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Welding pad structure of printed circuit board

A technology for printed circuit boards and solder pads, which is applied in the directions of printed circuit components and electrical components to assemble printed circuits, and can solve the problems of increased spacing between solder pads 81, difficult to remove, and high defect rate of circuit boards.

Inactive Publication Date: 2004-02-18
UNITED TEST CENTER INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, the traditional manufacturing method will still make the manufactured circuit board have a high defect rate
[0006] In addition, the increase of the size of the circuit layout 82 at the position of the bonding pad 81 will cause the pitch of the bonding pad 81 to increase. In this way, in the same area, the flip chip 90 can only have a smaller number of bumps 91, or must Increase the size of flip chip 90
[0007] Furthermore, after the flip chip 90 is installed, flux residue 92 is often accumulated in the microhole 84, which is difficult to remove.

Method used

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  • Welding pad structure of printed circuit board
  • Welding pad structure of printed circuit board
  • Welding pad structure of printed circuit board

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Embodiment Construction

[0029] see image 3 As shown, the pad structure of the printed circuit board provided by a preferred embodiment of the present invention includes:

[0030] A substrate 10, made of multi-function epoxy resin, is provided with a circuit layout 20, which is a circuit formed by a plurality of copper wires, and a solder resist layer 30, covering the circuit Predetermined part of layout 20. The solder resist layer 30 is also made of multifunctional epoxy resin. The printed circuit board of the present invention can be a single-layer printed circuit board, of course it can also be a multi-layer printed circuit board.

[0031] The solder resist layer 30 is provided with a plurality of microholes 31 at predetermined positions to expose predetermined portions of the circuit layout 20 . image 3 It also shows that the micro-holes 31 are shifted due to the photographic development process, therefore, the exposed portion of the circuit layout 20 is located on one side of each of the mic...

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Abstract

The structure includes a substrate with a circuit layout on it and an antiwelding layer on the substrate to cover preset portion of the circuit layout. Multiple microvoids are set on this antiweldinglayer in order to expose wires located below the microvoid and multiple welding pad layer is also set as it has an internal layer (copper foil) and an external layer (nickel-gold) with the internal layer being sticked at sidewall of the microvoid and being electric-connected to exposed wire below the microvoid, with the external layer being sticked on the internal layer to form the welding pad.

Description

technical field [0001] The invention relates to electronic products, in particular to a welding pad structure of a printed circuit board. Background technique [0002] In today's electronic manufacturing industry, technologies such as Direct Chip Attach (DCA) and Chip Size Package (CSP) are widely used in the manufacture of Printed Circuit Boards (PCBs). Bonding pads are provided on the printed circuit board so that the bare chip can be electrically connected to the circuit board when the flip chip is loaded. Most of the welding pads are made by means of photographic development, and microholes are provided on the solder resist layer of the printed circuit board to expose the predetermined position of the circuit layout. A nickel-gold layer is electroplated on the exposed copper wires of the circuit layout to form the aforementioned pads. [0003] In the aforementioned photographic development process, when the film is attached to the substrate, alignment errors will inevi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H05K1/02H05K3/34
Inventor 马崇仁池万国邹镜华
Owner UNITED TEST CENTER INC