JPH1056257A - Method for mounting terminal to circuit board and circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly and effectively carry out soldering through mechanical work without resulting in defectives such as drop of positional accuracy of a terminal even when only the connecting end of a terminal having a connecting end and a non-connecting end is soldered. SOLUTION: This method includes an application step for applying a solder paste 3 to a desired circuit board 1, an overlapping step for overlapping a connecting end 4a of a terminal 4 having a connecting end 4a and a non- connecting end 4b on a part applied with the solder paste 3, a step for preheating/melting the solder paste 3 to solder the connecting end 4a to the board 1. In this case, mutually separated parts 3a to 3d applied with solder paste are provided in the board 1 through the application step, and the connecting end 4a is overlapped over a plurality of parts 3a to 3d applied with solder paste through the overlapping step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting terminals on a circuit board constituting a desired electronic circuit or electric circuit, and a circuit board used for the method.

[0002]

2. Description of the Related Art Conventionally, as an example of a structure in which terminals are mounted on a circuit board, there is, for example, a structure shown in FIG. In the structure shown in the figure, the terminal 9 is a thin metal plate and has a connection end 9a and a non-connection end 9b. The connection end 9a
Are soldered to the circuit board 1E, and the non-connection ends 9b protrude outside the circuit board 1E. According to such a configuration, as shown by the imaginary line in the figure, the non-connection end 9b can be bent as needed, and the non-connection end 9b can be connected to a battery electrode or a terminal of another circuit board. It is convenient to make contact. In the specification of the present application, the connection end is one end of the terminal in the longitudinal direction of the terminal which is to be soldered to the circuit board, and the non-connection end is another end which is not to be soldered to the circuit board. Is the end.

If the worker solders the terminal 9 manually, the work efficiency is poor. Therefore, conventionally, a reflow soldering method has been adopted as a method of soldering the terminal 9. In this reflow soldering method, a step of applying a solder paste to the surface of the circuit board 1E, and the connection end 9a
And a step of heating and melting the solder paste, so that a series of these steps can be automated.

[0004]

However, conventionally, when the connection end 9a is soldered to the circuit board 1E by using a reflow soldering method, there are the following problems.

That is, for example, as shown in FIG.
When the two ends 9c and 9d of the terminal 9A having a fixed length are superimposed on the two solder paste application sections 35 and 35 on which the solder paste is applied, a self-alignment effect is obtained. This is because, when the solder paste of the two solder paste application sections 35, 35 is heated and melted, the surface tension of the molten solder is increased at the both end portions 9c, 9c.
9d, and the terminal 9A as a whole is
This is because a force for positioning the two solder paste application sections 35, 35 is exhibited. As described above, in order to obtain the self-alignment effect by the reflow soldering method, the surface tension of the molten solder must act on a plurality of portions of the terminal.

On the other hand, in the structure shown in FIG. 18, only the connection end 9a of the terminal 9 is soldered to the circuit board 1E, and only the surface tension of the molten solder acts on this portion. Therefore, conventionally, when the terminals 9 are mounted on the circuit board 1E, there is a problem that a self-alignment effect cannot be obtained and positioning accuracy of the terminals 9 is deteriorated.

Conventionally, as means for improving the positioning accuracy of the terminals 9, there is also a means for providing pins for positioning the terminals 9 on the circuit board 1E. However, with such means, the terminals 9 are provided on the circuit board 1E.
There is a case where the above-mentioned pins hinder the mounting of the terminal 9 and it becomes difficult to automatically insert the terminal 9 by an automatic mounter. Further, there is another problem that the operation of providing the pins in advance on the circuit board 1E becomes complicated.

The present invention has been devised in view of such circumstances, and even when only the connection ends of the terminals having the connection ends and the non-connection ends are soldered to the circuit board, It is an object of the present invention to allow a soldering operation to be appropriately and efficiently performed by a mechanical operation without causing a problem that a positional accuracy of a terminal is deteriorated.

