Technical Library | 2015-02-12 16:57:56.0
Electronic systems are known to be affected by the environmental and mechanical conditions, such as humidity, temperature, thermal shocks and vibration. These adverse environmental operating conditions, with time, could degrade the mechanical efficiency of the system and might lead to catastrophic failures.The aim of this study is to investigate the mechanical integrity of lead-free ball grid array (BGA) solder joints subjected to isothermal ageing at 150°C for up to 1000 hours. Upon ageing at 150°C the Sn-3.5Ag solder alloy initially age-softened for up to 200 hours. This behaviour was linked to the coarsening of grains. When aged beyond 200 hours the shear strength was found to increase up to 400 hours. This age-hardening was correlated with precipitation of hard Ag3Sn particles in Sn matrix. Further ageing resulted in gradual decrease in shear strength. This can be explained as the combined effect of precipitation coarsening and growth of intermetallic layer. The fractured surfaces of the broken solder balls were also investigated under a Scanning Electron Microscope. The shear failures were generally due to ductile fractures in bulk solders irrespective of the ageing time.
Industry Directory | Manufacturer
BLIND RIVETS,BLIND NUTS,BLIND RIVETING TOOLS,STAINLESS STEEL CABLE TIES
New Equipment | Solder Materials
SM-150G and SM-155P are single component epoxy adhesive, specifically designed for the bonding of surface mount devices to PCB in the lead-free process. SM-150G is suitable for glue dot process and SM-155P is suitable for the printing machine process
Industry Directory | Manufacturer / Research Institute / Laboratory / School
Manufacturer of surface deposition and plasma surface cleaning and etching equipment offering reliable, repeatable cleaning and etching of PCBs and other materials.
New Equipment | Solder Materials
KappTecZ is a high temperature, high strength solder that may be used on most metals, but works extremely well on aluminum, copper and stainless steel. It has a high tolerance to vibration and stress, and good elongation for use on dissimilar metals.
Industry Directory | Manufacturer / Other
STAINLESS STEEL CABLE TIES,BLIND RIVETS,BLIND NUTS,FASTENERS,TOOLS
Industry Directory | Manufacturer
blind rivets,stainless steel cable ties,blind nuts,blind riveting tools,fasteners
Technical Library | 2020-12-16 18:38:49.0
Fabrication of large structures using out-of-autoclave prepreg materials will lead to a great amount of savings in manufacturing costs. In the out-of-autoclave processing method, the presence of voids inside the laminate has been an issue due to the lack of high pressure during manufacturing. This study aims primarily to observe the moisture absorption response of composite samples containing different levels of void. By changing the vacuum level inside the bag during the manufacturing process, three different unidirectional laminates at three levels of void have been manufactured. After immersing the samples in warm water at 60°C for about one year, the moisture absorption level was monitored and then diffusion coefficients were calculated using Fick's law. Results show that the moisture absorption coefficient changes by %8 within the experimental range of void contents. The mechanical behaviour of these laminates has been studied at four different moisture levels by performing dynamic mechanical analysis (DMA) and short beam shear tests. Empirical results indicate that, in general, interlaminar shear strength and glass transition temperature decrease by moisture build-up inside the samples. DiBenedetto equation is proposed to make a correlation between the moisture content and glass transition temperature.
Technical Library | 2021-11-03 17:05:39.0
Additively printed circuits provide advantages in reduced waste, rapid prototyping, and versatile flexible substrate choices relative to conventional circuit printing. Copper (Cu) based inks along with intense pulsed light (IPL) sintering can be used in additive circuit printing. However, IPL sintered Cu typically suffer from poor solderability due to high roughness and porosity. To address this, hybrid Cu ink which consists of Cu precursor/nanoparticle was formulated to seed Cu species and fill voids in the sintered structure. Nickel (Ni) electroplating was utilized to further improve surface solderability. Simulations were performed at various electroplating conditions and Cu cathode surface roughness using the multi-physics finite element method. By utilizing a mask during IPL sintering, conductivity was induced in exposed regions; this was utilized to achieve selective Ni-electroplating. Surface morphology and cross section analysis of the electrodes were observed through scanning electron microscopy and a 3D optical profilometer. Energy dispersive X-ray spectroscopy analysis was conducted to investigate changes in surface compositions. ASTM D3359 adhesion testing was performed to examine the adhesion between the electrode and substrate. Solder-electrode shear tests were investigated with a tensile tester to observe the shear strength between solder and electrodes. By utilizing Cu precursors and novel multifaceted approach of IPL sintering, a robust and solderable Ni electroplated conductive Cu printed electrode was achieved.
Industry News | 2016-02-25 14:29:00.0
SHENMAO Features a new Sn-3.0Ag-0.5Cu Lead-Free Solder Paste PF606-P133H for laser soldering applications. Dispensed from syringes, it is developed for automatic laser soldering processes in the packaging and assembly of surface mount devices and microelectronics. Laser energy is applied at the precise location in a non-contact procedure to create high shear strength well-formed solder joints during the lower thermal stress process while reducing intermetallic formation. PF606-P133H solder paste produces minimal flux residue and no-splash or solder balling issues. It is well suited for high yield soldering of sensitive electronic components in manufacturing or repair of electronic devices that can-not tolerate conventional reflow-oven temperature.