CN211959707U

CN211959707U - Steel mesh structure for improving welding yield of close-spacing BGA device

Info

Publication number: CN211959707U
Application number: CN202020670471.4U
Authority: CN
Inventors: 王辉刚; 郝彦霞; 汤昌才
Original assignee: Shenzhen Edadoc Circuit Co ltd
Current assignee: Shenzhen Edadoc Circuit Co ltd
Priority date: 2020-04-28
Filing date: 2020-04-28
Publication date: 2020-11-17
Anticipated expiration: 2030-04-28

Abstract

The utility model discloses a steel mesh structure for improving close interval BGA device welding yields in the circuit board field is equipped with a plurality of steel mesh units on the steel mesh template, and every steel mesh unit is the square, the center of every steel mesh unit and the centre of a circle coincidence of the circular pad that matches with it, and the four sides of every steel mesh unit all with it match the outer border tangent of the circular pad. The beneficial effects of the utility model reside in that, when close-spaced BGA device and circular pad welding, under the prerequisite that the tin cream after preventing adjacent pad liquefaction from linking the tin and causing the short circuit, through be equipped with the square steel mesh unit that big and apex angle have the circular arc such as the diameter of a plurality of and circular pad on this steel mesh structure, increase the area of every steel mesh unit, increase the tin volume on every solder ball during welding, thereby it is more firm to make the welding between close-spaced BGA device and the circular pad, the yields of close-spaced BGA device welding has been improved, especially improve 0.5mm and following close-spaced BGA device welded yields.

Description

Steel mesh structure for improving welding yield of close-spacing BGA device

Technical Field

The utility model relates to a circuit board field especially relates to a steel mesh structure for improving close interval BGA device welding yields.

Background

With the continuous development of packaging technology and the continuous improvement of user requirements, BGA packaging devices are developing towards dense pitch and miniaturization, and in order to relieve the shortage of PCB space, dense pitch BGA devices of 0.5mm or less are widely used. Because the PIN interval is relatively close, the bonding pad is too large, and when the BGA device with the dense interval is welded with the round bonding pad, the liquefied solder paste of the adjacent bonding pad is easy to be connected with the tin to cause a short circuit problem; the pad is too little, and traditional steel mesh design becomes to be the circular steel mesh of equidimension with the pad, because the pad of 0.5mm and following close interval BGA device is less, and the tin cream volume that can bear with big circular steel mesh such as pad is also less, the problem that BGA device welding yields is low easily appears during the welding.

The above disadvantages need to be improved.

Disclosure of Invention

In order to overcome the not enough of current technique, the utility model provides a steel mesh structure for improving close interval BGA device welding yields.

The utility model discloses technical scheme as follows:

the utility model provides a steel mesh structure for improving close interval BGA device welds yields, is equipped with a plurality of steel mesh units, every on the steel mesh template the steel mesh unit is the square, every the center of steel mesh unit and the centre of a circle coincidence of the circular pad that matches with it, and every the four sides of steel mesh unit all with match with it the outer border of circular pad is tangent.

According to above-mentioned scheme the utility model discloses, its characterized in that, the PIN interval of close interval BGA device is not more than 0.5 mm.

According to the above scheme the utility model discloses, its characterized in that, four apex angles of steel mesh unit are circular arc chamfer.

According to above-mentioned scheme the utility model discloses, its characterized in that, the central angle of circular arc chamfer is 90.

According to the above scheme the utility model discloses, its characterized in that, a plurality of the steel mesh unit is the matrix arrangement and is in on the steel mesh template.

According to the above scheme the utility model discloses, its beneficial effect lies in, when close interval BGA device and circular pad welding, prevent that the tin cream after the liquefaction of adjacent pad from even under the tin causes the prerequisite of short circuit, there is the square steel mesh unit of circular arc through big and apex angle such as the diameter of being equipped with a plurality of and circular pad in this steel mesh structure, increase the area of every steel mesh unit, increase the tin volume on every solder ball during the welding, thereby it is more firm to make the welding between close interval BGA device and the circular pad, the yields of close interval BGA device welding has been improved, especially improve 0.5mm and following close interval BGA device welded yields.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the figure, 100, steel mesh template, 10, steel mesh unit, 20, circular pad.