[0009]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

According to the first aspect of the present invention, an application step of applying a solder paste to a desired circuit board, and the connection end of a terminal having a connection end and a non-connection end is overlapped with the solder paste application portion. The overlapping process,
A step of heating and melting the solder paste to solder the connection end to the circuit board, wherein the applying step comprises applying a plurality of solder pastes separated from each other to the circuit board. A portion is provided on the circuit board, and in the overlapping step, the connection end is overlapped so as to straddle the plurality of solder paste application portions.

According to a second aspect of the present invention, there is provided a circuit board to which a solder paste for soldering the connection end of a terminal having a connection end and a non-connection end is applied. Are separately applied to a plurality of locations, so that a plurality of solder paste application sections separated from each other are provided, and the plurality of solder paste application sections are arranged so that the connection ends are laid over them. It is characterized by being close to each other in a superimposable manner.

In the present invention, since the connection ends of the terminals are overlapped over a plurality of solder paste application portions separated from each other, the solder paste application portion is heated to melt the solder paste. For example, the respective surface tensions of the molten solder separated at a plurality of locations act on the plurality of locations at the connection end. Therefore,
As a result, a self-alignment effect of aligning the connection end overlapped on the molten solder with the solder paste application portion can be obtained. That is, when the solder paste is not separated into a plurality of places and is applied collectively, the self-alignment effect by the molten solder is not obtained, but as in the present invention, the solder paste is applied to the plurality of places. If the solder paste is separated, a self-alignment effect can be obtained in which the connection ends of the terminals are aligned with respect to the solder paste application portion when the solder paste is melted.

Therefore, in the present invention, even when only the connection end of the terminal, that is, only one end of the terminal is soldered to the circuit board, it is possible to appropriately position the entire terminal by utilizing the self-alignment effect. As a result, the positioning accuracy of the terminals can be improved. As a result, the yield in manufacturing various electronic circuits and electric circuits obtained by mounting terminals on a circuit board can be improved.

In addition, in the present invention, as described above, as a result of obtaining the self-alignment effect, it is not necessary to employ a means for preventing the positional displacement of the terminals, such as raising the pins for positioning on the circuit board. . Therefore, the total number of work steps can be reduced, and furthermore, the work of superimposing the connection end of the terminal on the solder paste application section is performed, for example, by mounting the terminal on a circuit board using a chip mounter used for automatic mounting of electronic components. By doing so, it is also possible to perform the processing appropriately and at high speed. As a result, the work efficiency of the terminal mounting operation can be increased, and the production cost can be significantly reduced.

In a preferred embodiment of the present invention, at least three solder paste application portions are provided, and each of these solder paste application portions is provided in each of the longitudinal direction and the lateral direction of the terminal. Are arranged at intervals.

According to this configuration, when the solder paste is heated and melted, the molten solder is dispersed and arranged in at least three places at intervals in the longitudinal direction and the lateral direction of the terminal. And each of the molten solders at those places can be brought into contact with the connection end of the terminal. Therefore, a self-alignment effect can be obtained in which the connection end can be aligned in both directions of the longitudinal direction and the lateral direction of the terminal, and the operation of aligning the terminal can be made more reliable and accurate.

In another preferred embodiment of the present invention,
A pad portion having a substantially rectangular shape in plan view for achieving electrical connection with the terminal is provided, and the plurality of solder paste application portions are provided at four corners of the pad portion.

According to such a configuration, it is possible to keep the plurality of solder paste application sections apart from each other as much as possible while preventing the plurality of solder paste application sections from protruding from the pad section. On the other hand, when the self-alignment effect is exhibited by the molten solder separated at a plurality of locations, a more effective self-alignment effect can be expected as the distance between the molten solders is increased. Therefore, according to the above configuration, a more effective self-alignment effect can be obtained because the plurality of solder paste application portions can be largely separated from each other.

In another preferred embodiment of the present invention,
At a substantially central portion of the pad portion, another solder paste applying portion separated from the plurality of solder paste applying portions is further provided.

