JPH11121896A - Circuit wiring board and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: The present invention relates to a circuit wiring board suitable for realizing a high-density three-dimensional mounting structure and a method of manufacturing the same. The present invention includes a motherboard, a subsidiary board mounted on the motherboard, and a solder joint for electrically and mechanically connecting the motherboard and the subsidiary board. I do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit wiring board in which a sub wiring board is assembled on a mother wiring board (mother board) and a method of manufacturing the same.

[0002]

2. Description of the Related Art In general, a mother wiring board (mother board) 8
In the case of assembling and mounting the sub wiring board 82 with respect to No. 1, the connector 83 soldered to the mother wiring board 81 is used as shown in FIG. The connector 83 includes a box-shaped frame 84 having an open top, leads 86 extending from both sides of the frame 84 and soldered to the electrodes 85 of the motherboard 81, and fitting of the frame 84. Hole 8
4 and a contact 87 provided on the inner wall surface for electrical connection with the sub-wiring board 82. That is, the sub wiring board 82 is mechanically held by the fitting holes 84 a and is electrically connected by the contact points 87.

[0003]

However, the method of assembling and mounting the slave wiring board 82 on the mother wiring board 81 via the conventional connector 83 is the same as that of the connector 83.
However, the use of separate components such as these has the drawback that not only the number of components and the number of mounting steps increase but also the number of connection points is restricted.

[0004] For this reason, when a plurality of sub-wiring boards 82 are mounted on the mother wiring board 81, an extra space is required for the interposition of the connector 83, which is an obstacle to space saving. This has hindered the realization of a high-density three-dimensional mounting structure that has been strongly promoted in recent years. SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described conventional drawbacks, and has as its object to provide a circuit wiring board suitable for realizing a high-density three-dimensional mounting structure and a method for manufacturing the same.

[0005]

According to a first aspect of the present invention, there is provided a circuit wiring board comprising: a mother wiring board; a sub-wiring board mounted on the mother wiring board; A mechanically connected solder joint.

According to a second aspect of the present invention, in the first aspect, a terminal electrode is formed on the mother wiring substrate and the slave wiring substrate, and the solder joint is joined to the terminal electrode.

According to a third aspect of the present invention, there is provided the circuit wiring board according to the first aspect, wherein a plurality of the sub wiring boards have their main plate faces on the main plate face of the mother wiring board and the solder joints on the main plate face of the mother wiring board. Are implemented orthogonally.

According to a fourth aspect of the present invention, there is provided the circuit wiring board according to the first aspect, wherein the solder joint is attached to a pair of sub-wiring boards adjacent to the plurality of sub-wiring boards mounted on the mother wiring board with a main plate surface orthogonal thereto. Another sub-wiring board is mounted in parallel with the mother wiring board.

According to a fifth aspect of the present invention, in the circuit wiring board according to the first aspect, the mother wiring board is also connected to an end opposite to the end of the slave wiring board connected to the mother wiring board. 7. The method for manufacturing a circuit wiring board according to claim 6, further comprising a mother wiring board, and a sub-wiring board mounted on the mother wiring board, and terminal electrodes corresponding to the mother wiring board and the sub-wiring board. In the method for manufacturing a circuit wiring board, each of which is provided separately, a solder bump forming step of forming a solder bump on the terminal electrode, and positioning the slave wiring board on the mother wiring board after the solder bump forming step. A board assembling step of bringing the solder bumps of the terminal electrodes having the corresponding relationship close to each other, and after the board assembling step, the solder bumps are reflowed so that the adjacent solder bumps are fused and cooled, and then the mother wiring board is cooled. A solder joint forming step of obtaining a solder joint for electrically and mechanically connecting to the slave wiring board.

According to a seventh aspect of the present invention, in the method of the sixth aspect, the shape of the solder bump formed in the solder bump forming step is cylindrical. In a method of manufacturing a circuit wiring board according to claim 8, in claim 7, the spherical solder bump is formed by selective solder plating by covering a region other than the terminal electrode with a resist film.

According to a ninth aspect of the present invention, in the method for manufacturing a circuit wiring board according to the seventh aspect, columnar solder bumps are protruded along the two rows on the mother wiring board. The slave wiring board is temporarily fixed to the mother wiring board by solder bumps.

