JP4727793B2 - Treatment liquid supply method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the supply of processing liquid to the surface of a flat plate material such as a wiring board. More specifically, when there is a concave area surrounded by convex objects such as solder resist on the surface of the flat plate material, the processing liquid is supplied well to the bottom of the area. The present invention relates to a processing liquid supply method that can be performed.
[0002]
[Prior art]
Conventionally, a pad area for solder connection with a mounted component is provided on the surface of the wiring board. Here, since the soldering is not always performed immediately after the formation of the pad area, it is necessary to apply a rust prevention treatment to the pad area. This is because if the pad area is rusted, the solderability is poor. Therefore, the wiring board is dipped in a rust preventive solution such as a chelating agent solution. In this way, rust prevention treatment is applied to the pad area, and efforts are made to prevent the pad area from being rusted until the soldering process is performed.
[0003]
[Problems to be solved by the invention]
However, the conventional techniques described above have the following problems. In other words, the wiring board cannot be dipped into the antirust treatment liquid immediately after the pad area is formed. Before that, a solder resist must be formed. This is because the adhesion of the solder resist is poor after the application of the antirust treatment liquid. When the solder resist is formed, the pad region is surrounded by the surrounding solder resist and becomes the bottom of the concave portion. For this reason, even if the wiring board is dipped in the antirust treatment liquid, it is difficult for the antirust treatment liquid to contact the core pad area. Therefore, as a result, rust is also generated and soldering failure tends to be caused.
[0004]
The present invention has been made to solve the above-described conventional problems. In other words, the problem is that the processing liquid can be supplied satisfactorily to a region surrounded by a convex object and having a concave shape, such as a pad region surrounded by a solder resist. The object is to provide a liquid supply method.
[0005]
[Means for Solving the Problems]
The present invention, which has been made for the purpose of solving this problem, is a method of supplying a treatment liquid to a region surrounded by a convex object on the surface of a flat plate, and is capable of rotating about an axis and a shaft. The position of the plate is movable in the vertical direction, and at least a part of the surface of the roll formed of an elastic body is brought into contact with the treatment liquid, and the surface with the plate material region is brought into contact with the surface of the roll from below. A process liquid supply method in which the flat plate is advanced in the in-plane direction, the roll is lifted by the flat plate by the thickness of the flat plate, and the process liquid is brought into contact with the area of the flat plate by the surface of the rotating roll. is there. The roll pair is preferably formed of an elastic body. This is to prevent excessive damage to the convex object.
[0006]
According to this method, a rotatable roll in which at least a part of the surface is in contact with the treatment liquid is used. And a roll is rotated by making a flat plate material contact a roll and making a flat plate material advance in an in-plane direction. Then, the processing liquid is rubbed into the surface of the flat plate material by the surface of the rotating roll. For this reason, the processing liquid is satisfactorily supplied to the region on the surface of the flat plate.
[0007]
The treatment liquid supply method of the present invention is particularly significant when the area on the surface of the flat plate is a conductor area on the surface of the wiring board and is surrounded by a convex object. In general, it is not so easy to supply the processing liquid to such an area well, but the processing liquid can be supplied to such an area by using the processing liquid supply method of the present invention. is there. That is, the processing liquid carried on the surface of the roll is pushed into the area as the roll rotates and spreads all the way to the bottom.
[0008]
A representative example of the treatment liquid is an aqueous solution of an organic chelating agent for forming a rust preventive film in the conductor pad region. This is because when this processing liquid is supplied to the conductor pad area on the surface of the wiring board, the area is surrounded by the solder resist formed around the area and becomes the bottom of the concave portion .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. In the present embodiment, the present invention is applied to a process of applying a rust prevention treatment to a copper pad region after the formation of a solder resist with an organic chelate type rust prevention treatment liquid in the production of a wiring board.
[0010]
The target product in this embodiment is a wiring board formed by laminating a conductor layer and an insulating layer, in which the uppermost copper layer is patterned and a solder resist is further formed thereon. Is. As shown in the plan view of FIG. 1, the uppermost copper layer is provided with a pad 11 for solder connection with a mounting component such as an IC chip as a part of the pattern 10. The region other than the pad 11 is covered with the solder resist 12. This is to protect from molten solder during soldering. The area of the pad 11 is surrounded by a solder resist 12 on all sides. The planar dimension of the pad 11 is about 1 mm ² . A cross-sectional view of this state is shown in FIG. As shown in FIG. 2, the solder resist 12 is raised from the surface of the pad 11. The gap is about 10 to 20 μm. That is, the region of the pad 11 is the bottom surface of the concave portion surrounded on all sides by the raised solder resist 12.
[0011]
