JP2002100865A - Forming method of end-surface electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming an end-surface electrode where, related to a substrate where a side-surface electrode is formed at the end of a gap, an end-surface electrode is surely formed with a solder at a position where the side-surface electrode is formed, without effected by a fixing jig for holding a solid solder. SOLUTION: A linear gap 12 is formed at a parent substrate 10 so that a module substrate 14 and a waste substrate 16 are formed. A side-surface electrode 20 is formed on an end on the gap side 12 of the module substrate 14. A solid solder 22 is press-fitted in the formation part of the side-surface electrode 20 of the gap 12 and a reflow jig 26 is installed. A flux is applied on the solid solder 22, which is heated to melt the solid solder 22, so that an end-surface electrode is formed at the side-surface electrode 20 which protrudes toward the substrate surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming an end face electrode, and more particularly, to a method of forming an end face electrode by soldering on an end face of a substrate on which an electronic component such as a module component is mounted. About.

[0002]

2. Description of the Related Art FIG. 18 is a plan view showing an example of a parent substrate used in a conventional method for forming an end face electrode. Parent board 1
, A plurality of linear gaps 2 are formed. Due to these gaps 2, a plurality of rectangular module substrates 3 are formed on the parent substrate 1, and a discard substrate 4 is formed therearound. A plurality of side electrodes 5 are formed on the end surface of the module substrate 3 facing the disposal substrate 4 with the gap 2 therebetween. An electrode pattern (not shown) is formed on the module substrate 3. Then, electronic components (not shown) are mounted on the module substrate 3, the electronic components and the electrode patterns are connected, and a circuit is formed. In order to connect the formed circuit to an external circuit, an electrode pattern is connected to the side electrode 5 formed at the end of the module substrate 3.

[0003] On the side surface electrode 5 of the module substrate 3, an end electrode protruding from the parent substrate 1 is formed by soldering. Therefore, as shown in FIG. 19, a fixing jig 6 for fixing the solid solder is placed on the mother board 1. Note that a flux is applied to the parent substrate 1 in advance. A through hole 7 is formed in the fixing jig 6 at a position corresponding to the side electrode 5, and a spherical solid solder 8 is inserted into the through hole 7. By heating in this state, the solid solder 8 is melted and hangs down on the side electrode 5. after that,
By cooling the parent substrate 1, as shown in FIG.
An end face electrode 9 made of solder is formed on the side face electrode 5.

After the end surface electrodes 9 are formed, a plurality of module components are obtained by cutting the parent substrate 1. At this time, the discarded substrate 4 is removed. When the module component thus obtained is mounted on a motherboard, the end face electrode 9 is placed on an electrode formed on the motherboard, and the motherboard and the module component are connected by reflow.

[0005]

However, in the conventional method for forming an end face electrode, a fixing jig is used to dispose solid solder on a side electrode forming portion, so that the position of the side electrode and the fixing jig are used. If the positions of the through holes do not completely correspond to each other, displacement of the solid solder may occur, or non-contact between the side electrode and the solid solder may occur. for that reason,
A case may occur where the end face electrode made of solder is not formed on the side face electrode portion. Further, since the solid jig is heated to melt the solid solder in a state where the fixing jig is placed on the mother board, a large amount of jigs are required at the time of mass production of module components. Furthermore, when thermal deformation occurs or a flux adheres to the fixing jig, defective formation of the end face electrode occurs.

Therefore, a main object of the present invention is to form an end face electrode by solder reliably at a position where a side face electrode is formed, without being affected by a fixing jig for holding solid solder. An object of the present invention is to provide a method for forming an end face electrode.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a step of preparing a substrate having a gap and having a side electrode formed on one of the ends facing the gap, and press-fitting solid solder into the gap between the boards. Holding the solid solder on the side surface electrode forming portion in the gap, and heating the substrate into which the solid solder has been pressed to melt the solid solder, thereby forming a convex end surface electrode with respect to the surface of the substrate. And a step of forming an end face electrode. In such a method of forming an end face electrode, a part or all of the solid solder can be press-fitted into the gap. Further, it is preferable that a concave portion is formed at least at an end of the substrate where the side electrode is formed. Further, after the solid solder is pressed into the gap, it is preferable to apply a flux or a solder paste to the press-fitted portion of the solid solder.

By press-fitting the solid solder into the gap between the substrates, the solid solder can be reliably held at the side electrode forming portion. Therefore, by melting the solid solder held in the gap, it is possible to form an end electrode made of solder that is convex with respect to the surface of the substrate in the side electrode.
When press-fitting the solid solder into the gap, a part of the solid solder may be press-fitted, or the whole may be press-fitted, as long as the solid solder is held in contact with the side electrode. At this time, the solid solder may be deformed or may be held in a state where it is hardly deformed. By forming a recess at the end of the substrate where the side electrode is formed, the solid solder can be positioned by the recess. At this time,
A concave portion may be formed in a portion facing the side electrode with a gap therebetween. After the solid solder is pressed into the gap between the substrates, by applying a flux, when the solid solder is melted, the wettability of the solder to the side electrodes can be increased, and the end electrodes can be securely attached to the side electrodes. Can be formed. Further, if a solder paste is used instead of the flux, the electronic component can be mounted on the substrate and connected to the side electrodes, and the end electrodes can be formed on the side electrodes.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the accompanying drawings.

[0010]

FIG. 1 is a plan view showing an example of a parent substrate used in a method of forming an end face electrode according to the present invention.
A plurality of linear gaps 12 are formed in the parent substrate 10. By these gaps 12, a plurality of rectangular module substrates 14 are formed, and a discard substrate 16 is formed therearound. A plurality of hemispherical concave portions 18 are formed at an end of the module substrate 14 on the side of the gap 12 at intervals. The side surface electrode 20 is formed in the concave portion 18 so as to extend from the end surface to one main surface or both main surfaces.
An electrode pattern (not shown) is formed on one surface of the module substrate 14, and an electronic component (not shown) is attached to the electrode pattern to form a plurality of circuits. Then, in order to connect the formed circuit to an external circuit, the electrode pattern is connected to the side electrode 20. By cutting the plurality of circuits, a plurality of module components are formed.

In order to mount the finally obtained module component on a mother board or the like, an end surface electrode made of solder is formed on the side surface electrode 20. Therefore, as shown in FIG. The solder 22 is placed. At this time, a transfer jig 24 having a through hole formed at a position corresponding to the side surface electrode 20 is used. By transferring the solid solder 22 into the through-hole 24 a of the transfer jig 24, the solid solder 22 is placed on the side electrode 20. Since the concave portion 18 is formed in the portion of the module substrate 14 where the side electrode 20 is formed, the solid solder 22 is positioned in the concave portion 18 portion. Therefore, the through-hole 24 a formed in the transfer jig 24 does not fix the solid solder 22, but may be any size that can transfer the solid solder 22 to the vicinity of the side surface electrode 20.

Solid solder 22 mounted on side electrode 20
Is pressed into the gap 12 by a press as shown in FIG. Pressing is performed between the mother board 10 and the solid solder 2 between the flat plates.
For example, the pressing is performed with a pressing pressure of 10 kg / point. By pressing the solid solder 22 into the gap 12 in this manner, the solid solder 22 is held in a state of being in contact with the side electrode 20. Then, a flux is applied onto the mother board 10 and reflowed under a condition of 220 to 240 ° C. in an N ₂ atmosphere, whereby the solid solder 22 is melted. At this time, in order to prevent deformation of the mother board 10, FIG.
As shown in (1), a plate-shaped reflow jig 26 may be provided along the parent substrate 10 except for the gap 12 and the side electrode 20.

When the solid solder 22 is melted, the wettability with the side electrode 20 is improved by the action of the flux, and the molten solder adheres to the side electrode 20. By cooling in this state, as shown in FIG. 4, an end face electrode 28 made of solder that is convex with respect to the surface of the parent substrate 10 is formed on the side face electrode 20. Parent substrate 1 on which end electrode 28 is formed
0 is a module substrate 1 on which a circuit has been cut and a circuit has been formed.
4 are cut off to obtain a plurality of module parts.
At this time, the discarded substrate 16 is removed. When the module component is mounted on a motherboard or the like, the end face electrodes 28 are placed on the electrode pattern of the motherboard, and the side electrodes 20 of the module component and the electrode pattern of the motherboard are soldered by reflow.

