JPH0745977Y2 - Board connection structure - Google Patents

Description

[Detailed Description of the Invention] [Outline] When the sub-board on which the hybrid IC or the like is formed is inserted into the main board and attached by soldering, the first land through is placed on the main board at a symmetrical position with the sub-board interposed therebetween. A pair of holes is provided, a pair of second land through holes are provided on the sub-board at symmetrical positions with the main board sandwiched therebetween, and the pair of the first and second land through-holes are soldered to each other. A reinforcing rod that is integrally connected and that is inserted through one of the pair of second land through holes and that has a diameter substantially the same as that of the second land through hole is connected to the second land through hole. The board connection structure is configured to project from both ends of the hole, and the soldering strength of the sub-board to the main board can be improved.

[Industrial application field]

The present invention relates to a board connection structure for connecting various sub-boards by soldering to a main board forming a main part of an electronic circuit in an electrical component or the like.

In recent years, in order to achieve high-density mounting of electronic circuits on a board, a part of the electronic circuit is hybridized (hereinafter, hybrid IC is abbreviated as HIC) to form a small sub-board. There is. Each of these sub-boards is mounted on the main board as an HIC package after processing such as lead terminal drawing and molding. However, the HIC package becomes expensive due to the extra steps such as the lead terminal drawing. The present invention refers to one measure for reducing the steps such as the lead terminal drawing.

[Prior art]

3A, 3B and 3C are views showing a conventional board connecting structure, FIG. 3A is a perspective view from above, FIG. 3B is a perspective view from below, and FIG. 3C is a perspective view. It is CC sectional drawing of FIG. 3A.
However, in this case, a case where one sub-board 2 on which HIC or the like is formed is vertically arranged on the surface of the main board 1 on which various electronic components 8 such as transistors are mounted, that is, on the surface of the main board 1. Shown as a representative example. Furthermore, in FIG. 3B,
It shows a state before the sub-board 2 is connected to the main board 1 by soldering.

Here, a mounting hole 7 for mounting the sub-board 2 is formed in advance on the main board 1, and further, a plurality of first terminal portions 5 made of conductors having a substantially uniform thickness are provided on the back surface side of the main board 1. It is formed in advance. On the other hand, a plurality of second terminal portions 6 corresponding to the first terminal portions 5 are formed in advance at one end of the sub-board 2. Next, one end of the sub-board 2 is inserted from the front surface of the main board 1 toward the back surface so that the second terminal portion 6 projects from the back surface. After that, if each of the first terminal portions 5 and each of the second terminal portions 6 are connected by soldering or the like, the sub-board 2 is fixed to the main board 1 via the solder S. That is, in this case, the sub-board 2 can be fixed to the main board 1 without the need to pull out the lead terminals and the like from the sub-board 2.

[Problems to be solved by the device]

As described above, conventionally, the sub-board 2 on which HIC etc. are formed
Was directly attached to the main board 1 by simple soldering and electrically and mechanically connected, thereby saving extra steps such as lead terminal drawing.

However, in this case, since only the second terminal portion 6, which is a small portion of the sub-board 2, is connected to the main board 1 by the solder S, the area of the soldering portion is small and sufficient soldering strength can be obtained. The inconvenience of difficulty arises. Therefore, a crack may occur in the solder S due to heat shock or vibration, or the first and second terminal portions 5 and 6 may be peeled off to cause poor contact.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a board connection structure that provides sufficient soldering strength when a sub-board is directly attached to a main board by soldering. It is a thing.

[Means for Solving the Problems]

The present invention is directed to the sub-board 2 from the front surface to the back surface of the main board 1.
The main board 1 and the sub-board 2 through the solder.
In the board connection structure for mounting on the main board 1,
Has a pair of first land through holes in a substantially symmetrical position with the sub-board 2 in between, and the sub-board 2 has a pair of second land through holes in a substantially symmetrical position with the main board 1 in between. And a pair of the first land through hole and the second pair
A substantially ring-shaped solder connecting portion that integrally connects the pair of land through holes via solder is provided, and is further inserted through one of the pair of second land through holes, and , A reinforcing rod having substantially the same diameter as the second land through hole. The reinforcing rod is provided so as to project from both ends of the second land through hole.

[Action]

In the present invention, in each of the main board 1 and the sub board 2,
Two lands formed by the terminal portions on both the front and back sides are connected to each other through the through holes to form land through holes. Furthermore, in the main board 1,
A pair of lands located at positions that are substantially symmetrical with respect to the sub-board 2
Through holes are provided. On the other hand, in the sub-board 2, a pair of land through holes are provided at positions substantially symmetrical with respect to the main board 1. If these four land through holes are integrally connected by soldering or the like, one ring-shaped solder connection portion is formed. Since the total area of the soldered portions in this ring-shaped solder connection portion is much larger than that of the conventional soldered portion (Fig. 3C), its strength is also increased.

Further, in the above-mentioned ring-shaped solder connection portion, an end portion most susceptible to the vibration of the sub-board 2, for example, a second land through hole on the back surface side of the main board 1 is reinforced with a conductor wire or the like. When the rod is inserted, the solder connection part becomes hard to move, and its strength is further increased.

In other words, in the present invention, when the main substrate 1 and the sub-substrate 2 are connected, the reinforcing rods protruding from both ends of the second land through hole come into contact with the main substrate 1, so that the sub-substrate 2 is It prevents horizontal vibration and eliminates poor solder contact. Further, by projecting the reinforcing rod, the area of the solder connecting portion (soldered portion) can be further increased, and therefore the strength of the solder connecting portion can be further increased.

Moreover, since the reinforcing rod has substantially the same diameter as the second land through hole, the reinforcing rod and the sub-board 2 are firmly fixed, and it is possible to further prevent horizontal vibration of the sub-board 2. it can.

Thus, in the present invention, the soldering strength of the sub-board to the main board is greater than in the conventional case, and the soldered portion is stable against heat shock, vibration and the like.

〔Example〕

Here, a substrate connection structure based on the basic principle of the present invention will be described in detail with reference to FIG. 1 so that a configuration of an embodiment (FIG. 2) of the present invention described later can be easily understood. And

FIG. 1 is a sectional view showing a structure based on the basic principle of the present invention. However, here, the side surface of the board connection structure in the case where one sub-board 2 is attached to the main board 1 is shown in cross section. The same components as those described above are designated by the same reference numerals.

In FIG. 1, each of the first land through hole 11 and the second land through hole 12 is formed by integrally forming a conductor of substantially uniform thickness on two lands and one through hole on both front and back surfaces of the substrate. It is manufactured by The first and second land through holes 11 and 12 are preferably formed in advance together with the conductor patterns for circuit wiring of the main board 1 and the sub board 2, respectively. Further, it is preferable to previously form a mounting hole 7 for vertically mounting the sub-board 2 at a predetermined position of the main board 1.

Here, when it is desired to connect the sub-board 2 and the main board 1, first, the sub-board 2 is inserted into the mounting hole 7 and then the second board is inserted.
One of the pair of land through holes 12 is projected from the back surface of the main substrate 1. Next, if the adjacent lands in the first and second land through holes 11 and 12 are connected to each other by soldering, the solder flows into the respective through holes and is connected to each other, and finally the mounting holes are formed. One ring-shaped solder connection portion 3 is formed around the center 7. The sub-board 2 and the main board 1 are securely connected electrically and mechanically via the ring-shaped solder connection portion 3.

In the configuration of FIG. 1 described above, since the ring-shaped solder connecting portion 3 is easily formed by the same simple soldering work as in the conventional case, the soldering strength can be improved without increasing the number of soldering steps. Can be achieved. Further, since the solder connection portion 3 is formed at the same position on the front surface and the back surface side of the main board 1, the area occupied by the solder connection portion 3 with respect to the main board 1 is increased as compared with the conventional case (FIG. 3C). There is no such thing. Therefore, when attaching a plurality of sub-boards 2 to the main board 1,
It is possible to achieve the same high density of board mounting as the conventional one.

FIG. 2 is a sectional view showing a side surface of an embodiment of the present invention. In FIG. 2, the reinforcing rod 4 is inserted through one of the pair of the second land through holes 12 shown in FIG. Note that, in FIG. 2, the configuration other than the portion where the reinforcing rod 4 is inserted is the same as the configuration of FIG. 1 described above, so the description thereof will be omitted. Here, it is preferable to use a conductor wire such as a copper wire having a diameter (0.5 to 0.8 mm) similar to that of the through hole. If an external force or the like is applied to the upper end of the sub-board 2 and the sub-board 2 vibrates in the horizontal direction, the largest couple is generated at the lower end thereof. Therefore, in order to counteract this couple, before the soldering is performed, the reinforcing rod is placed in the through hole of the second land through hole 12 located at the lower end portion of the sub-board 2 and on the back surface of the main board 1. It is preferable to insert 4 in advance. Further, it is preferable that the reinforcing rod 4 is projected from both ends of the through hole by substantially the same length so that the soldering strength of the solder connecting portion 3 is reinforced by the reinforcing rod 4 in a laterally balanced manner.

In the above-described embodiment, since the reinforcing rod 4 is arranged in the through hole in advance and then the solder connection with the first and second land through holes 11 and 12 is performed, the soldering can be performed without increasing the man-hour for soldering. It is possible to dramatically improve the attachment strength.

[Effect of device]

As described above, according to the present invention, when the sub-board is directly attached to the main board by soldering, the reinforcing rod having almost the same diameter as the land through hole is inserted so as to protrude from the land through hole. To be
Since the area of the soldered portion is further increased, the soldering strength can be improved as compared with the conventional case. Therefore,
The soldered portion becomes stable against heat shock, vibration, etc., preventing contact failure and improving reliability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure based on the basic principle of the present invention, FIG. 2 is a cross-sectional view showing a side face of an embodiment of the present invention, and FIG. 3A is a conventional board connecting structure from above. FIG. 3B is a perspective view of the conventional board connecting structure seen from below, and FIG. 3C is a sectional view taken along line CC of FIG. 3A. In the figure, 1 ... Main board, 2 ... Sub board, 3 ... Solder connection part, 4 ...
… Reinforcing rod, 11 …… First land through hole, 12…
… Second land through hole.

Claims (1)

[Scope of utility model registration request] 1. A sub-board (2) is inserted from the front surface to the back surface of the main board (1), and the sub-board (2) is inserted through solder.
In the board connection structure for attaching the first land through hole (11) to the main board (1), the main board (1) has a pair of first land through holes (11) at substantially symmetrical positions with respect to the sub-board (2). The sub-board (2) has a pair of second land through holes (12) at substantially symmetrical positions with respect to the main board (1), and the first land through hole (11). And a pair of the second land through hole (12) are integrally connected to each other through the solder, and have a substantially ring-shaped solder connection portion (3).
And a reinforcing rod (4) which is inserted through one of the pair of second land through holes (12) and has a diameter substantially the same as that of the second land through holes (12). ), The reinforcing rod (4) is projected from both ends of the second land through hole (12).