KR20020050109A - Parts-housing substrate and the method of manufacturing the same - Google Patents

Abstract

PURPOSE: To improve the reliability of soldered connections at the time of soldering electronic parts to a printed wiring board by using lead-free solder. CONSTITUTION: At the time of soldering the electronic parts 22 to the printed wiring board 21 by using the lead-free solder 23, conductor inserting holes 28 are made parts 22 are inserted. In addition, auxiliary conductors 30 which electrically connect conductor patterns 25 and 25 to each other are provided in the holes 28. Even when lift-off phenomena occur on the upper surface sides of the portions to which the leads 22a of the parts 22 are soldered, the auxiliary conductors 30 can supplement the electrical connection between the conductor patterns 25 and 25.

Description

PARTS-HOUSING SUBSTRATE AND THE METHOD OF MANUFACTURING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a component mounting board and a method for manufacturing the same, wherein the wiring board having a conductive pattern on both sides is soldered with an electric component using lead-free solder containing no lead.

Conventionally, when soldering an electrical component to a printed wiring board as a wiring board, a process solder which is an alloy of tin and lead has been used from the standpoint of its manufacturability and reliability. Process solder is an alloy of 63% by weight tin and 37% by weight lead. However, at the time of disposal of the product, the component mounting substrate soldered using the process solder is generally embedded. In recent years, when acid rain falls on landfills, lead components in the process solder melt, causing environmental problems.

In order to cope with this environmental problem, research and development of solders containing no lead have been actively made in recent years. The solder which does not contain lead is generally called "lead free solder." Lead-free solder is mainly made of tin, and is an alloy in which tin is mixed with a few percent silver or copper. One of the problems in the case of using this lead-free solder is a phenomenon called lift-off.

For example, in a printed-wiring board (double-sided board) provided with a conductor pattern (printed circuit) on both sides of a glass-reinforced epoxy substrate or the like, soldering is performed using the lead-free solder described above. When this is done, a phenomenon occurs in which peeling occurs between the solder and the land of the conductor pattern on the surface (surface of the side where the electrical component is arranged) of the printed wiring board. This phenomenon is called lift off.

Printed wiring boards having conductor patterns on both sides have conventionally been subjected to surface treatment by soldering. In this process, the printed wiring board is immersed in the molten solder containing lead, and when the printed wiring board is extracted from the molten solder, hot air is blown to remove the solder in the through-hole in the printed wiring board, and the exposure in the conductive pattern is performed. It is called a hot air leveler process (henceforth a HAL process) by making the film thickness of the solder of a part constant. By carrying out this HAL treatment, the solderability at the time of soldering an electrical component improves.

7 shows a double-sided substrate subjected to such HAL processing. In FIG. 7, the base material 2 of the printed wiring board 1 which is a wiring board is made of glass epoxy, for example, and the copper conductor pattern 3 is provided in the front and back surfaces of this base material 2, and A resist 4 is provided in the conductor pattern 3 to prevent solder from adhering. A through hole 5 is formed in the printed wiring board 1. The through hole 5 is for inserting a lead of an electrical component (not shown), for example, and a connection pattern 3a for electrically connecting the conductor patterns 3 on both front and back surfaces is also provided on the inner circumferential surface thereof. . The HAL treatment is performed on the surfaces of the portions (landing portions) of the good conductor patterns 3 on both front and back surfaces that are not covered by the resist 4 and on the surfaces of the connection patterns 3a in the through holes 5. The process solder layer 7 formed by this is provided.

However, when soldering an electric component to the printed wiring board 1 which HAL-processed in this way using the said lead-free solder (solder which does not contain lead), the phenomenon called lift-off may arise. FIG. 8 is a diagram for explaining a phenomenon called the lift off, and the lift off phenomenon will be described using FIG. 8.

When the lead 8 of the electrical component is inserted into the through hole 5 of the printed wiring board 1 and soldered with lead-free solder in an automatic soldering tank (dip soldering), the molten state The lead-free solder 9 passes between the inner surface of the through hole 5 and the lead 8 from the lower surface (solder surface) side of the printed wiring board 1, and the upper surface (component) of the printed wiring board 1 And the lead solder 8, the upper and lower conductor patterns 3, and the connection pattern 3a are soldered by the pre-solder 9.