If such a method of forming the end face electrodes is adopted, the solid solder 22
And the side electrode 20 can be reliably obtained, and the end surface electrode 28 can be reliably formed on the side electrode 20. Therefore, the non-defective product rate of the end face electrode 28 can be improved. In addition, since a jig for positioning the solid solder 22 is not required, cost can be reduced. Furthermore, when the solid solder 22 is melted, a jig for positioning the solid solder 22 is not used,
It is possible to prevent defects due to adhesion of flux to the jig.

When the solid solder 22 is press-fitted into the gap 12, it may be press-fitted to the middle of the thickness of the parent board 10 as shown in FIG. 5, or as shown in FIG. The lower surface may be press-fitted. When the solid solder 22 is pressed into the lower surface of the mother board 10, the solid solder 22 may be in a state in which the solid solder 22 is not so deformed as shown in FIG. 6, and as shown in FIG. May be press-fitted so as to close off. As described above, regardless of the degree of press-fitting of the solid solder 22 and the presence or absence of deformation, the solid solder 22 is
If the end face electrode 2 is held in contact with the
8 can be formed.

As shown in FIG. 8, after the solid solder 22 is pressed into the gap 12 of the mother board 10, a solder paste 30 is printed on one surface of the mother board 10, and the solid solder 22 is melted to form an end face. The electrode 28 may be formed. In this case, the solder paste 30 improves the wettability between the side electrode 20 and the molten solid solder 22, and also allows the electronic component mounted on the module substrate 14 to be soldered to the electrode pattern. As described above, by using the solder paste 30 instead of the flux, the end face electrode 2
8 and the mounting of electronic components can be performed simultaneously. In this case, it is desirable that the solid solder 22 be deformed so as to cover the recess 18.

Concave portion 1 formed in module substrate 14
8 may be not only a semicircular shape as shown in FIG. 2 but also a rectangular shape as shown in FIG.
As shown in FIG. in this way,
The shape of the concave portion 18 formed in the module substrate 14 can be arbitrarily changed, as long as the solid solder 22 can be positioned on the side electrode 20. Also, as shown in FIG.
The recess 18 may not be formed. In this case, it is necessary to take measures to prevent the displacement of the solid solder 22. However, if the solid solder 22 is press-fitted into the gap 12, the end face electrode 28 is surely formed similarly to the parent substrate 10 having the concave portion 18. be able to.

In order to further increase the positioning accuracy of the solid solder 22, a semicircular recess 32 may be formed in the discarded substrate 16 facing the recess 18, as shown in FIG. In this manner, by forming the concave portion 32 also on the disposal substrate 16 side, the positioning accuracy of the solid solder 22 can be enhanced in cooperation with the concave portion 18 on the module substrate 14 side. Needless to say, a rectangular concave portion 32 as shown in FIG. 13 or a triangular concave portion 32 as shown in FIG.

Furthermore, the gap is not limited to a linear one, but may be a recess 18 of the module substrate 14 and the discarded substrate 16.
A gap may be formed with the concave portion 32 of FIG. That is, FIG.
As shown in FIG. 2, two concave portions 18 and 32 are formed between the module substrate 14 and the disposal substrate 16, and the module substrate 14 and the disposal substrate 16 adhere to each other except for these concave portions 18 and 32. The structure may be as follows. Also in this case, by forming the side electrode 20 in the concave portion 18 of the module substrate 14, the solid solder 22 can be pressed in contact with the side electrode 20. Of course, the shape of the concave portion 32 of the discard substrate 16 may be a semicircle as shown in FIG. 15, a rectangular shape as shown in FIG. 16, or a triangular shape as shown in FIG. It may be. In FIGS. 15 to 17, a cut between the module substrate 14 and the waste substrate 16 may not be formed. In this case, a module component can be obtained by finally cutting the mother board 10 between the two concave portions 18 and 32.

The shape of the solid solder 22 is not limited to a sphere, but may be a column, a cone, a hemisphere, a prism, a pyramid, a T-shape, or any other shape that can be pressed into the recess 18.
Any shape may be used. As a material of the solid solder 22, for example, SnPb, SnAg, SnC
Any metal composition such as u, SnSb, SnBi, SnZn, SnAgCu, etc., and a surface-coated product may be used.