According to this configuration, when the solder paste is heated and melted, in addition to the surface tension of the molten solder of the solder paste application portion provided at the four corners of the pad portion, the solder paste is positioned at the center thereof. The surface tension of the molten solder in the other solder paste application section can also act on the connection end. Therefore, in addition to the increase in the number of contact points of the molten solder with the connection ends, a self-alignment effect of aligning the connection ends between the various portions of the molten solder can be expected. A force is generated to shift the connection end not only in the direction but also in a direction inclined with respect to those directions, and a more excellent effect of aligning the connection end can be expected. As a result, it is possible to further improve the positioning accuracy of the terminals.

In another preferred embodiment of the present invention,
The circuit board is provided with a plurality of metal surface portions separated from each other, and the plurality of solder paste application portions are provided by dispersing and applying the solder paste to respective surfaces of the plurality of metal surface portions. .

According to such a configuration, since the molten solder has a characteristic of being easily adapted to the metal surface portion, when the solder paste dispersed and applied to the plurality of metal surface portions is heated and melted, the molten solder is melted. Is difficult to flow out of each of the metal surfaces. Further, even if the solder paste slightly protrudes from each metal surface portion, an effect of being pulled back onto each metal surface portion at the time of melting can be expected. Therefore, when the solder paste is heated, it is possible to prevent or suppress such a problem that the molten solder that should be dispersed at a plurality of locations is aggregated together, and the self-alignment effect of the molten solder can be more reliably obtained. You can do so.

According to a third aspect of the present invention, an application step of applying a solder paste to a desired circuit board, and overlapping the connection end of a terminal having a connection end and a non-connection end with the application portion of the solder paste. The overlapping process,
A step of heating and melting the solder paste to solder the connection end to the circuit board, a method of mounting a terminal on the circuit board, wherein in the coating step, a plurality of bulges are formed on an outer peripheral edge. Providing the solder paste application part having the following on the circuit board, and in the superimposing step, superimposing the connection end on the solder paste application part such that the plurality of bulging portions protrude outside the connection end. It is characterized by.

According to a fourth aspect of the present invention, there is provided a circuit board to which a solder paste for soldering the connection end of a terminal having a connection end and a non-connection end is applied. Is characterized by being applied in a shape having a plurality of bulging portions which can protrude outside the connection end when the connection end is superimposed on the application region of the solder paste.

In the present invention, when the solder paste is heated and melted, the molten solder of the plurality of bulging portions of the solder paste application portion can act on a plurality of locations at the connection ends of the terminals. Therefore, the self-alignment effect of positioning the terminal at a desired position with respect to the solder paste application portion can be obtained, even though only the connection end of the terminal is soldered to the circuit board. As a result, similar to the first and second aspects of the present invention, the positioning accuracy of the entire terminal can be improved by utilizing the self-alignment effect. In addition, since there is no need to set up pins for positioning on the circuit board, the number of overall work steps can be reduced, and in addition, the work of superimposing the connection end on the solder paste application section is performed by mechanical work using a chip mounter. It can be performed efficiently and the production cost can be reduced. Further, after the soldering of the terminal is completed, the hardened solder protrudes to the outside of the connection end of the terminal, so that by looking at this solder from the outside, the soldering of the terminal is appropriately performed. It is also possible to easily determine whether or not the product inspection has been performed, and an advantage such that the product inspection work can be facilitated.

In a preferred embodiment of the present invention, the connection end has a first edge extending in the short direction of the terminal and two second edges connected to the first edge and extending in the longitudinal direction of the terminal. And the plurality of bulging portions are provided at least at three or more locations so as to protrude outside each of the first edge and the two second edges.

According to such a configuration, when the solder paste is heated and melted, the molten solder of the plurality of bulging portions of the solder paste application portion is formed by at least the first edge of the connection end and the two second edges. It can be brought into contact with a total of three or more places with the edge. In addition, the molten solder of the plurality of bulging portions can be placed in a state where the molten solder is disposed at intervals in the longitudinal direction and the lateral direction of the terminal. Accordingly, the surface tension of the molten solder at the bulging portion exerts a force for shifting the terminal in both the longitudinal direction and the lateral direction, and an excellent self-alignment effect can be obtained.