In the present embodiment, the product is subjected to rust prevention treatment as shown in FIG. That is, a part of the container for storing the rust preventive liquid 4 is composed of a roll pair including the roll 2 and the roll 3. The nip portion of this roll pair is the entrance of the product 1. Both the roll 2 and the roll 3 are cylindrical members having a diameter of about 5 cm formed of a resin material having a certain degree of elasticity such as ethylene propylene rubber. Both of these do not have a rotational drive source, but are provided so as to be rotatable about an axis. The position of the rotating shaft of the lower roll 3 is fixed. On the other hand, as shown in FIG. 4, for the upper roll 2, the bearing hole 23 of the rotating shaft 21 is a long hole that is long in the vertical direction. Its length is longer than the thickness of the product 1. Thereby, the roll 2 can move up and down. The antirust treatment liquid 4 is an aqueous solution of an organic chelating agent.
[0012]
Therefore, the product 1 is pushed into the nip portions of the roll pairs 2 and 3. When the product 1 has the pad 11 on only one side, the surface with the pad 11 should be upward. Then, the upper roll 2 is lifted by the thickness of the product 1, and the product 1 enters the antirust treatment liquid 4 through the gap formed between the roll pairs 2 and 3. The rolls 2 and 3 are driven to rotate as the product 1 advances. Note that a load corresponding to the weight of the roll 2 is applied to the product 1 passing between the roll pairs 2 and 3. However, since the rolls 2 and 3 are made of an elastic material, the solder resist 12 and the like are not damaged by this load. And the product 1 will be immersed in the antirust treatment liquid 4 by passing between the roll pairs 2 and 3. Further, when the product 1 passes between the roll pairs 2 and 3, the rust prevention liquid 4 slightly flows out from both sides of the product 1 between the roll pairs 2 and 3. However, for this, it is possible to provide a separate mechanism for catching the rust prevention liquid 4 that has flowed out and returning it to the container.
[0013]
Here, when the product 1 passes between the roll pairs 2 and 3, the rolls 2 and 3 come into contact with the product 1. For this reason, the antirust treatment liquid 4 is pushed into the pad 11 which is a recessed area on the surface of the product 1 by the surfaces of the rolls 2 and 3. Further, since both rolls 2 and 3 are immersed in the antirust treatment liquid 4 at the right side in FIG. 3, it is considered that a small amount of the antirust treatment liquid 4 is carried on the surface when rotating. And when contacting the surface of the product 1, it is thought that there exists an effect which pushes the carrying | support rust prevention liquid 4 to the pad 11. FIG. Further, it is considered that there is an effect that air is expelled from the recessed portion by contact with the surfaces of the rolls 2 and 3. For this reason, the rust prevention liquid 4 is satisfactorily supplied to the pad 11. In this way, the surface of the pad 11 and the rust preventive liquid 4 are reliably in contact. Thereby, on the surface of the pad 11, a chelate complex layer in which chelating agent molecules are chelate-bonded to copper atoms is formed all over. Therefore, the pad 11 is held without rusting until the soldering process is performed, and the soldering is performed well.
[0014]
As described in detail above, in the present embodiment, the roll pair 2 and 3 are provided in the container of the antirust treatment liquid 4, and the product 1 enters the antirust treatment liquid 4 through the gap between the roll pair 2 and 3. I am going to do that. Thus, there is a processing liquid supply method that can reliably supply the antirust treatment liquid 4 to the pad 11 that is the bottom surface of the concave region of the surface of the product 1 and can form an antirust treatment layer on the surface of the pad 11. It has been realized. Thus, the pad 11 of the product 1 can be held without being rusted until the soldering process is performed. Further, the rolls 2 and 3 are made of an elastic material to prevent damage to the solder resist 12 and the like.
[0015]
Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, in the present embodiment, the roll pairs 2 and 3 are provided at the entrance to the rust preventive liquid 4, but may be in the liquid or at the exit. Of course, you may provide in two or more places among an entrance, a liquid, and an exit.
[0016]
【The invention's effect】
As is apparent from the above description, according to the present invention, the treatment liquid can be satisfactorily applied to a region surrounded by a convex object and having a concave shape, such as a pad region surrounded by a solder resist. A treatment liquid supply method that can be supplied is provided.
[Brief description of the drawings]
FIG. 1 is a plan view of a wiring board to which the present invention is applied.
FIG. 2 is a cross-sectional view of a wiring board to which the present invention is applied.
FIG. 3 is a view showing a pair of rolls at the entrance to an antirust treatment liquid.
FIG. 4 is an explanatory view showing vertical movement of a roll shaft.
[Explanation of symbols]
2, 3 Roll 4 Antirust treatment liquid 11 Pad 12 Solder resist

Claims (2)

In the method of supplying the processing liquid to the area surrounded by convex objects on the surface of the flat plate,
The shaft is rotatable and the position of the shaft is movable in the vertical direction, and at least a part of the surface of the roll formed of an elastic body is brought into contact with the treatment liquid.
The role the flat plate with the flat plate is allowed to proceed in the plane direction while contacting from below the region of the surface of the flat plate on the surface of the roll is rotated to lift corresponding to the thickness of the flat plate,
A treatment liquid supply method, wherein the treatment liquid is brought into contact with the region of the flat plate material by a surface of a rotating roll. In the processing liquid supply method according to claim 1,
The region of the flat plate is a conductor pad regions on the surface of the wiring board,
Process liquid supply method, wherein the processing liquid is an organic chelating agent aqueous solution for forming a rust preventing film on the conductor pad region.

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