Rapid repairing method for superdense-pitch quad fiat no-lead (QFN) device on printed board assembly

A printed board and spacing technology, which is applied in the fields of printed circuit manufacturing, electrical components, printed circuits, etc., can solve problems such as difficult repair, difficult alignment, uncontrollable demoulding, etc., and achieve fast repair, high success rate, low cost effect

Active Publication Date: 2015-11-25
NO 8357 RES INST OF THE THIRD ACADEMY OF CHINA AEROSPACE SCI & IND
View PDF5 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For conventional QFN devices (Ptich is 1mm), use the commonly used method of printing solder paste on the PCB part or component end, and then use welding equipment to solder the device to achieve rework, but for ultra-fine-pitch QFN devices, Ptich less than 0.5mm, such as figure 1 For small and m

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Rapid repairing method for superdense-pitch quad fiat no-lead (QFN) device on printed board assembly
  • Rapid repairing method for superdense-pitch quad fiat no-lead (QFN) device on printed board assembly

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0025] Example 1

[0026] The following describes the process method of the fast rework of the ultra-dense-pitch QFN device on the printed board assembly of the present invention in conjunction with Example 1: Using the ERSAIR550A / PL550A rework station to rework the ultra-dense-pitch QFN device in the form of DMLF package on the printed board assembly.

[0027] 1. Print solder paste used for ultra-fine pitch QFN devices in the form of DMLF package to be repaired. The specific method is to directly transfer the solder paste to a flat steel sheet or sheet with a solder mask effect using the steel mesh during the production of the printed circuit board assembly to be repaired.

[0028] 2. Mount the ultra-fine pitch QFN device in the form of DMLF package on the printed solder paste. Use the equipment with the aligning and mounting function, namely the ERSAIR550A / PL550A rework station, to mount the MELF components to be reworked on the printed solder paste;

[0029] 3. Melt the solder pas...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention belongs to the technical field of application of quad fiat no-lead (QFN) devices, particularly relates to a rapid repairing method for a superdense-pitch quad fiat no-lead (QFN) device on a printed board assembly, and aims at improving the repairing success rate. The rapid repairing method is particularly applied to rapid repairing of the superdense-pitch QFN device on the printed board assembly in electric installation. According to the technical scheme, soldering paste is arranged at the end of a component in advance and forms a solder column after being fused, and then rapid and reliable repairing of the device is realized through a mounting method; the first repairing success rate is 100%; printing can be realized by a steel mesh during production of the repaired printed board assembly; the required steel mesh does not need to be individually customized; and the rapid repairing method has the characteristics of high efficiency, high success rate and low cost. According to the rapid repairing method, the problem of low success rate caused by a conventional QFN device repairing technique is solved; and rapid repairing of the superdense-pitch QFN device is realized.

Description

technical field [0001] The invention belongs to the technical field of application of QFN devices, and in particular relates to a rapid repair method for ultra-fine-pitch QFN devices on printed board assemblies, which improves the success rate of repair and is specifically applied to ultra-dense pitches on printed board assemblies in electrical assembly Rapid rework of QFN devices. Background technique [0002] With the application of QFN devices with ultra-fine pitch (Ptich less than 0.5mm) on printed board components in military products, the rework of QFN devices has become a key factor restricting the quality of rework. In rework, solder must be used to electrically connect the pads on the printed board assembly to the pads of ultra-fine-pitch QFN devices. For conventional QFN devices (Ptich is 1mm), use the commonly used method of printing solder paste on the PCB part or component end, and then use welding equipment to solder the device to achieve rework, but for ultra...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): H05K3/34
CPCH05K3/34H05K2203/176
Inventor 苟俊锋曾立云谭磊焦淑萍
Owner NO 8357 RES INST OF THE THIRD ACADEMY OF CHINA AEROSPACE SCI & IND
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap