JPH06188554A - Lifting mechanism for printed board - Google Patents

Abstract

PURPOSE:To prevent downward warping of printed board by hunging a hunging member for a lifting metal after the tying part of the lifting metal is engaged with the engaging part of the printed board when the printed board is subjects to soldering. CONSTITUTION:When a lifting metal 2 lifting the central part of a printed board reaches the top end of a rail 3 that is fixed at a specified height, an engaging part 2d of the metal 2 is inserted into a groove part 3a of the rail 3. The metal 2 is a slided along the part 3a of the rail 3 accompanied with the conveyor movement in a state where it keeps lifting the board 11. At this moment, since the force applying on the metal 2 does not direct to the direction to remove the metal 2 from an engaging hole 11a of the board 11, the board 11 can be securely prevented thanks to the metal 2 from being warped downwardly in a vertical direction thereof due to the heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed board lifting mechanism used for dip soldering a printed board.

[0002]

2. Description of the Related Art For example, in dip soldering a printed circuit board, flux is applied to a substrate on which components are mounted and preheated to about 90 ° C. while being conveyed by a conveyor, and the lower surface of the substrate is melted to about 240 ° C. After immersing the solder in the solder for about 3 seconds, it is cooled. During that time, the printed board is heated from one surface and expands, so that the heated surface is deformed so as to be convex, and there is a moment when it reaches a temperature of about 180 ° C. for a short time.

The material of the printed circuit board is mainly composed of phenol resin, epoxy resin, etc., and its glass transition temperature is about 130 ° C. or lower, and when it is heated as described above, it suddenly softens, The printed circuit board is also warped downward due to the influence of gravity.

In this case, when the size of the component mounted on the printed circuit board is large, the printed circuit board warps downwards to form a mutual gap, which destroys the solder connection or cools while warped. If this happens, there is a risk that the printed circuit board will be subjected to an unreasonable force when it is attached to the device, and the printed circuit board will be destroyed.

[0005]

In order to avoid damage such as solder connection of the printed circuit board, conventionally, a rail-shaped lower receiving mechanism is provided below the substantially central portion of the width of the printed circuit board, or the printed circuit board is printed. The hooks hung from the rod placed on the board kept the printed board flat by lifting the printed board. However, the mechanism for receiving the lower part is complicated and hinders the work, and the upper hanging mechanism has to be attached by hand one by one, and the workability is poor.

Therefore, the present invention provides a printed board lifting mechanism capable of reliably preventing the warp of the printed board during soldering.

[0007]

In a printed circuit board hoisting mechanism for hoisting and holding a printed circuit board conveyed by a conveyor when soldering it, an engaging portion formed on the printed circuit board is engaged via a locking portion. The lifting metal fitting to be removed and the suspension member for suspending the lifting metal fitting are provided.

[0008]

When the printed circuit board is soldered, after the locking part of the lifting metal fitting is locked to the engaging part of the printed circuit board, the lifting metal fitting is suspended on the suspension member. As a result, the warp of the printed circuit board is surely prevented, and the printed circuit board is soldered while being kept flat.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 is a printed circuit board lifting mechanism. This printed circuit board lifting mechanism 1
A lifting metal fitting 2 which is engaged and disengaged with an engagement hole (engagement portion) 11a formed in a printed circuit board 11 conveyed by a conveyor 10 via a pair of front and rear leg portions (locking portions) 2b and 2c,
This lifting metal fitting 2 has an engaging portion 2d formed on the upper side thereof.
A rail (suspension member) 3 that is suspended via a pair of reinforcing members 4 and 4 that supports the front and rear edges of the printed circuit board 11 in the transport direction.

The lifting metal fitting 2 has a lifting metal fitting body 2a bent and formed in a substantially U shape. A substantially L-shaped, hook-shaped front leg portion 2b is integrally formed on the front bottom surface of the main body 2a by bending, and a T-shaped engaging portion 2d is integrally formed on the front upper surface thereof. The rear side of the main body 2a of the lifting metal fitting 2 has a single plate-like shape, and the rear leg portion 2c is formed at the rear lower side through a notch 2e.
Are integrally formed. Due to the notch 2e, the distance between the pair of front and rear leg portions 2b and 2c is elastically variable.

The rail 3 has a groove 3a having a T-shaped cross section. The engaging portion 2d of the lifting metal fitting 2 is inserted into the groove portion 3a of the rail 3 so as to be slidably suspended. The rail 3 is fixed to a conveyor main body (not shown) via a support mechanism (not shown), and is arranged in parallel between a pair of conveyors 10, 10 composed of a chain conveyor or the like along the transfer direction of the printed circuit board 11. . The pair of reinforcing members 4 and 4 are formed in the shape of a metal plate, and have a U-shaped holding piece 4a for holding the front and rear edges of the printed circuit board 11 and an upper edge of the holding piece 4a. The upright piece portions 4b are integrally formed so as to vertically project upward.

The printed circuit board 11 is fixed by the not-shown claws of the pair of conveyors 10 and 10 so as not to be displaced in the upper and lower positions. For example, the flux applying step → preheating step → dip soldering step. → It is designed to be transported with the cooling process. A rectangular engaging hole 11a is formed in the center of the printed board 11. The width of the engaging hole 11a is formed to be slightly wider than the pair of legs 2b and 2c of the lifting metal fitting 2 and is narrower than the width of the main body 2a of the lifting metal fitting 2. Further, the length of the engaging hole 11a is determined by the lifting metal fitting 2
Is formed slightly narrower than the distance between the outer surface of the body of the front leg 2b and the outer surface of the rear leg 2c, and the depth of the engaging hole 11a is the body of the front leg 2b. Is formed to have a length (excluding the hook portion at the tip). A component (not shown) to be dip-soldered is mounted on the printed circuit board 11, and the lead portion of the component projecting to the lower surface side of the printed circuit board 11 is soldered.

The printed circuit board lifting mechanism 1 of the above embodiment
When the printed circuit board 11 is conveyed to the cooling step by using, as shown in FIG. 2, first, the hook-shaped leg portion 2b on the lower front side of the lifting metal fitting 2 is set to the conveying direction side indicated by the arrow in the figure. The printed board 11 is inserted into the engaging hole 11a. Next, when the leg portion 2c on the lower rear side of the lifting metal fitting 2 is pushed into the engagement hole 11a of the printed circuit board 11, the lifting metal fitting 2
The leg portions 2b and 2c elastically repel each other, the front leg portion 2b is pressed against the peripheral edge portion of the engagement hole 11a, and the hook portion at the tip thereof is stable on the lower surface side of the printed circuit board 11. Can be hooked at. As a result, unless a force is applied to the engaging portion 2d on the upper front side of the lifting metal fitting 2 in the direction opposite to the conveying direction in which the lower rear leg portion 2c is lifted upward, the lifting metal fitting 2 is attached to the printed circuit board 11. Engagement hole 11a
It does not come off.

When the lifting metal fitting 2 which lifts the central portion of the printed circuit board 11 conveyed in such a state comes to the tip position of the rail 3 fixed at a predetermined height position, the engaging portion 2d of the lifting metal fitting 2 is formed. Is inserted in the groove portion 3a of the rail 3 and the lifting metal fitting 2 lifts the printed circuit board 11 by the movement of the pair of conveyors 10 and 10, for example, a flux applying step → a preheating step → a dip soldering step → a cooling step and a rail. 3 is slid along the groove 3a. At this time, the force applied to the lifting metal fitting 2 is not in the direction to disengage the lifting metal fitting 2 from the engaging hole 11a of the printed circuit board 11, so that the printed metal board 11 is heated by the lifting metal fitting 2 downward in the vertical direction (longitudinal direction) thereof. It is possible to reliably prevent the side from warping. As a result, the printed circuit board 11 is conveyed by the conveyor 10 while maintaining its flat state without warping. Further, the warp in the lateral direction of the printed circuit board 11 is reliably prevented by the pair of reinforcing members 4 and 4.

Since the lifting metal fitting 2 can be attached to the printed circuit board 11 together with other components by a component mounter, it does not take much time and a force is applied to the lifting metal fitting 2 in the direction opposite to the carrying direction. Just add it and it will fall naturally,
The lifting metal fitting 2 can be easily removed from the printed circuit board 11. As a result, the work of attaching the lifting metal fitting 2 can be automated by the component mounter, and can be easily removed. Further, the parts on the printed circuit board 11 where the components should not be arranged are only the parts of the lifting metal fitting 2 and the positions of the engaging holes 11a thereof are also free, so that there are almost no restrictions on the design of the printed circuit board 11. , Printed circuit board 1
There is a great merit that the 1 can be transported while being surely maintained in a flat state, and the soldering accuracy can be further improved.

In addition, according to the above-mentioned embodiment, the substantially central portion of the printed circuit board is hung up by one hoisting metal fitting, but in the printed circuit board which is longer in the longitudinal direction, the printed circuit board is hoisted by two or more hoisting metal fittings. The warp of the printed circuit board may be prevented. Further, the shape of the leg portion of the lifting metal fitting is not limited to the hook shape or the like, and the shape of the engaging portion of the lifting metal fitting is not limited to the T shape or the like. Further, the engaging portion formed on the printed circuit board is not limited to one rectangular engaging hole, but may be a pair of engaging holes or a circular engaging hole having a step or the like.

[0018]

As described above, according to the present invention, in the printed circuit board hoisting mechanism for hoisting and holding the printed circuit board conveyed by the conveyor during soldering,
Since the lifting metal fitting that is engaged with and disengaged from the engaging portion formed on the printed circuit board via the locking portion and the suspending member that suspends the lifting metal fitting are provided, The warp can be surely prevented, and the soldering accuracy can be further improved.

In addition, in front of the carrying direction of the lifting metal fitting,
Since a pair of locking parts are provided on the rear side and the front locking parts are formed in a substantially L-shaped hook shape, the lifting metal fitting can be easily attached to and detached from the printed circuit board, and Installation can be automated.

Further, since the pair of reinforcing members for supporting the front and rear edges of the printed circuit board in the conveying direction are provided, the warp of the front and rear edges of the printed circuit board can be surely prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of a printed board lifting mechanism showing an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the printed circuit board lifting mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printed-circuit board lifting mechanism 2 ... Lifting metal fittings 2b, 2c ... A pair of leg parts (a pair of locking parts) 3 ... Rails (suspending members) 4, 4 ... A pair of reinforcing members 10 ... Conveyor 11 ... Printed circuit board 11a ... Engagement hole (engagement part)

Claims (3)

[Claims] 1. A printed circuit board hoisting mechanism for hoisting and holding a printed circuit board conveyed by a conveyor during soldering, wherein hoisting is disengaged from an engaging portion formed on the printed circuit board via a locking portion. A printed circuit board lifting mechanism comprising a metal fitting and a suspension member for suspending the lifting metal fitting. 2. The printed circuit board lifting mechanism according to claim 1, wherein a pair of locking portions are provided on the front and rear sides of the lifting metal member in the conveying direction, and the locking portions on the front side have a substantially L-shaped hook shape. A printed circuit board lifting mechanism characterized by being formed. 3. The printed circuit board hoisting mechanism according to claim 1, further comprising a pair of reinforcing members for supporting front and rear edges of the printed circuit board in the conveying direction.