At this time, the lead component 10 contained in the process solder layer 7 formed by the HAL treatment melts out and enters into the lead-free solder 9 which is originally free of lead. When the lead-free solder 9 is cooled and hardened, the lead-free solder 9 is hardened in the order of a, b, c, and d on the upper surface side of the printed wiring board 1. When the portion a hardens, the tin having a high melting point hardens first, and the lead component 10 is pushed downward. At the same time, even when the part of b hardens, the lead component 10 is pushed down. In this way, the lead component 10 having a low melting point is collected in the portion of d. This is called segregation of lead. Therefore, the lead-free solder 9 is gradually hardened from the upper side on the upper surface side of the printed wiring board 1, and finally, the vicinity of d is hardened. Then, the upper portion is hardened and at the same time, the contracting force is generated, and the portion d which is not yet hardened is tensioned. In this way, lift-off occurs in which the lead-free solder 9 and the land 3b of the conductor pattern 3 on the upper surface side peel off at the upper surface side of the printed wiring board 1 (indicated by “11” in FIG. 8). Lift-off generating portion).

It is known that such lift-off does not occur in the lower surface side (solder surface side) of the printed wiring board 1. In addition to the above-described HAL treatment, the lift-off as described above may occur under the influence of lead even when the lead 8 of the electrical component is subjected to surface treatment with solder containing lead, for example.

If lift off occurs, the reliability of the connection of the solder joint is impaired. In addition, when a large current flows in the soldering part where this lift-off has occurred, the part may generate | occur | produce heat | fever, and smoke and ignition can also be considered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a component mounting substrate and a method for manufacturing the same, which can improve the reliability of the connection by soldering using lead-free solder containing no lead. have.

1 is a longitudinal sectional view of an essential part showing a first embodiment of the present invention;

2 is an equivalent view of FIG. 1 showing a second embodiment of the present invention;

3 is an equivalent view of FIG. 1 showing a third embodiment of the present invention;

4 is a longitudinal sectional view of a main part before soldering, showing a fourth embodiment of the present invention;

5 is an equivalent view of FIG. 1 showing a fifth embodiment of the present invention;

6 is an equivalent view of FIG. 1 showing a sixth embodiment of the present invention;

Fig. 7 shows a conventional example and is a longitudinal cross-sectional view of a printed wiring board in a state where HAL processing is performed;

8 is a longitudinal cross-sectional view for explaining a mechanism in which lift off occurs.

* Explanation of symbols for the main parts of the drawings

21: printed wiring board (wiring board) 22: electrical components

22a: Lead 23: lead free solder

25: conductor pattern 25a: connection pattern

27: lead insertion hole 28: conductor insertion hole

30: auxiliary conductor 30a: insertion

30b: substrate surface opposing part 31: auxiliary through hole

32: auxiliary conductor 33: exposed part

34: gold plating 35: through hole

36: electrical component 36a: lead

37: single through hole

In order to achieve the above object, the invention of claim 1 inserts a lead of an electrical component into a lead insertion hole of a wiring board having a conductor pattern on both sides, and does not contain lead and a conductor pattern on both sides of the wiring board. In a component mounting board having a configuration of soldering using lead-free solder, the wiring board is provided with a conductor insertion hole located in the vicinity of the lead insertion hole, and is inserted into the conductor insertion hole and soldered to the lead. An auxiliary conductor is provided for electrically connecting the two conductor patterns on both sides of the wiring board.

In the above means, the electrical connection between the conductor patterns on both sides of the wiring board on which the leads of the electrical components are soldered is also performed in the vicinity of the lead insertion hole where the leads of the electrical components are soldered, also in the auxiliary conductor portion. For this reason, even if the lift-off phenomenon occurs in the soldered part of the electrical component, the electrical connection between the conductor patterns on both sides of the wiring board can be assisted in the auxiliary conductor portion, so that the lead and the wiring board of the electrical component are consequently. The reliability of the electrical connection between the two-sided conductor patterns can be improved.

