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EPP Europe P2.2018

  • Text
  • Inspection
  • November
  • Manufacturing
  • Solder
  • Electronics
  • Software
  • Assembly
  • Components
  • Soldering
  • Solutions

PCB + ASSEMBLY Reflow

PCB + ASSEMBLY Reflow profiles with different peak temperature. Source: Koki Reflow profiles with different melt time. Source: Koki Joint structure via reflow profile of different peak temperature. Source: Koki Reflow profiles with different cooling rate. Source: Koki Varying peak temperatures The Sn phase coarsened in the solder joint structure with all surface finishes obtained via the reflow profiles while the peak temperature was at or less than 240 °C. The coarse IMC, presumably Cu 6 Sn 5 , was observed in the solder structure with all finishes except for ENIG, via the reflow profile with the peak temperature at 270 °C. It is possible that the IMC was formed due to a dispersion of copper from the test board. Varying melting times There was no major difference seen in the Sn phase within the solder joint structure that was obtained via reflow profiles, when the melting time was the standard 45 seconds or longer. However, when the melting time was longer, it resulted in a smaller Sn-Ag eutectic phase and the formation of Ag 3 Sn IMC. Varying cooling rates The solder joint structures obtained via reflow profiles with the different cooling rates were interesting to measure. The cooling rate of or below –2.0 °C/sec, resulted in the coarsened Sn phase, smaller Sn-Ag eutectic phase, and coarsening of presumably Cu 6 Sn 5 IMC for all surface finishes. Joint structure via reflow profile with different melt time. Zusammenfassung Dieser Artikel berichtet über den unvermeidlichen Einfluss der unterschiedlichen Reflow-Bedingungen auf die Lötstellenstruktur und stellt die Ergebnisse der Überprüfung nach der Implementierung mit SAC305 vor. Résumé Cet article rapporte l‘impact inévitable de différentes conditions de refusion sur la structure de joint de soudure et présente les résultats de la vérification post-implémentation (après la mise en œuvre) avec SAC305. Zusammenfassung russisch Эта статья рассказывает о неизбежном влиянии различных условий оплавления припоя на структуру точки пайки и представляет результаты проверки после внедрения SAC305. Source: Koki 38 EPP EUROPE November 2018

PCB + ASSEMBLY Source: Koki Versioned catalog production Perfect project management for highly complex jobs Tools for an efficient workflow TEST PROBES ARE HIGH-PRECISION PRODUCTS » For top quality standards » For a wide range of applications » Custom-made designs Joint structure via reflow profile with different cooling rate. VISIT US AT THE ELECTRONICA TRADE FAIR IN MUNICH FROM NOVEMBER 13 TO 16, 2018 Hall A3, Stand 429 Conclusion Findings from the evaluation of the effects of different reflow profile conditions are as follows: • When the peak temperature of a reflow profile was at or below 240 °C, the Sn phase coarsened in the solder structure. At or above 270 °C, the coarse IMC, presumably Cu 6 Sn 5 , precipitated when using the boards without Cu barrier. • Time exceeding 45 seconds that was above the reflow peak temperature resulted in a smaller Sn-Ag phase and precipitation of Ag 3 Sn. • When the cooling rate was at or less than –2 °C/sec., the Sn phase coarsened, Sn-Ag eutectic phase dwindled, and IMC of presumably Su 6 Sn 5 crystalized in the solder joint structure. producing media intelligently www.konradinheckel.de PTR HARTMANN GmbH Gewerbehof 38, 59368 Werne (Germany) www.ptr-hartmann.com Further discussion A customer once asked the company, Koki, to analyze an assembly soldered with SAC305 alloy that failed after less than 1000 thermal cycles. As a result of analysis, the company found that the BGA joint of a module substrate inside the shield case was fractured. In the fractured solder joint structure, the coarsening of Sn phase and the IMC was observed. At the time, the cause could not be identified, since the number of thermal cycles and the state of solder structure did not seem to be correlated. However, examining the results above, the company can now make an assumption that the solder joint structure was similar to that of a low-silver containing solder joint because it was slowly cooled inside the high heat capacitance shield case. A further investigation into the influences on the thermal cycling durability by the differences in solder joint structure will be done, to prove that not only is the alloy composition important, but the temperature conditions are also very important to improve the durability of solder joint. www.ko-ki.co.jp Yamaha True Total Line Solution is the industry leading portfolio in the market for entry level, high-mix low/medium-volume up to high-mix high-volume and ultra-mass production. The Yamaha Intelligent Factory Solutions offer the most complete software solution for Industry 4.0. In the Yamaha Intelligent Factory we focus on the 4M connection by digital technology inside electronics manufacturing: MACHINE – MATERIAL – HUMAN – METHOD. Maximize line productivity & factory efficiency with 4 x M2M connections: Machine to Machine, Material to Machine, Method to Machine and Machine to Human. CONTACT US! Yamaha Motor Europe N.V. · Robotics EPP Division EUROPE · SMT November Section 2018 39 Tel: +49-2131-2013 520 · info-ymeim@yamaha-motor.de · www.yamaha-motor-im.euor

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