WO2015117435A1

WO2015117435A1 - Printed circuit board

Info

Publication number: WO2015117435A1
Application number: PCT/CN2014/090572
Authority: WO
Inventors: 侯方西
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-08-19
Filing date: 2014-11-07
Publication date: 2015-08-13
Also published as: CN204069487U

Abstract

A printed circuit board, comprising at least one welding area. The welding area comprises a bonding pad group (11) and a rounding trench (13), wherein the bonding pad group (11) comprises one or more than one bonding pad, and the one or more than one bonding pad in the bonding pad group (11) is arranged on the surface of the welding area; and the rounding trench (13) is arranged inside the welding area surrounding the bonding pad.

Description

Printed circuit board

Technical field

The present invention relates to electronic devices, and in particular to a printed circuit board.

Background technique

The frequency at which the terminal falls is high, and the printed circuit board inside the terminal is the support of the device, which is the carrier connecting the devices. When the device on the printed circuit board is deformed by stress during the deformation process, it is prone to breakage or fall off from the printed circuit board and cause damage to the device. At present, most of the protection schemes for devices focus on forming a cavity on a printed circuit board using a metal member, or forming a support for a printed circuit board around the device by a structural housing to prevent deformation. In this type of protection scheme, the introduced metal piece or structural support occupies a large area, and the device layout position is required to be relatively concentrated, and the periphery of the device can be implemented. However, for the device at the edge of the printed circuit board, it is not enough to protect the periphery of the device. At this time, such additional object protection measures cannot be introduced.

Summary of the invention

In order to solve the existing technical problems, embodiments of the present invention are expected to provide a printed circuit board.

Embodiments of the present invention provide a printed circuit board including at least one soldering region, the soldering region being provided with a pad group and a surrounding trench, wherein

The set of pads includes one or more pads;

One or more pads in the set of pads are disposed on a surface of the soldering region;

The surrounding trench is disposed inside the soldering area around the pad group.

In the above solution, the depth V1 of the surrounding groove is smaller than the printed circuit board thickness L by 0.5 mm or more, that is, V1 <= L - 0.5; and the width of the surrounding groove is 0.2 mm or more.

In the above solution, the surrounding trench is a connectivity trench or two or more trenches that are not connected to each other.

In the above solution, the soldering region further includes: one or more bottom trenches; the bottom trenches are disposed inside the soldering region between the pads and the pads in the pad group.

In the above solution, the depth V2 of the bottom groove is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

The printed circuit board provided by the embodiment of the present invention includes at least one soldering region, the soldering region includes: a pad and a surrounding trench; wherein the pad is disposed on a surface of the soldering region; the surrounding trench is disposed on the soldering Inside the welded area around the disk. Thus, when the printed circuit board is subjected to an external force, the presence of the surrounding groove can prevent the device on the printed circuit board from being damaged by the force deformation or falling off the pad.

DRAWINGS

1 is a longitudinal sectional view showing a welded portion of a printed circuit board according to Embodiment 1 of the present invention;

2 is a schematic view showing a basic shape of a surrounding groove according to Embodiment 1 of the present invention;

3 is a schematic view showing a basic shape of a surrounding groove according to Embodiment 1 of the present invention;

4 is a longitudinal cross-sectional view showing a soldering region in a printed circuit board according to Embodiment 2 of the present invention;

FIG. 5 is an analysis diagram of stress conditions of a printed circuit board in the prior art; FIG.

FIG. 6 is an analysis diagram of a force receiving condition of a printed circuit board according to an embodiment of the present invention.

detailed description

In an embodiment of the present invention, there is provided a printed circuit board including at least one soldering region, the soldering region comprising: a pad group and a surrounding trench; wherein the pad group includes one or more pads; One or more pads in the pad set are disposed on a surface of the soldering region; the surrounding trench is disposed inside the soldering region around the pad.

The invention will be further described in detail below with reference to the drawings and specific embodiments.

Embodiment 1

Embodiment 1 of the present invention provides a printed circuit board, the printed circuit board including at least one soldering area;

The soldering region can be considered as a small printed circuit board, and an exemplary longitudinal section of the soldering region is as shown in FIG. 1. The soldering region includes: a pad group 11 and a surrounding trench 13;

The pad set 11 includes one or more pads;

One or more pads of the pad set 11 are disposed on the surface of the soldering region for soldering the device 12 to secure the device 12 to the soldering region; the device herein may be a patch component or other Electronic component

The surrounding trenches are disposed inside the soldering area around the pad group 11 for preventing damage to the device 12.

Specifically, the width and depth of the surrounding groove 13 are generally not limited. Preferably, the width of the surrounding groove may be set to 0.2 mm or more, and the depth of the surrounding groove may be arbitrarily set as long as it is smaller than the printed circuit. The thickness of the board is fine, but in order to prevent the printed circuit board from being easily broken when the groove is too deep, the depth of the surrounding groove (set to V1) is generally set to be smaller than the thickness of the printed circuit board (set to L) of 0.4 mm or more. , that is to say V1<=L-0.4, the unit is mm;

There is no particular limitation on the shape of the surrounding groove. However, since the surrounding groove is provided around the device, in order to maximize space saving, it is generally recommended to set the shape of the surrounding groove according to the shape of the device; when the shape of the device is circular The surrounding groove may be arranged in an annular shape as shown in FIG. 2(a); when the shape of the device is square, the surrounding groove may be set as a square ring as shown in FIG. 2(b); When the shape of the device is a triangle, the surrounding groove can be set to a triangular ring shape as shown in FIG. 2(c); in FIGS. 2(a) to 2(c), the shaded portion indicates a surrounding groove; With a few examples, the shape of the surrounding grooves can be varied;

In addition, the surrounding groove can be set not only as a connected groove but also as a The plurality of grooves are connected to each other, and the annular surrounding groove is taken as an example, and the shape shown in FIG. 3 can be set, that is, a plurality of grooves surround the periphery of the device to form a surrounding groove;

When setting the surrounding trench, it is necessary to slot the printed circuit board to remove the printed circuit board in the trench; specifically, according to the depth of the trench, one or more layers of copper on the printed circuit board need to be removed. And dielectric materials.

Embodiment 2

The second embodiment of the present invention provides another printed circuit board. The printed circuit board is further improved on the basis of the first embodiment. As shown in FIG. 4, in the welding area shown in FIG. Or more than one bottom trench 14; specifically, the bottom trench 14 is located under the entire pad group, inside the soldering region between the pad and the pad, since the pad group given in FIG. 1 is composed of two solders The disc is composed, therefore, only the bottom trench 14 is provided in the soldering region of FIG. 4, which is located in the region between the two pads in the pad group 11, as will be understood by those skilled in the art, the bottom The number of the trenches may be one or more. When the number of the pads exceeds two, a plurality of bottom trenches may be disposed in the soldering region between the pads and the pads;

In addition, considering that the bottom trench 14 is located below the pad group 11, there is often a trace below the pad group. Therefore, the depth V2 of the bottom trench 14 should not be too deep, generally set within the range of [0.1 mm, 0.2 mm]. That is, 0.1 mm <= V2 <= 0.2 mm.

The shape of the bottom groove 14 can be set as needed, and is not limited herein;

The grooved method of the bottom groove is the same as the surrounding groove, and will not be described here;

The principle of preventing damage to the surrounding groove and the bottom groove will be described in detail below;

5 is a diagram showing the stress analysis of the printed circuit board in the prior art. As shown in FIG. 5, the device 50 is attached to the printed circuit board 53 through the pads 51 and the pads 52. When the printed circuit board 53 is subjected to an external force. When bent, the printed circuit board is arched toward the device 50, and the direction of the force of the portions of the printed circuit board 53 and the device 50 is as indicated by the arrows in the figure. It can be seen that the device 50 is bent in the vicinity of the pad 51 and the pad 52 due to the tensile force and the force toward the printed circuit board 53, and the device 50 is bent under the external force and has a tendency to break toward the printed circuit board 53.

FIG. 7 is a diagram showing a stress analysis of a printed circuit board according to an embodiment of the present invention. As shown in FIG. 6, the device 60 is attached to the printed circuit board 63 through pads 61 and pads 62, and the pads 61 and pads 62 are attached. A peripheral groove 64 is provided around the periphery; when the printed circuit board 63 is bent away from the device 60 by an external force, the printed circuit board 63 is arched toward the device surface, and the bending force encounters the surrounding groove 64 due to the presence of the surrounding groove 64. It becomes a force that enlarges the caliber around the groove 64. At this time, only part of the force is transmitted to the printed circuit board area under the device, so that the bending angle of the printed circuit board under the device is very small, and the device 60 is subjected to the tensile force and the printing. The bending strength of the surface of the circuit board 63 also becomes very small (as indicated by the arrow in the figure), and thus, the surrounding groove can be used to prevent the device from being damaged by an external force.

In addition, in the prior art, when the printed circuit board is bent by the external force to the device surface, the device is subjected to the compressive force in the vicinity of the pad and the power facing away from the printed circuit board, so that the device is bent away from the printed circuit board under the external force. And there is a tendency to break away from the printed circuit board or fall off from the pad; however, after the printed circuit board is provided with the bottom trench as in the second embodiment of the present invention, under the same force, due to The presence of the bottom groove, the bending force encounters the bottom groove, becomes the force of the compression groove diameter, and only part of the force is transmitted to the printed circuit board area under the device, so that the bending angle of the printed circuit board under the device will become small. The bending strength of the device in the direction of compression and back to the printed circuit board is also small, thereby preventing damage to the device. When the device is in close contact with the printed circuit board, the gap between the two is very small (mostly through-holes Soldering to a printed circuit board) When the printed circuit board is deformed, the printed circuit board is arched away from the device surface, if the device is directly opposite the printed circuit board Touch, there is no gap, the printed circuit board and arching means between collisions, easy to damage the device. Therefore, in the embodiments of the present invention, it is considered to provide a surrounding trench and a bottom trench on the bottom of the device, on the printed circuit board, to remove copper and printed circuit board dielectric material on the board, one or more layers, and to prevent deformation of the printed circuit board. Squeeze the device.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Industrial applicability

The printed circuit board provided by the embodiment of the present invention is provided with a surrounding groove inside the soldering area around the pad, so that when the printed circuit board is subjected to an external force, the printed circuit board can be prevented from being deformed due to the existence of the surrounding groove. Squeeze the device to prevent damage or breakage of the device on the printed circuit board due to force deformation.

Claims

A printed circuit board comprising at least one: a soldering region, the soldering region being provided with a pad group and a surrounding trench, wherein

The set of pads includes one or more pads;

One or more pads in the set of pads are disposed on a surface of the soldering region;

The surrounding trench is disposed inside the soldering area around the pad group.
The printed circuit board according to claim 1, wherein said surrounding groove has a depth V1 smaller than a printed circuit board thickness L by 0.5 mm or more, that is, V1 <= L - 0.5; said surrounding groove has a width larger than Equal to 0.2 mm.
The printed circuit board according to claim 1, wherein said surrounding groove is a continuity groove or two or more grooves that are not connected to each other.
The printed circuit board of claim 1, wherein the soldering region further comprises: one or more bottom trenches; the bottom trench is disposed in a solder region between the pads and the pads in the pad group internal.
The printed circuit board according to claim 4, wherein the bottom groove has a depth V2 of 0.1 mm or more and 0.2 mm or less.