JP2002076600A - Method of printing conductive paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform die plate release smoothly even if fine pitch process is advanced at the time of printing solder paste onto a connection terminal on a substrate using a print mask. SOLUTION: A resist film 14 is provided on a substrate 12 around a connection terminal 13 provided on a substrate 12. The resist film 14 is 50-100 μm thick and thicker than the connection terminal 13 while a print mask 15 is 20-40 μm thick and thinner than the resist film 14. Since the print mask 15 is made relatively thin, die plate release can be performed smoothly even if fine pitch process is advanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing a conductive paste made of a solder paste or the like.

[0002]

2. Description of the Related Art For example, an LGA (land grid array) or Q
When electronic components such as FP (quad flat package) are surface-mounted on a substrate, the connection terminals of the electronic components can be joined to the connection terminals of the substrate via solder paste pre-printed on the connection terminals of the substrate. is there.

Next, an example of a conventional solder paste printing method in such a case will be described with reference to FIG. First, as shown in FIG. 2A, the substrate 2 is placed on the stage 1. A connection terminal 3 is provided at a predetermined location on the substrate 2.
And a resist film 4 is provided on the substrate 2 around the connection terminals 3. A print mask 5 is arranged above the stage 1. An opening 6 is provided in a portion of the print mask 5 corresponding to the connection terminal 3. In this case, the film thickness of the resist film 4 is approximately the same as the film thickness of the connection terminal 3 and is about 20 to 40 μm, and the film thickness of the print mask 5 is about 50 μm.

[0004] Next, as shown in FIG. 2 (B), the stage 1 is raised together with the substrate 2, and the upper surface of the resist film 4 is brought into close contact with the lower surface of the print mask 5. Next, as shown in FIG. 2C, the squeegee 7 is moved on the print mask 5 to print the solder paste 8, so that the solder paste is printed on the connection terminals 3 in the openings 6 of the print mask 5. 8
Print a. Next, as shown in FIG. 2D, the stage 1 is lowered together with the substrate 2, and the plate is separated. At this time, the lowering speed of the stage 1 is reduced so that the plate separation is performed smoothly. Thus, substrate 1
The solder paste 8a is printed on the connection terminals 3 of FIG.

[0005]

However, in such a conventional solder paste printing method, as the fine pitch progresses, the area of the opening 6 of the print mask 5 becomes smaller, and this smaller opening area and the print mask become smaller. Due to the relatively large film thickness of about 50 μm, even if the stage 1 lowering speed is reduced, the separation of the plate becomes worse, and the connection terminals 3
The printed shape of the solder paste 8a printed thereon deteriorates,
The reliability of bonding via the solder paste 8a may be reduced. An object of the present invention is to make it possible to smoothly release a printing plate even when the fine pitch is advanced.

[0006]

According to a first aspect of the present invention, there is provided a method of manufacturing a semiconductor device according to the first aspect of the present invention, comprising the steps of: When the conductive paste is printed on the substrate, the thickness of the resist film is larger than the thickness of the connection terminal, and the thickness of the print mask is smaller than the thickness of the resist film. According to a second aspect of the present invention, in the first aspect, the thickness of the resist film is about 50 to 100 μm, and the thickness of the print mask is about 20 to 40 μm. According to a third aspect of the present invention, in the first or second aspect, a solder paste is used as the conductive paste. According to the first aspect of the present invention, the thickness of the resist film is larger than the thickness of the connection terminal, and the thickness of the print mask is smaller than the thickness of the resist film. That is, since the thickness of the print mask is reduced to some extent, even if the fine pitch is advanced,
Plate separation can be performed smoothly.

[0007]

Next, a method of printing a solder paste (conductive paste) according to an embodiment of the present invention will be described with reference to FIG. First, as shown in FIG. 1A, a substrate 12 is placed on a stage 11. Substrate 1
A connection terminal 13 is provided at a predetermined position on the substrate 2, and a resist film 14 is provided on the substrate 12 around the connection terminal 13. A printing mask 1 is provided above the stage 11.
5 are arranged. An opening 16 is provided in a portion of the print mask 15 corresponding to the connection terminal 13. In this case, the thickness of the connection terminal 13 is about 30 μm, and the thickness of the resist film 14 is larger than the thickness of the connection terminal 13 by 50 μm.
The thickness of the print mask 15 is about 20 to 40 μm, which is smaller than the thickness of the resist film 14.

Next, as shown in FIG. 1B, the stage 11 is raised together with the substrate 12, and the upper surface of the resist film 14 is brought into close contact with the lower surface of the print mask 15. Next, FIG.
As shown in (C), the squeegee 17 is moved on the print mask 15 to print the solder paste 18, so that the solder paste 18 a is printed on the connection terminals 13 in the openings 16 of the print mask 15. Next, FIG.
As shown in (D), the stage 11 is slowly lowered together with the substrate 12 to release the plate. Thus, the substrate 11
The solder paste 18a is printed on the connection terminals 13 of FIG.

In this embodiment, the thickness of the resist film 14 is about 50 to 100 μm, which is larger than the thickness of the connection terminal 13, and the thickness of the print mask 15 is 20 to 40 μm.
Since the thickness of the resist film 14 is smaller than that of the resist film 14, that is, the thickness of the print mask 15 is reduced to some extent, the plate separation can be performed smoothly even when the fine pitch is advanced. As a result, the printed shape of the solder paste 18a printed on the connection terminals 13 of the substrate 11 is stabilized, and the reliability of bonding via the solder paste 18a can be improved.

The print mask 15 has a thickness of 20 to 40.
Since the solder paste 18a protrudes above the resist film 14, the protrusion height of the solder paste 18a is relatively low, such as about 20 to 40 μm. As a result, even when the solder paste 18a flows to the surroundings, the flow range thereof can be made relatively small, and even if the fine pitch is advanced, a short circuit between the adjacent solder pastes 18a is less likely to occur. it can. On the other hand, in the case of the conventional example shown in FIG. 2, since the thickness of the print mask 5 is relatively thick, about 50 μm, the height of the solder paste 8a is also relatively high, about 50 μm. Since the range is relatively large, when the fine pitch is advanced, a short circuit may occur between the adjacent solder pastes 8a.

In the above embodiment, the resist film 14 may be formed so as to be superimposed on the end edge of each connection terminal 13, and the solder paste 8 a may be provided only on the connection terminal 13.

[0012]

As described above, according to the present invention, the thickness of the print mask is reduced to some extent, so that even if the fine pitch is advanced, the separation of the plate can be performed smoothly, and the substrate can be removed. The printed shape of the conductive paste printed on the connection terminal is stabilized, and the reliability of bonding via the conductive paste can be improved.

[Brief description of the drawings]

FIGS. 1A to 1D are cross-sectional views showing respective printing steps of a solder paste according to an embodiment of the present invention.

FIGS. 2A to 2D are cross-sectional views showing respective printing steps of a conventional solder paste.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Stage 12 Substrate 13 Connection terminal 14 Resist film 15 Printing mask 16 Opening 17 Squeegee 18, 18a Solder paste

Claims (3)

[Claims] When a conductive paste is printed on the connection terminals by closely contacting a print mask on the resist film provided on the substrate around the connection terminals provided on the substrate, the film of the resist film is formed. A method for printing a conductive paste, wherein the thickness is greater than the thickness of the connection terminal, and the thickness of the print mask is smaller than the thickness of the resist film. 2. The conductive paste printing method according to claim 1, wherein the resist film has a thickness of about 50 to 100 μm, and the print mask has a thickness of about 20 to 40 μm. Method. 3. The method according to claim 1, wherein the conductive paste is a solder paste.