, the front door 8 and the rear door 9 are configured to perform opening / closing operations opposite to each other such that when one is opened, the other is closed. The outlet-side airtight holding chamber 7 is configured to communicate with the inside of the tunnel furnace A by sequentially opening the doors. 8a is an air cylinder for controlling the opening and closing of the front door, and 9a is an air cylinder for controlling the opening and closing of the rear door. Reference numeral 10 denotes a carry-in endless chain conveyor provided adjacent to the entrance of the inlet-side airtight holding chamber 4 for carrying a soldering target into the entrance-side airtight holding chamber 4. Reference numeral 11 is an endless chain conveyor for feeding, which is accommodated in the inlet side airtight holding chamber 4, and is for feeding the product to be soldered into the tunnel furnace A. The conveyor 11 is entirely housed in the inlet side airtight holding chamber 4. Reference numeral 12 denotes an endless chain conveyor for transfer accommodated in the tunnel furnace A, which is for moving the soldering target product from the inlet side to the outlet side in the tunnel furnace A. The conveyor 12 is entirely housed in the tunnel furnace A. Reference numeral 13 is an endless chain conveyor for taking out, which is housed in the outlet side airtight holding chamber 7, and is for taking out the soldered product from the tunnel furnace A. The conveyor 13 is entirely housed in the outlet side airtight holding chamber 7. Reference numeral 14 denotes an unloading endless chain conveyor provided adjacent to the outlet of the outlet side airtight holding chamber 7 and for delivering the soldered product from the outlet side airtight holding chamber 7. Where, the above-mentioned carry-in endless chain conveyor 10, feed-in endless chain conveyor 11, moving endless chain conveyor 12, take-out endless chain conveyor 13,
The endless chain conveyor 14 for carrying out, each of these conveyors has the following configuration. a is a double endless first endless chain, and b is a double endless second endless chain, both chain
a and b are configured to perform parallel rotation in a state where they are symmetrically opposed to each other while keeping a predetermined interval (width of a product to be soldered). Reference numerals c and d denote soldering target product mounting projections projecting from the inner surfaces of the first endless chain a and the second endless chain b, respectively. It is for doing. Reference numerals e and f are receiving pieces attached to the inner side surfaces of the first endless chain a and the second endless chain b, respectively, so as to face each other.
If an unexpected drop from c or d occurs, catch it and
This is to prevent it from falling outside the conveyor. Reference numerals g and h denote falling product holding pieces that are raised near the base ends of the receiving pieces e and f. Among the above-mentioned conveyors, at least the feeding endless chain conveyor 11 and the moving endless chain conveyor 1
2. Conveyors housed in a closed chamber, such as the endless chain conveyor 13 for sending out, have the above-mentioned configuration. Reference numeral 15 is a first cooling pipe, which is also for causing a cooling action by causing a refrigerant gas such as CFC to circulate in the tubular body wound in a coil shape. And the said 1st cooling pipe 15 is in the transfer path of the endless chain conveyor 12 for movement accommodated in the tunnel furnace A,
It is provided in a portion adjacent to the first preparation heating chamber 1 and the second preparation heating chamber 2. That is, the first cooling pipe 15 is
The moving endless chain conveyor 12 is provided so as to wind at the above position. Reference numeral 16 is a second cooling pipe having the same form as the first cooling pipe 15 described above, and is provided in the central portion of the second preheating chamber 2. Reference numeral 17 is a third cooling pipe having the same configuration as the first cooling pipe 15 described above, and is provided in a portion of the second preheating chamber 2 near the outlet. Reference numeral 18 denotes a fourth cooling pipe having the same form as the first cooling pipe 15 described above, and is provided in a portion adjacent to the second preparatory heating chamber 2 and the main soldering heating chamber 3. Each of the cooling pipes 15, 16, 17, 18 described above has a temperature that prevents the products to be soldered sent through the conveyor from becoming highly heated before reaching the main heating chamber 3 for soldering. This is for increasing the temperature, that is, for increasing the temperature as shown in FIG. The temperature of each cooling pipe is usually 5 ° C to 10 ° C.
Although it is a degree, this is for controlling the temperature rise of the product to be soldered as described above, and therefore is appropriately adjusted depending on the size and mass of the product to be soldered. Reference numeral 19 is a fifth cooling pipe having the same configuration as the first cooling pipe 15 described above, and is provided in the outlet side airtight holding chamber 7. Then, the fifth cooling pipe 19 has a function of quenching the product after the soldering process, and eliminates the deterioration of the product due to the high temperature residual heat due to the soldering process.

[Effect of device]

