JPH08162749A - Cream solder coater - Google Patents

Abstract

PURPOSE: To obtain a cream solder coater for soldering an electronic chip device, in which correction is not required after soldering. CONSTITUTION: Cream solder filling holes for mounting an electronic device 4 disposed on a screen are made at positions where an insulator 6 is superposed on the electrode 5 of the electronic device 4. Consequently, a cream solder 12 abuts against the bulging insulator 6 and the electronic device 4 is pulled by surface tension of the cream solder 12 and soldered surely to a land 11 on a printed board 10. Consequently, no correction work is required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cream solder applicator for soldering and mounting chip parts of electronic devices and the like.

[0002]

2. Description of the Related Art A conventional cream solder coating apparatus will be described below.

A conventional cream solder coating apparatus is shown in FIG.
As shown in FIG. 1, the cream solder 3 is applied onto the soldering land 2 of the printed board 1 by screen printing or the like.
Then, after mounting the corner chip resistor 4 on the printed circuit board 1, reflow soldering was performed to solder-connect the soldering electrode 5 of the corner chip resistor 4 and the soldering land 2 of the printed circuit board 1 (reflow soldering). The state after attachment is not shown). At this time, the filling hole for adhering the square chip resistor 4 provided on the screen was designed not to overlap the insulator 6 provided between the electrodes 5 of the square chip resistor 4. As a result, the applied shape of the cream solder 3 was also prevented from overlapping the insulator 6 between the electrodes 5.

[0004]

However, in such a conventional structure, in the bulk mounting in which the front surface or the back surface of the chip component 4 is randomly mounted, the square chip resistor (used as an example of the electronic component) 4 is exposed. / Backward will be mounted in any direction. Therefore, the insulator 6 bulging from the surface of the electrode 5 is not always the upper surface, and the insulator 6 shown in FIG.
As shown in (3), the case where the insulator 6 (glass coat in the case of a square chip resistor) is mounted facing the surface of the substrate 1 also occurs.
In this case, if there is a step L1 between the insulator 6 and the electrode 5, and if there is another pattern 7 between the soldering lands 2, an insulator resist 8 is formed on the pattern 7. Since the coating is applied, the square chip resistor 4 is in a state of being considerably floated above the substrate 1. That is, as shown in FIG. 12, when the square chip resistor 4 is mounted on the substrate 1 with the insulator 6 facing downward, the square chip resistor 4 is mounted with the top 8a of the resist 8 serving as a fulcrum in the direction of the soldering land 2a. To be done. Then, the electrode 5a on the floating side (the electrode on the right side in this case) does not come into contact with the cream solder 3a. as a result,
As shown in FIG. 13, after the reflow soldering process, the right electrode 5a and the right land 2b corresponding to the electrode 5a may not be mechanically and electrically connected by the cream solder 3a. In order to correct this, there was a problem that the corrector had to make a soldering correction.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a cream solder applicator which requires no correction work.

[0006]

To achieve this object, a screen used in the cream solder applicator of the present invention has a corresponding cream solder filling for mounting electronic components provided on the screen. The hole is provided at a position overlapping the electrode of the electronic component and the insulator.

[0007]

With this configuration, the cream solder is applied to the position where it overlaps with the insulator of the electronic component, so that the cream solder contacts the insulator provided in the bulging shape, and at this time, it is pulled by the surface tension of the cream solder. The electronic component is securely soldered to the land of the printed circuit board.
Therefore, the correction work becomes unnecessary.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a first embodiment of the present invention and is a cross-sectional view of an essential part of a cream solder coating apparatus. In FIG. 1, the cream solder 12 is applied on the soldering land 11 of the printed board 10 by a screen printing method or the like. Then, after mounting the square chip resistor 4 on the printed circuit board 10, reflow soldering is performed to solder-connect the soldering electrodes 5 of the square chip resistor 4 and the soldering lands 11 of the printed circuit board 10. At this time, the filling hole for mounting the square chip resistor 4 provided on the screen of the screen used in the cream solder coating apparatus is provided so as to bulge between the electrode 5 and the electrode 5 of the square chip resistor 4. Insulator 6
It is provided so as to overlap with the. Therefore, when the square chip resistor 4 is mounted on the printed circuit board 10, the cream solder 12 is in a state of overlapping with the insulator 6 between the electrodes 5. In this embodiment, the cream solder 12 is applied to the upper surface of the soldering land 11 and the lower part of the insulator 6.

FIG. 2 is a cross-sectional view of an essential part when the square chip resistor 4 is mounted while being inclined. Even if the electrode 5a on the floating side of the square chip resistor 4 comes into contact with the bulging-shaped insulator 6 even if it does not come into contact with the cream solder 12a, the surface tension of the cream solder 12a causes the square chip resistor 4 to remain even after reflow. ,
It is pulled to the side of the soldering land 11a and soldered to the electrode 5a.

FIG. 3 is a cross-sectional view of essential parts showing a soldering state after reflow according to the present invention, showing a good soldering state.

