Method for improving poor bubbles of QFN bottom bonding pad and bonding pad

A technology of bottom pads and pads, applied in the electronic field, can solve problems affecting chip heat dissipation and PCBA reliability, and achieve the effects of improving reliability, reducing large bubbles, and ensuring conductivity

Inactive Publication Date: 2020-12-25
SUZHOU LANGCHAO INTELLIGENT TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0002] In the rapid development of the electronics industry, PCBA has become an important part of the hardware in the server architecture, and PCB, as the basic carrier board of PCBA, determines the quality of PCBA to a large extent. At present, the QFN pad design uses Via holes The design is evenly distributed on the large pads, and green oil half-plugged holes are used. After reflow, large air bubbles are prone to occur. Large air bubbles will affect the heat dissipation of the chip, thereby affecting the reliability of the PCBA.

Method used

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  • Method for improving poor bubbles of QFN bottom bonding pad and bonding pad
  • Method for improving poor bubbles of QFN bottom bonding pad and bonding pad
  • Method for improving poor bubbles of QFN bottom bonding pad and bonding pad

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Embodiment Construction

[0017] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.

[0018] see figure 1 with figure 2 , the embodiment of the present invention includes:

[0019] See figure 1 , a method for improving the bad air bubbles of the QFN bottom pad, including: designing the position of the Via hole according to the shape of the QFN pad, canceling the Via hole in the middle of the pad, and appropriately adding some Via holes on the edge of the pad according to the actual size of the pad To meet the conductivity of PCBA. It can not only reduce the occurrence rate of air bubbles but also keep you ventilating and dissipating heat. In addition, it can better improve the poor air bubbles. According to the pad design of ...

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Abstract

The invention discloses a method for improving poor bubbles of a QFN (Quad Flat No-lead) bottom bonding pad and the bonding pad. The positions of Via holes are designed according to the shape of the QFN bonding pad, the Via holes in the middle of the bonding pad are canceled, and a plurality of Via holes are properly added on the edge of the bonding pad according to the actual size of the bondingpad to meet the conductivity of a PCBA. The occurrence rate of bubbles can be reduced and through-flow heat dissipation can be improved; in order to better improve poor bubbles, a hole plugging mode of the material bonding pad is designed and then updated, a green oil half hole plugging mode is changed into a resin hole plugging mode, the hole plugging ratio is improved, and then the bubble problem caused by insufficient green oil hole plugging is solved. The plurality of Via holes are changed from 0.04mm to 0.03mm. And the circulation rate can be satisfied. By means of the mode, the design ofthe Via hole of the QFN bonding pad can be optimized, large bubbles generated by the QFN grounding bonding pad can be reduced; meanwhile, the flow conductivity of the bonding pad is guaranteed, and then the reliability of a PCBA is improved.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a method and a pad for improving the bubble defect of a pad at the bottom of a QFN. Background technique [0002] In the rapid development of the electronics industry, PCBA has become an important part of the hardware in the server architecture, and PCB, as the basic carrier board of PCBA, determines the quality of PCBA to a large extent. At present, the QFN pad design uses Via holes The design is evenly distributed on the large pads, and the holes are half-plugged with green oil. After reflow, large air bubbles are easy to occur. Large air bubbles will affect the heat dissipation of the chip, and then affect the reliability of the PCBA. Contents of the invention [0003] The main technical problem to be solved by the present invention is to provide a method and a pad for improving the bad air bubbles of the QFN bottom pad, which can reduce the impact of the middle Via hole...

Claims

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Application Information

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IPC IPC(8): H05K1/11H05K3/40
CPCH05K1/111H05K1/116H05K3/4007H05K2201/09372
Inventor 卢伟杰
Owner SUZHOU LANGCHAO INTELLIGENT TECH CO LTD
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