The present invention defines a first preparation heating chamber 1, a second preparation heating chamber 2, and a soldering main heating chamber 3 in a tunnel furnace A, and each heating chamber has a heater for heating. An automatic soldering machine configured to form an independent temperature atmosphere by providing a stirring fan, wherein each heating heater and the entire stirring fan portion have a lattice-like surface or a mesh-like surface for hot air dissipation. Because it was configured to cover with a cover body,
The hot air radiated into the furnace by the stirring fan causes no temperature unevenness. This is because the hot air sent through each of the agitation fans is a hot air in which a linear flow is gathered by the hot air diffusion cover body, and therefore, the temperature unevenness when sent by the agitation fan is the hot air. This is because it is completely eliminated by passing through the diffusion cover body. Further, the present invention is to allow a refrigerant gas to flow in a tubular body wound in a coil shape at required portions of the first preparation heating chamber 1, the second preparation heating chamber 2, and the soldering main heating chamber 3 described above. Based on the configuration of providing a cooling pipe configured to perform a cooling action based on the above, soldering to a product that is weak to heat, such as a printed circuit board on which electronic components such as IC are set, can be extremely well performed. Will be made. That is, in the conventional automatic soldering machine, the heating mode for the product to be soldered (temperature rise rate based on heating)
Shows a curve shown by a dotted line in FIG. 7, that is, a temperature curve in which the temperature rises gradually and reaches the maximum temperature at the time of soldering, in other words, a temperature curve in which the rate of heat rise is proportional to time. Met. Therefore, if the product to be soldered is a printed circuit board on which electronic components such as ICs are set, it will be exposed to a high temperature atmosphere for a long time (dotted line curve 2 in FIG. 7). It was inevitably accompanied by problems such as the failure of being affected by the high heat. On the other hand, according to the present invention, the heating portion of the second preparatory heating chamber 2 is the solid curve of the portion 2 shown in FIG.
Specifically, the printed board is preliminarily heated to a certain temperature for soldering, and based on the cooling action of the cooling pipe 15, the preparatory heating temperature is maintained and momentarily during the soldering work. As described above, the high temperature atmosphere is completed and the soldering process is completed, and the high temperature atmosphere can be set for only a short time during the soldering work. Therefore, the above problems in the conventional art are completely eliminated. It Then, in order to take such a temperature form, it can be called an absolute condition to completely eliminate the occurrence of the temperature unevenness, but the action and effect based on the configuration of the above-mentioned claim 1 is exactly This is the case. In the case where the present invention is configured as described in claim 4, that is, when the cooling pipe is provided in the outlet side airtight holding chamber (7) connected so that the outlet part of the tunnel furnace (A) can communicate with each other. A rapid cooling effect is exerted on the product after the soldering process, so that the problem of defective product due to high temperature residual heat due to the soldering process is completely eliminated.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a vertical sectional front view of the present invention, FIG.
The same figure shows a vertical side view, FIG. 4 is a perspective view of a cover for hot air diffusion, FIG. 5 is a plan view showing the main part of an endless chain conveyor, and FIG. 6 is an enlarged view taken along line XX in FIG. A cross-sectional view and FIG. 7 are temperature graphs showing the heating state of products by a tunnel furnace. A ... Tunnel furnace 1 ... 1st preparation heating chamber, 1a ... Heating heater 1c ... Stirring fan 1d ... Hot air diffusion cover body 2 ... Second preparation heating chamber 2a, 2b ... Heating heater, 2c …… Stirring fan 2d …… Hot air diffusion cover 3 …… Soldering main heating chamber 3a …… Main heating heater, 3c …… Stirring fan 3d …… Hot air diffusion cover 4 …… Inlet side airtightness Room, 5 front door 5a, front door opening / closing air cylinder 6, rear door 6a, front door opening / closing air cylinder, 7 outlet airtight holding chamber, 8 front door 8a, front Door opening / closing control air cylinder 9 …… Rear door 9a …… Rear door opening / closing control air cylinder 10 …… For loading Endless chain conveyor 11 …… For feeding in Endless chain conveyor 12 …… For moving Endless chain conveyor 13 …… For taking out Endless chain conveyor 14 …… Endless chain for unloading Chain conveyor 15 …… First cooling pipe 16 …… Second cooling pipe 17 …… Third cooling pipe 18 …… Fourth cooling pipe 19 …… Fifth cooling pipe a …… First endless chain b …… Second endless chain c, d …… Product mounting protrusion e, f …… Receiving piece g, h …… Falling product holding piece

Claims (4)

[Scope of utility model registration request] 1. A tunnel furnace (A) is provided with a first preparation heating chamber (1), a second preparation heating chamber (2), and a soldering main heating chamber (3), and An automatic soldering machine configured to provide a heating heater and a stirring fan in each heating chamber to form an independent temperature atmosphere. The heating heater and the stirring fan are entirely covered by a grid-like surface. Alternatively, an automatic soldering machine configured so as to be covered with a hot air diffusion cover body having a mesh surface. 2. Refrigerant gas in a tubular body wound in a coil at required places of the first preparation heating chamber (1), the second preparation heating chamber (2), and the main heating chamber for soldering (3). 2. A cooling pipe is provided so as to exert a cooling action based on the circulation of water.
Automatic soldering machine described in. 3. A first cooling pipe (15) is provided at a portion adjacent to the first preparation heating chamber (1) and the second preparation heating chamber (2).
In the central part of the preparation heating chamber (2), the second cooling pipe (1
6) is placed in the second preparatory heating chamber (2) at the portion near the outlet
The cooling pipe (17), further comprising a fourth cooling pipe (18) provided adjacent to the second preparation heating chamber (2) and the main soldering heating chamber (3), respectively. The automatic soldering machine according to claim 2. 4. An inlet side airtight holding chamber (4), which is provided with a front door (5) and a rear door (6) which can be opened and closed, is connected to the entrance portion of the tunnel furnace (A) so that they can communicate with each other. At the same time, an outlet side airtight holding chamber (7), which is provided with a front door (8) and a rear door (9) which can be opened and closed, is connected to the exit portion of the tunnel furnace (A) so that they can communicate with each other. The automatic soldering machine according to claim 1, wherein a cooling pipe is provided in the outlet side airtight holding chamber (7).