JP2002141649A - Mask for coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask for coating by which a flux 32 or the like can be coated simply on the land 28 of a printed-wiring board 30, and by which the coated flux 32 is not damaged or removed. SOLUTION: In the mask 10 for coating a low-fluidity substance is coated on the land 28 of the printed-wiring board 30 in which a circuit is formed on the surface. The mask 10 for coating can be achieved in such a way that a coating hole 12 is formed in the mask 10 for coating in a position corresponding to the land 28 of the board 30, and that a part which corresponds to the coating hole 12 is cured so as to separate the coating hole 12 from the board 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a coating mask for coating a low-fluid substance on a land of a display substrate.

[0002]

2. Description of the Related Art A circuit is formed on the surface of a printed circuit board. Paste solder is applied on the land of the printed circuit board, electronic components are arranged on the paste solder, and the electronic components are fixed by reflow. ing. In order to apply paste solder or the like on the land, a coating mask is generally used so that the solder is not applied to portions other than the land.
That is, holes are formed only in portions where paste solder or the like is applied. A conventional coating method will be described with reference to FIG. Using a coating mask with a uniform thickness with holes at the positions corresponding to the lands, sandwich the pipe-shaped tube between the coating mask and the printed board at both ends of the coating mask, and place the coating mask on the printed board. Press and apply paste solder or the like from above the application mask. When the pressing force is released after the application is completed, the coating mask is raised almost vertically due to the repulsive force of the tubes sandwiched between both ends, so that the applied paste solder is not damaged.

[0003]

In the structure of the coating mask as described above, the thickness of the coating mask must be equal to the coating height.
When the thickness is less than 2 mm, the thickness becomes extremely thin and the strength becomes weak. When the thickness becomes more than 0.4 mm, there is a problem to be solved such that the mask does not rise almost vertically and the paste solder is hardly removed from the mask hole. Was. Conventionally, after coating the paste solder with a tube interposed between the coating mask and the printed board, the coating mask is raised almost vertically, but depending on the size of the coating mask, There is also a problem that it is difficult to raise the paste vertically, and the applied paste solder is damaged or the paste solder is removed. Damage to the applied paste solder or removal of the paste solder may cause poor connection.

The present invention has been made in view of such a conventional problem, and can easily apply paste solder or the like to a land of a printed circuit board, thereby damaging or removing the applied paste solder. An object of the present invention is to provide a coating mask which does not have any problems.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating mask for applying a low-fluid substance such as flux or paste solder on a land of a printed circuit board on which a circuit is formed. This can be achieved by providing the application mask with an application hole at a position corresponding to the land of the printed circuit board and curving a portion corresponding to the application hole so that the application hole is separated from the substrate. A groove is provided at a portion corresponding to the coating hole on a side opposite to a surface in contact with the printed board, and the coating mask is curved by providing the groove. A groove is formed by grinding the coating mask to a coating amount. The coating mask is naturally curved by cutting heat when forming the groove. The coating mask is curved so as to exceed the coating thickness. When the curving is performed so as to exceed the thickness of the coating amount and the force applied to the coating mask is released, the thickness of the coating mask naturally rises above the vertically applied thickness.

[0006]

[Function] Since the coating mask is curved at the center, after applying the paste solder or the like, the coating mask can be raised vertically only by releasing the force applied to the coating mask. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coating mask according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a jig on which a coating mask and a printed board of the present invention are mounted, and FIG. 2 is a partial cross-sectional view for explaining a state until solder balls are fixed to the printed board. Coating mask 1 of the present invention
Numeral 0 is for applying a material having low fluidity (for example, flux 32 or the like) on the land 28 of the printed circuit board 30. The coating mask 10 has a substantially concave shape.

The coating mask 10 is provided with a coating hole 12 at a position corresponding to the land 28 of the printed circuit board 30, and the size of the coating hole 12 is substantially the same as that of the land 28. A flux 32 is applied to the application hole 12.
Enters the land 28 of the printed circuit board 30 with flux 3
2 will be applied. Further, a groove 14 is provided in the center of the coating mask 10, and the depth of the groove 14 is appropriately designed so that the coating hole 12 is coated with the flux 32. The groove 14 is formed by grinding or the like, and the center of the coating mask 10 is curved by heat generated during the grinding. After the flux 32 or the like has been applied, the amount of this curvature is
The coating mask 10 is appropriately designed so as to rise vertically and not to contact the flux 32 in the raised state only by releasing the force applied to the mask. Considering such a role and workability, the material of the coating mask 10 preferably has a spring property such as stainless steel.

