JPH0615800A - Screen printing apparatus for cream solder and method thereof - Google Patents

Abstract

PURPOSE:To prevent a pattern hole from clogging and deformation of a solder after transferring by a method wherein an extrusion member is extruded in a screen mask and a cream solder filled up in a pattern hole is extruded on an electrode on a substrate to transfer it thereon. CONSTITUTION:After a screen mask 2 is disposed on an under receiving member 30, a squeegee 17 is slid to fill up a pattern hole 3 with a cream solder 4. After the squeegee 17 is turned out right under a squeegee turnout section, an elevating plate 23 is fallen down by a motor so that a pressing member 29 presses the mask 2, thereby a part of the pressing member 29 is pressed into an inner section of the pattern hole 3 by the elastic deformation of itself to stiffen the solder 4 therein. Consequently, the elevating plate 23 is raised up, then the mask 2 is transported from a filling device to a base 40 of a transferring device by a conveyor. The falling down of an extrusion member by a motor causes the mask 2 to be extruded by a protrusion 44 for extruding so that the solder 4 is transferred on an electrode 7 on a substrate S.

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 a screen printing method, and more particularly, to preventing clogging of pattern holes of a screen mask and deformation of cream solder printed on a substrate. The present invention relates to a screen printing device and a screen printing method for cream solder.

[0002]

Prior to mounting electronic parts such as ICs, LSIs, capacitor chips, and resistance chips (hereinafter referred to as "chips") on a substrate, cream solder is transferred onto the electrodes of the substrate by a screen printing device. It FIG. 4 shows a state in which cream solder is transferred to a substrate by a conventional screen printing device. Reference numeral 101 is a screen mask, and pattern holes 103 are formed at the transfer portions of the cream solder 102. A squeegee 104 is arranged on the screen mask 101. By sliding the squeegee 104 on the screen mask 101, the cream solder 102 is transferred onto the electrode 105 of the substrate S through the pattern hole 103.

[0003]

However, in the above-mentioned conventional means, the squeegee 104 is slid on the screen mask 101 to transfer the cream solder 102 onto the electrode 105. Therefore, the substrate S is lowered and the screen mask 10 is moved.
1 away from the cream solder 102 in the pattern hole 103
When transferring the image to the electrode 105, the cream solder 102 does not easily come off from the pattern hole 103, and the cream solder 102 is applied to the inner edge of the pattern hole 103 of the screen mask 101.
Remained, and the pattern holes 103 were easily clogged. When the pattern hole 103 is clogged and the area of the hole is reduced, the transfer amount of the cream solder 102 onto the subsequent substrate S is likely to be too small.

Therefore, conventionally, the cream solder remaining on the screen mask 101 is cleaned by wiping it with paper or cleaning it with a solution. However, such cleaning work is very troublesome and the screen mask 101 However, there is a problem in that it requires a lot of trouble and time for maintenance management. In addition, since the cream solder 102 is soft and has a considerable fluidity, it is easy to lose its shape after being transferred onto the electrode 105, flowing out to the side, and the adjacent cream solders 102 stick to each other,
There is a problem that a solder bridge, which causes a short circuit of the circuit pattern, is likely to occur.

Therefore, it is an object of the present invention to provide a screen printing apparatus and a screen printing method for cream solder which can prevent clogging of pattern holes of a screen mask and deformation of the cream solder transferred to an electrode of a substrate. .

[0006]

To this end, the present invention does not directly transfer the cream solder to the electrodes of the substrate through the pattern holes of the screen mask, unlike the conventional means. Then, the pattern hole of the screen mask is once filled with the cream solder by sliding the squeegee on the upper surface thereof. Next, this screen mask is placed on the substrate, and the extruding member is pressed against the screen mask to extrude and transfer the cream solder in the pattern holes onto the electrodes of the substrate. Furthermore, the cream solder filled in the pattern holes is compacted by the pressing member.

[0007]

According to the present invention, after the cream solder is filled in the pattern holes of the screen mask, the filled cream solder is extruded by the extruding member and transferred to the electrode of the substrate, so that the cream solder remains in the pattern holes. There is no sticking and therefore no clogging of the pattern holes occurs. Further, by compacting the cream solder in the pattern holes with the pressing member, the cream solder transferred to the electrodes is less likely to lose its shape.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view of a screen printing apparatus.

Reference numeral 1 denotes a conveyer for conveying the substrate S in the X direction, and a filling device 5 for filling the cream solder 4 in the pattern hole 3 formed in the screen mask 2 is provided on the side of the conveyer 1. It is provided. A transfer device 8 is provided in the middle of the conveyor 1 and pushes out the cream solder 4 in the pattern hole 3 onto the electrode 7 of the substrate S to transfer the cream solder 4.
Further, a Y-direction conveyor 10 is provided between the filling device 5 and the transfer device 8 to reciprocate the screen mask 2 between the devices 5 and 8. Next, the filling device 5 will be described in detail with reference to FIGS. 1 and 2.

In FIG. 1, 11 is a screen mask 2
Is a mask holder that holds a guide rail 12 in the Y direction. Reference numeral 30 denotes a plate-shaped lower receiving member provided below the mask holder 11.
Reference numeral 13 is a sliding plate, which is laid across the guide rails 12 on both sides via a slider 14. This sliding plate 1
A cylinder 15 is provided on the rod 3, and its rod 1
A squeegee 17 is held at 6. When the rod 16 of the cylinder 15 is projected and retracted, the squeegee 17 moves up and down, and the lower end portion thereof comes into contact with and separates from the upper surface of the screen mask 2.

A nut 18 is mounted on one side of the sliding plate 13. A ball screw 19 parallel to the guide rail 12 is screwed into the nut 18, and when the motor 20 is driven to rotate the ball screw 19, the squeegee 17 slides on the screen mask 2. These components 12 to
The reciprocating means of the squeegee 17 is constituted by 14, 18 to 20.

Reference numeral 22 is an elevating guide rod which is provided upright at the four corners of the lower receiving member 30. Reference numeral 23 denotes an elevating plate provided above the lower receiving member 30, which is attached to the guide rod 22 via a guide ring 24 so as to be vertically movable. Figure 2
In the figure, reference numeral 25 denotes a mounting bracket which is provided upright on the rear portion of the lower receiving member 30, and a motor 26 is arranged above the mounting bracket 25. Reference numeral 27 denotes a nut provided on the rear portion of the elevating plate 23, to which a vertical ball screw 28 is screwed. When the motor 26 is driven to rotate the ball screw 28, the lift plate 23 moves up and down along the guide rod 22.

A pressing member 29 for compressing the cream solder 4 filled in the pattern holes 3 of the screen mask 2 from above is provided on the lower surface of the lift plate 23. As the pressing member 29, a plate material made of an elastic material having some elasticity is used. On the rear side of the lift plate 23, the lift plate 23 lowered to the position indicated by the chain line in FIG.
The escape part 31 of this squeegee 17 so as not to hit 7.
Is bent in an inverted U shape, and the cream solder 4 remaining on the screen mask 2 is provided on the front part of the elevating plate 23.
The escape recess 32 is formed. These constituent parts 22 to 28 constitute a pressing means for pressing the pressing member 29 against the screen mask 2 from above. Next, the transfer device 8 will be described in detail with reference to FIG.

Reference numeral 40 denotes a base, and guide shafts 41 are provided upright at four corners of the base 40. Reference numeral 42 denotes a plate-shaped pushing member for pushing the cream solder 4 in the pattern hole 3 of the screen mask 2 onto the electrode 7 of the substrate S, and the guide shaft 4 via the guide ring 43.
1 is mounted so that it can move up and down. A thin plate 33 is mounted on the lower surface of the pushing member 42, and a pushing protrusion 44 of the cream solder 4 is formed on the lower surface of the thin plate 33 in a rib shape in the same pattern as the pattern hole 3 of the screen mask 2. There is. The protrusions 44 are formed by the same means as the means for forming the pattern holes 3 in the screen mask 2 such as an etching method.

Reference numeral 45 denotes a bracket which is erected on the front part of the base 40, and a motor 46 is provided above the bracket 45.
Is provided. Reference numeral 47 is a nut provided on the front portion of the pushing member 42, and a vertical ball screw 48 is screwed therein. When the motor 46 is driven, the ball screw 48 rotates and the pushing member 42 moves up and down along the guide shaft 41. These components 41, 43, 45, 46 push the pushing member 42 against the screen mask 2 placed on the substrate S from above to push the cream solder 4 in the pattern holes 3 onto the electrodes 7 of the substrate S. A pressing means for transferring the image is constituted.

This screen printing apparatus has the above-mentioned structure, and its operation will be described below. As shown in Figure 1,
The screen mask 2 is placed on the lower receiving member 30. Next, the motor 20 is driven to slide the squeegee 17 as shown in FIG. 3A, and the cream solder 4 is filled in the pattern holes 3. Next, in FIG. 2, the squeegee 17 is slid to the left to move the cream solder 4 remaining on the screen mask 2 to just below the recess 32, and then the squeegee 17 is slid to the right to escape. The part is evacuated right below the part 31. Next, when the motor 26 is driven to lower the elevating plate 23 to the position indicated by the chain line in FIG. 2, the pressing member 29 presses the screen mask 2. Then, as shown in FIG. 3B, the pressing member 29 is elastically deformed and a part thereof is pushed into the pattern hole 3, whereby the cream solder 4 in the pattern hole 3 is compressed and compacted. In this case, as shown by the chain line in FIG. 2, the cream solder 4 remaining on the screen mask 2 has escaped into the concave portion 32, and the squeegee 17 has escaped into the escape portion 31.
The squeegee 17 does not hinder the downward movement of the pressing member 29.

