JPH08116164A - Manufacture of solder precoated substrate - Google Patents

Abstract

PURPOSE: To provide a method for manufacturing a solder precoated substrate on which solder sections of a uniform height can be formed. CONSTITUTION: A circuit pattern which includes a plurality of electrode patterns 2, 3 where electrodes of electronic components are to be mounted and a connection pattern 4 to connect the electrode patterns 2, 3 is formed on a substrate 1. Solder 5, 6 is supplied onto the electrode patterns 2, 3 and/or the connection pattern 4. By melting this solder 5, 6, the solder 5, 6 on the electrode patterns 2, 3 is allowed to flow through the connection pattern 4. The connection pattern 4 and a part or all of the solder 7 is removed and the electrode patterns 2, 3 which are connected with the connection pattern 4 are electrically disconnected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a solder precoated substrate in which the solder on an electrode pattern has a uniform height.

[0002]

2. Description of the Related Art In recent years, with high integration of electronic parts,
Electronic parts such as SOP, QFP, BGA (ball grid array), etc., which have a large number of electrodes, are increasing in number. Therefore, a large number of electrode patterns are formed in groups on a substrate for mounting these electronic components. The solder pre-coated substrate is a substrate in which solder portions for soldering are previously formed on these many electrode patterns.

When forming this solder pre-coated substrate, it is necessary to form a solder portion on the electrode pattern. As a method therefor, a plating method, an organic acid solder method, a cream solder printing reflow method and the like are known. .

[0004]

Whatever method is used to form the solder portion, the conventional solder precoat manufacturing method forms the independent solder portion only on the electrode pattern. However, as described above, when the number of electrode patterns per electronic component increases, the height of the solder portion formed on each electrode pattern tends to vary. If there is this variation, when mounting the electronic component on the substrate in a later process, among the many electrodes such as leads or bumps of the electronic component, some may be mounted on the solder part,
Some things will not be listed. As a result, when the bonding process of the electronic components is completed, defective bonding such as solder opening occurs. As described above, the conventional method for manufacturing a solder pre-coated substrate has a problem that the height of the solder on the electrode pattern varies, which easily causes defective adhesion of electronic components.

Therefore, it is an object of the present invention to provide a method for manufacturing a solder pre-coated substrate capable of forming a solder portion having a uniform height.

[0006]

A method of manufacturing a solder pre-coated substrate according to the present invention comprises a large number of electrode patterns on which electrodes of electronic parts are to be mounted, and a connecting pattern for connecting all or a part of these electrode patterns to each other. A step of forming a circuit pattern including a wiring pattern on the substrate, supplying solder to the electrode pattern and / or the connection pattern, and melting the solder to flow the solder on the electrode pattern through the connection pattern; Removing all or a part of the solder on the pattern and the connection pattern so that the electrode patterns connected by the removed connection pattern are electrically disconnected.

[0007]

In the above structure, when the solder is melted, the surface tension of the solder causes the solder to move from the electrode pattern supplied with a relatively large amount to the electrode pattern supplied with a relatively small amount. As a result, variations in the amount of solder on the electrode patterns are eliminated, and solder portions having a uniform height are formed on each electrode pattern. Then, by the above removing step, a short circuit between the electrode patterns can be prepared for the electronic component mounting step.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is an enlarged plan view of a solder precoated substrate according to the first embodiment of the present invention, and FIG. 2 is an enlarged perspective view of the solder precoated substrate according to the first embodiment of the present invention, FIGS. FIG. 5 is an enlarged side view of the solder precoated substrate in the first embodiment of the present invention. First, FIG. 1 to FIG.
The basic form of the method for manufacturing a solder pre-coated substrate of the present invention (first embodiment; an example of handling two electrode patterns) will be described with reference to FIG.

In FIG. 1, 1 is a substrate, 2 and 3 are substrates 1.
2 is an electrode pattern formed on the surface of the. These electrode patterns 2 and 3 are for electronic parts such as QFP or SOP and have a rectangular shape. Reference numeral 4 is a thin connection pattern that directly connects the electrode patterns 2 and 3 adjacent to each other. Here, the circuit patterns such as the electrode patterns 2 and 3 are usually formed by an etching method or the like, but when the electrode patterns 2 and 3 are formed, the connection pattern 4 is also formed together. The electrode patterns for the same electronic component usually have the same shape (especially the width and area are the same).

FIG. 2 shows a state in which solder is supplied to the electrode patterns 2 and 3 of FIG. 1 and the solder is melted. In this example, as shown in FIG. 3, when the solder is supplied, the amounts of the solder 5 on the electrode pattern 2 and the solder 6 on the electrode pattern 3 are different, and the solder 5 on the electrode pattern 2 is different. ,
It is higher than the solder 6 on the electrode pattern 3. Then, when the solder is melted, the solder tends to take a shape having a lower curvature and a smaller curvature due to the surface tension thereof. Therefore, the solder 5 on the high electrode pattern 2 changes to the solder 6 on the electrode pattern 3. A flow phenomenon of solder occurs as shown by an arrow N1. This flow phenomenon stops when the surface tension of the solder 5 on the electrode pattern 2 and the surface tension of the solder 6 on the electrode pattern 3 are balanced. That is, when this flow phenomenon ends, as shown in FIG. 4, the solder 5 on the electrode pattern 2 and the solder 6 on the electrode pattern 3 are at the same height, which is high due to variations in the amount of supplied solder. Unevenness will be eliminated. Then
As shown in FIG. 5, the solder 7 and the connection pattern 4 on the connection pattern 4 are removed by the removal tool 8 such as a dicing saw.
Is partially removed to release the short circuit between the electrode pattern 2 and the electrode pattern 3. At this time, in short, the electrode pattern 2 and the electrode pattern 3 need only be disconnected, and it is not necessary to remove all of the connection pattern 4 and the solder 7 on the connection pattern 4.

