JPS63192556A - Vapor type soldering device - Google Patents

Abstract

PURPOSE:To precisely control a soldering temp. and preheating by controlling the vertical velocity of a rail and its stoppage optionally so that a base plate on rail vertically moving between the upper part opening and lower part of a vapor tank may receive a preheating and the main heat in soldering. CONSTITUTION:A carry-in conveyor 13 carrying in a base plate is arranged on one part of the opening part of a vapor tank 11. A carry-out conveyor 14 is arranged on the other part of the opening part so as to extend the carry-in conveyor 13. The rail 13 capable of connecting the carry-in and out conveyors 13, 14 is arranged and fitted freely movably vertically to the columns 17a, 17b provided in the vertical direction of the vapor tank 11. The rail 15, therefore, moves vertically between the opening part of the vapor tank and the liquid 12 of the bottom part. The vertically driving device 18 vertically driving the rail 15 descends the rail 15 as well simultaneously with driving a belt 18a in an arrow mark direction, and is driven by the controller 19 set by a program and capable of freely setting the vertical motion velocity, stopping position, number of stoppages, etc., of the rail 15.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention is a method of arranging components on a printed circuit board via a solder component, and fixing the components by melting the solder component in a heated atmosphere. The soldering that can be obtained is related to the equipment, especially the part that creates the heating atmosphere, and the performance of the system control and soldering has been improved.

(Prior Art) Various methods have been developed for soldering electronic components to printed circuit boards. In this process, electronic components are placed in advance at predetermined positions on the printed circuit board, paste solder is sandwiched between the electrodes of the electronic components and the pattern of the printed circuit board, and solder is temporarily attached. A device has been developed that fixes components by melting paste solder by passing it through a board. This soldering device is a special public Sho 5B-4093
No. 4, Japanese Patent Publication No. 54-14066, etc.

In conventional top soldering, the part that creates the heating atmosphere of the device consists of a steam tank. When soldering is performed, a method is used in which the printed circuit board with electronic components is placed on a continuous belt conveyor that descends in an arc from above and moves through the steam tank. has been done.

(Problems to be Solved by the Invention) Conventional steam soldering equipment has the performance and workability to accurately solder electronic components to various printed circuit boards with different heat capacities such as thickness and size. is inferior. In other words, when a printed circuit board with a small thermal capacity is to be soldered, the conveyance speed of the continuous belt conveyor must be increased.Also, when a printed circuit board with a large thermal capacity is to be soldered, The speed of the continuous belt conveyor must be slowed down.In this way, in conventional steam soldering equipment, the size of the steam tank is fixed and the path of the printed circuit board passing through it is also fixed, so the soldering It is inconvenient to set various temperature conditions and lacks flexibility.

Therefore, the present invention aims to provide a steam-type soldering device that can freely set the soldering temperature and preheat even if various types of printed circuit boards are to be soldered, and that can be realized in a small size. purpose.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a rail that can move up and down between the two-part opening of a steam tank and the lower part of the tank, and allows substrates to be moved through this rail. It is used as an intermediary between the carry-in belt conveyor and the substrate carry-out belt conveyor.

And, for a vertical drive device that drives the rail -I- downward, it is necessary to drive the rail up and down.
The vertical drive device is configured such that the downward movement speed and stop can be arbitrarily controlled, and the printed circuit board on the rail can receive the main heat for preheating and soldering caused by the difference in steam density inside the steam tank device. A speed control device is provided.

(Function) With the above means, by controlling the vertical drive device in a narrow steam tank using a control program, it is possible to create various temperature setting conditions such as preheating and main heating according to the heat capacity of the printed circuit board. .

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and 1] is a steam tank having an opening formed at the top and a liquid 12 for generating steam stored at the bottom. - A carry-in belt conveyor 13 for carrying in printed circuit boards is arranged horizontally in one of the openings of the steam tank 11 in the horizontal direction. Further, in the other horizontal direction of the opening, an output belt conveyor 1 is provided so as to extend the input belt conveyor 13.
4 are arranged.

Furthermore, a rail 15 that continuously connects the carry-in belt conveyor 13 and the carry-out belt conveyor 14 is horizontally arranged on a horizontal plane that is substantially the same as the opening. This rail 1
5 consists of left and right guide portions 15a, 5b, as shown in FIG. The guide members 15a1] and 5b have guide grooves in opposing parts thereof, and can guide the printed circuit board by locking the edge of the printed circuit board in the guide groove. The guide members 15a, 15b are further supported by a support device 16 to maintain their parallel state. The support device 16 has a parallelogram-shaped support part together with the guide member 15a115b, and the steam tank 1
Supports 17a, 1 provided vertically along the vertical direction of 1
7b so that it can move up and down. Therefore, the rail 15 can move up and down between the opening of the steam tank 11 and near the liquid 12 at the bottom.

