High creep resistance rareearth contained tin base leadless soldering-flux and preparation method thereof

A lead-free solder and creep technology, which is applied in manufacturing tools, welding equipment, metal processing equipment, etc., can solve the problems of lead pollution sensitivity, brittleness, environmental pollution, etc.

Inactive Publication Date: 2002-12-18
YIYUAN ELECTRONICS TECH
View PDF4 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, with the acceleration of the lead-free process, some large companies have successively launched lead-free wave soldering machines and lead-free reflow soldering machines, and the peak temperature of soldering can reach about 250°C. Under the current situation, the problem of melting point of lead-free solder is no longer a very prominent problem
In addition, Bi-containing solder is prone to undercutting defects during brazing, and it is easy to form a low-melting eutectic with lead, so it is more sensitive to lead pollution, and the brittleness of Bi is also an unfavorable factor.
In addition, Bi is a by-product of lead, and the use of Bi-containing solder will inevitably increase the mining of lead ore, causing environmental pollution
The abundance of In in the earth's crust is very low, and it is expensive, not suitable for large-scale use

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
  • High creep resistance rareearth contained tin base leadless soldering-flux and preparation method thereof
  • High creep resistance rareearth contained tin base leadless soldering-flux and preparation method thereof
  • High creep resistance rareearth contained tin base leadless soldering-flux and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0021] Example 1: 26 grams of potassium chloride and 20 grams of lithium chloride mixed salt were melted at 460 ° C and poured on 97.775 grams of tin. Raise the temperature of the furnace to 620°C to melt the tin and the mixed salt, then add 2 grams of Ag and 0.2 grams of Cu to the tin liquid while stirring continuously to form an alloy; The base mixed rare earth is quickly pressed into the above molten alloy and stirred continuously until the rare earth is completely melted. Keep warm for 1 hour, stirring constantly to homogenize the alloy. Stand still and take out the furnace, and remove the mixed salt on the surface after the alloy is solidified. Lower the furnace temperature to 360°C to reheat and melt the solder block, and then pour it into strips on the angle iron for use.

example 2

[0022] Example 2: 26 grams of potassium chloride and 20 grams of lithium chloride mixed salt were melted at 460°C and poured on 96.0 grams of tin. Raise the temperature of the furnace to 780°C, melt the tin and the mixed salt, add 2 grams of Ag and 1 gram of Cu to the tin liquid, and stir continuously at the same time to form an alloy; The base mixed rare earth is quickly pressed into the above molten alloy and stirred continuously until the rare earth is completely melted. Keep it warm for 1.5 hours and keep stirring to homogenize the alloy. Stand still and take out the furnace, and remove the mixed salt on the surface after the alloy is solidified. Lower the furnace temperature to 380°C to reheat and melt the solder block, and then pour it into strips on the angle iron for use.

example 3

[0023] Example 3: 23.4 grams of potassium chloride and 18 grams of lithium chloride mixed salt are poured on 94.775 grams of tin after melting at 450°C. Raise the temperature of the furnace to 650°C to melt the tin and the mixed salt, then add 5 grams of Ag and 0.2 grams of Cu to the tin liquid while stirring continuously to form an alloy; The base mixed rare earth is quickly pressed into the above molten alloy and stirred continuously until the rare earth is completely melted. Keep warm for 1 hour, stirring constantly to homogenize the alloy. Stand still and take out the furnace, and remove the mixed salt on the surface after the alloy is solidified. Lower the furnace temperature to 360°C to reheat and melt the solder block, and then pour it into strips on the angle iron for use.

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 present invention relates to a high creep resistance rare earth containing tin base leadless brazing filler metal and its preparation method. Said material contains (wt%) 2-5% of Ag, 0.2-1% of Cu, 0.025-1.0% of commercially-available Ce base mixed rare earth and the rest is Sn. Its preparation method includes the following steps: melting mixed salt of potassium chloride and lithium chloride with weight ratio of 1-1.6:0.8-1.2, pouring it on the Sn, after the Sn is melted, adding the weighed Ag and Cu into Sn solution to melt Ag and Cu, then using bell jar whose wall has hole to press the Ce base rare earth into the above-mentioned mixed salt and Sn-Ag-Cu alloy, turning bell jar, heat-insulating for 1-2 hr., stirring, standing still, setting and removing mixed salt from surface so as toobtain the invented brazing fill metal.

Description

technical field [0001] A rare earth-containing tin-based lead-free solder with high creep resistance and a preparation method thereof belong to the technical field of lead-free solder manufacturing for surface assembly in the microelectronics industry. Background technique [0002] With the rise and wider application of surface mount technology, as well as the ultra-fine pitch design of electronic circuit boards, new lead-free solders are required not only to have good process performance, but more importantly, to have higher Mechanical properties to meet the growing reliability requirements of the electronics industry to ensure reliable operation during service. The mechanical properties of brazed joints are largely affected by their creep deformation behavior. For SnAgCu solder, its melting temperature is roughly between 215°C and 218°C. In this way, even at room temperature, the deformation behavior of the brazed joint belongs to high temperature creep. This higher tem...

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
Patent Type & Authority Applications(China)
IPC IPC(8): B23K35/26B23K35/362
Inventor 史耀武陈志刚夏志东雷永平李晓延
Owner YIYUAN ELECTRONICS TECH
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