JPS6232637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a through-hole printed wiring board, and more particularly to a double-sided or multilayer printed wiring board for high-density wiring having through-hole plated connection holes.

The circuit pattern of a conventionally manufactured printed wiring board is as shown in the enlarged plan view of FIG. Grid lines 1 having equal intervals of, for example, 2.5 mm are crossed on the printed wiring board, and through holes are bored at the intersections 1a using an automatic drilling machine or the like. Next, the printed wiring board with the through holes drilled therein is sequentially used for plating, photoresist printing, etching, etc., to pass through the land portions 2 and the through holes continuous with the land portions 2 in the desired areas. A hole 3 and a circuit 4 are formed. For this reason, in a conventional printed wiring board, when at least three circuits 4 are arranged in a portion where the interval of the grid line 1 is divided into 16 equal parts, for example, the second signal circuit 4a is
The wiring termination is restricted by the first signal circuit 4b and the second signal circuit 4c, and in order to route the wiring without crossing the first signal circuit 4b and the second signal circuit 4c, a first signal connection through hole is required. Perforated hole wall 3a
A third signal circuit 4d whose wiring direction has been changed is placed on the back surface or inner layer of the board, and is further connected to the same surface as the second signal circuit 4a through a second signal connection through-hole plating hole wall 3b. Therefore, it was necessary to pull out the second signal circuit 4a and subsequently wire the second signal circuit 4a.

In this way, when the wiring density of the circuit 4 becomes three or more, adjacent parallel circuits mutually influence the wiring density and the wiring position relationship on the printed wiring board.
Furthermore, parts are inserted to use a part of the through-hole plating through-hole 3 formed on the grid line 1 as the first signal connection through-hole plating hole wall 3a, the second signal connection through-hole plating hole wall 3b, etc. There is a limit to its use as a plating through hole or an inner layer circuit connection hole, and the unwired rate increases compared to the theoretical wiring density and component mounting density, and the circuit wiring rate is limited to 20 to 30%. A problem arose.

An object of the present invention is to provide a through-hole printed wiring board for high-density wiring which solves the drawbacks of the conventional printed wiring boards.

According to the present invention, a first land group having a through hole for inserting a component positioned at the intersection of first grid lines assumed along the orthogonal XY axis directions on one surface of the printed wiring board; Y of the second grid line assumed to be orthogonal at a position shifted by 1/2 grid from the first grid line
A land outer diameter that is positioned at the intersection of the first signal circuit wired along the axial direction and the second grid line, is electrically connected to the first signal circuit, and is smaller than the land outer diameter of the first land group. a through hole for connecting a signal circuit, and a second signal circuit located on both sides of the first signal circuit and wired to sandwich the through hole, with the second signal circuit being separated. A through-hole printed wiring board is obtained in which adjacent through-holes are electrically connected to each other by a third signal circuit wired along the X-axis direction on the other surface of the printed wiring board.

The present invention will be explained in detail below using the drawings.

FIG. 2 is an enlarged plan view of a circuit pattern of a through-hole printed wiring board for high-density wiring according to the present invention. For example, 2.5 mm (or
Second grid lines 1 having equal intervals of 2.54 mm) are intersected vertically and horizontally, and desired through-holes, for example, first through-holes 5 having a diameter of 0.3 mm, are bored on the intersections 1a using an automatic drilling machine or the like. Furthermore, the second grid line 1 is 1/2
First grid lines 7 are arranged vertically and horizontally at grid offset positions, and a through hole having a larger diameter than the first through hole 5, for example, 1.0 mm in diameter, is formed on the intersection 7a of the first grid lines surrounding the first through hole 5. The second through holes 6 are sequentially drilled using an automatic drilling machine. Next, the perforated printed wiring board is successively plated, photoresist printed, etched, etc., to the desired position to form a land portion 2, a through-hole plated through hole 3 connecting the land portion 2, A signal connection through hole plating through hole 8, a small land portion 9, and a circuit 4 (4a to 4d) are formed. In FIG. 2, the signal connection through-hole plated through-hole 8 uses a circular small land portion 9 different from the through-hole plated through-hole 3.