As mentioned above, the means for controlling the vertical movement of the rail 15 is
A vertical drive device 18 is connected to the support device 16. The vertical drive device 18 is provided on the back wall of the device, and is configured, for example, by a belt drive system. Belt 1
When 8a is driven in the direction of the illustrated arrow, the support device 16 descends, and at the same time the rail 15 also descends. The pulley 18b of the vertical drive device 18 is driven by a control device 19 set by a program, and is driven by a control device 19 set by a program.
You can freely set the vertical movement speed, stop position, number of stops, etc.

As mentioned above, the rail 15 is driven up and down, but the steam W! When it is at the opening position of Ill, it receives the printed circuit board sent from the carry-in belt conveyor 13,
Further, the printed circuit board supported by itself can be delivered to the delivery belt conveyor 14.

As described above, the printed circuit board is carried in by the carry-in belt conveyor 13, then subjected to preliminary heating and main heating inside the tank 11 at the rail 15 section, and then to the carry-out belt conveyor 1.
Sent at 4. Here, the printed circuit board is subjected to a cleaning process on the way to the carry-in belt conveyor 13, and is also preheated to avoid warping or the like when the substrate is rapidly heated. As for the cleaning process,
The cleaning device 10A sprays liquid in the form of a mist using a fan, for example, and preheating is performed by the preheating device 10B. This heating is effective when the substrate is thick. Further, the soldered printed circuit board is subjected to cooling and cleaning processing by the cooling and cleaning device 10C midway through the delivery belt conveyor 14.

As mentioned above, the printed circuit board is soldered in the steam tank 11, and an example of the processing process will be explained with reference to FIG. 4. First, as shown in FIG. 5(b), when the printed circuit board 1a carried in is at the position P1 of the opening of the steam tank, the printed circuit board 1a receives primary heat for a certain period of time, and
When it reaches about 0°C, it is lowered at an arbitrary speed. Then, for example, it is stopped at an intermediate position P2 for an arbitrary period of time, and 130
Receives secondary preheating of about 6C. Thereafter, it is further lowered and reaches the bottom dead center position P3, where it receives main heat of about 250°C and is stopped for an arbitrary period of time. During this time, the paste solder 1b between the electrodes of the electronic component 1c and the pattern of the printed circuit board 1a is melted, and soldering is performed, as shown in FIG. 4(c). After this arbitrary period of time has elapsed, the printed circuit board is lifted up and delivered to the delivery belt conveyor 14. The relationship between temperature change of the substrate and time is as shown in FIG.

As mentioned above, this device effectively utilizes the fact that when the liquid 12 is heated to generate steam, this steam has a density difference in the downward direction, and the heating effect differs depending on the upper and lower positions. This allows for a preheating process. Moreover, since the preheating temperature can be arbitrarily changed in the stopping position and stopping time of the substrate, it can be freely handled even if the thickness of the substrate is different.

Here, in this apparatus, heat is applied to the printed circuit board by controlling the rail 15 up and down. When processing in this manner, it is preferable that the rail 15 is one that can accurately apply heat to the printed circuit board and that does not easily affect the temperature distribution inside the steam tank 11. In order to reduce the effect that vertical movement of the rail 15 has on temperature distribution, the structure of the rail 15 and its support means should be designed as much as possible.
9- It is better to use a simple material with good heat transfer properties. Therefore, in this device, the material of the rail 15 is
For example, aluminum is used.

Furthermore, the configuration around the rail 15 is simplified as much as possible.

The configuration around the rail 15 will be further described with reference to FIG. The printed circuit board PCI sent from the carry-in belt conveyor 13 is sent to the position of the printed circuit board PC2 by the feeding claw 20a of the feeding device 20. The feed pawl 20a has a U-shape as shown in FIG.
Push the rear part of the CI in the feeding direction, and use the front claw to push the rear part of the printed circuit board PC2 on the rail 15 toward the carry-out belt conveyor 14 side. As a result, the printed circuit board on the rail is moved to the PCB position, and the printed circuit board on the carry-in belt conveyor 13 is moved to the PC2 position. When the feed pawl 20 moves to the illustrated position Sl, it is raised by the pawl control device 20b to a position where it does not engage the board, and is moved as indicated by arrows a1 and a2.
, a3 and waits for the next substrate feeding.

Next, a guide width adjustment mechanism is provided for the conveyance device composed of the above-mentioned carry-in belt conveyor 13, rail 15, and carry-out belt conveyor 14, so that the mechanism can accommodate the conveyance of printed circuit boards of various widths. ing. In FIG. 2, reference numerals 21 and 22 are motors that operate synchronously, and this motor 21 can rotate the bolt 21a forward or reverse.

The carry-in belt conveyor 13 has left and right parallel guide sections 131.
It has 132. The bolt 21 a passes through a holding rail 13 a that constitutes the guide section 131 and is supported by a holding rail 13 b that constitutes the guide section 132 . Similarly, the motor 22 can rotate the bolt 22a forward or reverse. The input belt conveyor 14 has left and right parallel guide sections 141 and 142. The bolt 22a is attached to the guide portion 14
The guide portion 142 passes through the holding rail 14a that constitutes the
It is bearingly supported by a holding rail 14b that constitutes the main body.

