Solderable 고분자 복합 소재의 환원제 함유량이 저융점 합금 입자의 융합 및 젖음 거동에 미치는 영향

초록

In this paper, four types of solderable polymer composites (SPCs) with different reductant concentration (0, 7.5, 15 and 30 phr) were formulated to investigate the influence of reductant concentration within the SPCs on the coalescence and wetting behaviors of low-melting-point alloy (LMPA) fillers. Two types of wettability test including solder ball wetting (solder ball diameter: 760 ㎛) and solder powder wetting (solder powder diameter: 42 ㎛ and 30 vol%) tests were conducted. Additionally, to examine the chemical reactions of polymer composite depending on the reductant concentration, differential scanning calorimetry (DSC) analysis was conducted for the mixture of polymer and reductant. The LMPA fillers within the SPC with a reductant concentration of 15 phr showed excellent coalescence and wetting behaviors for the Cu metallization because of the favorable removal of surface oxide film on the LMPA fillers and metallization. Meanwhile, the selective wetting properties of LMPA with a reductant concentration greater than 15 phr showed decreasing tendency due to the shift of curing temperature to the low temperature range because of the increased chemical reaction between the reductant and epoxy. These results demonstrate that the optimal reductant concentration exist to achieve the most favorable coalescence and wetting behaviors of LMPA fillers for the metallization.

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