JPH03196592A - Printed circuit board - Google Patents

Abstract

PURPOSE:To enable execution of wiring of high density with the cost reduced, by removing lands of through holes in a row in an outside area through which a wiring pattern passes and by passing the wiring pattern from the inside to the outside. CONSTITUTION:The surface and the rear of a board 1 are formed of a component mounting surface 1A and a soldering surface 1B respectively and a number of through holes 2 and 3 are bored in such a manner that they are juxtaposed in inside and outside areas in the shape of a zigzag arrangement and that they are spaced by a prescribed gap L1 with a half pitch shifted from each other. Wiring patterns 4 printed on the component mounting surface 1A of the board 1 are so designed that they are connected to lands 21 fitted to the through holes 2 in a row in the inside area and can be led outward through between the through holes 3 in a row in the outside area. Since the wirable width between the through holes is enlarged by this constitution, such waste as increasing the number of layers of the board or stretching around the wiring other than the wiring patterns is eliminated and the wiring of high density can be executed inexpensively and easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) The present invention is directed to, for example, QFP (Quad FlatPa
The present invention relates to a printed circuit board used for mounting electronic components such as sockets for electronic cages with high-density wiring.

(Prior Art) Conventionally, in this type of printed circuit board, in order to mount electronic components on the component mounting surface, a large number of through holes are formed into which pins of the electronic components are inserted.

In such a printed circuit board, for example, Q
When installing parts such as FP sockets, a large number of through holes are drilled between the front and back surfaces of the board in a staggered arrangement in two rows of areas, the outside and the outside, and the through holes in the inner area are The row is surrounded by a row of through holes in the outer region.

However, with the above-mentioned conventional sliding structure, when mounting with high-density wiring, if lands are attached to the through-holes in the rows in the outer region, the land gaps between the through-holes will cause the wiring pattern to be printed. If the width is narrower than the width of the board, the wiring pattern connected to the through-hole row in the inner region using only the outermost layer on the front and back surfaces of the board cannot be routed outside the through-hole row in the outer region.

(Problem to be solved by the invention) For this reason, in the past, the number of printed circuit boards was increased by adding more layers.
Wiring must be done using the increased layer, or wiring must be routed using jumper wires without using a wiring pattern, resulting in unnecessary wiring work and increased costs.

The present invention has been made under the above circumstances, and an object thereof is to provide a printed circuit board that allows high-density wiring to be easily performed at low cost.

[Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a substrate having a wiring pattern printed on both the front and back surfaces, which are composed of a component mounting surface and a soldering surface, and A large number of through holes are formed between the front and back surfaces of the board in a staggered manner in parallel to the inner and outer regions, and the rows of the inner region are surrounded by the rows of the outer region, and the land gap is narrower than the width of the wiring pattern. holes, and when the wiring pattern connected to the through-holes in the row of the inner region is led out between the through-holes in the row of the outer region, the lands of the through-holes in the row of the outer region are removed. This is what I did.

(Function) In other words, the present invention has the above-described configuration, which widens the possible width of wiring between through-holes, thereby eliminating the need for unnecessary wiring such as increasing the number of circuit boards and routing wiring other than the wiring pattern. can be omitted.

(Example) Hereinafter, the present invention will be described in detail with reference to an illustrated example.

As shown in FIG. 2, numeral 1 in the figure is a substrate according to the present invention. The front and back surfaces of this board 1 are the 5 component mounting surface IA and the soldering surface I.
B, each of which has a component mounting surface IA and a soldering surface 1.
8, as shown in FIGS. 1 and 3, a large number of through holes 2... and 3... are arranged in a staggered manner in the inner and outer regions with a predetermined gap L1 while being shifted by half a pitch from each other. The holes are drilled in parallel to each other.

The through holes 2 in the inner region row are surrounded by the through holes 3 in the outer region row.

Further, numerals 4 and 5 in FIG. 1 are wiring patterns printed on the component mounting surface IA and the soldering surface IB of the board 1, respectively.

Wiring pattern 4 printed on the component mounting surface IA of the board 1
are connected to the lands 21.21 attached to the through holes 2 in the row of the inner region, and can be projected outward through the through holes 3.3 in the row of the outer region.

That is, the lands of the through holes 3 in the row in the outer region have been removed, and the gap L between the through holes 3 is made larger than the land gap L2 by that much. As a result, even if the land gap L2 is narrower than the width L0 of the wiring patterns 4 and 5, the wiring pattern 4 connected to the through-hole 2° in the row of the inner region can be connected to the through-hole of the row of the outer region. 3. Wiring can be drawn out through the space between 3 and 3.

On the other hand, as shown in FIG. 3, the wiring pattern 5 printed on the solder surface IB of the board 1 is directly connected to the land 31 attached to the through hole 3 in the row of the outer region, and is drawn out and wired to the outside. There is. Note that 22.22 in the figure indicates the through holes 2 and 22 in the inner region row on the solder surface IB side of the board 1.
It is a land attached to...

Incidentally, a QFP socket W into which a component mounted on the component mounting surface IA of the board 1, such as a QFP type integrated circuit IC, is inserted has a structure as shown in FIGS. 4 and 5. .

That is, on the lower surface of this QFP socket W, there are many pins P□, P in the same arrangement as the through holes 2 and 3.
2 are planted parallel to each other in the inner and outer regions in a staggered arrangement with a predetermined gap L3 while being shifted by half a pitch from each other, and the pins P□ and P2 of each row of these inner and outer regions are inserted into the through holes 2 and 3, respectively. It is designed to be inserted and soldered on the solder surface IB side of the board 1.

As described above, in the printed circuit board according to the present invention, the through-holes 2 in the rows in the inner region are made into double-sided lands 21, 22, and the through-holes 3 in the row in the outer region have wiring patterns only on the solder surface IB. Attach a runt 31 for drawing out 5. Then, the component mounting surface IA where wiring pattern 4 does not appear
The through-holes 3 in the rows of the outer region on the sides have their lands removed, thereby forming the through-holes 2 and 3 in the rows in the inner region.
The wiring patterns 4 connected to the runts 21 can be drawn out and routed through the through holes 3.3 of the runtless columns in the outer region.

[Effects of the Invention] As is clear from the above description, according to the present invention, the run 1 gap is narrower than the width of the wiring pattern.

This is because the land of the through-hole in the outer region column through which the wiring pattern passes is removed when the wiring pattern connected to the through hole in the inner region column surrounded by the through hole in the outer region column is drawn out. , the wiring pattern from the inside can be easily passed through to the outside.

This allows you to increase the number of calendars on the board as before,
It is possible to eliminate waste such as routing wiring other than the wiring pattern, and it is possible to perform high-density wiring while reducing costs.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged explanatory diagram of a component mounting surface on which a wiring pattern is printed, showing an embodiment of a printed circuit board according to the present invention;
Figure 2 is a cross-sectional view showing how the parts are mounted, Figure 3 is an explanatory diagram showing a partially enlarged solder surface of the printed circuit board on which the wiring pattern is printed, and Figure 4 is the parts mounted on the printed circuit board. FIG. 5 is an explanatory diagram showing the arrangement of pins provided on the same component. 1... Board, 1A... Component mounting surface, IB... Soldering surface, 2...
Through hole row in inner area, 21, 2 3 ・ ・ 31 ・ ・ 4 ・ ・ 5 ・ ・ ・ W ・ ・ ・ Lo ・ ・ ・ Ll ・ ・ L2 ・ ・ L, ・ ・ 2... Land, through-hole row in the outer area, ・Land, wiring pattern on component mounting side, wiring pattern on soldering side, component, P... Width of wiring pattern, gap between through holes, runt gap. Pin gap. bottle,

Claims (1)

[Claims] (1) A board on which wiring patterns are printed on both the front and back sides, consisting of a component mounting surface and a soldering surface, and holes that are parallel to the inner and outer regions in a staggered pattern between the front and back surfaces of this board, and the inner and outer regions of the board. The column is surrounded by the column in the outer region and is provided with a large number of through holes having land gaps narrower than the width of the wiring pattern, and the wiring pattern connected to the through hole in the column in the inner region is surrounded by the column in the outer region. A printed circuit board characterized in that lands of the through holes in the row of the outer region are removed when the printed circuit board is drawn out between the through holes.