JPH071815Y2 - Circuit wiring board cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is attached to a device for heating a circuit wiring board in a soldering process or the like, and cools the circuit wiring board discharged from the heating device with a cooling liquid. Cooling device.

(Prior Art) As a method of applying solder onto a circuit wiring board, the circuit wiring board is dipped in a solder bath containing molten solder, and soldered to a copper pattern or a land or pad for mounting components, and then soldered. There is a method of pulling up from the tank. The solder applied here is an alloy of tin and lead, protects the copper pattern on the circuit wiring board, and solders and mounts the component to the land or pad that is the component mounting portion of the circuit wiring board. At this time, the solder paste and the connectivity are improved (solder wettability is improved).

Explaining the structure of the circuit wiring board, the circuit wiring board is generally made of a glass cloth (glass epoxy) impregnated with an epoxy resin, and a copper foil is attached to one or both sides of the board. The copper foil is etched to form a wiring pattern. A single-layer or two-layer wiring board having the above-mentioned structure or a multilayer wiring board in which a plurality of these single-layer or two-layer wiring boards are laminated with a prepreg (glass cloth impregnated and cured with epoxy resin) interposed therebetween is used. .

The glass transition temperature of the epoxy resin used for these glass epoxy and prepreg is 130 to 140 ° C., and in the solder coating step, it is heated to about 230 ° C. which is higher than this glass transition temperature.

Then, the circuit wiring board heated to the glass transition temperature or higher in this solder coating step is cooled next. On this occasion,
For example, as shown in FIG. 5, a long roller conveyor 12 is used to convey a circuit wiring board, and when the circuit wiring board 12 is contacted with air for a long time to cool, the tin in the solder is removed during this cooling time. The copper of the copper pattern diffuses with each other (a diffusion layer of about 1 μm is formed in 15 seconds), copper enters into the solder, and the solder wettability at the time of mounting components is impaired.

Therefore, as a method of cooling the circuit wiring board heated in the solder applying step, a method of immersing the circuit wiring board in a cooling liquid and rapidly and forcibly cooling with the cooling liquid is generally adopted. .

(Problems to be solved by the invention) However, when such a forced cooling method is adopted, the circuit wiring board is sequentially cooled from its end portion, so that the cooling portion and the cooling portion are cooled in the cooling process. There is a problem that a part that is not formed is generated, and warping, twisting, and distortion are likely to occur based on this temperature difference.

The present invention was made based on these problems,
Soldering suitability of parts is good, and moreover, it warps the circuit wiring board,
It is an object of the present invention to provide a cooling device that does not cause twisting or distortion.

(Means for Solving the Problems) That is, the present invention conveys a heated circuit wiring board,
A roller conveyor that can be temporarily stopped on the way, a cooling tank that is located below this roller conveyor and that stores the cooling liquid that cools the circuit wiring board, and the surface of the circuit wiring board at the stop position is the liquid surface of the cooling liquid. An elevating mechanism for moving the roller conveyor or the cooling tank up and down to a position where the upper surface of the circuit wiring board contacts the cooling liquid while maintaining the parallel relative positional relationship.

(Example) This invention is demonstrated in detail according to an Example.

(Embodiment 1) FIG. 1 and FIG. 2 are sectional views for explaining this embodiment.

That is, reference numeral 11 in the drawing denotes a solder coating device, and this solder coating device 11 is provided with a roller conveyor 12 for placing and discharging the circuit wiring board 16 coated with the solder. Following the conveyor 12, a roller conveyor 12a that conveys the circuit wiring board 16 is provided.

The roller conveyor 12a is provided with a movable portion 14, and the roller conveyor 12a is temporarily stopped while the circuit wiring board 16 is being conveyed, and the movable portion 14 is driven in this state to drive the roller conveyor 12a. It can be moved up and down.

Further, below the roller conveyor 12a, a cooling tank 15 containing a cooling liquid is provided, and when the movable portion 14 is driven to lower the roller conveyor 12a, the cooling tank 15 is placed on the roller conveyor 12a. The upper surface of the placed circuit wiring board 16 is configured to be immersed in the cooling liquid (see FIG. 2).

The movable portion 14 can move the roller conveyor 12a up and down while keeping the surface of the circuit wiring board 16 placed on the roller conveyor 12a and the liquid surface of the cooling liquid in parallel. Therefore, when the movable portion 14 is driven to lower the roller conveyor 12a, the entire surface of the circuit wiring board 16 simultaneously comes into contact with the cooling liquid and is rapidly cooled.

After the circuit wiring board 16 is sufficiently cooled, the movable portion 14 is
Can be driven again to raise the roller conveyor 12a, and the circuit wiring board 16 can be conveyed to the next roller conveyor 13.

(Embodiment 1) FIGS. 3 and 4 are sectional views for explaining the present embodiment.

In this embodiment, the solder applicator 11 is provided with a roller conveyor 12 that discharges the circuit wiring board 16 to which the solder has been applied, and the roller conveyor 12 is, as shown in FIG. The circuit wiring board 16 discharged from the coating device 11 is provided so as to be raised once and then lowered.

Further, a cooling tank 15 is provided below the lowered position, and the cooling tank 15 is configured to be vertically movable by an elevating mechanism attached below the cooling tank 15.

Then, the circuit wiring board 16 discharged from the solder coating device 11 is conveyed by the roller conveyor 15 and first rises and then descends, and when the circuit wiring board 16 reaches the descending portion 21, the roller conveyor 12 is temporarily stopped. To do.

Next, the elevating mechanism is driven to raise the cooling tank 15, and the circuit wiring board 16 is immersed in the cooling liquid.

The elevating mechanism is configured so that the cooling tank 15 can be moved up and down while keeping the surface of the circuit wiring board 16 placed on the roller conveyor 12 and the liquid surface of the cooling liquid in parallel. Therefore, when the elevating mechanism is driven to raise the cooling tank 15, the entire surface of the circuit wiring board 16 simultaneously comes into contact with the cooling liquid and is rapidly cooled.

After the circuit wiring board 16 is sufficiently cooled, the elevating mechanism can be driven again to lower the cooling tank 15, and the circuit wiring board 16 can be conveyed to the next roller conveyor 13.

According to the present invention, the heated circuit wiring board can be rapidly cooled, so that there is no diffusion between the solder and the copper and the entire surface can be cooled at the same speed, so that there is no temperature unevenness. There is an effect that it is possible to obtain a circuit wiring board free from warpage, twisting, distortion, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 4 are sectional views for explaining an embodiment of the present invention. FIG. 5 is an explanatory view showing a conventional example. 11 …… Solder applicator 12 …… Roller conveyor 13 …… Roller conveyor 14 …… Movable part 15 …… Cooling tank 16 …… Circuit wiring board 21 …… Descent part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Shibayama 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. Inspector Kazuko Okada

Claims (1)

[Scope of utility model registration request] 1. A roller conveyer which can convey a heated circuit wiring board and can be temporarily stopped on the way, and a cooling tank which is located below the roller conveyor and which contains a cooling liquid for cooling the circuit wiring board. An elevating mechanism that moves the roller conveyor or the cooling tank up and down to the position where the upper surface of the circuit wiring board comes into contact with the cooling liquid while maintaining the relative positional relationship in which the surface of the circuit wiring board at the stop position is parallel to the liquid surface of the cooling liquid. A cooling device for a circuit wiring board, comprising: