JPH0568635U - Mask for solder paste printing - Google Patents

Abstract

(57) [Abstract] [Purpose] Even in the case of a printed circuit board with a joint-covering resin dam, the solder paste can be printed only on a necessary portion of the printed circuit board. [Structure] A portion 12 of a printing mask corresponding to a portion to be applied with a solder paste of a printed circuit board 11 with a joint portion coating resin dam is cut out, and a joint portion coating resin dam 11a of the printed circuit board 11 on the lower surface of the mask is cut out. It is characterized in that a recessed portion 13 capable of accommodating the joint portion covering resin dam 11a is provided at a location corresponding to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a solder paste printing mask used for printing a solder paste on a printed circuit board with a resin dam having a joint portion coating, for example.

[0002]

[Prior Art]

 Conventionally, when a circuit element such as an IC is mounted on a printed circuit board, the circuit element such as the IC is positioned at a predetermined position on the printed circuit board, and an appropriate wiring work is performed by wire bonding or the like. By covering the whole with a junction coating resin (hereinafter referred to as a joint coating resin), the protective film of this joint coating resin allows each circuit element, wiring, conductive pattern, etc. to come into contact with the outside. I try not to cause a short circuit.

Each circuit element is provided with a solder paste, for example, by printing, at an appropriate position on the printed circuit board before the circuit element is mounted at a predetermined position on the printed circuit board. After mounting, the whole solder paste is melted by heating and then cooled and hardened, so that necessary soldering can be performed.

That is, as shown in FIGS. 3 to 5, each circuit element, for example, IC3, is adhered to the printed circuit board 1 by Au paint or the like, the IC3 is connected by Au wire or the like, and then the whole is bonded. It is covered with a partial coating resin to form the protective film 4. At this time, since the joint portion coating resin dam 2 is formed, the joint portion coating resin does not spread and the protective film 4 can be made to have a constant thickness.

[0005]

[Problems to be solved by the device]

 However, in the case of such a printed circuit board 1 with a joint portion coating resin dam 2, when a solder paste is printed on the surface of the printed circuit board 1 for soldering each circuit element 3, solder is not applied to unnecessary parts. The printing mask used to prevent the paste from being printed does not adhere to the surface of the printed circuit board 1 due to the joint-covering resin dam 2 and rises, so that solder paste is applied even to unnecessary portions. It is easy for the strike to be printed, and thus it is difficult to print the solder paste using the printing mask. Therefore, in the case of the printed circuit board 1 with a resin dam on the joint portion, the solder paste for soldering each circuit element needs to be applied using a dispenser, which increases the mounting cost. There was a problem of waiting.

In view of the above points, the present invention makes it possible to apply the solder paste by printing only to a necessary portion on the printed circuit board even in the case of the printed circuit board with the joint portion coating resin dam. The purpose is to provide a paste printing mask.

[0007]

[Means for Solving the Problems]

 According to the present invention, the above-described object is to cut out a portion of a printed circuit board with a joint portion coating resin dam to which solder paste is to be applied, and to attach the joint portion coating resin dam of the printed circuit board on the lower surface thereof. This is achieved by a solder paste printing mask, which is provided with a recessed portion capable of accommodating the joint-covering resin dam at a corresponding position.

[0008]

[Action]

 According to the above configuration, the solder paste printing mask has a recessed portion capable of accommodating the joint-covering resin dam at the portion corresponding to the joint-covering resin dam provided on the surface of the printed board on which the solder paste is to be printed. Since the solder paste printing mask is placed on the printed circuit board, the contact portion coating resin dam on the printed circuit board is provided in the concave portion provided on the lower surface of the solder paste printing mask. Completely, and as a result, the entire lower surface of the solder paste printing mask can be brought into close contact with the surface of the printed circuit board. Therefore, the solder paste will not be printed to unnecessary parts through the cutout part of the solder paste printing mask, and the solder paste can be surely printed only to the necessary parts on the surface of the printed circuit board. It will be. Therefore, it is not necessary to apply the solder paste on the printed circuit board using a dispenser or the like, and the mounting cost is significantly reduced.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 shows a solder paste printing mask according to the present invention. The solder paste printing mask 10 is placed on a printed circuit board 11 with a resin dam having a joint portion covering the printed circuit board 11. The portion 12 corresponding to the portion to be printed with the solder paste is cut out, and the recessed portion capable of accommodating the joint covering resin dam 11a is formed on the lower surface at the portion corresponding to the joint covering resin dam 11a. 13 are provided.

In this case, the concave portion 13 is formed by etching, for example, but it is obvious that it may be formed by another method.

Since the solder paste printing mask 10 according to the present invention is configured as described above, when the solder paste printing mask 10 is placed on the printed circuit board 11, the bonding portion on the printed circuit board 11 is joined. The coating resin dam 11a is now completely housed in the recess 13 provided on the lower surface of the solder paste printing mask 10, and as a result, the entire lower surface of the solder paste printing mask 10 is printed on the printed circuit board 11. Will be able to adhere to the surface of. Therefore, if the solder paste is printed in this state, the solder paste will not be printed to unnecessary portions through the cutout portion 12 of the solder paste printing mask 10 and the printed circuit board 11 can be printed. Make sure the solder paste is printed only on the required areas of the surface. Therefore, it is not necessary to apply the solder paste on the printed circuit board 11 using a dispenser or the like, and the mounting cost is significantly reduced.

FIG. 2 shows another embodiment according to the present invention, which includes a first mask 10a having only a cutout 12a, a cutout 12b corresponding to the cutout 12a, and a print substrate 11. The second mask 10b having the cutout portion 13b corresponding to the joining portion coating resin dam 11a is bonded to each other to form the cutout portion 12 with the cutout portion 12a and the cutout portion 13b. The configuration is the same as that of FIG. 1 except that the concave portion 13 is formed from the lower surface of the second mask 10b.

[0013]

[Effect of the device]

 As described above, according to the solder paste printing mask of the present invention, even in the case of the printed circuit board with the resin resin dam having the joint portion coating, the solder paste is applied by printing only to a necessary portion on the printed circuit board. There is an important practical advantage of being able to do so.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a printing mask according to the present invention.

FIG. 2 is a schematic sectional view showing another embodiment of a printing mask according to the present invention.

FIG. 3 is a vertical cross-sectional view of an example of a conventional printed circuit board with a joint portion coating resin dam.

FIG. 4 is a plan view of the printed circuit board shown in FIG.

5 is a schematic cross-sectional view showing a state in which an IC is mounted on the printed circuit board of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Mask for solder paste printing 10a First mask 10b Second mask 11 Printed circuit board 11a Joint part covering resin dam 12 Cutout part 13 Recessed part

Claims (1)

[Scope of utility model registration request] 1. A printed circuit board with a joint portion coating resin dam is cut out at a portion corresponding to a portion to which a solder paste is to be applied, and the lower surface is joined to a portion corresponding to the joint portion coating resin dam of the printed circuit board. A mask for solder paste printing, comprising a concave portion capable of accommodating a partial coating resin dam.