[0028]

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

This embodiment will be described as an example in which an electronic circuit device for protecting a rechargeable battery is manufactured using the printed circuit board 1 shown in FIG. The printed board 1 is made of, for example, glass epoxy resin, and a plurality of pad portions 2 made of copper foil are provided on the surface thereof.
Each of the pad portions 2 is substantially rectangular in plan view. Although not shown in the drawing, a plurality of conductive wiring patterns that are electrically connected to the plurality of pad portions 2 are formed on the surface of the printed board 1, and predetermined electronic components are mounted on the printed board 1. By doing so, a protection circuit for a rechargeable battery can be manufactured. The printed circuit board 1 has a shape elongated in the left-right direction in FIG. The plurality of conductive wiring patterns and the plurality of pad portions 2 are provided so that a large number of rechargeable battery protection circuits can be formed on the printed circuit board 1.
It is provided regularly in the longitudinal direction of the printed circuit board 1. The virtual lines N and N ′ shown in FIG.
3 shows a position for cutting the printed circuit board 1 so as to separate a large number of rechargeable battery protection circuits into individual protection circuits.

To manufacture the electronic circuit device using the printed circuit board 1, first, as shown in FIG. 2, a solder paste 3 is applied to each of the pad portions 2 by screen printing to an appropriate thickness. In this case, as shown in FIG.
By dispersing and applying the solder paste 3 to each of the four corners of each of the pad portions 2, a total of four solder paste application portions 3a to 3d separated from each other at predetermined intervals are provided. Such a solder paste application operation can be performed at the same time as a solder paste application operation for soldering predetermined electronic components constituting the protection circuit to other portions of the printed circuit board 1.

Next, as shown in FIG.
(4A, 4B) is placed on the printed circuit board 1. In this case, as best seen in FIG. 5, the connection end 4a of each of the terminals 4 is superposed over all of the solder paste application portions 3a to 3d and is overlapped. As the terminal 4, for example, a thin metal plate made of nickel or the like is applied. In the present embodiment, as described later, a self-alignment effect is obtained when the terminals 4 are soldered to the printed circuit board 1, and therefore, pins for positioning the terminals 4 on the printed circuit board 1 are provided. It is not necessary to provide.
Therefore, the operation of mounting the terminals 4 can be efficiently performed using a general chip mounter used for mounting a chip-shaped electronic component on a desired printed circuit board.

Some of the terminals 4 (4
When A) is arranged on the first side edge 1a extending in the longitudinal direction of the printed circuit board 1, the non-connecting end 4b has a piece that is projected outward of the first side edge 1a. State. The solder paste application parts 3a to 3d have adhesiveness, and the terminal 4
When mounting (4A) on the printed circuit board 1, the connection end 4a can be pressed against the solder paste application sections 3a to 3d with a constant pressure. Therefore, the connection end 4a of the terminal 4 (4A) can be adhered to the solder paste application sections 3a to 3d, and the terminal 4 (4A)
A) can be prevented from easily falling off the printed circuit board 1. On the other hand, with respect to the other terminals 4 (4B), their non-connection ends 4b are arranged in a narrow region S between the virtual lines N and N '. The operation of mounting such terminals can be performed efficiently together with the operation of mounting predetermined electronic components constituting the protection circuit on the printed circuit board 1 using a chip mounter.

After the terminal mounting operation is completed, the printed circuit board 1 is transferred into a solder reflow furnace.
The solder paste 3 in the solder paste application sections 3a to 3d is heated and melted. When the solder paste 3 is melted, as shown in FIG. 5, a surface tension is generated in each of the solder paste applied portions 3a to 3d arranged vertically and horizontally, and the surface tension aligns the terminals 4 with each other. Thus, a self-alignment effect can be exhibited.

