JPH03126290A - Printed wiring board - Google Patents

Abstract

PURPOSE:To enable leads of electronic components to be connected to a conductor terminal while preventing the conductor terminal from deviating from the pitch of the leads by providing a cut part which is narrower than the width of the gap between terminals and is longer than a conductor terminal length between the conductor terminals to be formed at a printed-wiring board and by dividing into small blocks with a plurality of conductor terminals. CONSTITUTION:A longer edge part 15 is provided on a printed-wiring board 14 and two protruding parts 20 are also provided at the opposite side. The pitch between terminal center lines of the conductor terminal 16 corresponds to the pitch between lead center lines of a lead 13 of a fluorescent display board 11. Also, three cut-out parts 17 are provided between the conductor terminals 16 at equal interval and are divided into four small blocks 19 and the bottom part 18 is cut in circular shape, thus preventing any crack from occurring. The protruding part 20 forms two connector connection parts 21. The lead 13 is matched to the conductor terminal 16 through a solder 26 and soldering is performed. Then, the longer edge part 15 shrinks thermally for each small block 19 but is absorbed by each cut-out part 25, thus preventing positional deviation from being accumulated and achieving connection.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to electrical connections between electronic components such as fluorescent display tubes and liquid crystal displays and printed wiring boards.

(Prior Art) Conventionally, soldering, for example, has been used to connect the leads of electronic components such as fluorescent display tubes to the conductor terminals of flexible printed wiring boards (hereinafter referred to as printed wiring boards). For example, a conductive connection is used to connect a flat plate electrode of a component to a conductor terminal of a printed wiring board (for example, Japanese Patent Publication No. 63-9092).

As a means for connecting the conductor terminals of the printed wiring board to the leads of the fluorescent display tube, for example, as shown in FIG.
The long end 5 of the printed wiring board 4 is
Conductor terminals 6 are formed side by side, and these conductor terminals 6 and leads 3 are connected to each other independently by soldering.

(Problems to be Solved by the Invention) However, according to the conventional method of connecting and reading printed wiring boards, the long end of the printed wiring board 4 becomes hot because the connecting portion locally becomes hot due to heating during soldering. 5 thermally shrinks from the position of the broken line shown in FIG. 6 to the position of the solid line after cooling, and at the edge 5a of the long end 5 in the longitudinal direction, as shown in FIG.
The misalignment between the facing positions of the leads 3 of the fluorescent display tube 1 and the conductor terminals 6 of the printed wiring board 4 accumulates, causing the leads 3 and the conductor terminals 6 to overlap.
There was a problem with the connection being incomplete. In particular, in large electronic components with a large number of conductor terminals or precision electronic components with a narrow lead pitch, the misalignment between the leads and the conductor terminals during heat shrinkage is noticeable.

The present invention was made to solve this problem, and even if the spacing between conductor terminals on a printed wiring board shrinks due to thermal changes during soldering, the pitch of the leads arranged in parallel on an electronic component remains the same. On the other hand, it is an object of the present invention to provide a printed wiring board in which leads of an electronic component and conductor terminals of a printed wiring board can be connected without shifting the conductor terminals.

(Means for Solving the Problems) To achieve this, the printed wiring board of the present invention includes a plurality of conductors electrically connected to a plurality of leads arranged on the end face of an electronic component and having a pitch corresponding to the pitch of the leads. A printed wiring board for forming terminals, wherein a cut portion is provided between the conductor terminals formed on the printed wiring board and is narrower than the width of the inter-terminal gap and longer than the length of the conductor terminal, and the cut portion It is characterized in that the printed wiring board is divided into small blocks each having a plurality of conductor terminals.

(Function) According to the printed wiring board of the present invention, a notch is provided between the conductor terminals formed on the long end of the printed wiring board to divide the long end into small blocks. When soldering or hot-pressing the conductor terminals of the wiring board, thermal contraction of the long end occurs in each small block after cooling, and the thermal strain is absorbed by the notch, which reduces the lead pitch of electronic components. The misalignment of the conductor terminal relative to the printed wiring board will not accumulate to the long edge of the printed wiring board. Therefore, the conductor terminal formed on the long end of the printed wiring board is connected to each lead in alignment from one edge of the long end of the printed wiring board to the other edge without deviation.

(Example) Embodiments of the present invention will be described below based on the drawings.

In the first embodiment of the present invention, a printed wiring board 14 is connected to a fluorescent display board 11, as shown in FIG.

The fluorescent display board 11 has a rectangular parallelepiped main body and a long end surface 12 thereof.
It consists of a linear glue 13 protruding in a direction substantially perpendicular to the top.

A large number of leads 13 are arranged on the long end surface 12 in a comb shape.

The printed wiring board 14 has a long end 15 on which a conductor terminal 16 is formed, and two protrusions 20 on the opposite side of the long end 15.
and is provided.

The width (pitch) between the terminal center lines of the conductor terminals 16 corresponds to the width between the lead center lines of the leads 13 of the fluorescent display panel 11. Further, this long end portion 15 is provided with three notches 17 at equal intervals between a large number of conductor terminals 16. This notch 17 divides the long end 5 on which the conductor terminal 16 is formed into four small blocks 19, and the bottom 18 of the notch 17 is cut into a circular shape. This is to avoid stress concentration and prevent cracking.

Two connector connecting portions 21 are formed on the convex portion 20, and a reinforcing plate 22 is adhered to the surface opposite to the connector connecting portions 21.

As shown in FIG. 2, the printed wiring board 14 has a cover film 24 covering the upper surface of the conductor 28 formed on the base film 23. As shown in FIG.

The connection between the fluorescent display board and the printed wiring board constructed as described above is performed as follows.

As shown in FIG.
When the leads 13 are joined together through the heater 27 and soldered using the heater 27, the long end portions 15 of the printed wiring board 14 are thermally contracted in the longitudinal direction for each small block 19, and this contraction is caused by each notch 25. Because it is absorbed by the long end 1 as in the conventional
It is possible to connect the leads 13 and the conductor terminals 16 with corresponding pitches without accumulating misalignment between the leads 13 and the conductor terminals 16 at the edge of the cutout. Since the circular bottom part 18 is formed in the notch part 17, the contraction that occurs in each small block causes the notch part 17 to
Stress that tries to widen the cut width acts on the cut width, but this stress concentration is absorbed by the circular bottom part 18,
This prevents the cut portion 17 from cracking or breaking.

A second embodiment of the present invention is a planar electrode 31a of an electronic component 31 such as a liquid crystal display or a printed circuit board, as shown in FIG.
The conductor terminals 32a of the printed wiring board 32 are connected to the conductor terminals 32a of the printed wiring board 32 using a conductive adhesive.

The long end 33 of the printed wiring board 32 has two notches 34.
The cut portion 34 is divided into three small blocks 35 by
The bottom part 36 of is cut in a semicircular shape.

When the planar electrode 31a of the electronic component 31 and the long end portion 33 of the printed wiring board 32 on which the conductor terminal 32a is formed are heat-pressed via a conductive adhesive 44 in accordance with the electrode pitch of the planar electrode 31a, the first As in the embodiment described above, the long end portion 33 serving as the connecting portion is subjected to heat shrinkage, and this heat shrinkage is absorbed by the cut portion 34 of each small block 35. For this reason,
The conductor terminal 32a formed on the long end portion 33 should be connected to the flat electrode 31a of the electronic component 31 without shifting.

In a third embodiment of the present invention, as shown in FIG.
A connecting portion 39 is provided at the long end portion 37 and a notched elongated hole 41 extending from the long end portion 37 to the connecting portion 39 is formed.

As shown in FIG. 5(B), the connecting portion 39 is formed with a stepped portion 39a. For this reason, the fluorescent display tube 4
0 lead 40a and the conductor terminal 37 of the printed wiring board 38
The stepped portion 39a plays the role of a stopper when aligning the position a, making the alignment work easier. Also,
The elongated notch hole 41 has a circular hole 42 at both ends thereof, the diameter of which is larger than the length of the notch. The long end portion 37 is divided into four small blocks 43 by these long notched holes 41 .

Therefore, according to the printed wiring board 38 of the third embodiment, the notch elongated hole 41 tends to be expanded due to the heat contraction of each small block 43 that occurs during soldering, but this expansion does not occur when both ends are closed. The conductor terminal 37a and the lead 40a are suppressed by the circular hole 42 of the notched elongated hole 41.
The positional deviation can be further reduced compared to the case of one small block shown in the first embodiment.

Note that the electronic components connected to the printed wiring board of the present invention are as follows:
The types of electronic components are not limited to fluorescent display tubes and liquid crystal displays.

(Effects of the Invention) As explained above, according to the printed wiring board of the present invention, the leads of electronic components etc. and the conductor terminals of the printed wiring board are connected by applying heat to the connection part by soldering or the like. In this case, since the long end of the printed wiring board is divided into multiple small blocks by the notch, heat shrinkage occurs for each of these small blocks, so that the long end of the printed wiring board is Conductor terminals can be connected according to the lead pitch□

[Brief explanation of the drawing]

FIG. 1 shows a first embodiment of the present invention, in which (A) is a plan view thereof, (B) is a side view thereof, and FIG. 2 is a long end portion of a printed wiring board in the first embodiment. (A) is a cross-sectional view of the edge, (B) is a plan view thereof, and FIG. 3 is a side view showing the state of connection by the heater of the first embodiment.
4 shows a second embodiment of the present invention, (A) is a plan view thereof, (B) is a side view thereof, and FIG. 5 shows a third embodiment of the present invention (A). ) is its plan view, (B)
6 shows the conventional example, (A) shows the plan view, (B) shows the side view, and FIG. 7 shows the edge of the long end of the printed wiring board in the conventional example. FIG. 1 3 4 5 6 ... Fluorescent display tube (electronic component), ... Lead, ... Printed wiring board, ... Long end, ... Conductor terminal, 7 ... Notch, ・...Small block.

Claims (1)

[Claims] (1) A printed wiring board forming a plurality of conductor terminals that are electrically connected to a plurality of leads arranged on an end surface of an electronic component and have a pitch corresponding to the pitch of the leads, the printed wiring board being formed on the printed wiring board. a notch narrower than the width of the gap between the terminals and longer than the length of the conductor terminal is provided between the conductor terminals, and the printed wiring board is divided into small blocks having a plurality of conductor terminals by the notch. A printed wiring board featuring: