Technical Library | 2023-08-16 18:13:53.0
In one of our Consumer Electronics projects, a smart lighting company wished to dispense silicone-based LED encapsulation material for two different product sizes. The larger product had a 9mm circular dam which required silicone dispensing flush with the top of the dam. The smaller product had a 1mm LED die that required only the top to be encapsulated. The material consisted of two parts which were mixed by weight in a 1:1 ratio. A phosphor powder was added totaling 10% of the overall weight. The phosphor required agitation to remain suspended.
Technical Library | 2008-10-01 14:02:27.0
This paper proposes an integrated system for film application process than consists of closed loop mass calibration to assure film thickness, a noncontact fast jetting process with high edge definition capable of applying films for highly selective areas and patterns. A system to obtain homogeneity of the solid-fluid mix is described and results are shared.
Technical Library | 1999-08-27 09:29:49.0
Contract packaging houses have to contend with a large mix of die types and products. Flexibility and quick turnaround of package types is a must in this industry. Traditional methods of die encapsulation, (i.e., use of transfer-molding techniques), are only cost effective when producing a large number of components. Liquid encapsulants now provide similar levels of reliability1, and are cost effective...
Technical Library | 2022-10-31 17:25:37.0
Mixed formulation solder alloys refer to specific combinations of Sn-37Pb and SAC305 (96.5Sn–3.0Ag–0.5Cu). They present a solution for the interim period before Pb-free electronic assemblies are universally accepted. In this work, the surfaces of mixed formulation solder alloys have been studied by in situ and real-time Auger electron spectroscopy as a function of temperature as the alloys are raised above the melting point. With increasing temperature, there is a growing fraction of low-level, bulk contaminants that segregate to the alloy surfaces. In particular, the amount of surface C is nearly _50–60 at. % C at the melting point. The segregating impurities inhibit solderability by providing a blocking layer to reaction between the alloy and substrate. A similar phenomenon has been observed over a wide range of (SAC and non-SAC) alloys synthesized by a variety of techniques. That solder alloy surfaces at melting have a radically different composition from the bulk uncovers a key variable that helps to explain the wide variability in contact angles reported in previous studies of wetting and adhesion. VC 2011 American Vacuum Society. [DOI: 10.1116/1.3584821]
Technical Library | 2015-11-19 18:15:07.0
The move to lead free (Pb-free) electronics by the commercial industry has resulted in an increasing number of ball grid array components (BGAs) which are only available with Pb-free solder balls. The reliability of these devices is not well established when assembled using a standard tin-lead (SnPb) solder paste and reflow profile, known as a backward compatible process. Previous studies in processing mixed alloy solder joints have demonstrated the importance of using a reflow temperature high enough to achieve complete mixing of the SnPb solder paste with the Pb-free solder ball. Research has indicated that complete mixing can occur below the melting point of the Pb-free alloy and is dependent on a number of factors including solder ball composition, solder ball to solder paste ratio, and peak reflow times and temperatures. Increasing the lead content in the system enables full mixing of the solder joint with a reduced peak reflow temperature, however, previous research is conflicting regarding the effect that lead percentage has on solder joint reliability in this mixed alloy solder joint.
Technical Library | 2011-08-04 19:29:53.0
This work covers two major projects aimed at increasing quality and efficiency on a high mix, low volume surface mount electronics production line. Specifically the installation of a ten zone reflow oven and an enhanced changeover method for SMT pick and
Technical Library | 2021-08-11 00:52:35.0
Formulators of multi-component adhesives, potting and encapsulation materials are careful not to supply products with entrapped air. They do this by manufacturing under vacuum or degassing them before supplying to the end user. Consequently, entrapped air in a mixed material is usually a processing issue.
Technical Library | 2018-02-07 22:50:31.0
The architecture of vehicle electrical systems is changing rapidly. Electric and hybrid vehicles are driving mixed voltage systems, and cost pressures are making conductor materials like aluminum an increasingly viable competitor to copper. This paper presents tradeoff studies at the vehicle level, and how to automatically generate an electrical Failure Mode Effects and Analysis (FMEA) report, as well as how to optimize wire sizes for both copper and aluminum at the platform level.
Technical Library | 2023-09-26 19:14:44.0
The transition from tin-lead to lead free soldering in the electronics manufacturing industry has been in progress for the past 10 years. In the interim period before lead free assemblies are uniformly accepted, mixed formulation solder joints are becoming commonplace in electronic assemblies. For example, area array components (BGA/CSP) are frequently available only with lead free Sn-Ag-Cu (SAC) solder balls. Such parts are often assembled to printed circuit boards using traditional 63Sn-37Pb solder paste. The resulting solder joints contain unusual quaternary alloys of Sn, Ag, Cu, and Pb. In addition, the alloy composition can vary across the solder joint based on the paste to ball solder volumes and the reflow profile utilized. The mechanical and physical properties of such Sn-Ag-Cu-Pb alloys have not been explored extensively in the literature. In addition, the reliability of mixed formulation solder joints is poorly understood.
Technical Library | 2010-02-03 14:50:51.0
This paper will consider the unique characteristics of the renewable energy and clean-tech sectors and explore how a smartly optimized electronics manufacturing outsourcing model can help OEMs accelerate their timeto- market and support their cost-per-kilowatt reduction goals.