More specifically, since the solder paste application sections 3a and 3b and the solder paste application sections 3c and 3d are spaced from each other in the longitudinal direction of the terminal 4,
The surface tension of the molten solder exerts a self-alignment effect of shifting the connection end 4a in the short direction (the direction of the arrow N1) of the terminal 4. Further, since the solder paste application sections 3a and 3d and the solder paste application sections 3b and 3c are spaced apart in the short direction of the terminal 4,
The surface tension of the molten solder further exerts a self-alignment effect of shifting the connection end 4a in the longitudinal direction of the terminal 4 (the direction of the arrow N2). Therefore, when the solder pastes of the solder paste application sections 3a to 3d are melted, the connection end 4a is shifted to a position where the arrangement of the solder paste application sections 3a to 3d has no distortion or the distortion is small. Thus, the terminal 4 can be accurately arranged at a desired position. The soldering of the terminals 4 is completed when the molten solder cools and hardens.

In order to reliably obtain the above-described self-alignment effect, it is desirable to increase the size between the solder paste application sections 3a to 3d. On the other hand, in the present embodiment, the solder paste
Since a to 3d are arranged at each of the four corners of each of the pad portions 2, the solder paste application portions 3a to 3d
Are prevented from protruding from the respective pad portions 2, and the interval between them can be maximized. Therefore, the self-alignment effect of the terminal 4 can be more reliably obtained.

After the above steps, as shown in FIG. 6, the printed circuit board 1 is cut at the positions of the virtual lines N and N '. Thereby, a plurality of electronic circuit devices A can be obtained. The electronic circuit device A has a configuration in which the plurality of terminals 4 are soldered to the cut printed board 1 ′, and their non-connection ends 4 b protrude outward from the printed board 1 ′. .

The electronic circuit device A can be used by bending the terminals 4 as shown in FIG. 7, for example. More specifically, the two terminals 4 </ b> A can be spot-welded by contacting the two electrodes 50 of the rechargeable battery 5. Further, the two terminals 4B can be arranged along both side portions 5a, 5a of the rechargeable battery 5 so as to sandwich the rechargeable battery 5. The two terminals 4B can be used, for example, to establish electrical continuity with a predetermined electronic circuit incorporated in the main body of the mobile phone into which the rechargeable battery 5 is loaded. As described above, each of the terminals 4 is
Since the printed circuit board 1 ′ is accurately soldered to a desired position by the self-alignment effect, the terminals 4 can be appropriately brought into conductive contact with predetermined positions in relation to the rechargeable battery 5. .

In the present invention, the specific configuration of the solder paste application section may be, for example, a configuration as shown in FIGS.

That is, in the configuration shown in FIG. 8, a total of four solder paste coating portions 3a to 3d are provided at the four corners of the pad portion 2A having a substantially rectangular shape in a plan view. Solder paste application part 3 in the center part
e is provided. The solder paste application section 3e is separated from each of the solder paste application sections 3a to 3d. According to such a configuration, in addition to the self-alignment effect of aligning the terminals 4C in the longitudinal direction and the short direction by the solder paste applying sections 3a to 3d, the solder paste applying sections 3a to 3d can be obtained.
A self-alignment effect of positioning the terminals 4C also in the arrangement direction (the directions of the arrows N3 and N4) in the relationship between each of the solder paste application portions 3e and each of the solder paste application portions 3e is obtained. Therefore, it can be more preferable for accurate positioning of the terminals.

In the configurations shown in FIGS. 9 to 11, when the solder paste 3 is applied to the pad portion 2A, the shape, size, and arrangement of the applied portion are variously changed. In any of these cases, a self-alignment effect is obtained, and the terminal 4C can be positioned. As described above, according to the present invention, the solder paste application section can have various modes. However, in the present invention, it is preferable that the longitudinal direction and the lateral direction of the terminal can be aligned. To this end, for example, as shown in FIG. 12, the solder paste 3 is dispersed in at least three regions. It is desired that the coating is performed such that the coating portions are located at an interval in the longitudinal direction and the lateral direction of the terminal 4C.

