CN102143653B

CN102143653B - Printed circuit board for preventing point discharge

Info

Publication number: CN102143653B
Application number: CN 201010301092
Authority: CN
Inventors: 周玮洁; 陈俊仁; 何敦逸; 黄宗胜
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2010-02-02
Filing date: 2010-02-02
Publication date: 2013-07-03
Anticipated expiration: 2030-02-02
Also published as: CN102143653A

Abstract

The invention relates to a printed circuit board for preventing point discharge, comprising a plurality of board layers; all board layers are provided with a plurality of circular penetrating holes; a circle of isolating rings are respectively arranged at the periphery of each penetrating hole in a surrounding manner; and the acute angle between two tangent lines at the intersection of two adjacent isolating rings is larger than 20 degrees. In the printed circuit board for preventing point discharge, the point discharge can be prevented so as to protect an electronic element from being damaged.

Description

Prevent the printed circuit board (PCB) of point discharge

Technical field

The present invention relates to a kind of printed circuit board (PCB) that prevents point discharge.

Background technology

In the design process of multilayer board, the perforation quantity of each layer is all more.Usually, the perforation inwall scribbles the metal level of conduction, like this, has just realized electric connection by metal level between each layer, and the perforation periphery arranges a circle shading ring to prevent perforation and electric connection with other parts of one deck.But when leaning on very closely as if two adjacent perforations, overlapped situation can appear in its shading ring, causes the intersection point place of two adjacent shading rings a tip to occur, and the tip refers to the place that body surface curvature is big, as the sharp-pointed part of object, the wedge angle of fines etc.

At tip place, cause electric charge accumulation, charge density bigger easily, make electric field strength stronger, cause near it portion gas breakdown and discharge, this phenomenon is called point discharge.Static electric field and electrostatic induced current that point discharge produces easily cause damage to the high density electronic devices and components on the circuit board, in the time of seriously even can influence the operation of whole electronic apparatus system.

Summary of the invention

In view of above content, be necessary to provide a kind of printed circuit board (PCB) that prevents point discharge, to prevent from damaging the electronic devices and components on the printed circuit board (PCB).

A kind of printed circuit board (PCB) that prevents point discharge comprises some flaggies, and each flaggy is provided with some circular perforations, surrounds each perforation one circle shading ring all is set, and acute angle folded between two tangent lines of the intersection point of two adjacent shading rings is greater than 20 degree.

The present invention prevents that acute angle folded between two tangent lines of printed circuit board (PCB) by the intersection point of two adjacent shading rings of point discharge from spending to prevent the point discharge of printed circuit board (PCB) greater than 20, thereby can protect the electronic devices and components on the printed circuit board (PCB) not to be damaged.

Description of drawings

Fig. 1 is the schematic diagram of the preferred embodiments of the present invention's printed circuit board (PCB) of preventing point discharge.

Fig. 2 is the two adjacent perforations of the printed circuit board (PCB) that prevents point discharge of Fig. 1 and the schematic diagram of shading ring.

Fig. 3 is the curve chart that the acute angle number of degrees folded between two tangent lines of intersection point of two adjacent shading rings and printed circuit board (PCB) generation leakage current concerned between the time.

The main element symbol description

Embodiment

As shown in Figures 1 and 2, the present invention prevents that the preferred embodiments of the printed circuit board (PCB) of point discharge from comprising some flaggies, for example in regular turn overlapping 3 layers be respectively bus plane 10, dielectric substance layer 20, ground plane 30.Described bus plane 10, dielectric substance layer 20 and ground plane 20 are provided with some circular perforations 100,102,200,202,300 and 302.Surround perforation 100,102,200,202,300,302 a circle shading ring be set respectively, for example surround perforation 100,102 shading ring 104,106, with prevent perforation 100,102 and bus plane 10 on other parts electrically connect.Shading ring 104,106 the center of circle respectively with its perforation that surrounds 100,102 center of circle overlaid roughly.Perforation 100,102,200,202,300 and 302 inwall all scribble metal, as copper, tin etc., to guarantee the electric connection between each layer.

For guaranteeing that two adjacent perforations are (with perforation 100; 102 is example) because of shading ring 104; thereby 106 overlapping tips of causing are not too too sharply to prevent the electronic devices and components on the point discharge phenomenon protection printed circuit board (PCB); namely should guarantee two shading rings 104; the tangent line L1 of 106 intersection points B; acute angle A1 folded between the L2 is greater than a preset angles; carry out experimental verification as shown in Figure 3; abscissa is represented tangent line L1; the number of degrees of folded acute angle A1 between the L2; ordinate is represented the time of printed circuit board (PCB) generation leakage current; and the time that leakage current takes place, more long then expression more was not easy to take place point discharge phenomenon; the time of leakage current takes place as can be seen from Figure 3 with tangent line L1; the increase of folded acute angle A1 between the L2 and increasing; therefore in the present embodiment, preset angles is decided to be 20 degree.

The radius of setting

shading ring

104 and 106 is respectively R1, R2, angle between the line O2B between line O1B between the center of circle O1 of shading ring 104,106 intersection points B and perforation 100 and the center of circle O2 of intersection points B and perforation 102 is A2, angle A2 and angle A1 supplementary angle each other then, therefore in triangle O1O2B, the distance R 3 between the center of circle O1 of perforation 100 and the center of circle O2 of perforation 102 satisfies following formula:

Because shading

ring

104 and 106 radius R 1, R2 and angle A2 are all known, then can try to achieve the length of the distance R 3 between the center of circle O2 of the center of circle O1 of perforation 100 and perforation 102 according to above-mentioned formula.

Folded acute angle spends to prevent the point discharge of printed circuit board (PCB) greater than 20 between two tangent lines of the intersection point of printed circuit board (PCB) of the present invention by setting two adjacent shading rings, thereby prevents from damaging the electronic component on the circuit board.So, namely reached the purpose of protection electronic component.

Claims

1. printed circuit board (PCB) that prevents point discharge, comprise some flaggies, each flaggy is provided with some circular perforations, it is characterized in that: surround each perforation one circle shading ring all is set, acute angle folded between two tangent lines of the intersection point of two adjacent shading rings is greater than 20 degree.

2. the printed circuit board (PCB) that prevents point discharge as claimed in claim 1, it is characterized in that: the inwall of described perforation all scribbles metal to guarantee the electric connection between each layer.

3. the printed circuit board (PCB) that prevents point discharge as claimed in claim 2, it is characterized in that: described metal is copper or tin.

4. the printed circuit board (PCB) that prevents point discharge as claimed in claim 1 is characterized in that: the center of circle overlaid of the perforation that the center of circle of described shading ring and described shading ring surround.