Soft solder die attach is a widely used process for power and high-reliability automotive devices because soft solder has excellent heat-dissipation properties and outstanding robustness against delamination compared to traditional epoxy die attach. However, die tilt is usually one of the important issues and challenges during the soft solder process. The soft solder with Ni balls was introduced to reduce and control die tilt. During solder process, the Ni balls will not melt and will keep the ball shape, which would help control bond line thickness (BLT). The creep fatigue failure is one typical failure mechanism for solder material under thermal cycling. So it is essential to investigate the effect of Ni ball on the material properties and reliability of the solder joint layer. In this work, tensile creep tests for solder wire with and without Ni ballss have been conducted at various temperatures and stress levels using Dynamic Mechanical Analyzer (DMA) to obtain the creep properties of the solders. The steady-state creep strain rates are similar for both solder typesl, which means that the Ni ball addition does not affect the creep behaviour of soft solder significantly. Creep constitutive models were developed and the material constants of the model were determined based on experimental results for both solders. The creep constitutive models can be implemented in finite element analysis (FE A) to investigate the creep behavior of solder in the power packages for evaluation of package reliability. = 8.0 4 x 105 [sinh(0.0 5 2(J )p58 ex p ( _ 7 � 0 )In above equations, Be is the steady-state creep strain rate, (J is the applied stress, and T is the absolute temperature. In the subsequent section, the thermal cycling finite element simulation for power package was conducted by applying these creep models for solder die attach material.

This research studied the chemical and organoleptic characteristics of sambal ronto at various spice concentrations. Sambal ronto is a typical chili sauce from the coastal community of South Kalimantan which is made from ronto mixed with spices and sautéed with cooking oil. The spices used are chilies, shallots, garlic, lemongrass, laos, bay leaves, and palm sugar. The research was conducted with a completely randomized design. The treatments consisted of concentrations of ronto and spices ratio, (1: 1) O, (1: 2) A, (1: 3) C, and (1: 4) D. The proximate test consists of water, ash, protein, fat, carbohydrate (by different) content, and pH. The organoleptic test was carried out by testing the preference for the parameters of color, aroma, texture, taste, and appearance. The results showed that the best ronto: spice ratio was treatment B (1: 3). The chemical characteristics of the best sambal ronto are 44.21% moisture content, 4.20% ash content, 5.92% protein content, 14.47% fat content, carbohydrate content (31.22% by different) and pH 4.79. Organoleptic values for the parameters of color, aroma, texture, taste, and appearance were 4.5, 4.9, 4.9, 4.5, and 4.8, respectively. All parameters indicate a value close to very like.