Further, in the present invention, a solder paste application step may be performed as follows. That is, as shown in FIGS. 13A and 13B, after a predetermined conductive wiring pattern (not shown) is formed on the printed board 1A, the surface is covered with the green resist layer 7. Is made. This is for the purpose of insulating the conductive wiring pattern. In this case, by providing a plurality of opening windows 70 in the green resist layer 7 above the copper foil pad portion 2B, a plurality of metal surface portions 28 whose metal surfaces of the copper foil are exposed to the outside are formed. .
The plurality of metal surface portions 28 are surfaces at four corners of the pad portion 2 and are separated from each other by being separated by a part of the green resist layer 7. Each opening window 70
Can be provided by performing an etching process on the green resist layer 7 after forming the green resist layer 7. Next, as shown in FIGS. 14A and 14B, the solder paste 3 is dispersed and applied to each surface of the plurality of metal surface portions 28,
A plurality of solder paste application sections 3f to 3i are provided. The area of each of the plurality of solder paste application sections 3f to 3i is preferably smaller than the area of each metal surface section 28. After the solder paste 3 is applied,
The connection end 4a of the terminal 4D is superimposed on the solder paste application sections 3f to 3i.

After the above series of working steps, the solder paste of the solder paste application sections 3f to 3i is heated and melted.
8 hardly flows out. This is because the molten solder is easier to adapt to the metal surface than the green resist layer 7. For the same reason, if the solder paste application unit 3
Even if f to 3i have some protrusion beforehand outside the opening window 70, the molten solder is not applied to each of the metal surface portions 2.
8 can be expected to gather. Therefore, it is possible to prevent the molten solders of the solder paste application sections 3f to 3i from being aggregated together without significantly increasing the positioning accuracy of the solder paste application sections 3f to 3i. As a result, a self-alignment effect using the surface tension of the molten solder separated at a plurality of locations can be appropriately obtained. Of course, in the present invention, the specific method of forming the metal surface portion is not limited to the above method. Also,
Regarding the specific arrangement of the metal surface portion, for example, FIG.
As in the case of the arrangement of the solder paste application section shown in FIG.

Next, another embodiment of the present invention will be described.
This will be described with reference to FIGS.

In this embodiment, first, as shown in FIG. 15, when a pad portion 2C made of copper foil is formed on the surface of the printed board 1B, three side edge portions 2 of the pad portion 2C are formed.
A semicircular projection 20 is formed at the center of each of the a to 2c in the longitudinal direction. Then, as shown in FIG.
The solder paste 3 is applied to the surface of the pad 2C. In this case, the solder paste 3 is also applied to the surfaces of the three projections 20. Thus, a solder paste application portion 3j having a total of three bulges 30 on the outer peripheral edge in a semicircular shape in plan view is provided on the pad portion 2C.

After the solder paste application operation is completed, as shown in FIG. 17, the terminal 4E is placed on the printed circuit board 1B, and the connection end 4a is overlaid on the solder paste application section 3j. The connection end 4a has a first edge 40a extending in the short direction of the terminal 4E, and a second edge 4a connected to the first edge 40a and extending in the longitudinal direction of the terminal 4E.
When the connection end 4a is superimposed on the solder paste application portion 3j, each of the three bulging portions 30 has the first edge 40b, 40c.
The edge 40a and the second edges 40b, 40c protrude outward. In this manner, the operation of superimposing the terminal 4E on the solder paste application section 3j can be performed using a chip mounter, as in the previous embodiment.

Next, the printed circuit board 1B is transferred into a solder reflow furnace, and the solder paste
Heat and melt the solder paste j. Then, the surface tension of the molten solder of the three bulging portions 30 acts on the first edge 40a and the second edges 40b and 40c. In this case, the above-mentioned three bulging portions 30
Are separated from each other in the short direction of the terminal 4E, and one bulge 30 (30a) and the other two bulges 3
0 (30b, 30c) is spaced apart in the longitudinal direction of the terminal 4E. Therefore, by the action of the surface tension of the molten solder, the connection end 4a is displaced in the short direction and the long direction of the terminal 4E, and the connection end 4a is disposed at the center of the three bulging portions 30. Thus, a self-alignment effect can be obtained. Therefore, the connection end 4a can be accurately soldered onto the pad portion 2C. Further, after the soldering is completed, the bulging portion 30 can be easily visually observed from the outside, and it can be easily and accurately determined whether or not the soldering of the terminal 4E is properly performed.

