JP3198331B2 - Method of manufacturing circuit board having metal terminal strip, circuit board obtained by this manufacturing method, and method of connecting conductor piece to this circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a circuit board in which a metal terminal piece made of nickel or the like is connected to a board body constituting an electronic circuit or an electric circuit, a circuit board obtained by this manufacturing method, and a circuit board obtained by the method. The present invention relates to a method for connecting a conductor piece to a circuit board.

[0002]

2. Description of the Related Art Conventionally, as an example of a circuit board, there is, for example, one shown in FIGS. The circuit board 1 shown in FIG. 7 has one end 11 of a thin metal terminal strip 11.
Only A is soldered to the surface of the substrate body 10, and the other end 11 B of the terminal strip 11 is projected outside the substrate body 10. The circuit board 1 shown in FIG. 8 has a configuration in which the entire thin metal terminal strip 11 is soldered to the surface of the board body 10. In any of the circuit boards 1 described above, a metal conductor piece 12 is further joined to the terminal piece 11, and a distal end portion of the conductor piece 12 is bent.
For example, it may be used as a protection circuit for the rechargeable battery by contacting the electrode of the rechargeable battery used as a power source of a mobile phone or the like.

[0003]

However, when the terminal piece 11 as shown in FIG. 7 is soldered to the substrate body 10, a reflow soldering method will be described below. As described above, at the time of reflow (remelting) of the solder, a so-called self-alignment effect cannot be obtained, which causes a problem.

[0004] That is, the self-alignment effect at the time of solder reflow is, for example, as shown in FIG.
Both ends 30a, 30b of terminal piece 30 having a fixed length
Are soldered using two solders 35, 35 located at a certain interval, the surface tension of the solders 35, 35 generated when the solders 35, 35 are heated and melted. Both ends 30 of terminal strip 30
This is an effect obtained by acting on each of the terminals 30a and 30b. With this effect, the entire terminal piece 30 is aligned with reference to the application positions of the solders 35 and 35. Therefore, conventionally, as shown in FIG.
When only one end 11A of the terminal strip 11 is soldered to the board main body 10, a self-alignment effect at the time of solder reflow cannot be expected, and the positioning accuracy of the terminal strip 11 with respect to the board main body 10 deteriorates. Had occurred.

Further, as shown in FIG. 10, the substrate body 10 is obtained as one of a large number regularly arranged on a single original substrate 3, and a terminal piece 11 for the substrate body 10 is provided. Is performed in a state where a large number of substrate bodies 10 are arranged and formed on one original substrate 3. That is, how to efficiently obtain a large number of substrate bodies 10 from one original substrate 3 becomes a problem. However, in the circuit board 10 having a configuration in which the other end 11B of the terminal strip 11 projects outward from the board body 10, the terminal board 11 has
That is, the board bodies 10 formed adjacent to each other in the longitudinal direction of the board body 10 are arranged at regular intervals in consideration of the length of the other end 11B of the terminal plate 11 protruding outward. It is formed. Therefore, when manufacturing the circuit board 10 as described above, the number of circuit boards 10 obtained from one original board 3 is reduced. In other words,
The efficiency of removing the original substrate 3 is reduced, which leads to an increase in cost.

On the other hand, when the terminal strip 11 of the circuit board 1 as shown in FIG. 8 is soldered to the board main body 10, a so-called self-alignment effect is expected when a reflow soldering method is employed. it can.
That is, the entire terminal strip 11 is soldered to the surface of the circuit board 10, and the self-alignment effect is improved by soldering both ends of the terminal strip 11 to the surface of the board body 10. can get. Therefore, the positioning accuracy of the terminal strip 11 when the terminal strip 11 is soldered to the substrate body 10 is increased.

When the circuit board 1 is used as a protection circuit for the rechargeable battery by bringing the circuit board 1 into contact with an electrode of a rechargeable battery used as a power source for a portable telephone or the like, As described above, it is necessary to join the conductor piece 12 to the terminal piece 11. Usually, when joining the conductor piece 12 to the terminal piece 11, so-called spot welding is adopted.

