Correlation studies for component level ball impact shear test and board level drop test

A Novel Mechanism of Embrittlement Affecting the Impact Reliability of Tin-Based Lead-Free Solder Joints

“…21 Since the solder joints tested in this work were reflowed twice, the thickness of the interfacial IMC layers is expected to be larger than after a single reflow, contributing to the high amount of interfacial IMC failures observed in this work. The apparent disagreement between this work and prior studies, which reported exclusively ductile failures in the joint bulk for Sn-Pb solders on ENIG finish, 7,8,10,17,18,30 may be explained in terms of the employed loading rates that were usually lower than the loading rate used in this study (3.16 m/s). A study supporting the findings of the present work reported the decrease in the amount of ductile failures in the bulk of Sn-37%Pb joints on ENIG finish (in this case, formed after a single reflow) from $95% at a loading rate of 10 mm/s to $40% at a rate of 3 m/s during high-speed ball shear tests.…”

“…One of the main reliability concerns related to the performance of these solders is their undesirably high sensitivity to impact when compared with the Sn-37%Pb solder, which exhibits better impact resistance. [1][2][3][4][5][6][7][8][9][10] This has been attributed to the fact that Sn-37%Pb is more compliant than the Sn-based solders: its greater ability to deform allows better accommodation of the stresses at the solder/bond pad interface before the stress level in the interfacial intermetallic compounds (IMCs) becomes critical and leads to their failure. 3,11 The satisfactory impact reliability required from portable electronics essentially means that a portable device must survive many accidental drops, each one of which produces local strain rates of $1000 s À1 .…”

“…[32][33][34]36 The study presented in this article focuses on a new mode of brittle failure; this failure mode occurs in the solder bulk, unlike the other modes of brittle failure so far identified in the literature. In fact, the previous studies recognized explicitly three basic failure modes for Sn-based solders: ductile failures in the solder bulk, brittle failures at the interfacial IMC layers, and mixed ductile-brittle failures; 1,2,[7][8][9][10][11]15,[18][19][20] some studies further divided mixed failures into quasi-ductile (>50% of the bond pad is covered by solder) and quasi-brittle (<50% of the bond pad is covered by solder). 5,16,[26][27][28] The conviction that all failures in the solder bulk are ductile as opposed to the brittle failures occurring in the interfacial IMC layers is also reflected in two Joint Electron Devices Engineering Council (JEDEC) standards: (a) JESD22-B117A on ''Solder Ball Shear,'' 37 and (b) JESD22-B115 on ''Solder Ball Pull,'' 38 the latter including high-speed testing.…”

Predicting the Drop Performance of Solder Joints by Evaluating the Elastic Strain Energy from High-Speed Ball Pull Tests

“…Nevertheless, the JEDECÕs standard board-level drop test method is generally too costly and time consuming to be viable. 10,11 Furthermore, the data obtained from this technique make it rather difficult to determine the inherent resistance of the solder joint to impact loadings. This is because it is almost impossible to distinguish between the impact responses of the solder material, the board, and any other packaging materials.…”

Drop impact reliability of edge-bonded lead-free chip scale packages

“…There has been a significant amount of research done in the last few years on drop impact reliability [1][2][3][4][5][6][7][8][9][10]. The JEDEC standard JESD22-B111 [11] for the board level and related standards [12,13] for the subassembly level have been developed for drop testing handheld electronics.…”