JP3019617B2 - Cream solder screen 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 screen printing apparatus, and more particularly, to a cream solder screen printing apparatus provided with a side squeegee for preventing cream solder from leaking sideways.

[0002]

2. Description of the Related Art Before mounting electronic components on a printed circuit board, cream solder is applied to electrodes of circuit patterns on the board by a screen printing apparatus. In this screen printing, the substrate is brought close to the lower surface of the screen mask, and a pair of left and right squeegees alternately land on the screen mask,
By reciprocating sliding, cream solder is applied to the substrate through the pattern holes opened in the screen mask.

FIGS. 7A and 7B are plan views showing a state where cream solder is applied by a conventional screen printing apparatus. FIG. 7A shows a state in which the left squeegee 17A lands on the screen mask 2 and the right squeegee 17B is lifted from the screen mask 2 and slid in the right direction N1. In this case, cream solder 18
Is applied to the substrate through the pattern holes 4 formed in the screen mask 2 while being pressed against the front surface of the left squeegee 17A.

[0004] At both ends of the squeegees 17A and 17B,
A side squeegee 20 for preventing the cream solder 18 from leaking sideways is mounted. However, it is extremely difficult to mount the side squeegee 20 completely in close contact with both side ends, and there is a slight gap between the two. A large gap G is generated (see the partially enlarged view of FIG. 7A). For this reason, squeegee 1
When 7A slides in the right direction N1, the cream solder 18
Leaks parallel from the gap G to the rear and leaks solder 1
8A results. Next, as shown in FIG. 7 (b), one squeegee 17A is raised, and the other squeegee 17B is landed on the screen mask 2, so that the squeegees 17A, 17
B is slid in the leftward direction N2. At this time, the cream solder 18 leaks from both ends of the squeegee 17B to generate leaked solder 18B, and the leaked solder 18A leaked earlier.
Then, the side squeegee 20 of the squeegee 17B enters and the leaked solder 18A is diffused to the periphery as illustrated.

[0005]

As described above, each time the squeegees 17A and 17B are repeatedly slid back and forth, the cream solder 18 leaks from both ends of the squeegees 17A and 17B to generate leaked solders 18A and 18B. Although it is unavoidable, the leaked solder 18A, 18B gradually accumulates in large quantities and contaminates the screen mask 2 and the side squeegee 20.
A, 18B and leaked solder 18A, 18B adhering to the outer surface of the side squeegee 20 must be cleaned and removed from time to time.
There has been a problem that maintenance and management are troublesome.

Accordingly, an object of the present invention is to provide a screen printing apparatus that can easily perform post-processing of leaked solder.

[0007]

SUMMARY OF THE INVENTION To this end, the present invention relates to a squeegee in which the outer ends of side squeegees mounted on both side ends of the squeegee are bent inward to form bent portions, and the interval between the bent portions is defined as the distance between the bent portions of the squeegee. It is smaller than the width.

[0008]

According to the above construction, when the squeegee is slid, the leaked solder leaking from both ends thereof is guided to the inside of the squeegee, so that the leaked solder does not diffuse outside the squeegee. Therefore, when the squeegee performs a normal sliding operation, the squeegee is reliably collected on the front side of the squeegee.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a screen printing apparatus. In the drawing, 1 is a frame-shaped mask holder, 2 is a screen mask held by the mask holder 1, and 3 is a frame body of the screen mask 2. Screen mask 2
Pattern holes 4 are formed.

Reference numeral 5 denotes a sliding plate suspended over the mask holder 1. A slider 6 is mounted on the lower surface of the end of the sliding plate 5, and the slider 6 is fitted on a guide rail 7 provided on one side of the mask holder 1. A nut 11 is mounted on the lower surface of the other end of the sliding plate 5.
Reference numeral 12 denotes a ball screw provided on the other side of the mask holder 1, and reference numeral 13 denotes a motor for rotating the ball screw 12. The ball screw is screwed to a nut 11, and when the motor 13 is driven to rotate the ball screw 12, the sliding plate 5 is rotated.
Slides along the guide rail 7 and the ball screw 12.

At the center of the sliding plate 5, two cylinders 15 are provided.
Are provided. As shown in FIG.
A pair of left and right squeegees 17 are provided at the lower end of the rod 16 of FIG.
(17A, 17B) is held, and when the rod 16 protrudes and retracts, the squeegee 17 moves up and down individually and comes into contact with and separates from the screen mask 2. 18 is squeegee 17A and squeegee 1
This is the cream solder supplied during 7B. Motor 13
Is driven, the squeegee 17 slides back and forth on the screen mask 2 and applies cream solder 18 to the electrodes of the circuit pattern formed on the upper surface of the substrate 8 close to the lower surface of the screen mask 2 through the pattern holes 4. . In FIG. 1, reference numeral 19 denotes a syringe as a supply means of the cream solder 18, and when the remaining amount of the cream solder 18 becomes small, the cream solder 18 is supplied onto the screen mask 2.