According to a tenth aspect of the present invention, there is provided a method for manufacturing a circuit wiring board.
In claim 6, the shape of the solder bump formed in the solder bump forming step is spherical. In a method of manufacturing a circuit wiring board according to an eleventh aspect, in the tenth aspect, the spherical solder bump is formed by melting a solder ball disposed on the terminal electrode.

[0013]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a circuit wiring board 1 of this embodiment. The circuit wiring board 1 includes a pair of upper and lower mother wiring boards 2, and a plurality (for example, 7) assembled and mounted with the board surfaces orthogonal to the mother wiring board 2 and sandwiched therebetween.
), And a solder joint 4 made of, for example, eutectic solder for electrically and mechanically connecting the mother wiring board 2 and the sub-wiring board 3. Although not shown, electronic components are mounted on the mother wiring board 2 and the sub wiring board 3.

As shown in FIG. 2, the mother wiring board 2 is made of a rectangular body made of, for example, glass epoxy resin and has a length of, for example, 200 mm, a width of 50 mm, and a thickness of 1.0 mm. A copper terminal electrode 2b having a circular shape (diameter of, for example, 0.6 mm) laid in two rows (arrows R1 and R2 directions) at equal intervals along the central portion in the longitudinal direction of one main surface of the main body 2a; And a wiring pattern (not shown) formed on the surface and electrically connected to the terminal electrode 2b.

On the other hand, as shown in FIG. 3, the slave wiring board 3 is made of a rectangular epoxy glass resin, for example, having a length of 40 mm, a width of 50 mm, and a thickness of 1.0 mm. A circular (diameter of, for example, 0.6 mm) copper terminal electrode 3b laid in a row at equal intervals along the longitudinal edges of both main surfaces;
and a wiring pattern (not shown) that is formed on the main surface of a and electrically connected to the terminal electrode 3b.

Here, a pair of terminal electrodes 2b are arranged corresponding to one terminal electrode 3b. Although not shown, chip-shaped components are mounted on the wiring patterns of the mother wiring board 2 and the sub wiring board 3.

As shown in FIGS. 4 and 5, the solder joint 4 has an arc shape, and both ends are joined to the pair of terminal electrodes 2b. Further, an intermediate portion of the solder joint 4 is joined to the terminal electrode 3b. As a result, the slave wiring board 3 is mechanically fixed to the upper and lower wiring boards 2 at equal intervals (for example, 15 mm intervals) via the solder joints 4 and is also electrically connected. Fifty such solder joints 4 are provided on both sides of the lower end portion and both sides of the upper end portion of each slave wiring board 3 at, for example, 1.27 mm intervals.

Thus, the circuit wiring board 1 of this embodiment
Can simultaneously obtain an electrical connection and a mechanical connection without the need for a connecting means such as a connector. Further, space saving is possible as compared with the case of using a connecting means such as a connector, so that the arrangement interval of the sub-wiring board 3 with respect to the mother wiring board 2 can be reduced, which contributes to promotion of high-density mounting. it can. Furthermore, since the number of parts can be reduced as compared with the case where a connecting means such as a connector is used,
It can also contribute to cost reduction. Further, the electrical connection using solder has higher reliability than the electrical connection using a connector, which can contribute to the improvement of the quality of an apparatus incorporating the circuit wiring board 1.

Next, a method of manufacturing the circuit wiring board 1 having the above configuration will be described. As shown in FIG. 6, the method for manufacturing the circuit wiring board 1 according to this embodiment has a diameter of, for example, 0.6 m on the terminal electrodes 2b, 3b of the mother wiring board 2 and the sub wiring board 3.
The solder bump forming step (see step S1 in FIG. 6) for forming the columnar solder bumps 6 and 7 of the m. A board assembling process (see step S2 in FIG. 6) for forming an assembling temporary circuit wiring board 1a through
After this board assembling process, the soldering joint is formed by heating the temporary circuit wiring board 1a in a reflow furnace (not shown) at, for example, 200 ° for 3 minutes to melt and cool the solder bumps 6, 7 mutually to form a solder joint 4. Forming step (see step S3 in FIG. 6). Although not shown, electronic components are mounted on the mother wiring board 2 and the sub wiring board 3.

In the solder bump forming step, for example, when the mother wiring board 2 is described, the solder resist forming step of forming the solder resist 11 on the board body 2a (FIG. 7)
7A), an exposure step of selectively exposing only the terminal electrode 2b area after the solder resist forming step, and an etching step of removing only the exposed area by etching after this exposure step to form the columnar recess 12 (FIG. 7 ( b))
And a solder plating step of filling the solder into the cylindrical concave portion 12 formed by the etching step by solder plating to form the solder bump 6 (see FIG. 7C), and removing the solder resist 11 after the solder plating step. And a solder resist removing step (see FIG. 7D).

Thus, the solder bumps 6 formed on the mother wiring board 2 are provided in two rows for each of the slave wiring boards 3 so as to sandwich each of the slave wiring boards 3 (FIG. 8). Arrows R1, R2 directions). In addition, as shown in FIG. 8, the solder bumps 6 arranged in each row have a pair of solder bumps 6a,
The pair of solder bumps 6a and 6b are arranged at equal intervals and opposed to each other at equal intervals along each row. As shown in FIG. 9, each solder bump 7 protruding from each sub-wiring board 3 is arranged at a position where it is loosely inserted into a pair of solder bumps 6 a and 6 b formed on the mother wiring board 2. I have.

On the other hand, the board assembling process is performed as shown in FIGS.
As shown in FIG. 3, the slave wiring board 3 is loosely inserted between a pair of opposed solder bumps 6 provided on two rows of the mother wiring board 2 and at the same time, the solder bumps 7 of the slave wiring board 3 are 2 corresponding pairs of solder bumps 6 provided on the same row.
This is performed by temporarily fixing the slave wiring board 3 to the mother wiring board 2 by loosely inserting the wiring board between a and 6. in this case,
The difference (gap) between the distance between the pair of solder bumps 6a and 6b and the diameter of the solder bump 7 is set to, for example, 0.5 mm. In this board assembling step, the sub wiring board 3 is temporarily fixed to the lower mother wiring board 2 (FIG. 10).
(a) and (b)) and a step of temporarily fixing the upper motherboard 2 to the subordinate board 3 temporarily fixed to the lower motherboard 2 (see FIG. 10 (c)). ).

In the solder joint forming step,
When the solder bumps 6 and 7 are melted, due to the surface tension of each melt itself, the two are fused and integrated into an arc shape.
The melt united by the fusion is solidified by cooling at room temperature to form a solder joint 4 (see FIGS. 4 and 5). The solder joint 4 is integrally connected to the pair of terminal electrodes 2b and the terminal electrodes 3b, so that the upper and lower mother wiring boards 2
The sub wiring board 3 is mechanically fixed and electrically connected via the solder joint 4.

As described above, the method of manufacturing the circuit wiring board 1 according to this embodiment does not require any connecting means such as a connector, and does not depend on the number of the sub-wiring boards 3 to be connected. Even in the case of the original structure, the electrical connection and the mechanical joining can be achieved simultaneously, collectively and reliably by performing only one reflow step. As a result, it is possible to contribute to an improvement in the production efficiency of the circuit wiring board 1.

Although the shape of the solder joint 4 in the above embodiment is arc-shaped, the same effect can be obtained by arranging a plurality of linear solder joints 40 side by side as shown in FIGS. It becomes possible. As shown in FIGS. 14 and 15, the method of manufacturing the solder joint 40 is such that the solder resist described above is so arranged that two parts on the mother wiring board 2 are equidistant and opposed to each other at equal positions. A columnar solder bump 60 is formed by the method used, and the solder bump 60 is formed when the sub-wiring board 3 is erected on the mother wiring board 2.
A solder bump forming step of projecting a columnar solder bump 70 at a position immediately above the solder bump 70 (see FIG. 14), and the lower end of the subordinate wiring board 3 is loosely inserted into the solder bumps 60 provided along two rows. A board assembling step for fixing (see FIG. 15), and solder bumps 60,
And a solder joint forming step of forming a solder joint 40 by mutually melting and cooling the solder joints 70.

Further, the circuit wiring board 1 having the structure shown in FIG.
However, the present invention is not limited to this. Like the circuit wiring board 100 shown in FIG. May be supported by the solder joint 4a. By doing so, a higher-density three-dimensional mounting structure can be obtained. In this case, solder bumps 60a and 60b for locking the sub wiring board 30 are formed on one main surface of the sub wiring board 3 (see FIG. 17).

The method of manufacturing the circuit wiring board 100 includes a step of locking the wiring board 30 to the sub wiring board 3 via the solder bumps 6a and 6b (see FIGS. 17A and 17B). ,
A step of temporarily fixing the slave wiring board 3 on which the slave wiring board 30 is locked to the lower mother wiring board 2, and a step of temporarily fixing the slave wiring board 3 to the lower mother wiring board 2. For temporarily fixing the upper motherboard 2 to the substrate (see FIG. 17C)
And a reflow step of heating, fusing, and cooling the solder bumps 6a, 6b, 7, 60a, 60b.

The method for manufacturing the circuit wiring board 100 has the same effect as the method for manufacturing the circuit wiring board 1. Further, in the above embodiment, the columnar solder bumps 6 and 7 are formed on the terminal electrodes 2b and 3b of the mother wiring board 2 and the sub wiring board 3, but instead of this, spherical solder bumps 81 are provided. It may be formed (see FIG. 18).
The solder joint 4 can also be obtained by performing a reflow process on such a solder bump 81.

The method of manufacturing such a spherical solder bump 81 is based on the terminal electrodes 2 b and 3 of the mother wiring board 2 and the sub wiring board 3.
The process includes a step of arranging the solder balls 91 on the contact electrodes b (see FIG. 19) and a step of reflowing the solder balls 91 arranged on the terminal electrodes 2b and 3b.

Similarly, the solder joints 40 are also formed with spherical solder bumps 81 so that the opposing ones at equal intervals and along the two rows on the mother wiring board 2 are located at the same position. It can be obtained by forming a spherical solder bump 81 at a position directly above the solder bump 81 when the substrate 3 is erected on the mother wiring board 2 (see FIG. 20) and performing a reflow process.

Further, as shown in FIG. 21, the solder joint 4 is formed in a columnar (or spherical) shape provided on one terminal electrode 2b of the mother wiring board 2 and two terminal electrodes 3b of the sub wiring board 3. )
May be formed by reflowing the solder bump.

[0032]

According to a first aspect of the present invention, there is provided a circuit wiring board comprising: a mother wiring board; a sub-wiring board mounted on the mother wiring board; Since a solder joint for mechanical connection is provided, electrical connection and mechanical connection can be obtained at the same time without the need for connecting means such as a connector. Further, space saving is possible as compared with the case where a connecting means such as a connector is used, so that the arrangement interval of the slave wiring board with respect to the mother wiring board can be reduced, which can contribute to promotion of high-density mounting. Furthermore, the number of components can be reduced as compared with the case where a connecting means such as a connector is used, which can contribute to cost reduction. In addition, the electrical connection using solder has higher reliability than the electrical connection using a connector, which can contribute to the improvement of the quality of a device incorporating the circuit wiring board.

A method of manufacturing a circuit wiring board according to any one of claims 6 to 11, comprising a mother wiring board and a sub-wiring board mounted on the mother wiring board, wherein the mother wiring board and the sub-wiring board are In a method for manufacturing a circuit wiring board, wherein terminal electrodes in a corresponding relationship are separately provided, a solder bump forming step of forming a solder bump on the terminal electrode terminal electrode,
After the solder bump forming step, the sub-wiring board is positioned on the mother wiring board, and the solder bumps of the terminal electrodes in the corresponding relationship are brought close to each other, and the solder bump is reflowed after the board assembling step. A solder joint forming step of obtaining a solder joint for electrically and mechanically connecting the mother wiring board and the sub wiring board by cooling after the adjacent solder bumps are fused together, and the connector No connection means is required, regardless of the number of sub-wiring boards to be connected, and even in the case of a complicated three-dimensional structure, electrical connection and mechanical bonding can be performed only by performing a single reflow process. Can be achieved simultaneously, collectively and reliably. As a result, it is possible to contribute to an improvement in the production efficiency of the circuit wiring board.

[Brief description of the drawings]

FIG. 1 is a front view of a circuit wiring board according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view of a main part of the circuit wiring board of FIG. 1;

FIG. 3 is an enlarged plan view of a main part of the circuit wiring board of FIG. 1;

FIG. 4 is an enlarged front view of a main part of the circuit wiring board of FIG. 1;

FIG. 5 is an enlarged side view of a main part of the circuit wiring board of FIG. 4;

FIG. 6 is a flowchart illustrating an outline of a method for manufacturing a circuit wiring board according to one embodiment of the present invention.

FIG. 7 is an explanatory diagram of a method for manufacturing a circuit wiring board according to one embodiment of the present invention.

FIG. 8 is an explanatory diagram of a solder bump forming step of the method for manufacturing a circuit wiring board according to one embodiment of the present invention.

FIG. 9 is an explanatory diagram of a board assembling step of the method for manufacturing a circuit wiring board according to one embodiment of the present invention.

FIG. 10 is an explanatory diagram of a board assembling step of the method for manufacturing a circuit wiring board according to one embodiment of the present invention;

FIG. 11 is an explanatory diagram of a board assembling step of the method for manufacturing a circuit wiring board according to one embodiment of the present invention.

FIG. 12 is an enlarged front view of a main part of a circuit wiring board according to another embodiment of the present invention.

FIG. 13 is an enlarged side view of a main part of a circuit wiring board according to another embodiment of the present invention.

FIG. 14 is an explanatory diagram of a method for manufacturing a circuit wiring board according to another embodiment of the present invention.

FIG. 15 is an explanatory diagram of a method for manufacturing a circuit wiring board according to another embodiment of the present invention.

FIG. 16 is a front view of a circuit wiring board according to another embodiment of the present invention.

FIG. 17 is an explanatory diagram of a method for manufacturing a circuit wiring board according to another embodiment of the present invention.

FIG. 18 is a front view of a circuit wiring board according to another embodiment of the present invention.

FIG. 19 is an explanatory diagram of a method for manufacturing a circuit wiring board according to another embodiment of the present invention.

FIG. 20 is an explanatory diagram of a method for manufacturing a circuit wiring board according to another embodiment of the present invention.

FIG. 21 is an enlarged front view of a main part of a circuit wiring board according to another embodiment of the present invention.

FIG. 22 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

1: circuit wiring board, 2: mother wiring board, 3: slave wiring board,
4: solder joint, 2b, 3b: terminal electrode, 6a, 6b,
7: Solder bump.

Claims (11)

[Claims] A first wiring board mounted on the first wiring board; and a solder joint for electrically and mechanically connecting the first wiring board and the second wiring board. Characteristic circuit wiring board. 2. The circuit wiring board according to claim 1, wherein terminal electrodes are formed on the mother wiring board and the slave wiring board, and the solder joint is joined to the terminal electrodes. 3. A method according to claim 1, wherein the plurality of sub-wiring boards are mounted on the main board surface of the mother wiring board with their main board faces orthogonal to the main board face of the mother wiring board via the solder joints. The circuit wiring board according to claim 1, wherein: 4. A pair of sub-wiring boards adjacent to a plurality of sub-wiring boards mounted on the main wiring board with a main plate surface orthogonal to the other sub-wiring board, the other sub-wiring board being connected to the main wiring board via the solder joint. 4. The mounting method according to claim 3, wherein
The circuit wiring board as described. 5. The circuit wiring according to claim 3, wherein the mother wiring board is also connected to an end of the slave wiring board opposite to the end connected to the mother wiring board. substrate. 6. A mother wiring board, and a sub-wiring board mounted on the bus wiring board, wherein the mother wiring board and the sub-wiring board are provided with corresponding terminal electrodes. In the method for manufacturing a circuit wiring board, a solder bump forming step of forming solder bumps on the terminal electrodes, and after the solder bump forming step, positioning the slave wiring board on the mother wiring board and soldering the corresponding terminal electrodes A board assembling step of bringing the bumps close to each other, and after the board assembling step, the solder bumps are reflowed to fuse the adjacent solder bumps and then cooled to electrically and mechanically connect the mother wiring board and the sub wiring board. And a solder joint forming step of obtaining a solder joint to be electrically connected. 7. The solder bump formed in the solder bump forming step has a columnar shape.
A method for manufacturing the circuit wiring board according to the above. 8. The method according to claim 7, wherein the spherical solder bump is formed by selective solder plating by covering a region other than the terminal electrode with a resist film. 9. The mother wiring board has columnar solder bumps protruding along two rows, and in the board assembling step,
8. The method for manufacturing a circuit wiring board according to claim 7, wherein said slave wiring board is temporarily fixed to said mother wiring board by said solder bumps. 10. The solder bump formed in the solder bump forming step is spherical in shape.
A method for manufacturing the circuit wiring board according to the above. 11. The method according to claim 10, wherein the spherical solder bump is formed by melting a solder ball disposed on the terminal electrode.