Technical Library | 2014-01-02 15:56:55.0
With ROHS compliance the transition to lead-free is inevitable. Several lead-free alloys are available in the market and its reliability has been the main concern. The results from this experimental research aims at making a comparison of different lead-free alloy combinations. Thermal shock and drop tests are a part of this experimental study.
Technical Library | 2020-09-30 19:23:47.0
There is an increase in the number of optical sensors and cameras being integrated into electronics devices. These go beyond cell phone cameras into automotive sensors, wearables, and other smart devices. The applications can be lens bonding, waveguide imprinting, or other applications where the adhesive is in the optical pathway. To support these various optical applications, new materials with tailorable optical properties are required. There is often a mismatched refractive index between plastic lenses such as PC (Poly Carbonate), COP (Cyclo Olefin Polymer), COC (Cyclo Olefin Copolymer), PMMA (Poly Methyl Methacrylate), and UV curable liquid adhesive. A UV curable liquid adhesive is needed where you can alter the refractive index from 1.470 to 1.730, and maintain high optical performance as yellowness index, haze, and transmittance. This wide range of refractive index possibilities provides optimized optical design. Using particular plastic lens must consider how chemical attack is occurring during the process. Another consideration is that before the UV curable liquid adhesive is cured, chemical raw component can attack the plastic lens which then cracks and delaminates. We will also show engineering and reliability data which defined root cause and provided how optical performance is maintained under different reliability conditions.
Technical Library | 2022-10-31 09:05:54.0
Warranty: 3 Months Precision: High Precision Certification: CE，ROHS Wight: 1kg Automatic Grade: Automatic Trademark: Ultra High-speed Chip Mounter High Light: 00345186, 00345186 smt pick and place parts, 00345186 SMT Spare Parts
Technical Library | 2019-09-24 15:41:53.0
This paper focuses on three different coating material groups which were formulated to operate under high thermal stress and are applied at printed circuit board manufacturing level. While used for principally different applications, these coatings have in common that they can be key to a successful thermal management concept especially in e-mobility and lighting applications. The coatings consist of: Specialty (green transparent) liquid photoimageable solder masks (LPiSM) compatible with long-term thermal storage/stress in excess of 150°C. Combined with the appropriate high-temperature base material, and along with a suitable copper pre-treatment, these solder resists are capable of fulfilling higher thermal demands. In this context, long-term storage tests as well as temperature cycling tests were conducted. Moreover, the effect of various Cu pre-treatment methods on the adhesion of the solder masks was examined following 150, 175 and 200°C ageing processes. For this purpose, test panels were conditioned for 2000 hours at the respective temperatures and were submitted to a cross-cut test every 500 h. Within this test set-up, it was found that a multi-level chemical pre-treatment gives significantly better adhesion results, in particular at 175°C and 200°C, compared with a pre-treatment by brush or pumice brush. Also, breakdown voltage as well as tracking resistance were investigated. For an application in LED technology, the light reflectivity and white colour stability of the printed circuit board are of major importance, especially when high-power LEDs are used which can generate larger amounts of heat. For this reason, a very high coverage power and an intense white colour with high reflectivity values are essential for white solder masks. These "ultra-white" and largely non-yellowing LPiSM need to be able to withstand specific thermal loads, especially in combination with high-power LED lighting applications. The topic of thermal performance of coatings for electronics will also be discussed in view of printed heatsink paste (HSP) and thermal interface paste (TIP) coatings which are used for a growing number of applications. They are processed at the printed circuit board manufacturing level for thermal-coupling and heat-spreading purposes in various thermal management-sensitive fields, especially in the automotive and LED lighting industries. Besides giving an overview of the principle functionality, it will be discussed what makes these ceramic-filled epoxy- or silicone-based materials special compared to using "thermal greases" and "thermal pads" for heat dissipation purposes.
Technical Library | 2015-09-17 17:36:56.0
RoHS legislated restrictions on the materials used in electronics manufacture have imparted significant challenges on the electronics industry since their introduction in 2006. The greatest impacts have been felt by the mandated elimination of lead from electronic solder followed by the demand for the elimination of haloids from flame retardants used in traditional PCB laminates. In the years which have followed the electronics industry has been beset with a host of new challenges in its effort to comply. Failure mechanisms, both new and old, have surfaced which demand solution and the industry suppliers and manufacturing technologists have worked diligently to remedy those vexing faults through the development of a wide range of new materials and equipment for both board manufacture and assembly, along with modifications to the processes used in the manufacture and assembly of printed circuit boards.
Technical Library | 2014-06-19 18:13:23.0
For high-density electronic packaging,the application of flip-chip solder joints has been well received in the microelectronics industry. High-lead(Pb) solders such as Sn5Pb95 are presently granted immunity from the RoHS requirements for their use in high-end flip-chip devices, especially in military applications. In flip-chip technology for consumer electronic products, organic substrates have replaced ceramic substrates due to the demand for less weight and low cost. However, the liquidus temperatures of high-Pb solders are over 300°C which would damage organic substrates during reflow because of the low glass transition temperature. To overcome this difficulty, the composite solder approach was developed...
Technical Library | 2017-01-05 16:55:11.0
The July 2006 implementation of ROHS exempted automotive applications from converting to lead free technology. Nine years later, all major OEM and Tier 1 automotive manufacturers have converted or are in the process of converting to lead free circuit assembly processing. Starting with SAC (SnAgCu) alloys as a baseline for lead free soldering, in the last years several specific alloys were developed in order to improve resistance to high temperature creep, vibration survival and the ability to withstand thermal cycling and thermal shock.The paper compares three different solder alloys and two flux chemistries in terms of void formation and mechanical / thermal fatigue properties. Void content and reliability data of the alloys will be presented and discussed in relation to the acceptance criteria of a Tier 1 /OEM automotive supplier. As a result, a ranking list will be presented considering the combined performance of the alloys. In order to analyze the void formation and mechanical behavior of different solder alloys and flux chemistry combinations, statistical methods are used.
Technical Library | 2015-01-08 17:26:59.0
Regardless of the accelerating trend for design and conversion to Pb-free manufacturing, many high reliability electronic equipment producers continue to manufacture and support tin-lead (SnPb) electronic products. Certain high reliability electronic products from the telecommunication, military, and medical sectors manufacture using SnPb solder assembly and remain in compliance with the RoHS Directive (restriction on certain hazardous substances) by invoking the European Union Pb-in-solder exemption. Sustaining SnPb manufacturing has become more challenging because the global component supply chain is converting rapidly to Pb-free offerings and has a decreasing motivation to continue producing SnPb product for the low-volume, high reliability end users. Availability of critical, larger SnPb BGA components is a growing concern
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