JPH0715106A - Printed board - Google Patents

Abstract

PURPOSE:To prevent the drop of electric property such as the signal deterioration, etc.. at the time of having connected a rigid board and a flexible board directly. CONSTITUTION:In contact patterns 3 and 13 consisting of narrow patterns for directly connecting a rigid board 1 with a flexible board 11, ground patterns G are arranged at a rate of one piece per n pieces of signal patterns S. By arranging them this way, the impedance of the contact patterns 3 and 13 becomes stable, and it becomes hard to be influenced by noise or static electricity, and the deterioration of signal by the crosstalk noise between fellow signal patterns S is reduced, and the drop of electric property is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board for high density mounting in which a rigid printed circuit board and a flexible printed circuit board are connected.

[0002]

2. Description of the Related Art Conventionally, in an electronic device such as a personal computer, a rigid rigid printed circuit board (hereinafter referred to as a rigid substrate) on which electronic components are mounted and a flexible flexible printed circuit board (hereinafter referred to as a flexible printed circuit board) are provided. (Hereinafter referred to as)), a method of connecting via connectors is used. The method of connecting a rigid board and a flexible board via these connectors has the physical size of the connectors and the minimum required spacing between connection pins, etc. There was a limit to.

Therefore, a method of directly connecting a narrow-pitch pattern formed on a rigid substrate and a flexible substrate, for example, a pattern having a center-to-center pitch of 0.3 mm or less, without using a connector has been considered. This connection method is
The contact patterns are formed at the ends of the wiring patterns formed on the rigid substrate and the flexible substrate, respectively, and a bonding material such as solder is sandwiched between these contact patterns for connection.

[0004]

However, in the above-mentioned direct connection method, since the contact patterns to be connected are formed with a narrow pitch and are arranged in a plane on the substrate, they are affected by noise and static electricity. In some cases, there is a problem in that electrical characteristics are deteriorated, such as deterioration of signals due to crosstalk noise between signal patterns.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a printed circuit board that prevents deterioration of electrical characteristics such as signal deterioration when a rigid board and a flexible board are directly connected.

[0006]

In order to achieve the above object, the present invention provides a plurality of signal patterns for transmitting electric signals in a printed circuit board in which a rigid printed circuit board and a flexible printed circuit board are directly connected by a contact pattern. , A grounding pattern mixed between the signal patterns and a contact pattern in which a grounding pattern is arranged.

[0007]

Since the present invention is configured as described above, the impedance of the contact pattern is stabilized, is less susceptible to the influence of noise and static electricity, and the deterioration of the signal due to the crosstalk noise between the signal patterns is reduced. The drop is prevented.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a layout of patterns of a printed circuit board according to an embodiment of the present invention, FIG. 2 (a) is a plan view of a rigid printed circuit board, FIG. 2 (b) is a sectional view thereof, and FIG. FIG. 3B is a plan view of the flexible printed circuit board, FIG. 3B is a sectional view thereof, and FIG. 4 is a sectional view when the rigid printed circuit board and the flexible printed circuit board are connected.

In the figure, 1 is a rigid rigid board on which electronic parts and the like are mounted, and a wiring pattern 2 consisting of a signal pattern for transmitting electric signals and a ground ground pattern is wired on the rigid board 1. There is. The wiring pattern 2 is a contact pattern consisting of a so-called narrow pattern, which is arranged on one end side of the rigid substrate 1 at a predetermined interval, for example, with a center-to-center pitch of 0.3 mm.
3 is formed, and the contact portion of the contact pattern 3 is formed of a bonding pad 4 made of copper foil or the like for connection with another printed board, for example, the flexible board 11.

Further, the flexible substrate 11 is the rigid substrate 1
Similarly, the wiring patterns 12 and the contact patterns 13 of the same number as the contact patterns 3 of the rigid substrate 1 are arranged at the same pitch, and the contact patterns 13 are formed by the bonding pads 14.

In the rigid substrate 1 and the flexible substrate 11 on which the contact patterns 3 and 13 are arranged as described above, the bonding pads 4 and 14 of the contact patterns 3 and 13 are made to face each other, and bonded as shown in FIG. Bonding material 5 consisting of solder between the pads 4 and 14
Connected by.

By the way, the rigid substrate 1 and the flexible substrate 11
As shown in FIG. 1, the contact patterns 3 and 13 arranged in the ground pattern are a signal pattern S and a predetermined number of signal patterns S, for example, ground signal grounds arranged at a ratio of one to n signal patterns S. It consists of pattern G. Where n
Is an integer of 1 or more.

By forming the contact patterns 3 and 13 by the signal pattern S and the ground ground pattern G arranged in this way, the impedance of the contact patterns 3 and 13 is stabilized, and the contact patterns 3 and 13 have noise and static electricity. Is less likely to be affected, and signal deterioration due to crosstalk noise between the signal patterns S is reduced, and deterioration of electrical characteristics is prevented.

In the above embodiment, the ground ground pattern G is arranged at a ratio of one to n signal patterns S. However, the present invention is not limited to this, and as shown in FIG. A ground grounding surface 15 may be formed on the entire back surface of 11 and the grounding grounding surface 15 and the grounding grounding pattern G of the contact pattern 13 of the flexible substrate 11 may be connected via the through hole 16. By configuring, the function of the present invention against static electricity and noise can be further enhanced.

Further, in the above embodiment, the ground ground pattern G is arranged for every n signal patterns S, but the invention is not limited to this, and the ground ground pattern G is arranged at random with respect to the signal pattern S. However, the same effect can be obtained, and the point is that the grounding ground patterns G are mixed between the signal patterns S.

Further, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0018]

As described above in detail, according to the printed circuit board of the present invention, since the ground pattern is mixed in the contact patterns between the signal patterns,
Impedance of the wiring pattern or contact pattern is stabilized, it is less susceptible to noise and static electricity, and signal deterioration due to crosstalk noise between signal patterns is reduced, and deterioration of electrical characteristics can be prevented.

[Brief description of drawings]

FIG. 1 is a layout view of patterns on a printed circuit board according to an embodiment of the present invention.

FIG. 2 is a diagram showing a rigid printed circuit board shown in FIG.
Is a plan view and FIG. 2B is a cross-sectional view thereof.

FIG. 3 is a diagram showing a flexible printed circuit board.
FIG. 3A is a plan view and FIG. 3B is a sectional view thereof.

FIG. 4 is a cross-sectional view when a rigid printed board and a flexible printed board are connected.

FIG. 5 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 ... Rigid printed circuit board 3 ... Contact pattern 11 ... Flexible printed circuit board 13 ... Contact pattern G ... Ground ground pattern S ... Signal pattern

Claims (1)

[Claims] 1. A printed circuit board in which a rigid printed circuit board and a flexible printed circuit board are directly connected by a contact pattern, wherein a plurality of signal patterns for transmitting electric signals and ground ground patterns mixed between the signal patterns are arranged. A printed circuit board having a contact pattern.