Search results

Presents the results of a study of the effects of solder ball pad metallurgy, intermetallic compound (IMC) thickness and thermal cycling on the shear strengths of PBGA package solder balls. The study of the microstructures of solder balls revealed that only a very thin layer of intermetallic compound existed between solder balls and Ni or Ni alloy barrier layers immediately after ball placement and reflow. The protective Au layer was dissolved completely and a needle like AuSn₄ intermetallic compound was then formed and dispersed evenly in the solder balls. The overall thickness of the IMC layers was thicker than 15μm after storage at 150°C for 1,000 hours. During the shear tests failure occurred at the interface of the two IMC layers. The fracture surfaces of solder balls with electrolytic Ni and thick Au layers were smooth and brittle fracture was observed. The ball shear strength decreased dramatically with the formation of IMC layers. For the solder balls with electroless Ni and thin Au layers, only a single IMC layer was formed at the interface and its thickness was only 2.5 μm after storage at 150°C for 1,000 hours.

Lead frame tape is a crucial support for lead frames in the IC assembly process. The tape residue on the quad flat non-leaded (QFN) could result in low reliability and failure in electrical conductivity tests. The tape residue would affect overall performance of the chips and contribute to low pass yield. The purpose of this paper is to present an in-depth study of tape residue and factors that may affect it.

An experiment using lead frame and tapes from three manufacturers with two types of die bond adhesives, namely, die attach film (DAF) and wafer back coating (WBC), was conducted. Copper (Cu) wire bonding and die bonding performances were measured in terms of process capability, stitch bond strength and die attach strength.

Results showed that no tape residue was observed on the thermoplastic adhesive-based lead frames manufactured by Hitachi after the de-taping process because of the tape’s thermoplastic adhesive properties.

This paper studies the occurrence of tape residue and a viable solution for it through the correct process optimization and combination of semiconductor manufacturing materials. Factors that may affect tape residue have also been studied and further research can be done to explore other options in the future as an alternate solution.

Develops and exemplifies the proposition that the key factors determining the success of packaging innovation can be unified by considering them as consumer driven, technology driven, and distribution driven. The concept of the packaging and distribution mix is developed to show how organisations can respond, through marketing variables under their control, to attempt to gain a competitive advantage over rivals. A packaging optimisation strategy is described, based on a total systems approach, which proposes a balance between the complex mix of external influences.

The purpose of this paper is to identify and describe the strategic potential of logistics‐driven packaging innovation in retail supply chains, and suggest propositions for further research and development, providing practitioners with a better basis on which to make strategic packaging and logistics decisions.

An in‐depth case study was conducted at a large global retailer which had implemented an innovative unit load carrier. The case study highlights a previously inaccessible phenomenon, as this type of unit load carrier has only been implemented on a large‐scale in the studied retailer's supply chain. In order to explore the impact of the innovative unit load carrier, the case study draws on a longitudinal research approach.

The case study demonstrates the potential of logistics‐driven packaging innovation in retail supply chains. It provides detailed insights into the impact of an innovative unit load carrier on different supply chain echelons. These insights emphasise the need for a systems perspective in order to understand the total impact of packaging innovations on supply chains.

The case study focuses on the impact of a particular innovation on a particular supply chain. Even though the consequences in other supply chains may be different, this study provides detailed explanations and illustrative examples which generate insights relevant to other firms and supply chains.

This paper provides an understanding of potential trade‐offs between standardised and differentiated packaging, providing practitioners with a better basis for making decisions on packaging design and development.

The paper illustrates the need to consider packaging as a strategic component which contributes to overall supply chain performance. To support strategic packaging decision‐making propositions for packaging innovation in retail supply chains are provided.

The innovativeness of dressmakers is a concern to respondents to satisfy their clothing needs. The purpose of this study is to determine the criteria that respondents use to judge the quality of clothing and its influences on the innovative ability of dressmakers in the clothing manufacturing industries.

Three hundred and ninety-seven (397) respondents in the Takoradi Metropolis of Ghana filled out a questionnaire, and the results were used to compile data for the study. The sample size was calculated using Miller and Brewer formula. The data was analysed using structural equational modelling with the SmartPLS v.4 software.

The results showed that respondents are very interested in the calibre of clothing produced by their dressmakers. However, the study revealed that when evaluating the quality of a garment, respondents do not simply accept what has been sewn for them but also consider the performance, appearance, fit and shape of the garment. Findings revealed that there was a significant relationship between garment appearance quality (t = 2.605; p < 0.05), garment performance quality (t = 3.915; p < 0.05), garment shape quality (t = 6.248; p <0.05) and fashion innovations. Subsequently, the evaluation of garment fit quality by respondents revealed it does not bring about innovations (t = 1.310; p > 0.05).

The continuous evaluation of custom-made clothing from customers will go a long way towards highlighting the relative criteria they use to evaluate the innovation of dressmakers. This will help improve the creativity of the dressmakers since such feedback will help them understand and innovate their production skills to meet the preferences of customers.

The present study provides an in-depth understanding of how garment quality evaluation by customers influences the innovation of dressmakers in Takoradi, Ghana. The constructs were developed for the study to capture the appropriate data from customers for the study. This presents an evaluation criterion on four garment quality variables imperative for use or modification by other studies.

Cargo loss has been a major issue in logistics management. However, few studies have tackled the issue of cargo loss severity via business analytics. Hence, the purpose of this paper is to provide guidance about how to retrieve valuable information from logistics data and to develop cargo loss mitigation strategies for logistics risk management.

This study proposes a research design of business analytics to scrutinize the causes of cargo loss severity.

The empirical results of the decision tree analytics reveal that transit types, product categories, and shipping destinations are key factors behind cargo loss severity. Furthermore, strategies for cargo loss prevention were developed.

The proposed framework of cargo loss analytics provides a research foundation for logistics risk management.

Companies with logistics data can utilize the proposed business analytics to identify cargo loss factors, while companies without logistics data can employ the proposed cargo loss mitigation strategies in their logistics systems.

This pioneer empirical study scrutinizes the critical cargo loss issues of cargo damage, cargo theft, and cargo liability insurance through exploiting real cargo loss data.

The fan-out wafer level package (FOWLP) becomes more and more attractive and popular because of its flexibility to integrate diverse devices into a very small form factor. The strength of ultrathin FOWLP is low, and the low package strength often leads to crack issues. This paper aims to study the strength of thin FOWLP because the low package strength may lead to the reliability issue of package crack.

This paper uses the experimental method (three-point bending test) and finite element method (ANSYS simulation software) to evaluate the FOWLP strength. Two theoretical models of FOWLP strength are proposed. These two models are based on the location of FOWLP initial fracture point.

The results show that the backside protection tape does not have the ability to enhance the FOWLP strength, and the strength of over-molded structure FOWLP is superior to that of other structure FOWLPs with the same thickness level.

There is ample research about the silicon strength and silicon die strength. However, there is little research about the package level strength and no research about the FOWLP strength. The FOWLP is made up of various materials. The effect of individual component and external environment on the FOWLP strength is uncertain. Therefore, the study of strength behavior of FOWLP is significant.

The use of Taguchi experimental design techniques to examine the effects of package type, solder paste type and solder reflow technique on the quality of fine pitch surface mount IC package solder joints is described. In particular, the effect of the use of ceramic or plastic packages, copper or Alloy 42 leadframes, silver loaded or non‐silver loaded solder paste and infra‐red, laser or hot‐bar reflow on solder joint metallurgical structure, electrical resistance and mechanical strength is evaluated. In addition to these solder joint parameters, an associated visual inspection was used to find the best process parameters to minimise solder balling, bridging etc. and a correlation between paste contacts at placement and solder bridges after reflow was also conducted. The experiment used an L9 array to find the optimum parameters from three factors, each at three levels. An extension to the basic Taguchi array was included in the form of an outer (noise) factor to include the effect of climatic stress on the solder joints under investigation. Response tables separate out the contribution of each factor level to the mechanical strength and electrical resistance of the assemblies. By comparing the response tables before and after climatic testing it is possible to estimate the effect of each factor level on the long‐term quality of the solder joints. It is shown how Taguchi experimental design techniques can be used to minimise the number of experiments required to predict optimum solder assembly process parameters. The accuracy of the prediction is shown by the results of a confirmation run which yielded mechanical strengths very close to those predicted, both before and after highly accelerated stress testing of the solder assemblies.