Detailed Description

The invention is further described with reference to the following figures and embodiments:

as shown in FIG. 1, a steel mesh structure for improving the yield of a fine-pitch BGA device during soldering is provided, wherein a plurality of steel mesh units 10 are arranged on a steel mesh template 100, each steel mesh unit 10 is square, the center of each steel mesh unit 10 coincides with the center of a circular pad 20 matched with the steel mesh unit, and the four sides of each steel mesh unit 10 are tangent to the outer edge of the circular pad 20 matched with the steel mesh unit.

The top angle of the steel mesh unit 10 is an arc chamfer, the central angle of the arc chamfer is 90 degrees, the side length of the four sides of the steel mesh unit 10 is the same as the diameter of the circular pad 20, and the steel mesh units 10 are arranged on the steel mesh template 100 in a matrix manner. Preferably, the steel mesh structure is also suitable for a PIN pitch of a dense pitch BGA device of 0.5mm or less.

During operation, the steel mesh template 100 is laid above the circular bonding pad 20, the four sides of the steel mesh unit 10 are arranged in a tangent mode with the outer edge of the circular bonding pad 20, the steel mesh is removed after tin paste is brushed, the BGA device with the close spacing is placed above the circular bonding pad 20, and after the BGA device with the close spacing is liquefied, welding of the BGA device with the circular bonding pad 20 is completed. The traditional steel mesh is the circular steel mesh big with circular pad 20 etc, the required tin cream volume leads to the welding insecure less during the welding, and this steel mesh structural design becomes the square steel mesh unit 10 that has the circular arc with big and apex angle such as the diameter of circular pad 20, through the area of increase every steel mesh unit 10, multiplicable tin cream volume during the welding, it is more firm to make the welding between its close-spaced BGA device and the circular pad 20, steel mesh unit 10 in the steel mesh structure designs into big with the diameter of circular pad 20 etc. greatly, its purpose is close-spaced BGA device when welding with circular pad, the tin cream after the liquefaction of adjacent pad prevents to link tin and causes under the prerequisite of short circuit that the area of enlarging steel mesh unit 10 reaches the mesh that improves close-spaced BGA device welding yields, especially improve the yields of 0.5mm and following close-spaced device welding.

It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are considered to be within the scope of the invention as defined by the following claims.

The above exemplary description of the present invention is made in conjunction with the accompanying drawings, and it is obvious that the present invention is not limited by the above manner, and various improvements made by the method concept and technical solution of the present invention or by directly applying the concept and technical solution of the present invention to other occasions without improvement are all within the protection scope of the present invention.

Claims

1. The utility model provides a steel mesh structure for improving close interval BGA device welds yields, its characterized in that is equipped with a plurality of steel mesh units, every on the steel mesh template the steel mesh unit is the square, every the center of steel mesh unit and the centre of a circle coincidence of the circular pad that matches with it, and every the four sides of steel mesh unit all with it matches the outer border of circular pad is tangent.

2. The steel mesh structure for improving yield of soldering of the dense-pitch BGA device according to claim 1, wherein the PIN pitch of the dense-pitch BGA device is not more than 0.5 mm.

3. The steel mesh structure for improving the yield of the welding of the dense-pitch BGA device according to claim 1, wherein four top corners of the steel mesh unit are rounded.

4. The steel mesh structure for improving yield of welding of the dense-pitch BGA device according to claim 3, wherein the central angle of the circular arc chamfer is 90 °.

5. The steel mesh structure for improving the yield of the welding of the dense-pitch BGA device according to claim 1, wherein a plurality of the steel mesh units are arranged on the steel mesh template in a matrix.