In the present invention, the specific number of the bulging portions provided in the solder paste application portion is not limited. In the present invention, three or more bulging portions may be provided. Also,
For example, a total of three bulging portions 30 (30a to 30a) shown in FIG.
30c), it is possible to provide only two bulging portions 30b and 30c without providing one bulging portion 30a. Even with such a configuration, the self-alignment effect can be obtained by the surface tension action of the molten solder at the two bulging portions 30b and 30c. However, in the present invention, it is preferable that at least three bulging portions are provided so that the terminals can be aligned in the longitudinal direction and the lateral direction.

The present invention is not limited to the contents of the above-described embodiments. The present invention can be applied to a case where a terminal is mounted so that a non-connection end does not protrude outside a printed circuit board. Further, the solder paste and the solder referred to in the present invention are not limited to Sn-Pb-based alloys, but also include various electronic industrial solders having other components. Further, the circuit board in the present invention is not limited to a printed board made of epoxy resin or the like, but is a concept including, for example, a flexible board. Of course, the specific configuration of the electronic circuit and the electric circuit manufactured on the circuit board is not limited. The present invention can be applied to a case where a solder paste is applied to a portion of a printed circuit board where no pad portion is provided.

[Brief description of the drawings]

FIG. 1 is a plan view of an essential part showing an example of a printed circuit board to which a method of mounting terminals on a circuit board according to the present invention is applied.

FIG. 2 is a plan view of an essential part showing an example of a state where a solder paste is applied to the printed circuit board shown in FIG.

FIG. 3 is an enlarged plan view of a main part of FIG. 2, showing an example of a solder paste application unit.

FIG. 4 is a plan view of an essential part showing an example of a state in which terminals are mounted on a printed board.

FIG. 5 is an enlarged plan view of a main part of FIG. 4;

FIG. 6 is a plan view illustrating an example of a process of cutting a printed circuit board.

FIG. 7 is a perspective view showing an example of use of an electronic circuit device manufactured by mounting terminals on a printed circuit board.

FIG. 8 is an explanatory view showing another example of a solder paste application section.

FIG. 9 is an explanatory view showing another example of a solder paste application section.

FIG. 10 is an explanatory view showing another example of a solder paste application section.

FIG. 11 is an explanatory view showing another example of a solder paste application section.

FIG. 12 is an explanatory view showing another example of a solder paste application section.

13A is a plan view of a principal part showing another example of a printed circuit board, and FIG. 13B is a cross-sectional view of the same taken along line X1-X1.

14 (a) is a plan view of a principal part showing a state where a solder paste is applied to the printed circuit board shown in FIG. 13 (a), and FIG. 14 (b) is a cross-sectional view along line X2-X2.

FIG. 15 is a plan view of a principal part showing another example of a printed circuit board to which the method of mounting terminals on a circuit board according to the present invention is applied.

16 is a main part plan view showing a state where a solder paste has been applied to the printed circuit board shown in FIG. 15;

FIG. 17 is a plan view of relevant parts showing a state where terminals are superimposed on a solder paste applied portion shown in FIG. 16;

FIG. 18 is an essential part perspective view showing a conventional example of a structure in which terminals are mounted on a circuit board.

FIG. 19 is an explanatory diagram of a self-alignment effect obtained by a reflow soldering method.

