JP2868466B2 - Cream solder printing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cream solder printing apparatus for screen printing cream solder on a circuit board.

[0002]

2. Description of the Related Art Conventionally, in such a cream solder printing apparatus, cream solder having a thickness of usually 100 to 200 .mu.m is printed on a circuit board. As an apparatus for measuring the print amount of cream solder, for example, there is a printed screen solder appearance inspection apparatus described in Surface Mounting Technology, February 1994, pp. 78-79. This inspection device
Laser light is applied to the cream solder on the circuit board, the locus of the laser light is read by a CCD camera, and image processing is performed. That is.

[0003]

Conventionally, in order to make the print amount of cream solder appropriate, it is necessary to measure the print amount using the above-described special inspection device. Such inspection equipment was expensive. Further, when there is no inspection device, the operator has to rely on the operator's can, and it has been extremely difficult to stably and uniformly maintain the print amount.

Therefore, the present invention easily and appropriately adjusts the print amount of cream solder without using a special inspection device.
It is an object of the present invention to provide a cream solder printing apparatus capable of saving.

[0005]

The cream solder of the present invention is provided.
Printing apparatus, the solder paste printing apparatus for screen printing solder paste on the surface of the circuit board, the surface of the screen, sectional staircase having different depths in a plurality of stages
Forming a screen-shaped recess, the surface of the screen and the plurality of
In the recess with a stepped cross-section with different depths
Check the amount of solder
It is characterized in that the printing amount of the solder is adjusted .

[0006]

Next, embodiments of the present invention will be described in detail with reference to the drawings. First, the clear of the present invention
A reference example of a solder paste printing machine is explained with reference to FIG.
I will tell. In FIG. 1, reference numeral 1 denotes a metal screen for screen-printing the cream solder 2. Reference numeral 3 denotes a squeegee provided at a position above the squeegee, which is a member for pushing the cream solder 2 onto the metal screen 1. An opening 5 for printing the cream solder 2 on the circuit board 4 is formed in the metal screen 1, and the cream solder 2 is printed on the circuit board 4 in a portion where the opening 5 is provided. Further, on the surface of the metal screen 1, there is formed a concave portion 6 for visually confirming the printing amount (thickness) of the cream solder 2 as described later in detail.

The squeegee 3 is a member for extruding the cream solder 2 onto the metal screen 1 and printing the cream solder 2 on the circuit board 4 as described above, and is made of hard rubber. . The squeegee 3 can be moved up and down by a mechanism (not shown), and has a function of adjusting the print amount of the cream solder 2 as described later in detail. FIG. 1 shows a state in which the metal screen 1 and the squeegee 3 after screen printing have been moved above the circuit board 4.

Here, when the screen printing as described above is performed, the cream solder 2 remaining on the surface of the metal screen 1 and the concave portion 6 formed on the surface of the metal screen 1 is visually confirmed, and the cream solder 2 is formed.
It is possible to determine whether or not the print amount is appropriate.

More specifically, FIG. 2A shows a state where the amount of the cream solder 2 is larger than an appropriate amount. That is, when the amount of the cream solder 2 is excessive, the excess cream solder 2 adheres to the entire surface of the metal screen 1 as shown in FIG. Therefore, in such a case, since the cream solder 2 not only remains in the concave portion 6 but also adheres to the surface of the metal screen 1, when the cream solder 2 is visually adhered to the entire surface of the metal screen 1. Is cream solder 2
Can be determined to be larger than the appropriate amount.

FIG. 2B shows a state where the amount of the cream solder 2 is proper. When the amount of the cream solder 2 is appropriate, that is, when the thickness of the cream solder 2 is the same as the thickness of the metal screen 1, there is no excess cream solder 2, so that as shown in FIG. Remains only inside the recess 6. Therefore, when the cream solder 2 remains only in the concave portion 6 and does not adhere to the surface of the metal screen 1, the amount of the cream solder 2 may be determined to be appropriate.

FIG. 2C shows a state in which the amount of the cream solder 2 is less than the proper amount. When the amount of the cream solder 2 is insufficient, the cream solder 2 does not adhere to the recess 6 or the surface of the metal screen 1 as shown in FIG. In other words, it can be determined that the cream solder 2 is insufficient than the appropriate amount.

In FIG. 1, the amount of the cream solder 2 is visually checked in this manner . If the amount of the cream solder 2 is excessive or insufficient, the squeegee 3 is moved up and down. Thus, the printing amount of the cream solder 2 can be adjusted. That is, since the squeegee 3 has a structure that can be moved in the vertical direction by a mechanism (not shown) as described above, if the cream solder 2 is excessive as shown in FIG.
Is finely moved downward so as to adjust the printing amount of the cream solder 2 to an appropriate amount. When the amount of the cream solder 2 is insufficient as shown in FIG. 2C, the squeegee 3 is moved upward to adjust the printing amount of the cream solder 2 to an appropriate amount.

Here, the depth of the concave portion 6 is desirably about the diameter of the particles of the cream solder 2 (usually about 20 to 50 μm) so that the cream solder 2 is also printed inside the concave portion 6. . The squeegee 3 is made of a hard rubber as described above, but preferably has a hardness of 70 to 90 degrees so that the cream solder 2 is printed in the recess 6. Further, the position of the concave portion 6 is preferably formed near the opening 5 where the cream solder 2 is printed on the circuit board 4 in order to reduce the measurement error.

In the reference example of FIG . 1, since the concave portion 6 for confirming the print amount of the cream solder 2 is formed on the surface of the metal screen 1, the degree of adhesion of the cream solder 2 on the concave portion 6 and the surface of the metal screen 1 is determined. It is possible to easily determine whether the amount of the cream solder 2 is appropriate only by visual inspection. Further, since the printing amount of the cream solder 2 is adjusted by moving the squeegee 3 up and down, the cream solder 2 can be printed uniformly and stably. In this case, as shown in FIG. 3, recesses 6 are formed at positions corresponding to the four corners of the circuit board 4 on the surface of the metal screen 1 and whether the printing amount of the cream solder 2 is appropriate at each of the recesses 6 By judging whether or not, the printed amount of the cream solder 2 can be made uniform over the entire surface of the circuit board 4.

FIG. 4 shows a cream solder printing apparatus according to the present invention.
It is a figure showing composition of one embodiment. In the present embodiment, FIG.
As shown in FIG. 4, concave portions 7 having different depths are formed on the metal screen 1 at a plurality of stages. In FIG. 4, 4
The concave portion 7 is formed in a stepped cross section at a depth of one step, and the printing amount of the cream solder 2 can be determined in five steps as a whole. By doing so, the print amount of the cream solder 2 can be determined in fine steps, so that the print amount of the cream solder 2 can be easily adjusted.

[0016]

According to the present invention, as described above ,
Sectional floor with different depths on the clean surface in multiple stages
Special inspection equipment is required due to the stepped recess
And without depth on the screen surface and multiple steps
Of cream solder in recess with step-shaped cross section
Can be easily confirmed by simply checking
Can be adjusted to an appropriate amount .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a reference example of a cream solder printing apparatus of the present invention.

FIG. 2 is a diagram for explaining a method of determining a print amount of cream solder in the reference example of FIG. 1;

FIG. 3 is a plan view showing a reference example in which concave portions are formed at positions corresponding to four corners of a circuit board of a metal screen.

FIG. 4 is a sectional view showing an embodiment of a cream solder printing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal screen 2 Cream solder 3 Squeegee 4 Circuit board 5 Opening 6,7 Recess

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoru Kudo 2-6-80 Shimohanazawa, Yonezawa City, Yamagata Prefecture Inside Yonezawa NEC Corporation (56) References JP-A-6-87206 (JP, A) ( 58) Field surveyed (Int.Cl. ⁶ , DB name) H05K 3/34 505 H05K 3/12 610 H05K 3/24

Claims (1)

(57) [Claims] 1. A cream solder printing apparatus for screen-printing cream solder on a surface of a circuit board, wherein a sectional floor having a depth different in a plurality of stages is formed on the screen surface.
Forming a stepped recess, the surface of the screen and the duplication
The clearance in the recess with a stepped cross section
Check the amount of solder
A cream solder printing apparatus characterized in that the amount of solder paste can be adjusted .