Next, the motor 26 is driven in the reverse direction to raise the elevating plate 23 to the position shown by the solid line in FIG. 2, and the pressing state of the pressing member 29 is released. Next, the screen mask 2 is moved from the filling device 5 to the base 40 of the transfer device 8 by the conveyor 10.
It is conveyed upward (see the chain line in FIG. 1).

As shown in FIG. 3C, on the base 40,
The substrate S is placed, and the screen mask 2 is placed on the substrate S with a slight gap t. Next, the pushing member 42 is lowered by driving the motor 46, the pushing member 42 is pressed against the screen mask 2 from above as shown in FIG. 3D, and the inside of the pattern hole 3 is compressed by the pushing protrusion 44. Cream solder 4 on board S
It is extruded and transferred onto the electrode 7 of. Next, in FIG. 1, the motor 46 is driven in the reverse direction to raise the pushing member 42, the conveyor 10 returns the screen mask 2 to the filling device 5, and the conveyor 1 transfers the substrate S to which the cream solder 4 is transferred. Transfer to the next process.

As described above, in this apparatus, the pushing member 42 is pressed against the screen mask 2 and the cream solder 4 compressed in the pattern hole 3 by the pushing projection 44 is pushed onto the electrode 7 of the substrate S and transferred. As a result, the cream solder 4 does not remain attached to the inner edge of the pattern hole 3 and the cream solder 4 filled in the pattern hole 3 is applied to the substrate S.
Can be reliably transferred to the electrode 7. Therefore, the pattern holes 3
Can be prevented, the amount of cream solder 4 transferred can be prevented from becoming too small at the time of printing the subsequent substrate S, and the cleaning of the screen mask 2 by a cleaning device can be eliminated. Further, since the cream solder 4 in the pattern hole 3 is compacted by the pressing member 29 and then transferred to the substrate S, it is possible to prevent the cream solder 4 transferred onto the substrate S from losing its shape.

[0020]

As described above, according to the present invention, the extruding member is pressed against the screen mask so that the cream solder filled in the pattern holes by the extruding projections is extruded and transferred onto the electrode of the substrate. Therefore, the cream solder is surely transferred onto the electrode without remaining attached to the inner edge of the pattern hole, and therefore clogging of the pattern hole can be prevented. Further, the cream solder in the pattern hole is compacted by the pressing member and then transferred to the electrode of the substrate, so that the shape of the cream solder after transfer can be prevented.

[Brief description of drawings]

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

FIG. 2 is a side view of a cream solder filling device according to an embodiment of the present invention.

FIG. 3 (a) is a cross-sectional view of a main part of a pattern solder according to an embodiment of the present invention during filling with cream solder. (B) A cross-sectional view of a main part of a cream solder according to an embodiment of the present invention during compression. c) Sectional view of the main part of the cream solder according to one embodiment of the present invention during transfer (d) Sectional view of the main part of the cream solder according to one embodiment of the present invention during transfer

FIG. 4 is a side view of a conventional screen mask cleaning device.

[Explanation of symbols]

 2 Screen Mask 3 Pattern Hole 4 Cream Solder 7 Electrode 17 Squeegee 20 Reciprocating Means 26 Elevating Drive Means 27 Elevating Drive Means 28 Elevating Drive Means 29 Pressing Members 30 Lower Support Members 42 Extruding Members 44 Extrusion Protrusions 46 Pressing Means S Substrate

Claims (3)

[Claims] 1. A screen mask, a base member on which the screen mask is placed, and a squeegee which slides on the screen mask to fill the pattern solder formed in the screen mask with cream solder. , A reciprocating means for sliding the squeegee, an extruding member having a protrusion for extruding cream solder in the same pattern as the pattern hole of the screen mask, and the extruding member from above on the screen mask placed on the substrate. A screen printing apparatus for cream solder, comprising: a pressing unit that presses a member to extrude and transfer the cream solder in the pattern hole onto the electrode of the substrate. 2. The cream filled in the pattern holes by the squeegee by being pressed by the screen mask before the cream solder in the pattern holes is pushed out and transferred to the electrodes of the substrate by the pushing member. A pressing member made of an elastic member for compacting the solder, and a lifting drive means for the pressing member are provided.
The screen printing device for cream solder as described. 3. A screen mask is placed on the base member,
Next, slide the squeegee over this screen mask to fill the pattern holes opened in this screen mask with cream solder, then place this screen mask on the substrate, and then the pattern holes in this screen mask. The extruding member having the extrusion pattern for extruding the cream solder in the same pattern as that is pressed against the screen mask to extrude and transfer the cream solder in the pattern hole onto the electrode of the substrate by the extrusion protrusion. Screen printing method for cream solder.