The heat produced within the device in its package depends on the power supplied to each IP block. The improper placement of an IP block with high power consumption can become a reliability risk for IC packages, as it can significantly affect the reliability of solder balls due to thermal, mechanical, and electrical factors. It also mitigates the effect of thermal cycling, because it depends upon heat management within the package. Improper IP block placement can block heat flow paths, which results in poor thermal dissipation and higher temperature which can create a higher strain on the solder balls affecting their lifetime. Therefore, it is crucial to understand the interplay between the correct placement of IP blocks and solder balls to enhance solder ball reliability. COMSOL-based simulation study will be done on a WLCSP (Wafer Level Chip Scale Package) mounted on a PCB board on which solder balls are connected to copper layers on the die and PCB sides. Variations in the placement of the IP blocks. Thermal cycling and the variations in the placement of the IP block within the package will be taken as a loading condition. Therefore, this influences the susceptibility of device failure due to solder ball fatigue. Based on board-level passive cycling, the solder balls which are located under the IP blocks are the most likely ones affected by this stress. The results will be analyzed to optimize the layout of the IP blocks, concerning accumulated plastic strain on the solder balls at different locations of the IP block placement. It can help to understand the influence of the position of the IP block, reduce stress concentration, and minimize thermal cycling effects, which leads to an increase in the reliability of the solders joint and IC package itself.

Electronic packages with solder interconnects, such as Chip Scale Packages (CSP) and Ball Grid Arrays (BGA), are extensively utilized in various applications, including cell phones, smartwatches, and electric vehicles. The advancements in technology and the features within these applications have led to an increase in power cycles within the packages. This combined with a reduced time to market makes their reliability testing more challenging. With the increased power cycles, even the small temperature variations (ΔT) within an Integrated Circuit (IC) package contribute to the increased susceptibility of devices to failures, often triggering a complex interplay of competing failure modes. Thus, it is crucial to understand the interplay between various failure mechanisms in real-world scenarios for evaluating and overseeing the dependability and efficiency of electronic systems. This paper presents an overview of the impact of small temperature variations on component reliability. In addition, a simulation-based preliminary study is carried out on a Wafer-Level Chip Scale Package (WLCSP) by implementing a thermal load corresponding to an active power cycle. The results are analyzed to locate possible failure locations within the solder bumps based on the accumulated plastic strains for different amplitudes of thermal load (ΔT). Finally, the necessity for a new testing strategy based on variable (ΔT) is highlighted.

Board level reliability can be of high interest for automotive electronic components when exposed to vibration-prone environments. However, the absence of an industry standard for board level vibration testing poses several challenges in establishing a well-characterized test setup. One of the challenges is that automotive applications can induce abnormal stresses on components that can lead to early failures in the field. Such loading conditions are not always covered in the current board level vibration test methods. This paper aims to correlate the stresses from automotive modules to board levels by measuring the printed circuit board (PCB) vibration spectrum. Firstly, the study compares and assesses several module board level vibration measurement units, such as LASER Doppler Vibrometer (LDV), strain gauges, and accelerometers. Experiments and simulations show that LDV enables good correlation with Micro-electro Mechanical Systems (MEMS) accelerometers. Secondly, the module-board interaction unveils insights into several module design features that impact the PCB vibration response and solder joint interconnect reliability. These findings underscore the necessity for the user to correctly validate the reliability of packages beyond board level testing, i.e., at the module level. This reliability test approach enables the translation of reliability test results from the lab to the field life of components once built in the final application equipment.

Board level vibration testing is a commonly used method to predict the solder joint reliability of surface-mounted components seated onto printed circuit boards (PCB). Current board level vibration test methods are mainly developed from a solely mechanical stress application standpoint. This makes such stress tests one dimensional in nature and translation from experimentally obtained test results to the field life of components experiencing combined stress environments become ambiguous. This investigation provides insights to develop a highly accelerated vibration test approach to cover simultaneous vibration and temperature loading situations in the field. In this paper, test board layouts from the board level drop test method, JESD22-B111 (rectangular PCB), and JESD22-B111A (square PCB), prescribed by the Joint Electronic Device Engineering Council (JEDEC), are used to understand the combined stress applied to the solder interconnects. The evaluation process is carried out by means of simulations, supported by targeted experiments on ball grid array (BGA) packages with dimensions sizing from 12x12mm to 15x15mm. The results on rectangular test board assembly show reduced characteristic lifetime of solder joints when stressed under combined temperature-vibration test conditions. On the other hand, the square-shaped board type exhibits a different acceleration factor with a longer solder fatigue lifetime than that of the rectangular-shaped PCB type. Finite element simulation results complement well with this finding.

Board level vibration testing is intended to assess prediction of the reliability of solder joint interconnects that are formed between electronic components and printed circuit boards (PCB). Frailties in the stress test experiment might lead to false board level reliability (BLR) evaluations. Therefore, it is essential to have a well-characterized board level vibration test method. Currently, there is no industrial test standard that prescribes board level vibration test method for electronic components at the PCB level. This paper examines the vibration test standards that are currently available in the industry and their applicability at the solder joint interconnect level. Next to that, it surveys the state-of-the-art board level vibration test setups and their impact on PCB dynamic loading and reliability at solder joint-PCB interface. It collates research on major building blocks of a board level vibration test method that includes vibration measurement techniques, PCB assemblies under test, board mounting schemes, operating environments, fault detection systems, and vibration test stress conditions that are currently used in the domain of solder joint level vibration testing. The findings from this paper are expected to reveal pitfalls and challenges while setting up board level vibration test experiments for electronic components. In addition, this paper attempts to identify research efforts that are required to make board level vibration testing a more credible means for assessing solder joint reliability. Outcomes from this study can further be used to guide future board level vibration specifications for electronic components.