Dissertation > Excellent graduate degree dissertation topics show

Non-cyanide Electroplating of Au-Sn Alloy

Author: ZhangFuShun
Tutor: HuangMingLiang;WangLai
School: Dalian University of Technology
Course: Materials Science
Keywords: Au-Sn eutectic non-cyanide plating co-electroplating lead-free solder
CLC: TQ153
Type: Master's thesis
Year: 2008
Downloads: 243
Quote: 1
Read: Download Dissertation

Abstract


LEDs were applied in many fields as a long-life,energy efficient,environmentally friendly and multi-use light source in modem life.The flip-chip technology improved the thermal dissipation and luminescence efficiency of High-power LEDs,but higher requirements were submitted to the packaging technology.Our purpose was to develop an Au-Sn bumping process on high-power LED flip-chip technology.This paper focused on the influence of non-cyanide plating solution stability,the electroplating parameters on the thickness of cladding,and the preparation of Au70Sn30 eutectic bump.The main results indicated that:1.A new non-cyanide co-electroplating solution for Au-Sn alloys was developed based on D. G.Ivey’s solution which was stable at room temperature.NaSO3 and EDTA were used as golden complexing agent,potassium pyrophosphate as stannous complexing agent,pH value was adjusted from 6.0 to 8.0.The high-temperature stability of this solution was improved(it was still stable after heating to 50℃).2.When the NaAuCl4·2H2O concentration in bath was 4,10,15,20g/L respectively,a peak of growth rate appeared for 10g/L under T=45℃.When NaAuCl4·2H2O concentration was 4g/L, heavy current made the plating films porous;as NaAuCl4·2H2O concentration increasing,the plating solution stability became worse.The suitable NaAuCl4·2H2O concentration in bath was 10g/L.3.The plating temperature had an obviously effected on the surface topography of Au-Sn films.When the temperature was in the range from 35℃to 65℃,the lower the temperature the rougher the films;but the higher temperature also made the films rough owing to scorch of the films,and lowered the quality of Au-Sn alloys.The suitable plating temperature was 45℃.4.While Jwas set at 1,2,3,4,5,6,6.5,7,8,8.5,10mA/cm2 separately,the tin content was 16%for Au5Sn at 1mA/cm2 and the tin content was nearly 50%for AuSn when the current was higher than 3mA/cm2,the tin content of Au-Sn alloys was 30%(at.%)at 2mA/cm2.The morphologies of Au-Sn films became coursing with the increasing J value,and then the grain became rough.The growth rate of Au-Sn alloys increased firstly and then reduced,the fastest growth rate achieved 24μm/h when J=7mA/cm2.5.Two methods were performed to preparate Au70Sn30 alloys using co-electroplating in this study.The sequential electroplating Au5Sn and AuSn multi-layers had a lower growth rate because of the lower growth rate of the AusSn.However,the co-deposition of 30%tin content film had a faster growth rate under a varied impulse current,which can reach 13μm/h at 6.05mA/cm2,T=45℃.

Related Dissertations

  1. Influence of Cooling Rates on Microstructure and Properties of Zn-4Al-3Mg Alloy,TG146.13
  2. Microstructural Analysis of the Sn-Bi-Zn-Ag Lead-Free Solders and the Soldered Interfaces,TG42
  3. Solder joint reliability problems unleaded stacked CSP package drop test,TN405
  4. Add trace elements on Sn-0.7Cu lead-free solder performance,TG425
  5. Study on Wettability of Snagcu Lead-free Solder and Electromigration of Solder Joint,TG425.1
  6. Influences of Minor Elements Addition on the Interfacial Reactions Between Lead-free Solders and Common Substrates,TG425
  7. Research on Bending Performance and Brazing Perform Ance of Copper Alloy Material Used for Lead Frame,TG146.11
  8. The Properties of New Lead-free Solder Sn-Sb-Cu-Ni,TG42
  9. Interfacial Evolution and Reliability of Lead-free Solder Joint in BGA,TN405
  10. Microstructural Formation of Sn-Ag-Zn Solder and Its Jointed Interfaces,TG404
  11. Study of Intermatallic Compounds and Kirkendall Voids in Solder Joints of Lead-free Solder,TG40
  12. Study of the Reliability of Power Device with SnAgCu Lead-free Attachment,TN305
  13. BGA packaged devices solder ball shear experiments and simulation studies,TN405
  14. Effect of the Addition of Al or in on the Microstructural Formation of Sn-Ag-Zn Solder and the Exploration of the Soldered Interface,TG42
  15. Investigation of Electromigration on Lead-Free Solder Bump in Flip Chip Packaging,TN405
  16. Study of Flux for Microelectronics Soldering and Microstructure of Solder Joint,TG42
  17. A Study of the Creep Property of Sn-9Zn Solder and Its Strengthen,TG425
  18. Organization of Ce Sn-based lead-free solder , performance and interface impact,TG42
  19. Magnesium Alloy Plating Preparation of Ni-B coatings with lead-free solder interfacial reactions,TG174.4
  20. Multiaxial Ratcheting Deformation and Low Cycle Fatigue of Lead-free Solder Sn-3.5Ag,TG425

CLC: > Industrial Technology > Chemical Industry > Electrochemical industries > Electroplating industry
© 2012 www.DissertationTopic.Net  Mobile