As shown in FIG. 11, the above-described spot welding is performed by sandwiching a portion to be joined between the negative and positive electrodes 2A and 2B and applying a current between the electrodes to heat the portion to be joined. This is the welding method to be performed.
Therefore, the terminal strip 1 of the circuit board 1 as shown in FIG.
When the conductor piece 12 is bonded to the
The portion to be joined cannot be sandwiched by B. For this reason, when connecting the conductor pieces 12 on the circuit board 1, as shown in FIG. 12, the upper end of the conductor piece 12 whose end is overlapped on the terminal piece 11 is connected to the negative and positive electrodes 2A, 2B. And a current must flow between the electrodes. When a current flows in such a state, Joule heat generated by the flow of the current also diffuses to the terminal strip 11 and the circuit board 10. Therefore, the circuit board 10 and the terminal strip 1
Solder part A that holds 1 is melted,
There has been a problem that the terminal piece 11 that has been positioned with high accuracy is displaced.

The present invention has been conceived in view of the above circumstances, and allows a metal terminal piece to be accurately soldered onto a substrate main body and causes a positional shift of the metal terminal piece positioned at one end. It is an object of the present invention to be able to connect a metal conductor piece to the terminal piece without the need.

[0010]

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, a through hole or a notch is formed in an appropriate portion of the substrate main body, and a plane sandwiching the through hole or the notch on the surface of the substrate main body. Forming a conductive pad consisting of a group of electrically separated small pads, applying solder paste separately for each small pad, and a flat metal terminal to which a flat conductive piece is connected later A piece
Placing the intermediate portion over the through hole or notch, and placing the lower surface of both ends on the substrate body such that the lower surfaces of the both ends adhere to the small pads to which the solder paste is applied; After heating and melting the paste,
And a step of cooling. A method for manufacturing a circuit board having a metal terminal strip is provided.

According to this manufacturing method, a circuit board is soldered to the board main body so that the terminal piece straddles the through hole or the notch. In this circuit board, the terminal piece is soldered to the board body so as to face the through hole or the notch. Therefore, in the case where a conductor piece is connected to the terminal piece, the terminal piece and the conductor piece can be sandwiched by the negative and positive electrodes at a portion straddling the through hole or the notch. For this reason, even when a current flows between the above-described electrodes, Joule heat generated by flowing the current diffuses to the solder portion that holds the substrate body and the terminal piece together, and this solder portion is diffused. There is no re-melting.
Therefore, it is possible to avoid such a problem that the solder portion is re-melted by spot welding when the conductor piece is connected to the terminal piece, and the terminal piece once positioned is displaced.

[0013]

In the above-mentioned manufacturing method, it is necessary to use a long terminal piece protruding outward from the substrate body in order to employ spot welding when connecting a conductor piece to the terminal piece. Absent. For this reason, when arranging and forming the substrate main bodies on the original substrate in order to obtain a large number of circuit boards from one original substrate, the distance between the substrate main bodies adjacent to each other in the longitudinal direction of the substrate main body is set to be small. Can be. Therefore, by using a terminal piece whose terminal end does not protrude outward from the board body, the number of circuit boards obtained from one original board is large when a circuit board is manufactured. Become. In other words, the efficiency of removing the original substrate is improved, and the cost can be reduced.

[0015]

Further, in the above manufacturing method, a step of applying a solder paste to each of the conductor pads formed by a group of small pads separated from each other in a plane, and soldering the terminal pieces on the solder paste. Contains. In other words, when the solder paste is also formed by a group that is separated and applied to each other in a plane, and when the terminal paste is placed on such a solder paste and the solder paste is heated and melted, The so-called self-alignment effect is obtained as described above. Therefore, in the present invention, the terminal piece can be accurately soldered to the substrate body by the self-alignment effect.

According to a second aspect of the present invention, there is provided a circuit board having a metal terminal piece manufactured by the method according to the first aspect of the present invention.

In this circuit board, the terminal pieces are soldered to the board body with high precision. The terminal piece is soldered to the substrate body so as to face the through hole or the notch. Therefore, the effect described in the first aspect described above, that is, the effect that the terminal piece once positioned is not displaced by the heat at the time of spot welding when the conductor piece is connected to the terminal piece is enjoyed. can do.

According to a third aspect of the present invention, there is provided a method for connecting a conductor piece to a circuit board provided by the above-described second aspect, wherein the conductor piece projects from the circuit board onto the metal terminal piece. While overlapping the conductor pieces, in a portion straddling the through hole or the notch, both the metal terminal piece and the conductor piece are sandwiched between a pair of electrodes, and electricity is supplied between these electrodes, and the metal terminal A method for connecting a conductor piece to a circuit board is provided, wherein the method and the conductor piece are spot-welded to each other.

As described above, when the metal terminal piece and the conductor piece are spot-welded to each other at a portion straddling the through hole or the notch, the heat generated during the spot welding causes the substrate body and the terminal piece to be welded to each other. There is no re-melting of the solder portion that keeps the connection. Therefore, the conductor piece is connected to the terminal piece soldered to the board body with high accuracy, and the conductor piece also has
It will be connected with high precision on the terminal piece.

[0021] Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a perspective view of a main part of a circuit board 5 having metal terminal pieces according to the present invention. FIG. 2 is a plan view of an original substrate 7 used for manufacturing the circuit board 5. FIG. 3 shows a board body 50 constituting the circuit board 5.
FIG. 6 is a plan view of a state in which conductor pads 61 and 62 are formed at positions sandwiching notches 51 and 52 formed in FIG. FIG.
Solder paste 6 is applied on the conductor pads 61 and 62 shown in FIG.
It is a top view in the state where 1 'and 62' were applied. FIG.
FIG. 5 is a plan view of the original substrate 7 in which a large number of the substrate bodies 50 on which the terminal pieces 53 and 54 are mounted on the solder pastes 61 ′ and 62 ′ so as to straddle the notches 51 and 52 are arranged. . FIG. 6 is a cross-sectional view showing a state where the conductor pieces 8 are spot-welded to the terminal pieces 53 and 54.

The circuit board 5 includes the terminal pieces 53 and 54.
A conductor piece 8 made of nickel or the like having a predetermined length is connected thereto, and a predetermined position of the conductor piece 8 is bent so as to be brought into contact with an electrode of a rechargeable battery used as a power source of a mobile phone or the like. Used as a protection circuit for the rechargeable battery.

As shown in FIG. 1, the circuit board 5 has cutouts 51, 52 at one end and a side end adjacent thereto.
Substrate body 50 with the notches formed therein, and notches 51, 52
And terminal pieces 53 and 54 made of metal, for example, nickel, which are soldered so as to straddle them.

More specifically, the substrate main body 50 is formed of, for example, glass epoxy resin or the like.
As shown in FIG. 3, the conductor pads 61, 52 are provided at the portions sandwiching the cutouts 51, 52 formed at appropriate portions of the substrate main body 50.
62 are formed. Although not shown in the drawing, a conductive wiring pattern that is electrically connected to the conductor pads 61 and 62 is formed on the surface of the substrate main body 50. The components and the conductive pads 61 and 62 are configured to be electrically connected to each other. As shown in FIG. 4, solder pastes 61a and 62a are applied to the conductor pads 61 and 62, and the solder pastes 61a and 62a are melted.
By solidification, the terminal pieces 53 and 54 are soldered on the substrate body 50.

Hereinafter, a method for manufacturing the circuit board 5 will be specifically described. For convenience, an original substrate 7 on which a number of substrate bodies 50 constituting the circuit substrate 5 are formed will be described with reference to FIG.

As shown in FIG. 2, notches 51 and 52 are formed in the original substrate 7 at one end and a side end adjacent thereto.
A large number of substrate bodies 50 formed with are formed vertically and horizontally. The periphery of the substrate body 50 penetrates in a groove shape (indicated by reference numeral 70 in FIG. 2), and is supported in the original substrate 7 by a plurality of support portions 71.
That is, by cutting each of the support portions 71, one piece of the substrate body 50 can be taken out. The original substrate 7 is formed by punching a flat plate made of, for example, glass epoxy resin.

First, as shown in FIG.
Conductor pads 61 and 62 are formed at positions sandwiching the first and second pads 52. As the conductor pads 61 and 62, a plurality of pads formed for mounting desired electronic components on the substrate main body 50 can be simultaneously formed. Further, the above-mentioned conductor pads 61 and 62 are provided with solder pastes 61 ′ and 6 described later.
Small pads 61a, 61 which are separated from each other in a plane so as to exert a self-alignment effect by melting 2 '.
b, 61c, 61d, 62a, 62b, 62c, 62d
Are formed as a group. Thus, the small pads 61a, 6
1b, 61c, 61d, 62a, 62b, 62c, 62
In order to form d, for example, small pads 61a, 61b, 61 are applied to conductor pads 61, 62 of a predetermined size.
A green resist layer is formed on the substrate main body 50 so as to open a window for exposing regions to become c, 61d, 62a, 62b, 62c, and 62d.

Subsequently, as shown in FIG.
1a, 61b, 61c, 61d, 62a, 62b, 62
The conductor pads 61 formed as a group of c and 62d,
62 is a solder paste 61 '(61A, 61B, 61).
C, 61D), 62 '(62A, 62B, 62C, 62)
D) is applied. The above solder pastes 61 ', 62'
Can be applied to the surfaces of the conductor pads 61 and 62 by a printing method using a screen mask. The application of the solder paste 61 ′, 62 ′ to the conductor pads 61, 62 is performed by using
What is necessary is just to perform simultaneously with the application | coating work of a solder paste in order to mount a desired electronic component by soldering on it.

After the above operation is completed, as shown in FIG. 5, a terminal piece 53 made of metal, for example, nickel, is used.
54 is superimposed on the application area of the solder pastes 61 ′ and 62 ′ so as to straddle the notches 51 and 52. Such an operation is performed by mounting the chip-shaped electronic component on the substrate body 5.
This can be done automatically using the existing chip mounter used to mount on top. In this chip mounter, for example, a suction head capable of vacuum suctioning the terminal pieces 53 and 54 is configured to be movable at high speed in a horizontal direction and a vertical direction, and is stocked near a transfer path of the substrate body 50. Or supplied terminal strips 53 and 54
At a desired position on the substrate body 50 with high accuracy. Therefore, the work of placing the terminal pieces 53 and 54 can be performed efficiently and quickly.

Before and after the mounting of the terminal pieces 53 and 54, desired electronic components are mounted using the above-described chip mounter, and the substrate main body 50 is placed in a solder reflow furnace (not shown). Transfer and heat. During this heating, the solder pastes 61 ′ and 62 ′ are melted, but the solder pastes 61 ′ and 62 ′ are located at both ends of the terminal pieces 53 and 54 and are separated from each other in a plane and applied. The self-alignment effect described above can be expected. That is, the molten solder paste 6
When the terminal pieces 1a and 62a are cooled, the terminal pieces 53 and 5
4 is precisely soldered to a desired position.

Finally, the substrate body 50 is connected to the original substrate 7.
Code C _1, C _2, separate circuit board 5 as shown in FIG. 1 by cutting along the represented line by C ₃ is obtained in FIG. 5 the support portion 70 which supports the.

In the circuit board 5, the terminal pieces 5
3 and 54 are soldered to the substrate body so as to straddle the notches 51 and 52. That is, the terminal pieces 53 and 54 are soldered to the board main body 50 such that the terminal pieces 53 and 54 face the notches 51 and 52. Therefore, when spot welding is used to connect the conductor pieces 8 to the terminal pieces 53 and 54, as shown in FIG. 6, the yin-yang electrodes 2A and 2B are used to cover the cutouts 51 and 52. The terminal pieces 53 and 54 and the conductor piece 8 can be sandwiched. Therefore, even when a current flows between the electrodes, the Joule heat generated by the flow of the current spreads to the solder portion that holds the substrate body 50 and the terminal pieces 53 and 54 together. This solder portion is not re-melted. Therefore, it is possible to avoid such a problem that the solder portion is re-melted by spot welding when the conductor piece 8 is connected to the terminal pieces 53, 54, and the once-positioned terminal pieces 53, 54 are displaced. .

When the conductor pieces 8 are connected to the terminal pieces 53 and 54, spot welding performed by sandwiching the conductor pieces 8 between the electrodes 2A and 2B can be adopted. There is no need to use a long one that protrudes outward from the main body 50. For this reason, when the substrate main bodies 50 are arranged and formed on the original substrate 7 in order to obtain a large number of circuit boards 5 from one original substrate 7, the distance between the substrate main bodies 50 adjacent to each other in the longitudinal direction of the substrate main body 50 is increased. The distance can be set small. Therefore, by using the terminal pieces 53, 54 whose other end portions do not protrude outward from the board body 50, a single original board 7 is manufactured when the circuit board 5 is manufactured. Increases the number of circuit boards 5 obtained from the above. In other words, the efficiency of removing the original substrate 7 is improved, and the cost can be reduced.