[0021]

According to the present invention, the solid solder is held in a state in which the solid solder is securely brought into contact with the side electrode formed on the module substrate by press-fitting the solid solder into the concave portion formed on the module substrate. Can be. Therefore, it is possible to reliably form the end face electrode on the side face electrode by melting the solid solder. In addition, since a jig for positioning the solid solder is not required, flux does not adhere to the jig, and the formation of the end surface electrode by the jig does not occur. Therefore, the non-defective product rate of the end face electrode can be improved. Further, by pressing the solid solder into the recess and then printing the solder paste to form an end face electrode, the electronic component mounted on the substrate can be soldered to the electrode pattern by the solder paste. As described above, by using the solder paste, the formation of the end face electrode and the mounting of the electronic component can be performed at the same time, and the number of manufacturing steps and cost of the module component can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a parent substrate used in a method of forming an end face electrode according to the present invention.

FIG. 2 is an illustrative view showing a state where solid solder is transferred into a concave portion of the parent substrate shown in FIG. 1 using a transfer jig.

FIG. 3 is an illustrative view showing a state in which solid solder is pressed into a concave portion of a mother board and a reflow jig is installed.

FIG. 4 is an illustrative view showing a state where end electrodes made of solder are formed on side electrodes;

FIG. 5 is an illustrative view showing one example of a press-fit state of solid solder;

FIG. 6 is an illustrative view showing another example of a press-fit state of a solid solder;

FIG. 7 is an illustrative view showing still another example of a press-fit state of solid solder;

FIG. 8 is an illustrative view showing a state where a solder paste is printed on a solid solder pressed into a concave portion;

FIG. 9 is an illustrative view showing another example of the concave portion formed in the module substrate;

FIG. 10 is an illustrative view showing still another example of the concave portion formed in the module substrate;

FIG. 11 is an illustrative view showing an example in which a concave portion is not formed in the module substrate;

FIG. 12 is an illustrative view showing one example of a concave portion formed in a discard substrate;

FIG. 13 is an illustrative view showing another example of the concave portion formed in the discard substrate;

FIG. 14 is an illustrative view showing still another example of the concave portion formed in the discard substrate;

FIG. 15 is an illustrative view showing one example of a gap formed by a concave portion of the module substrate and a concave portion of the discard substrate;

FIG. 16 is an illustrative view showing another example of the gap formed by the concave portion of the module substrate and the concave portion of the discard substrate;

FIG. 17 is an illustrative view showing still another example of the gap formed by the concave portion of the module substrate and the concave portion of the discard substrate;

FIG. 18 is a plan view showing an example of a parent substrate used in a conventional method for forming an end face electrode.

FIG. 19 is an illustrative view showing a state where solid solder is held on a parent board by a conventional method;

FIG. 20 is an illustrative view showing a state where an end face electrode made of solder is formed on a side face electrode by a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Parent board 12 Gap 14 Module board 16 Discard substrate 18 Depression 20 Side electrode 22 Solid solder 28 End electrode 30 Solder paste 32 Depression

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B23K 101: 42 B23K 101: 42 F term (Reference) 5E317 AA22 BB01 BB11 CC15 GG07 GG16 5E319 AA03 AB05 BB01 BB05 BB07 BB08 CC33 CD04 CD21 CD23 CD25 GG15 5E338 AA00 BB47 BB65 BB75 CC01 CD33 EE33 EE51

Claims (4)

[Claims] A step of preparing a substrate having a gap and having a side electrode formed on one of ends facing the gap, wherein a solid solder is press-fitted into the gap of the board so that the solid solder is formed. The step of holding the side surface electrode forming portion in the gap, and heating the substrate into which the solid solder is press-fitted to melt the solid solder, thereby forming a convex end surface electrode with respect to the surface of the substrate. A method for forming an end face electrode, comprising a step of forming the end face electrode. 2. The method according to claim 1, wherein a part or all of the solid solder is press-fitted into the gap. 3. The method for forming an end face electrode according to claim 1, wherein a concave portion is formed at least at an end of the substrate where the side face electrode is formed. 4. The end face electrode according to claim 1, wherein a flux or a solder paste is applied to a press-fit portion of the solid solder after the solid solder is pressed into the gap. Method.