In this case, as in the invention of claim 2, it is preferable that the auxiliary conductor has a structure in which the substrate surface opposing portion is integrally opposed to the substrate surface on which the conductor pattern is provided on the wiring board.

According to this, lead-free solder easily enters between the substrate surface opposing portion of the auxiliary conductor and the conductor pattern during soldering with lead-free solder, and the soldered area of the auxiliary conductor and the conductor pattern can be increased, and furthermore, these auxiliary conductors. And the reliability of the connection of the soldered part of a conductor pattern can be improved.

The invention according to claim 3 is characterized in that the conductor insertion hole into which the auxiliary conductor is inserted is a through hole having a connection pattern electrically connected between the conductor patterns on both sides of the wiring board on the inner circumferential surface thereof.

When soldering with an auxiliary conductor inserted into the conductor insertion hole, lead-free solder easily enters the upper surface side (part surface side) of the conductor insertion hole, and the lead-free solder and the auxiliary conductor between the two conductor patterns on both sides of the wiring board. Can be easily and reliably connected. That is, when there is no connection pattern for electrically connecting the two conductor patterns on both sides of the wiring board on the inner circumferential surface of the conductor insertion hole, it is necessary to perform soldering of the auxiliary conductor and the conductor pattern on the upper and lower sides, but according to the invention of claim 3, the auxiliary Soldering of a conductor and a conductor pattern can be performed at once.

The invention of claim 4 is characterized in that the lead-free solder is mainly made of tin and that is tin plated on the surface as an auxiliary conductor.

According to this, the lead-free solder mainly made of tin and the auxiliary conductor tin-plated on the surface fuse well with each other and the solder adhesion becomes good.

In the invention of claim 2, in the invention of claim 2, an auxiliary through hole having a connection pattern electrically connected between the conductor patterns on both sides of the wiring board is provided on the inner circumferential surface at a portion of the wiring board facing the substrate surface opposing part of the auxiliary conductor. And lead-free solder is introduced into the auxiliary through hole.

According to this, when soldering with lead-free solder, lead-free solder easily enters between the substrate surface opposing portion and the conductor pattern of the auxiliary conductor even through the auxiliary through hole, and the soldering area of the auxiliary conductor and the conductor pattern is further increased. Further, the reliability of the connection between these auxiliary conductors and the soldered portion of the conductor pattern can be further improved.

The invention according to claim 6 is characterized in that the part for installing the auxiliary conductor is in the vicinity of the lead insertion hole into which the lead of the electrical component in which a relatively large current flows is inserted.

The reliability of the connection between the lead of an electrical component and the conductor pattern on both sides of the wiring board becomes more problematic as the current flowing through the electric component becomes larger. Therefore, the auxiliary conductor which auxiliaryly connects the conductor pattern to which the lead of the electrical component is connected is electrically connected. It is effective to install near the lead insertion hole into which the lead of the component is inserted.

In order to achieve the above object, the invention of claim 7 includes a lead-free lead containing no lead in an electrical component in a state in which a wiring board having a conductive pattern on both surfaces thereof is not subjected to HAL treatment with solder containing lead. It is a manufacturing method of a component mounting board which makes it solder with the said conductor pattern using solder.

According to this, since the soldering is performed using a lead-free solder that does not contain HAL and does not contain lead, the soldering can be performed without containing lead. Therefore, it is possible to prevent the occurrence of lift off caused by the inclusion of lead, and further improve the reliability of the connection by soldering. In addition, since the high temperature HAL treatment is not performed on the wiring board, the stress applied to the wiring board can be reduced as compared with the case of performing the HAL processing.

In order to achieve the same purpose as in the invention of claim 7, the lead of the electrical component is not included in the wiring board having the conductor pattern on both sides without performing HAL treatment with solder containing lead. And a lead-free solder that is soldered with the conductor pattern.

According to this, the same effect as the invention of claim 7 can be obtained.

The invention of claim 9 is characterized in that the plating of the exposed portion of the conductor pattern is performed on the wiring board in the invention of claim 8.

If the wiring board is not subjected to HAL treatment, the exposed portion of the conductor pattern may be corroded. However, the gold plating treatment may be performed on the exposed portion of the conductor pattern to prevent corrosion of the portion. Reliability can be improved.

In the invention of claim 8, in the invention of claim 8, a through hole having a connection pattern for electrically connecting the conductor patterns on both sides of the wiring board to the inner circumferential surface of the wiring board is shared with the lead insertion hole for inserting the lead of the electrical component. It is done.

If the wiring board is not subjected to the HAL treatment, lead-free solder hardly flows into the through-holes and the solder is hard to come out if it is a simple through-hole without inserting the lead of the electrical component. Therefore, by sharing the through hole with the lead insertion hole into which the lead of the electrical component is inserted, the lead-free solder easily flows into the through hole, and the solder easily comes out. Therefore, the lead patterns can be satisfactorily connected between the conductor patterns on both sides of the wiring board.

In the invention of claim 8, in the invention of claim 8, the inner peripheral surface of the wiring board has a connection pattern for electrically connecting the conductor patterns on both sides of the wiring board, and has a single through hole through which the lead of the electrical component is not inserted. In the case where lead-free solder is introduced into the single through hole, the inner diameter of the single through hole is set to 0.7 mm or more.

If the lead-free solder is not introduced into the single through hole where the lead of the electrical component is not inserted when the wiring board is not subjected to HAL treatment, the inner diameter of the single through hole is smaller than 0.6 mm. It was found that the lead-free solder did not rise to the upper surface side (component surface side) because it was too small. Therefore, when the inner diameter is set to 0.7 mm or more, the lead-free solder easily rises to the upper surface side. This makes it possible to satisfactorily connect the conductor patterns on both sides of the wiring board by lead-free solder.

Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows a state in which the electric component 22 is soldered using lead-free solder 23 containing no lead to the printed wiring board 21 constituting the wiring board. In FIG. 1, the base material 24 of the printed wiring board 21 is made of glass epoxy, for example, and the copper conductor pattern 25 is provided in the front and back both sides of this base material 24, and the conductor pattern ( A resist 26 is provided to prevent solder from adhering to 25).

In the printed wiring board 21, a lead insertion hole 27 for inserting the lead 22a of the electric component 22 is formed, and a conductor insertion hole 28 located in the vicinity of the lead insertion hole 27 is provided. ) Are formed. The lead insertion hole 27 and the conductor insertion hole 28 each comprise through-holes, and a connection pattern for electrically connecting the upper and lower conductive patterns 25 of the printed wiring board 21 to the respective inner circumferential surfaces thereof ( 25a) is installed. Among the upper and lower conductive patterns 25, the diameter A1 of the land 29a on the upper surface, which is the solder surface of the lead insertion hole 27, is smaller than the diameter A2 of the land 29b on the lower surface side. It is set (A1 <A2).

The lead 22a of the electrical component 22 is inserted into the lead insertion hole 27 from the upper part in the drawing, and the lead 22a and the conductor patterns 25 on both sides of the upper and lower sides are formed by the lead-free solder 23. Soldered In this case, the electric component 22 is a capacitor through which a relatively large current flows, for example, 1 A or more. The lead-free solder 23 is mainly composed of tin, for example, an alloy of 95.8 wt% tin, 3.5 wt% silver, and 0.7 wt% copper.

In the two conductor insertion holes 28, insertion portions 30a on both sides of the auxiliary conductor 30 having an almost inverted C shape are inserted from the top in the drawing, and the auxiliary conductor 30 and the upper and lower conductive patterns 25 is soldered by the lead-free solder 23. Therefore, the auxiliary conductor 30 electrically connects between the upper and lower conductor patterns 25 to which the leads 22a of the electrical component 22 are connected through the lead-free solder 23. The auxiliary conductor 30 integrally has a substrate surface opposing portion 30b that opposes the upper surface (substrate surface) of the printed wiring board 21, and the substrate surface opposing portion 30b and the upper portion of the printed wiring board 21. Lead-free solder 23 also enters between the conductor patterns 25 on the surface side. Lower ends of both insertion portions 30a of the auxiliary conductor 30 are also bent inward. In this case, as the auxiliary conductor 30, an interlocking wire with tin plating on the surface is used.