This paper aims to review recent advances and applications of abrasive processes for microelectronics fabrications.

More than 80 patents and journal and conference articles published recently are reviewed. The topics covered are chemical mechanical polishing (CMP) for semiconductor devices, key/additional process conditions for CMP, and polishing and grinding for microelectronics fabrications and fan-out wafer level packages (FOWLPs).

Many reviewed articles reported advanced CMP for semiconductor device fabrications and innovative research studies on CMP slurry and abrasives. The surface finish, sub-surface damage and the strength of wafers are important issues. The defects on wafer surfaces induced by grinding/polishing would affect the stability of diced ultra-thin chips. Fracture strengths of wafers are dependent on the damage structure induced during dicing or grinding. Different thinning processes can reduce or enhance the fracture strength of wafers. In the FOWLP technology, grinding or CMP is conducted at several key steps. Challenges come from back-grinding and the wafer warpage. As the Si chips of the over-molded FOWLPs are very thin, wafer grinding becomes critical. The strength of the FOWLPs is significantly affected by grinding.

This paper attempts to provide an introduction to recent developments and the trends in abrasive processes for microelectronics manufacturing. With the references provided, readers may explore more deeply by reading the original articles. Original suggestions for future research work are also provided.

The purpose of this paper is to discuss the use of epoxy‐based conducting adhesives in z‐axis interconnections.

A variety of conductive adhesives with particle sizes ranging from 80 nm to 15 μm were laminated into printed wiring board substrates. SEM and optical microscopy were used to investigate the micro‐structures, conducting mechanism and path. The mechanical strength of the various adhesives was characterized by 90° peel test and measurement of tensile strength. Reliability of the adhesives was ascertained by IR‐reflow, thermal cycling, pressure cooker test (PCT), and solder shock. Change in tensile strength of adhesives was within 10 percent after 1,000 cycles of deep thermal cycling (DTC) between −55 and 125°C.

The volume resistivity of copper, silver and low‐melting point (LMP) alloy based paste were 5 × 10⁻⁴, 5 × 10⁻⁵ and 2 × 10⁻⁵ Ω cm, respectively. Volume resistivity decreased with increasing curing temperature. Adhesives exhibited peel strength with Gould's JTC‐treated Cu as high as 2.75 lbs/in. for silver, and as low as 1.00 lb/in. for LMP alloy. Similarly, tensile strength for silver, copper and LMP alloy were 3,370, 2,056 and 600 ψ, respectively. There was no delamination for silver, copper and LMP alloy samples after 3X IR‐reflow, PCT, and solder shock. Among all, silver‐based adhesives showed the lowest volume resistivity and highest mechanical strength. It was found that with increasing curing temperature, the volume resistivity of the silver‐filled paste decreased due to sintering of metal particles.

As a case study, an example of silver‐filled conductive adhesives as a z‐axis interconnect construction for a flip‐chip plastic ball grid array package with a 150 μm die pad pitch is given.

A high‐performance Z‐interconnect package can be provided which meets or exceeds JEDEC level requirements if specific materials, design, and manufacturing process requirements are met, resulting in an excellent package that can be used in single and multi‐chip applications. The processes and materials used to achieve smaller feature dimensions, satisfy stringent registration requirements, and achieve robust electrical interconnections are discussed.