Szczegóły publikacji
Opis bibliograficzny
X-ray inspection and Six-Sigma in analysis of LED thermal pad coverage / Barbara DZIURDZIA, Janusz Mikołajek // Soldering & Surface Mount Technology ; ISSN 0954-0911. — 2017 — vol. 29 iss. 1 spec. iss., s. 28–33. — Bibliogr. s. 32–33. — 40th International-Microelectronics-and-Packaging-Society Poland International Conference (IMAPS Poland) : Wałbrzych, Poland, September 25–28, 2016
Autorzy (2)
- AGHDziurdzia Barbara
- Mikołajek Janusz
Słowa kluczowe
Dane bibliometryczne
| ID BaDAP | 104755 |
|---|---|
| Data dodania do BaDAP | 2017-05-19 |
| DOI | 10.1108/SSMT-10-2016-0028 |
| Rok publikacji | 2017 |
| Typ publikacji | referat w czasopiśmie |
| Otwarty dostęp |  |
| Czasopismo/seria | Soldering & Surface Mount Technology |
Abstract
Purpose The purpose of this paper is to evaluate selected methods of reduction voidings in lead-free solder joints underneath thermal pads of light-emitting diodes (LEDs), using X-ray inspection and Six Sigma methodology. Design/methodology/approach On the basis of cause and effect diagram for solder voiding, the potential causes of voids and influence of process variables on void formation were found. Three process variables were chosen: the type of reflow soldering, vacuum incorporation and the type of solder paste. Samples of LEDs were mounted with convection and vapour phase reflow soldering. Vacuum was incorporated into vapour phase soldering. Two types of solder pastes OM338PT and LFS-216LT were used. Algorithm incorporated into X-ray inspection system enabled to calculate the statistical distribution of LED thermal pad coverage and to find the process capability index (C pk ) of applied soldering techniques. Findings The evaluation of selected soldering processes of LEDs in respect of their thermal pad coverage and statistical C indices is presented. Vapour-phase soldering with vacuum is capable (C > 1) for OM338PT and LFS-216LT paste. Convection reflow without vacuum with LFS-216LT paste is also capable (C = 1.1). Other technological soldering processes require improvements. Vacuum improves radically the capability of a reflow soldering for an LED assembly. When vacuum is not accessible, some improvement of capability to a lower extent is possible by an application of void-free solder pastes. Originality/value Six Sigma statistical methodology combined with X-ray diagnosis was used to check whether applied methods of void reduction underneath LED thermal pads are capable processes.
