The Influence of Soldering Profile on the Thermal Parameters of Insulated Gate Bipolar Transistors (IGBTs)

Abstract

The effect of solder joint fabrication on the thermal properties of IGBTs soldered onto glass-epoxy substrate (FR4) was investigated. Glass-epoxy substrates with a thickness of 1.50 mm, covered with a 35 μm thick Cu layer, were used. A surface finish was prepared from a hot air leveling (HAL) Sn99Cu0.7Ag0.3 layer with a thickness of 1 ÷ 40 μm. IGBT transistors NGB8207BN were soldered with SACX0307 (Sn99Ag0.3Cu0.7) paste. The samples were soldered in different soldering ovens and at different temperature profiles. The thermal impedance Zth(t) and thermal resistance Rthof the samples were measured. Microstructural and voids analyses were performed. It was found that the differences for different samples reached 15% and 20% for Zth(t) and Rth, respectively. Although the ratio of the gas voids in the solder joints varied between 3% and 30%, no correlation between the void ratios and Rth increase was found. In the case of the different soldering technologies, the microstructure of the solder joint showed significant differences in the thickness of the intermetallic compounds (IMC) layer; these differences correlated well with the time above liquidus during the soldering process. The thermal parameters of IGBTs could be changed due to the increased thermal conductivity of the IMC layer as compared to the thermal conductivity of the solder bulk. Our research highlighted the importance of the soldering technology used and the thermal profile in the case of the assembly of IGBT components.

Cooling Systems of Power Semiconductor Devices—A Review

“…The problem of the effective cooling of electronic devices is a subject of the investigations of packaging constructors [6,7], as well as designers and constructors of electronic circuits containing these devices [8][9][10]. This paper [6] proves that the size of voids in the soldering joint practically has no influence on the efficiency of heat removal from a power semiconductor device.…”

“…The problem of the effective cooling of electronic devices is a subject of the investigations of packaging constructors [6,7], as well as designers and constructors of electronic circuits containing these devices [8][9][10]. This paper [6] proves that the size of voids in the soldering joint practically has no influence on the efficiency of heat removal from a power semiconductor device. In turn, the paper [8] presents the results of the measurements, which show that an increase in the dissipated power and the air flow speed led to an improvement in the efficiency of cooling of such devices.…”

Influence of the soldering paste type on optical and thermal parameters of LED modules

“…The papers of Jiang et al (2018), Skwarek et al (2017) analyse the influence of the application of various admixtures in classic soldering pastes on the physical properties of the solder joints obtained. In particular, the papers of Skwarek et al (2021), Pietruszka et al (2021) consider the influence of admixtures in the standard solder paste on the thermal resistance of the soldered semiconductor devices. In the paper of Ptak et al (2020), the influence of the use of various ovens in the soldering process, characterised by both a different number of heating zones and temperature profile, on the thermal The current issue and full text archive of this journal is available on Emerald Insight at: https://www.emerald.com/insight/0954-0911.htm…”

“…The intermetallic compound layers (IMC) at the solid interfaces and the dispersed IMC phases in the solder joints are most likely to have an impact on the thermal and electrical parameters of solder connections (Harris and Chaggar, 1998;Raypah et al, 2018;Adawiyah et al, 2021). Pietruszka et al (2021) investigated the IMC layer formation in solder joints under insulated gate bipolar transistors soldered with SACX0307 in a batch oven, 3-zone and 4-zone convection reflow ovens and a vapour phase soldering oven. They found significant differences in IMC layer thickness for the different soldering technologies.…”

“…Pietruszka et al (2021) investigated the IMC layer formation in solder joints under insulated gate bipolar transistors soldered with SACX0307 in a batch oven, 3-zone and 4-zone convection reflow ovens and a vapour phase soldering oven. They found significant differences in IMC layer thickness for the different soldering technologies.…”