FIG. 3 shows a printed wiring board formed by the same method as in FIG. 2, and in particular, the small land portion 9b connected to the signal connection through-hole plating through hole 8 has an octagonal shape. , the wiring at the bent portions of the second signal circuits 4a and 4c is connected to the first through hole 5.
The wiring interval is made large in the gap between the second through hole 6 and the second through hole 6 to facilitate pattern wiring.

Next, FIG. 4 shows an improvement on the circuit patterns shown in FIGS. 2 and 3, and a printed wiring board is formed by the same method as in FIG. Both the small land portion 9b and the land portion 2b of the through-hole plating through hole 3 are made octagonal, and the wiring spacing in the gap between the first through hole 5 and the second through hole 6 is made larger. This simplifies the wiring pattern.

According to the present invention, there are the following advantages.

When three circuits 4 are arranged in a part where the second grid line 1 is divided into 16 equal intervals, for example, by providing the signal connection through-hole plated through hole 8 on the intersection 1a of the second grid line 1, the first signal The circuit 4b is not affected by the wiring conditions of the second signal circuits 4a and 4c and can be connected to the back surface or inside of the printed wiring board without intersecting each signal circuit. Furthermore, the first through hole 5
Since the signal connection through-hole plated through hole 8 can be formed and used exclusively for connection of the inner layer circuit, the second through hole 6 can be used independently as a plated through hole for inserting components. .

Therefore, the theoretical wiring density and component mounting density are 20~
The unwired rate has improved by 30% and has become non-existent. Furthermore, as an improved example of this embodiment, by using a pattern in which one or both of the land portion 2b of the second through hole 6 and the small land portion of the first through hole 5 are changed to an octagonal small land 9b, A sufficient gap between the first through hole 5 and the second through hole 6 was obtained, and the wiring of the circuit 4 could be easily performed, thereby further improving the present invention.

[Brief explanation of the drawing]

FIG. 1 is an enlarged plan view of the main part of the circuit pattern of a conventionally used through-hole printed wiring board. Second
The figure is an enlarged plan view of the main part of the circuit pattern of the through-hole printed wiring board according to the present invention. Figures 3 and 4
The figure is an enlarged plan view of the main part of another embodiment of the circuit pattern of the through-hole printed wiring board according to the present invention. 1; Grid line or second grid line, 1a; Intersection of grid line or second grid line, 2; 2b; Land portion,
3; Through-hole plated through hole, 3a; First signal connection through-hole plated hole wall, 3b; Second signal connection through-hole plated hole wall, 4; Circuit, 4a;
Second signal circuit, 4b; First signal circuit, 4c;
Second signal circuit, 4d; Third signal circuit, 5; First through hole, 6; Second through hole, 7; First grid line, 7a; Intersection of first grid line, 8; Signal connection Through-hole plating through hole, 9, 9b; small land portion.

Claims (1)

[Claims] 1. A first land group having through-holes for inserting components positioned at intersections of first grid lines assumed along the orthogonal XY axis directions on one surface of the printed wiring board, and the first grid. A first signal circuit wired along the Y-axis direction of orthogonal second grid lines assumed to be shifted by 1/2 from each of the X and Y lines, and a first signal circuit positioned at the intersection of the second grid lines and through-holes for signal circuit connection that are electrically connected to the first signal circuit and have a land outer diameter smaller than the land outer diameter of the first land group; a second signal circuit wired to sandwich the through hole, and the through holes adjacent to each other with the second signal circuit in between are wired along the X-axis direction on the other surface of the printed wiring board. A through-hole printed wiring board characterized in that the through-hole printed wiring board is electrically connected by a third signal circuit.