When soldering the electrical component 22 or the auxiliary conductor 30 to the printed wiring board 21 is carried out as follows. First, the lead 22a of the electrical component 22 is inserted into the lead insertion hole 27 of the printed wiring board 21, and the insertion portion 30a of the auxiliary conductor 30 is inserted into each of the conductor insertion holes 28. Insert it. Then, in the automatic soldering tank, the bottom surface of the printed wiring board 21 is soldered by the dip soldering method of attaching the lead-free solder in the molten state. In this way, the electrical component 22 and the auxiliary conductor 30 are soldered by the lead-free solder 23 as shown in FIG.

According to the above embodiment, the following effects can be obtained.

Good conductor patterns on both sides of the printed wiring board 21 on which the leads 22a of the electric parts 22 are soldered in the vicinity of the lead insertion holes 27 where the leads 22a of the electric parts 22 through which a relatively large current flows are soldered. The electrical connection between the terminals 25 is also performed at the part of the auxiliary conductor 30. For this reason, for example, even if a phenomenon called lift-off occurs in a portion (a peripheral edge of the lead insertion hole 27) to which the lead 22a of the electric component 22 is soldered, Since the electrical connection between the good conductor patterns 25 can be assisted, the reliability of the electric connection between the lead 22a of the electric component 22 and the good conductor patterns 25 on both sides can be improved as a result. The provision of this auxiliary conductor 30 is particularly effective for the portion where a large current flows on the upper surface side of the printed wiring board 21.

The auxiliary conductor 30 has an almost inverted c-shape, and has a structure in which the printed wiring board 21 integrally includes a substrate surface opposing portion 30b that opposes the substrate surface (upper surface) on which the conductor pattern 25 is installed. Therefore, the lead-free solder 23 easily enters between the substrate surface opposing portion 30b of the auxiliary conductor 30 and the conductor pattern 25 during soldering with lead-free solder, and the auxiliary conductor 30 and the conductor The soldered area of the pattern 25 can be enlarged, and furthermore, the reliability of the connection of these auxiliary conductors 30 and the soldered part of the conductor pattern 25 can be improved.

In addition, the auxiliary conductor 30 has an almost inverted c-shape, and both insertion portions 30a are inserted into the conductor insertion holes 28 and soldered by the lead-free solder 23, so that the auxiliary conductor 30 And the soldered area of the conductor pattern 25 can be further increased.

Moreover, since each conductor insertion hole 28 is comprised by the through-hole which has the connection pattern 25a which electrically connects between the conductor patterns 25 of both upper and lower sides to the inner peripheral surface, when soldering, lead-free solder 23 ) Easily enters the upper surface side (part surface side) of the conductor insertion hole 28, and the lead-free solder 23 and the auxiliary conductor 30 can easily and reliably connect between the upper and lower conductor patterns 25 on both sides. Will be. That is, when there is no connection pattern for electrically connecting the upper and lower double-sided conductor patterns 25 on the inner circumferential surface of the conductor insertion hole 28, soldering of the auxiliary conductors 30 and the conductor patterns 25 can be performed on both the upper and lower sides. Although it is necessary, according to the present embodiment, soldering of the auxiliary conductor 30 and the conductor pattern 25 can be reliably performed at once.

In addition, since the lead-free solder 23 uses the tin mainly and the auxiliary conductor 30 uses the tin-plated on the surface, the tin-free solder 23 and the surface are tin-plated. The auxiliary conductors 30 fuse well with each other and have good solderability.

In the above-described embodiment, the diameter A1 of the land 29a on the upper surface side of the lead insertion hole 27 circumferential edge portion of the conductor patterns 25 on both the upper and lower sides is set to the diameter A2 of the land 29b on the lower surface side. Since it is set smaller than) (A1 &lt; A2), there is an advantage that a lift-off does not occur.

FIG. 2 shows a second embodiment of the present invention, which differs from the above-described first embodiment in the following points. In other words, two auxiliary through holes 31 are provided in the printed wiring board 21 at a portion of the auxiliary conductor 30 that faces the substrate surface opposing portion 30b. In this case, two auxiliary through holes 31 are provided. The lead-free solder 23 is also introduced. The inner circumferential surface of each auxiliary through hole 31 is also provided with a connection pattern 25a for electrically connecting the upper and lower both sides of the conductor pattern 25.

In such a configuration, the lead-free solder 23 at the time of soldering by the lead-free solder is also connected to the substrate surface opposing portion 30b and the conductor pattern 25 of the auxiliary conductor 30 through each of the auxiliary through holes 31. It becomes easy to enter in between, and the soldering area of the auxiliary conductor 30 and the conductor pattern 25 can be enlarged further, Furthermore, of the connection of the soldering part of these auxiliary conductor 30 and the conductor pattern 25 is carried out. The reliability can be further improved.

3 shows a third embodiment of the present invention, which differs from the above-described first embodiment in the following points. That is, the conductor insertion hole 28 is one, and the insertion part 32a of the auxiliary conductor 32 which forms pin shape is inserted in this conductor insertion hole 28, and this auxiliary conductor 32 and the upper and lower surfaces of both sides are inserted. The good conductor pattern 25 is soldered by the lead-free solder 23. The auxiliary conductor 32 has no substrate surface opposing portion 30b like the auxiliary conductor 30 of the first and second embodiments, but has a fixing portion 32b that is larger in the horizontal direction than the insertion portion 32a. have.

In this third embodiment as well, almost the same effects as in the first embodiment can be obtained.

In the first to third embodiments described above, the printed wiring board 21 may or may not be subjected to HAL processing.

Here, in the case of soldering with such lead-free solder, in order to minimize the amount of lead in the lead-free solder as much as possible, a printed wiring board not subjected to HAL treatment by process soldering containing lead is used. The mixing of lead can be further reduced and the occurrence of lift off can also be reduced.

4 shows a fourth embodiment of the present invention. Here, the printed wiring board 21 uses what is not HAL-processed by process solder containing lead. In the printed wiring board 21 which is not subjected to the HAL treatment, the exposed portion 33 of the conductive pattern 25, which is not covered with the resist 26, that is, the solder adhesion surface, is exposed to the copper of the conductive pattern 25. Since it becomes in the state which became a state, the corrosion of copper in atmosphere, such as hydrogen sulfide, is concerned. Therefore, in the fourth embodiment, the gold plating 34 is applied to the surface of the exposed portion 33 of the conductor pattern 25. FIG.

In such a configuration, the exposed portion 33 of the conductor pattern 25 is covered by the gold plating 34 to prevent corrosion of the exposed copper of the conductor pattern 25. In this case, since the printed wiring board 21 is not subjected to HAL treatment by the process solder containing lead, the incorporation of lead into the lead-free solder used for soldering can be further reduced and the occurrence of lift-off can be reduced. The highly reliable printed wiring board 21 can be provided.

5 shows a fifth embodiment of the present invention.

In the printed wiring board 21 which is not subjected to the HAL treatment, the lead-free solder is formed at the portion of the through hole that does not pass the lead of the electric component, that is, the simple through hole 5 for connecting between the upper and lower both sides of the conductor pattern 25. If soldering is carried out by 23), the state of rising from the lower surface side to the upper surface side of the solder becomes worse. Thus, in the fifth embodiment, the through hole 35 is designed to be shared with the lead insertion hole into which the lead 36a of the electric component 36 is inserted.

In such a configuration, the lead 36a of the electrical component 36 is inserted into the through hole 35 so that the lead-free solder 23 is soldered from the lower surface side to the upper surface side of the printed wiring board 21. The state of rise of the solder is improved, and the lead-free solder 23 can be satisfactorily connected between the upper and lower conductor patterns 25.

6 shows a sixth embodiment of the present invention.

This example is an example in which soldering with lead-free solder 23 is performed on a single through hole 37 in which the lead of an electrical component is not inserted in the same printed wiring board 21 not subjected to HAL processing.

In this connection, conventionally, the inner diameter of such a single through hole was 0.6 mm or less. When soldering with lead-free solder was applied to such single through-holes without performing HAL treatment, it was found that the solder did not rise to the upper surface side of the printed wiring board.

Thus, in the present embodiment, the inner diameter D of the single through hole 37 is set to 0.7 mm or more. As a result, the lead-free solder 23 easily rises from the lower surface side of the single through hole 37 to the upper surface side, whereby the conductor patterns 25 on both sides of the printed wiring board 21 are transferred to the lead-free solder 23. This makes it possible to connect satisfactorily.

The present invention is not limited to each of the above embodiments, but can be modified or expanded as follows.

The electrical component 22 through which a relatively large current flows may be a switching device, a diode, a coil, a transformer, or the like in addition to the capacitor.

As is clear from the above description, according to the present invention, the following effects can be obtained.

According to the invention of claim 1, in the vicinity of the lead insertion hole in which the lead of the electrical component is soldered, electrical connection between the conductor patterns on both sides of the wiring board on which the lead of the electrical component is soldered is also performed in the auxiliary conductor portion. Therefore, even if a phenomenon called lift-off occurs in the soldered part of the electrical component, the electrical connection between the conductor patterns on both sides of the wiring board can be assisted in the auxiliary conductor portion, so that the lead and the wiring of the electrical component are consequently. The reliability of the electrical connection between the conductor patterns on both sides of the substrate can be improved.

According to the seventh and eighth aspects of the present invention, since the soldering is performed using a lead-free solder that does not contain HAL and does not contain lead, the soldering can be performed without containing lead. Therefore, it is possible to prevent the occurrence of lift off caused by the inclusion of lead, and further improve the reliability of the connection by soldering. In addition, since the high temperature HAL treatment is not performed on the wiring board, the stress applied to the wiring board can be reduced as compared with the case of performing the HAL processing.

Claims (11)

Lead-free solder is inserted into a lead wire insertion hole of a wiring board having a conductor pattern on both sides, and lead-free solder containing lead and both conductor patterns on both sides of the wiring board In a component mounting board having a soldering structure using a lead-free solder, A conductor insertion hole located in the vicinity of the lead insertion hole is provided in the wiring board, and an auxiliary conductor for electrically connecting between the conductor patterns on both sides of the wiring board inserted into the conductor insertion hole and soldered to the lead is provided. Component mounting board characterized in that. The method of claim 1, An auxiliary conductor is a component mounting board, characterized in that the wiring board is provided with a substrate surface opposing unit integrally opposed to the substrate surface on which the conductor pattern is installed. The method according to claim 1 or 2, And a conductor insertion hole is a through-hole having a connection pattern electrically connecting the two conductor patterns on both sides of the wiring board to the inner circumferential surface thereof. The method according to any one of claims 1 to 3, A lead-free solder is composed mainly of tin, and a component mounting board using tin-plated on the surface as an auxiliary conductor. The method of claim 2, In the wiring board, an auxiliary through hole having a connection pattern for electrically connecting between the conductor patterns on both sides of the wiring board is provided on a portion of the wiring board facing the substrate surface opposing part, and lead-free solder is provided in the auxiliary through hole. Component mounting board, characterized in that the flow. The method according to any one of claims 1 to 5, A component mounting board is provided in the vicinity of a lead insertion hole into which a lead of an electrical component having a relatively large current flows is inserted. The wiring boards having the conductor patterns on both sides are soldered with the conductor pattern using lead-free solder containing no lead, without performing hot air leveler treatment with solder containing lead. A method of manufacturing a component mounting substrate, characterized in that. In order to solder the lead of the electric component to the wiring pattern having the conductor patterns on both sides with lead-free solder containing no lead, the lead of the electric component is not soldered. Component mounting board characterized in that. The method of claim 8, A component mounting board comprising a gold plating process on an exposed portion of a conductor pattern in a wiring board. The method of claim 8, A component mounting board, comprising: a through hole having a connection pattern for electrically connecting the conductor patterns on both sides of the wiring board to the inner circumferential surface of the wiring board and a lead insertion hole for inserting the lead of the electrical component. The method of claim 8, In the wiring board, the inner circumferential surface has a connection pattern for electrically connecting the conductor patterns on both sides of the wiring board, and has a single through hole through which the lead of the electrical component is not inserted, and lead-free solder is introduced into the single through hole. The component mounting board according to claim 1, wherein an inner diameter of the single through hole is set to 0.7 mm or more.