Therefore, by controlling the rotation of the motors 21 and 22,
The holding rail 13a1 of the carrying-in belt conveyor 13 and the holding rail 14a of the carrying-in belt conveyor 14 are indicated by arrows a4 or a.
It can be adjusted in five directions, and the guide width W of the printed circuit board can be set arbitrarily.

When the guide width W is varied in this way, the interval between the guide members 15a and 1.5b of the rail 15 is also adjusted to follow the holding rail 13a.

In order to cause the holding rail 13a and the guide member 15 to follow each other in the width direction, a means as shown in FIG. 3, for example, is used.

First, the specific structure of the carry-in belt conveyor 13 will be explained. This carry-in belt conveyor 13 consists of left and right guide parts 131 and 132, and since they are symmetrical, please refer to FIGS. 2 and 3. The configuration of the guide section 131 will be explained as a representative example.

The guide section 131 consists of a holding rail 13a having a U-shaped cross section, a belt 13d1 provided along the longitudinal direction inside the holding rail 13a, and a pulley 13b113c that drives the belt 13d. Pulley 13b, 1
Although not shown, 3c is driven by a motor that is controlled for conveying the substrate, and this motor is controlled by a system control device using a microcomputer. On the upper surface of the belt 13d, the rail 15 is connected to the steam tank 11.
is designed to be flush with the lower surface of the groove of the rail 15 when it is in the opening of the rail 15.

Here, the bolt 21a passes orthogonally through the side wall of the holding rail 13a. In this case, the penetration position of the bolt 21a is selected to be a position that does not hinder the conveyance of the printed circuit board. When the bolt 21a is rotated, the entire guide portion 131 is driven in the direction of the arrow a4 or a5 shown in the figure. At this time, since the guide member 15a is connected to the holding rail 13a by the connecting member 30, the guide member 15a also follows and is driven in the direction of arrow a4 or a5 in the figure.

The connecting member 30 is thus required to cause the guide member 15a to follow the holding rail 13a and to disguise the movement of the rail 15 when it is lowered. For this purpose, the guide member 1 has the shape shown in FIG. 3, for example.
The shape is such that it is released for vertical movement of 5a and locked for horizontal movement. That is, the shape when viewed from above is H-shaped, and one end of the guide member 15a can be engaged with one of the recesses. Further, one end of the holding rail 13a is engaged with and fixed to the other four parts of the connecting member 30.

Thereby, the function of releasing the guide member 15a when it moves downward and locking it when it moves in the horizontal direction is achieved. In the explanation of FIGS. 2 and 3, only the means for connecting the guide member 15a and the holding rail 13a have been explained, but the holding rail],
3b and the guide member 15b are also connected by a similar connecting member 3], and the vertical movement of the guide member 15b is released.

According to this device, the configuration around the rail 15 that moves up and down inside the steam tank 11 is made as simple as possible. In other words, even when changing the interval between the guide members 15a and 15b of the rail 15 according to the width of the printed circuit board, the rail 15 itself does not need to be equipped with a motor for width adjustment, and the means for connecting it to the carrying-in pelt conveyor 713 is devised. By doing so, the heat capacity around the rail 15 is suppressed as much as possible. This can eliminate disturbances in the temperature distribution inside the steam tank 11 and contribute to accurate and good solder finish.

[Effects of the Invention] As explained above, the present invention allows soldering to be performed in various types of printed circuit boards or soldering, and allows for precise setting of temperature and preheating, and can be realized in a small size. Steam soldering can provide the device.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention, FIG. 2 is a configuration explanatory diagram showing a part of the conveying device shown in FIG. 1,
FIG. 3 is a perspective view showing some parts of the conveying device and their operations, and FIG. 4 is an explanatory view showing an example of the operation of the device of the present invention. 11... Steam oak, 12... Liquid, 13... Carrying in belt conveyor, 14... Carrying out belt conveyor, 15...
...Re part, 15a, 15b...Guide member, 16.
... Support device, 17a, 17b... Support column, 18...
Vertical drive device, 19...control device, 20...feeding device, 20a...feeding claw, 20b... claw control device, 2
1.22...Motor, 30.31...Connection part shrine.

Claims (1)

[Claims] A steam tank device that stores a liquid at the bottom and heats the liquid to generate steam that reaches near the top opening, and a printed circuit board to be soldered to the opening of the steam tank device horizontally and with a slight inclination. a carry-in belt conveyor for carrying in the printed circuit board, and a rail supported horizontally and slightly inclined at the position of the opening, for receiving the printed circuit board from the carry-in belt conveyor horizontally and slightly inclined; A vertical drive device that supports this rail and can move it up and down between the opening of the steam tank and its lower part, and a printed circuit board on the rail with the rail located in the opening. and an unloading belt conveyor for receiving and unloading horizontally, and the vertical drive device drives the rail up and down, and can arbitrarily control the vertical movement speed and stop of the rail. A steam type soldering device, characterized in that the vertical drive device is provided with a speed control device so that main heat for preheating and soldering can be received inside the tank device.