Next, referring to FIG. 6 (plan view of the solder pre-coated substrate in the second embodiment of the present invention) and FIG. 7 (enlarged plan view of the solder pre-coated substrate in the third embodiment of the present invention), The formation of circuit patterns in the second and third embodiments will be described. First, in the second and third embodiments, the QFP is targeted. In FIG. 6 (second embodiment), the electrode patterns 9 are arranged directly at the positions corresponding to the four sides of the electronic component. Connection pattern 1
0 is connected. Others are the same as those in the first embodiment.

In FIG. 7 (third embodiment), the following device is further devised. That is, instead of directly connecting the adjacent electrode patterns 9 to each other, first, the first connection pattern 11 parallel to this row is formed at a position apart from the row of the electrode patterns 9. Further, the second connection pattern 12 is extended from each electrode pattern 9 toward the first connection pattern 11 and connected to the first connection pattern 11. Even in this manner, when the solder is melted, the solder can flow between the electrode patterns 9 via the second connection pattern 12, the first connection pattern 11, and the second connection pattern 12. You can Then, in the third embodiment, the deletion process shown in FIG. 5 can be simplified. That is, in the example of FIG. 6, it is necessary to cut the connection patterns 10 and the like between the electrode patterns 9 one by one (this is not the case if a tool capable of cutting all at once is prepared). In the third embodiment, by advancing the removal tool 8 in the direction of arrow N2, the short circuit of all the electrode patterns 9 shown in FIG. 7 can be released at once, and the tact time required for manufacturing can be shortened.

FIG. 8 is an enlarged plan view of a solder pre-coated substrate according to the fourth embodiment of the present invention. In the fourth embodiment, the BGA is targeted, and the bump electrode pattern 13 is formed in a circular shape. In addition, the bump electrode patterns 13 facing each other are connected by the second connection patterns 15, and the second connection patterns 15 are connected by a long first pattern.
Are connected by the connection pattern 14. By doing so, similarly to the third embodiment shown in FIG. 7, only the second connection pattern 15 and the solder on the second connection pattern 15 need to be collectively removed, and the tact time can be shortened. In the illustrated example, the connection pattern is formed in a grid pattern, but the connection pattern may be formed in various patterns such as a staggered pattern. Also QF
Not only P and SOP, it may be used for circuit patterns for electronic parts such as square chips and mini transistors.

[0015]

The method of manufacturing a solder pre-coated substrate according to the present invention includes a circuit pattern including a large number of electrode patterns on which electrodes of electronic parts are to be mounted and a connecting pattern for connecting all or some of these electrode patterns to each other. On the substrate, supplying solder to the electrode pattern and / or the connection pattern, and melting the solder to flow the solder on the electrode pattern through the connection pattern, and the connection pattern and the connection pattern. And removing all or a part of the solder on the electrode to electrically disconnect the electrode patterns connected by the removed connection pattern from each other, so that the electrode pattern is melted through the connection pattern. Flow the solder from the one with more solder to the one with less solder,
It is possible to eliminate the variation in the amount of solder on the electrode pattern and make the height of the solder portion uniform.

[Brief description of drawings]

FIG. 1 is an enlarged plan view of a solder precoated substrate according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a solder pre-coated substrate according to the first embodiment of the present invention.

FIG. 3 is an enlarged side view of the solder pre-coated substrate according to the first embodiment of the present invention.

FIG. 4 is an enlarged side view of the solder pre-coated substrate according to the first embodiment of the present invention.

FIG. 5 is an enlarged side view of the solder pre-coated substrate according to the first embodiment of the present invention.

FIG. 6 is a plan view of a solder precoated substrate according to a second embodiment of the present invention.

FIG. 7 is an enlarged plan view of a solder precoated substrate according to a third embodiment of the present invention.

FIG. 8 is an enlarged plan view of a solder precoated substrate according to a fourth embodiment of the present invention.

[Explanation of symbols]

 2 electrode pattern 3 electrode pattern 4 connection pattern 5 solder 6 solder 7 solder 9 electrode pattern 10 connection pattern 11 first connection pattern 12 second connection pattern 13 bump electrode pattern 14 first connection pattern 15 second connection pattern

Claims (5)

[Claims] 1. A step of forming, on a substrate, a circuit pattern including a large number of electrode patterns on which electrodes of an electronic component are to be mounted, and a connection pattern for connecting all or a part of these electrode patterns to each other, the electrode. Supplying solder to the pattern and / or the connection pattern, and melting the solder to cause the solder on the electrode pattern to flow through the connection pattern; and the solder on the connection pattern and the connection pattern. A step of removing all or part of the electrode patterns to electrically disconnect the electrode patterns connected by the removed connection pattern from each other. 2. The method for manufacturing a solder precoated substrate according to claim 1, wherein the connection pattern is arranged so as to directly connect adjacent electrode patterns. 3. The connection pattern comprises a first connection pattern arranged at a position distant from the electrode pattern, and a second connection pattern directly connected to the electrode pattern and connected to the first connection pattern. The method for manufacturing a solder precoated substrate according to claim 1, further comprising a connection pattern. 4. The method for manufacturing a solder precoated substrate according to claim 1, wherein the electrode pattern has a substantially rectangular shape. 5. The method for manufacturing a solder precoated substrate according to claim 2, wherein the electrode pattern has a substantially circular shape.