FIG. 4 is a plan view showing an application shape of the cream solder 12 applied with the cream solder by using the cream solder applying apparatus, and this shape is located at a position where it overlaps the electrode 5 and the insulator 6 of the square chip resistor 4. By making the shape and the convex shape (square shape) toward the opposite direction, even if the square chip resistor 4 is mounted on the cream solder 12, the cream solder 1 is formed on the side surface side 13 of the chip resistor 4.
2 does not stick out. As the cream solder 12 does not squeeze out, the adjacent chip resistors 4 as shown in FIG.
Since the cream solders 12 do not come into contact with each other, a solder short circuit between the chip resistor 4 and another chip resistor 4a can be prevented after reflow.

FIG. 6 is a perspective view of a screen device according to the present invention for applying the cream solder 12 to the printed circuit board 10. A metal screen 16 having a filling hole 15 for applying the cream solder 12 to the printed circuit board 10 is attached to the screen device 14. The filling hole 15 is provided at a position overlapping the electrode 5 and the insulator 6 of the chip resistor 4 and has a convex shape toward the facing filling hole 15.

FIG. 7 is a sectional view of the screen device 14 when the cream solder 12 is applied to the printed circuit board 10. By supplying the cream solder 12 onto the metal screen 16 and moving the squeegee 17 in the direction of the arrow A, the cream solder 12 is embedded in the convex filling hole 15 and the convex cream solder 12 on the printed circuit board 10.
Apply.

FIG. 8 is a sectional view of a pin transfer type cream solder applicator according to the second embodiment. In FIG. 8, the plate 18 is provided with a convex filling hole 19 toward the insulator for filling the cream solder 12 as in the first embodiment. The filling hole 19 has the same shape as the filling hole 19. It has a pin 20 that fits in. The cream solder 12 is embedded in the filling hole 19.

FIG. 9 is a cross-sectional view of the pin transfer method when the cream solder 12 is applied to the printed circuit board 10.
The solder 12 embedded in the filling hole 19 causes the pin 20 to fit into the filling hole 19 of the plate 18 and then the pin 20.
By inserting the, the cream solder 12 having a convex shape toward the insulator is attached to the tip of the pin 20. By pressing this solder 12 against the printed circuit board 10, the cream solder 12 is applied to the printed circuit board 10 as in the first embodiment.

In the present invention, the square chip resistor 4 has been described as a representative, but the present invention can be applied to other electronic parts, for example, surface mount parts such as the cylindrical chip part 21 shown in FIG.

FIG. 10 is a sectional view showing a state where the cylindrical chip component 21 is mounted on the printed circuit board 10. The cylindrical chip component 21 includes an insulator 2 between the electrode 22 and the swollen electrode.
3, the cream solder 12 is applied so as to overlap the electrode 22 and the insulator 23.

[0019]

As described above, according to the present invention, the cream solder filling hole for mounting the electronic component provided on the screen is provided so as to overlap the electrode and the insulator of the electronic component. During the reflow process, the surface tension of the cream solder pulls the electronic components to securely solder them to the lands of the printed circuit board. Therefore, the correction work becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a printed circuit board coated with cream solder in a cream solder coating apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of relevant parts showing a state where the rectangular chip resistor is tilted and mounted on a printed circuit board.

FIG. 3 is a sectional view of a main part showing a soldering state after reflow.

FIG. 4 is a plan view of the same.

FIG. 5 is a plan view of the case where a plurality of square chip resistors are mounted.

FIG. 6 is a perspective view of a cream solder applicator according to a first embodiment of the present invention.

FIG. 7 is a sectional view of the same.

FIG. 8 is a sectional view of an apparatus for applying cream solder by pin transfer according to a second embodiment of the present invention.

FIG. 9 is a sectional view of the same.

FIG. 10 is a cream solder applicator when a cylindrical chip part is mounted according to a third embodiment of the present invention;
Sectional view of the main part of a printed circuit board coated with cream solder

FIG. 11 is a cross-sectional view of a main part of a printed circuit board to which cream solder has been applied by a conventional cream solder application device.

FIG. 12 is a sectional view of relevant parts showing a state where the square chip resistors are tilted and mounted on a printed circuit board.

FIG. 13 is a sectional view of relevant parts showing the soldering state after reflow

[Explanation of symbols]

 4 Chip Resistor 5 Electrode 6 Insulator 10 Printed Circuit Board 12 Cream Solder 14 Screen Device 16 Metal Screen

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shunji Maho 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A cream solder applicator for mounting an electronic component, which has electrodes on both ends thereof and an insulating material bulging from the electrode surface between the electrodes, on a printed circuit board. The cream solder coating device is provided on a screen used in the coating device, the filling holes of the cream solder facing each other for mounting the electronic component being provided at positions overlapping the electrodes and the insulator. 2. The cream solder coating apparatus according to claim 1, wherein the cream solder filling holes are convex toward the facing filling holes. 3. A cream solder applicator for mounting an electronic component, which has electrodes at both ends thereof and is provided with an insulating material in a bulge shape from the electrode surface between the electrodes, on a printed circuit board. The coating device comprises a pin and a filling hole provided on a plate fitted to the pin, and the shape of the pin or the filling hole is a cream solder coating device provided at a position overlapping the electrode and the insulator. 4. The cream solder applicator according to claim 3, wherein the pin and the filling hole are convex toward the facing filling hole.