The positions, shapes and numbers of the notches 51 and 52 formed in the substrate body 50 are limited to the positions, shapes and numbers illustrated in the drawings referred to for describing the present invention. Various design changes are possible.

In addition, a through hole is formed in an appropriate portion of the substrate main body 50 instead of the cutouts 51 and 52, and the terminal pieces 53 and 54 are soldered so as to straddle the through hole. Needless to say, the effect is obtained.

Further, the above-mentioned solder pastes 61 ', 6
The position of the 2 'coating area, and each of the small areas 61A, 61B, 61C, 61D, 62'62A, 6
The design of the number of 2B, 62C, and 62D can be variously changed.

In addition, the formation position and the number of the support portions 70 for supporting the substrate main body 50 on the original substrate 7 are not limited to the example of the present embodiment.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a circuit board having a metal terminal piece according to the present invention.

FIG. 2 is a plan view of an original substrate used for manufacturing the circuit board.

FIG. 3 is a plan view showing a state in which a conductor pad is formed in a portion sandwiching a notch formed in a substrate main body constituting the circuit board.

FIG. 4 is a plan view showing a state where a solder paste is applied on the conductor pad of FIG. 3;

FIG. 5 is a plan view of an original substrate in which a large number of the above-mentioned substrate bodies are arranged on the solder paste of FIG. 4 with terminal pieces placed so as to straddle the notches.

FIG. 6 is a sectional view showing a state where a conductor piece is spot-welded to the terminal piece by a general method.

FIG. 7 is an explanatory diagram of a conventional example.

FIG. 8 is an explanatory diagram of a conventional example.

FIG. 9 is an explanatory diagram of a self-alignment effect by a reflow soldering method.

FIG. 10 is a plan view of an original substrate for manufacturing the circuit board of FIG. 7;

11 is a view showing a state where a conductor piece is spot-welded to a terminal piece of the circuit board of FIG. 7;

FIG. 12 is a diagram showing a state where a conductor piece is spot-welded to a terminal piece of the circuit board of FIG. 8;

[Explanation of symbols]

5 Circuit board 8 Conductor piece 50 Board body 51, 52 Notch 53, 54 Terminal piece 61, 62 Conductor pad 61 ', 62' Solder paste 61a, 61b, 61c, 61d Small pad (of conductor pad 61) 62a, 62b, 62c, 62d (the conductor pads 62) small pad 61A, 61B, 61C, 61D subregion '(the (solder paste 61 solder paste 62) of) 62A, 62B, 62C, 62D subregion' C _1, C _2, C ₃ Cutting part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-301185 (JP, A) JP-A-62-12982 (JP, A) JP-A-64-52389 (JP, A) JP-A-52-1 71677 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H05K 1/18 H05K 3/34 507

Claims (3)

(57) [Claims] 1. A through-hole or notch is formed in an appropriate portion of a substrate body, and a small pad group separated from each other in a plane is formed on each of the portions of the substrate body surface that sandwich the through-hole or notch. A step of forming a conductive pad, and a step of applying a solder paste separately for each of the small pads, and a flat metal terminal piece to which a flat conductive piece is later connected. A step of straddling a hole or a notch, and placing the lower surfaces of both ends thereof on the substrate main body so that the lower surfaces of the both ends adhere to the small pads to which the solder paste is applied, and heating and melting the solder paste And a step of cooling the circuit board. 2. A circuit board having a metal terminal strip manufactured by the method according to claim 1. 3. The method for connecting a conductor piece to a circuit board according to claim 2, wherein the conductor piece is overlapped on the metal terminal piece so as to protrude from the circuit board, and the through hole or notch is provided. In a region straddling, both the metal terminal piece and the conductor piece are sandwiched between a pair of electrodes, electricity is supplied between these electrodes, and the metal terminal piece and the conductor piece are spot-welded to each other. A method of connecting a conductor piece to a circuit board, which is characterized by the following.