As shown in FIG. 1, the mask 10 is inserted into the jig 16 on which the printed circuit board 30 is mounted from the direction of the arrow "a" and pressed with a certain force. In this embodiment, the positioning of the jig 16 and the coating mask 10 is performed by providing the insertion groove 24 having the same dimensions as the coating mask 10. Any method may be used as long as the land 28 is not displaced. For example, a positioning method in which a hole is formed in the coating mask 10 and a positioning pin is set on the jig 16 may be used. As a method of pressing the coating mask 10, a handle may be provided on the coating mask 10 and pressed by hand, or may be pressed by another jig or the like.

Referring to FIG. 2, the steps required until the solder balls 34 are mounted on the printed circuit board 30 will be described. As shown in the figure, a hole 20 is provided in a portion of the land 28 where the flux 32 or the like is applied. First, the printed circuit board 3
0 is mounted on the jig 16, and the coating mask 10 is pressed on the jig 16 with a certain force, and the flux 32 or the like is coated along the groove 14 in this state. It enters the hole 12 and is applied on the land 28. Next, when the pressing force is released, since the mask 10 is curved, the mask 10 is raised almost vertically by the repulsive force. Since it rises vertically, the flux 32 is not damaged or removed. Next, the solder ball positioning tool 38 is inserted into the jig 16 while being mounted on the jig 16, and the solder balls 34 are
Are put on the solder ball positioning tool 38 and the jig 16 is slightly moved, so that the solder balls 34
Mounted on top. Finally, the solder balls 34 are attached to the lands 28 of the printed circuit board 30 by reflowing with the solder balls 34 attached to the flux 32.

[0011]

As is clear from the above description, the coating mask according to the present invention has the following excellent effects. (1) In the coating mask 10 of the present invention, only the portion to which the flux 32 or the like is applied is made as thick as the application amount.
There is no weakening in strength. (2) Since the groove 14 is provided at the center of the coating mask 10, the flux 32 and the like can be easily applied to the land 28 of the printed circuit board 39. (3) Since the grooves 14 are formed by grinding the coating mask 10 to the amount to be coated, the coating mask 10 can be naturally curved by the cutting heat when forming the grooves 14. (4) Since the coating mask 10 is curved so as to exceed the thickness of the coating amount and the force applied to the coating mask 10 is simply released, the coating mask 10 naturally rises vertically.
In the raised state, it does not come into contact with the flux 32 or the like, and is not damaged or removed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a jig on which a coating mask and a display substrate of the present invention are mounted.

FIG. 2 is a partial cross-sectional view for explaining a state until a solder ball is fixed to a display substrate.

FIG. 3 is a partial cross-sectional view illustrating a state where a flux is applied to a land of a display substrate using a conventional application mask.

[Explanation of symbols]

 10, 60 Coating mask 12 Coating hole 14 Groove 16 Jig 18 Chip 20 Hole 22 Pattern 24 Insert groove 26 Overcoat 28 Land 30 Printed circuit board 32 Flux 34 Solder ball 36 Pipe tube 38 Positioning tool

Claims (4)

[Claims] An application mask for applying a low-flow material such as flux or paste solder on a land of a printed circuit board having a circuit formed on a surface thereof, wherein the application mask corresponds to the land of the printed circuit board. An application mask, wherein an application hole is provided at a predetermined position, and a portion corresponding to the application hole is curved so that the application hole is separated from the substrate. 2. The coating mask according to claim 1, wherein a groove is provided at a portion corresponding to the coating hole on a side opposite to a surface in contact with the printed circuit board, and the coating mask is curved by providing the groove. The coating mask described in the above. 3. The coating mask according to claim 1, wherein a groove is formed by grinding the coating mask to a coating amount. 4. The coating mask according to claim 1, wherein the coating mask is curved so as to exceed the thickness of the coating amount.