[Explanation of symbols]

 1, 1A-1B Printed circuit board (circuit board) 2, 2A-2C Pad part 3 Solder paste 3a-3j Solder paste application part 4, 4A-4E Terminal 4a Connection end 4b Non-connection end 28 Metal surface part 30 Swelling part

Claims (14)

[Claims] An application step of applying a solder paste to a desired circuit board; an overlapping step of superposing the connection end of a terminal having a connection end and a non-connection end on an application portion of the solder paste; Heating and melting the solder paste to solder the circuit board to the circuit board, wherein the applying step comprises: A method for mounting a terminal on a circuit board, the method comprising: providing a terminal on a circuit board; and, in the overlapping step, overlapping the connection end over the plurality of solder paste application sections. 2. The method according to claim 1, wherein at least three solder paste application portions are provided, and each of the solder paste application portions is arranged at an interval in each of a longitudinal direction and a lateral direction of the terminal. 2. The method for mounting a terminal on a circuit board according to 1. 3. The circuit board is provided with a substantially rectangular pad portion in plan view for electrical conduction with the terminal, and the plurality of solder paste application portions are provided at four corners of the pad portion. The method for mounting a terminal on a circuit board according to claim 1, wherein the terminal is provided. 4. The method for mounting a terminal on a circuit board according to claim 3, further comprising a solder paste application section separated from the plurality of solder paste application sections at a substantially central portion of the pad section. . 5. The circuit board is provided with a plurality of metal surfaces separated from each other, and the plurality of solder pastes are dispersed and applied to respective surfaces of the plurality of metal surfaces to form the plurality of solders. The method for mounting a terminal on a circuit board according to any one of claims 1 to 4, wherein a paste application section is provided. 6. A circuit board on which a solder paste for soldering the connection end of a terminal having a connection end and a non-connection end is applied, wherein the solder paste is applied separately at a plurality of locations. Thereby, a plurality of solder paste application parts separated from each other are provided, and these plurality of solder paste application parts are close to each other so as to be able to overlap each other with the connection end straddling them. A circuit board, characterized in that: 7. The solder paste application section is provided at at least three places, and each of the solder paste application sections is arranged at an interval in each of the longitudinal direction and the lateral direction of the terminal. Claim 6
A circuit board according to claim 1. 8. A pad having a substantially rectangular shape in plan view for electrical connection with the terminal, and the plurality of solder paste application sections are provided at four corners of the pad section. 8. The circuit board according to 6 or 7. 9. The circuit board according to claim 8, further comprising another solder paste application section separated from the plurality of solder paste application sections at a substantially central portion of the pad section. 10. The circuit board is provided with a plurality of metal surface portions separated from each other, and the solder paste is dispersed and applied to respective surfaces of the plurality of metal surface portions, so that the plurality of metal surface portions are separated from each other. The circuit board according to any one of claims 6 to 9, further comprising: 11. A step of applying a solder paste to a desired circuit board, a step of superimposing the connection end of a terminal having a connection end and a non-connection end on a portion to which the solder paste is applied, and the connection end A step of heating and melting the solder paste to solder the circuit board to the circuit board, wherein the soldering step has a plurality of bulges on an outer peripheral edge in the coating step. Providing a paste application portion on the circuit board, and, in the overlapping step, overlapping the connection end with the solder paste application portion so that the plurality of bulging portions protrude outside the connection end. Characteristic method of mounting terminals on circuit boards. 12. The connection end has a first edge extending in a short direction of the terminal, and two second edges connected to the first edge and extending in a longitudinal direction of the terminal. The circuit board according to claim 11, wherein the plurality of bulging portions are provided at least at three or more locations so as to protrude outside each of the first edge and the two second edges. How to mount the terminals. 13. A circuit board to which a solder paste for soldering the connection end of a terminal having a connection end and a non-connection end is applied, wherein the solder paste is provided on an area where the solder paste is applied. A circuit board having a plurality of bulging portions that can protrude outward from the connection end when the connection end is overlapped with the circuit board. 14. The connection end has a first edge extending in the lateral direction of the terminal and two second edges connected to the first edge and extending in the longitudinal direction of the terminal. 14. The circuit board according to claim 13, wherein the plurality of bulging portions are provided at at least three places so as to protrude outside each of the first edge and the two second edges.