Next, an assembly structure of the squeegee 17 will be described with reference to FIGS. The squeegee 17 is held by a squeegee holder 31. This squeegee 17
Is made of synthetic resin or rubber having some elasticity. Side squeegees 32 are provided at both ends of the squeegee 17.
Is attached. The side squeegee 32 is bent in a V shape, and the parallel portion 3 abutting on the side surface of the squeegee 17 is formed.
2a and a bent portion 32b bent inward of the squeegee 17. Therefore, as shown in FIG. 6A, the interval W between the outer ends of the bent portion 32b is smaller than the lateral width of the squeegee 17. 33 is a side squeegee 32 and a squeegee 17
And a bolt 36 screwed into a small hole 34 opened at the right end thereof and a bolt hole 35 opened at the end upper surface of the squeegee holder 31. Is done.

A small hole 37 is formed at the left end of the stop plate 33. A block 38 is provided on the back surface of the parallel portion 32a.
Is fixed. A coil spring 41 is interposed between the small hole 37 and the small hole 39 formed in
0, the side squeegee 32 is
3 40a is a fixing screw for the pin 40, 40b
Is a stop ring, and 40c is an insertion hole. The lower surface of the side squeegee 32 elastically contacts the screen mask 2 by the spring force of the coil spring 41.

The screen printing apparatus has the above-described configuration, and the operation will be described next.

First, as shown by the solid line in FIG. 5, the left squeegee 17A lands on the screen mask 2, the right squeegee 17B is raised, and the motor 13 is rotated forward in this state, so that the squeegees 17A and 17B are moved. Slide in the right direction N1. Then, the cream solder 18 is pushed on the front surface of the squeegee 17A and flows on the screen mask 2, and the cream solder 18 is applied to the substrate 8 through the pattern holes 4. FIG. 6A shows a plan view in this case, and the cream solder 18 on the front surface of the squeegee 17A is
Although the solder 18A leaks from the gap with the side squeegee 32, the leaked solder 18A is guided inward by the bent portion 32b of the side squeegee 32.

Next, as shown by the chain line in FIG. 5, the squeegee 17A on the left side is lifted, the squeegee 17B on the right side is landed, and the motor 13 is rotated in the reverse direction.
7B is slid leftward N2. FIG. 6B shows a plan view in this case, and the squeegee 18B slides in the leftward direction N2, so that the leaked solder 18A that has previously leaked becomes the cream solder 18 on the front surface of the squeegee 17B. And is collected. Also in this case, the squeegee 17
The leaked solder 18B leaks from both sides of B. Since the leaked solder 18B is also guided inward by the bent portion 32b, when the other squeegee 17A next lands and slides in the right direction N1, The leaked solder 18B is similarly collected. Thus, according to the present apparatus, the squeegees 17A, 1
7B performs the normal sliding operation and the cream solder 18
The solder 18A, 18B leaked from both sides of the squeegee 17 can be collected at the same time.

[0018]

As described above, according to the present invention, the outer ends of the side squeegees mounted on both side ends of the squeegee are bent inward to form bent portions, and the interval between the bent portions is defined as the width of the squeegee. It is possible to automatically collect the solder leaked from both sides of the squeegee while applying cream solder to the board by sliding the squeegee back and forth on the screen mask, No processing is required.

[Brief description of the drawings]

FIG. 1 is a perspective view of a screen printing apparatus according to an embodiment of the present invention.

FIG. 2 is an exploded view of a main part of a screen printing apparatus according to one embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a screen printing apparatus according to an embodiment of the present invention.

FIG. 4 is a plan view of a main part of a screen printing apparatus according to an embodiment of the present invention.

FIG. 5 is a side view of a main part of a screen printing apparatus according to an embodiment of the present invention.

6A is a partial plan view of a screen printing apparatus according to an embodiment of the present invention during printing. FIG. 6B is a partial plan view of a screen printing apparatus according to one embodiment of the present invention during printing.

7A is a partial plan view of a conventional screen printing apparatus during printing. FIG. 7B is a partial plan view of a conventional screen printing apparatus during printing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mask holder 2 Screen mask 4 Pattern hole 13 Motor (drive means) 15 Cylinder (vertical movement means) 17 Squeegee 18 Cream solder 32 Side squeegee 32b Bend

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B41F 15/40-15/44 B41F 15/08 H05K 3/12

Claims (1)

(57) [Claims] A mask holder; a screen mask held by the mask holder; a pair of left and right squeegees reciprocatingly sliding on the screen mask; a driving means for reciprocatingly sliding the squeegee; Up and down movement means for individually moving these squeegees up and down so as to separate from and contact with the mask, and side squeegees disposed at both side ends of the squeegee to prevent lateral leakage of cream solder are provided. A screen printing apparatus for cream solder, wherein an end portion is bent inward to form a bent portion, and an interval between the bent portions is smaller than a lateral width of the squeegee.