JPS6233490A - Circuit board device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit board device comprising a main circuit board and a plurality of sub circuit boards connected to the main circuit board.

[Conventional technology]

In recent years, in response to the miniaturization, high density, and multifunctionality of electronic devices, there has been a demand for an increase in the number of wiring connections between substrates and a finer pitch between them. In particular, flexible printed wiring boards have been used for a long time as they are suitable for signal connections from main circuit boards, but in response to the recent needs mentioned above, flexible printed wiring boards have been used for a long time.
There are often constraints.

Conventionally, in order to connect a flexible printed wiring board to the main circuit board, after aligning it with the connection terminals on the main circuit board, a heater chip was used to connect the flexible printed wiring board to the main circuit board by soldering, thermocompression bonding, or an anisotropic conductive film sheet. The connection method is used.

All of these methods involve heating connection or heating and pressure connection, but the length of the heater chip for this purpose and the total connection width (hereinafter referred to as width) of the flexible printed wiring board on which many fine leads are formed are required. The essential problem is the length relationship. In other words, with the formation of a large number of high-density leads, the lead pitch tends to become longer, and at the same time, the cumulative deviation of the lead pitch increases, resulting in a decrease in the yield of the flexible mark and the wiring board itself (due to poor acceptance). In addition, the heater chip is also required to have uniform temperature and no deformation due to use, so it is difficult to realize a long-axis heater chip. The limit is 80%-40mm (for example, Japan Avionics MODel).

Historically, these heater chips are made of hard and durable materials with little thermal deformation and are precisely machined to ensure uniform temperature distribution, so it is difficult to expect much variety in their axial lengths. On the other hand, the width of flexible printed wiring boards varies widely depending on the required specifications for each model.

Based on the above background, traditionally, the length of the heater chip and the unit of division in terms of circuit function were often considered, and the flexibility mark (S) was created.
(A wiring board is divided into many small pieces and connected to all these main circuit boards. This example is shown in the fifth section.
As shown in the figure. In the figure, (1) is a flexible printed wiring board having connection terminals (2), (31 is a main circuit board having a plurality of connection terminals (4) arranged in parallel, and (6)
is the heater chip.

Next, the connection method will be explained. First, a plurality of flexible printed wiring boards III are placed in parallel along the connection terminals (4) of the main circuit board (3), and each flexible printed wiring board (1) is connected Align the parts so that they line up in a straight line. Next, the preliminary solder (not shown) applied to one or both of the connection terminals 12) and 141 of the flexible printed wiring board III and the main circuit board (3) is melted by the knife-shaped thermal heater chimp (6). And both il+, +
Connect 31.

FIG. 6 1al e [The part α tangent to b+ is shown enlarged.

In the figure, (6) is preliminary solder applied to one or both of the connection terminals f21 and 141;
8 (f-1 FIG. 6 F1) I where the connection terminal (2) of the flexible printed wiring board II+ is formed on the board (1)
/ri flexible printed wiring board (11 short connection terminals (2)
Indicates a case where it protrudes from a part of.

[Problem that the invention seeks to solve]

The conventional circuit board device is constructed as described above, and the connecting portions of the slave circuit boards, that is, the flexible printed wiring board fi+ in the above example, are lined up in a straight line. Due to variations in the number of connections, there were cases where they overlapped and caused problems with the connection. Furthermore, since there are parts of the main circuit board (3) that are heated repeatedly, the number of heating times should be as small as possible and the temperature should be raised to the same temperature for the sake of the strength of the connection, its uniformity, and reproducibility. However, it is difficult to obtain such heating conditions, especially when using glass-based main circuit boards such as display devices, because the heat history causes the strength of the base material to deteriorate, making it difficult to connect. There was a problem with insufficient reliability.

As a countermeasure to these problems, the main circuit board (31 connection terminals +
41 is widened at the adjacent portion of the sub-circuit board 11''.

In other words, it is conceivable to configure the secondary circuit board Il+, which is in momentary contact, to be connected to the main circuit board (3) with a sufficient gap, but with this configuration, the connection area of the secondary circuit board fil increases. There was a problem that the external size of the main circuit board (3) became large. Also, with the long width sub-circuit board...the heater chip (
6) It is also conceivable to repeat the process by moving the lines horizontally many times and sequentially connecting them. However, in this method, problems arise as well, such as elongation and deformation of the secondary circuit board il+ due to heating and pressurization, resulting in increased cumulative displacement, and non-uniformity due to overlapping heating.

This invention was made to solve the above-mentioned problems, and aims to provide a circuit board device with excellent reliability and productivity without increasing the connection area of the sub-circuit board. .

[Means for solving problems]

A circuit board device according to the present invention includes a main circuit board having a plurality of connection terminals arranged in parallel, and at least a main circuit board having a plurality of connection terminals arranged in parallel so as to be connected along the connection terminals. 1゜Second slave circuit board? In the device, the connection portions of the first and second sub-circuit boards to the connection terminals are offset so that they are not aligned in a straight line.

[Effect]

In the circuit board device according to the present invention, the connection parts of the main circuit board and the sub circuit board are shifted so that they are not aligned in a straight line. It is possible to avoid heating the same part of the main circuit board redundantly, and to heat the connection part of the second (l) sub-circuit board when, for example, heating and connecting the first (second) sub-circuit board. Since there is no
Furthermore, the size of the heater chip is versatile, resulting in excellent productivity, and sufficient spacing between each sub-circuit board.
Since there is no need to leave space f, the connection area of the slave circuit board does not increase.

〔'Fire row〕

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows one embodiment of the present invention, and in the figure, each sub-circuit board is shifted so that one connection part is not aligned in a straight line.

Next, the connection method will be explained. First, as shown in FIG. 2, every other sub circuit board (1), that is, in this example, a flexible printed wiring board, is aligned with the main circuit board +31. Next, the heating heater chip (61'fto7 flexible mark 16
The preliminary solder (not shown) is completely melted to form a flexible mark 1 [i1J wiring board (1)].
The connection terminal (2) of the main circuit board (3) and the connection terminal (2) of the main circuit board (3)
4) Join. Next, the remaining flexible mark 1nlJ wiring board (1) is aligned with the main circuit board +31.

At this time, as shown in Fig. 1, the connecting part is adjacent to the OT flexible mark +1tlJ
Align it by shifting it so that it is not aligned with the connection part of the wiring board 1]). Below, ■Thermal heater chip +61
Connecting both III, +31'i from K is the same as in the first case.

By doing this, it is possible to connect the connecting terminal (21) of the adjacent flexible mark 11u wiring board (1) to the main circuit board (3) without heating it, and also to connect the main circuit board (3) to the main circuit board (3).
Is it reliable because the area is not heated multiple times? Furthermore, since the connecting terminals (21) of the flexible printed wiring board full can be heated within the effective range of the heater chip (6), the heating at both ends of the connecting terminals (2) can be heated. Soldering is less likely to cause defects.Furthermore, since it is not necessary to provide a sufficient interval for each flexible printed wiring board H1, the connection area of the flexible printed wiring board (1) can be reduced.

Furthermore, since the connecting portions of the adjacent flexible printed wiring boards il+ are shifted so that they are not aligned in a straight line, even if the dimensions of the heater chip +6+ are a little too long, the adjacent flexible printed wiring boards 111 Since the connecting portion is not heated, the heater chip (6) has versatility and productivity can be increased.

FIG. 8 is a plan view showing another embodiment of the invention, and FIG. 4 is an enlarged perspective view showing the connecting portion of FIG. 8.

In this example, the connection terminals (4) of the main circuit board (3) are arranged so that the spacing between the connecting terminals (4) on the flexible printed wiring board H1 is smaller than that of the connecting portion of the flexible printed wiring board H1. has been done. Therefore, even if the connecting portion of the flexible printed wiring board fl+ is heated by the heater chip (61), the connecting terminal (41) of the adjacent main circuit board (3) is not heated. Deterioration of the connecting terminal (4) can be prevented, and the eccentricity can be further improved.

In the above embodiment, the connection parts of the flexible printed wiring board Ill are alternately shifted every other board, but if the connection parts are aligned in a straight line, for example, if the connection parts are shifted in several steps, It suffices as long as it is shifted so that it does not occur, and is not limited to the above embodiment. Furthermore, the same effect as in the above embodiment can be obtained even when a plurality of flexible printed wiring boards 11+ are grouped together and shifted so that the connecting portions of the plurality of boards are not lined up on the -@ edge line.

Although the case where the 0T flexible printed wiring board is used as the slave circuit board il+ has been mainly described above, the same effects as in the above embodiment can be obtained even when other circuit boards are used.

In addition, although we have explained the case of joining by soldering as an example, the above method can also be used when joining using other methods that involve heating, such as thermocompression bonding method or method using an anisotropic conductive film sheet. Effects similar to those of the embodiments can be obtained. [Effects of the Invention] As described above, according to the present invention, there is provided a main circuit board for connecting a plurality of connection terminals arranged in parallel, and a main circuit board for connecting a plurality of connection terminals arranged in parallel. In a device comprising at least first and second sub-circuit boards arranged in parallel so as to be connected along the same, the connection portion of the first and second sub-circuit boards to the connection terminals is straight They are shifted so that they do not line up on the line,
So, what is the connection area of the slave circuit board? There is an effect that a circuit board device with excellent tiltability and productivity can be obtained without increasing the amount of product.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the invention, Fig. 2 is a perspective view illustrating the connection method shown in Fig. 1, Fig. 3 is a plan view showing another embodiment of the invention, and Fig. 4. 3 is an enlarged perspective view of the connecting portion of FIG. 3, FIG. 5 is a perspective view of a conventional circuit board device, and FIG. 6 a and b are perspective views of the connecting portion of FIG. and shows two connection methods. In the figure, 111 is a flexible stamp wiring board, +21. (4) is a connection terminal, (3) is a main circuit board, (5) is a preliminary solder, and a +61H heater chip. Note that the same reference numerals in each figure indicate the same portions corresponding to Id 1-fi.

Claims (3)

[Claims] (1) A main circuit board having a plurality of connection terminals arranged in parallel, and at least first and second slave circuits arranged in parallel so as to be connected along the connection terminals. 1. A circuit board device comprising a board, characterized in that connection portions of the first and second sub-circuit boards to the connection terminals are offset so that they are not aligned in a straight line. (2) The circuit board device according to claim 1, wherein the slave circuit board is a flexible printed wiring board. (3) The arrangement interval of the connection terminals is smaller in the adjacent part of the connection part than in the connection part of the slave circuit board.
The circuit board device according to item 1 or 2.