Technical Library | 2019-07-17 17:56:34.0
The increased demand for electronic devices in recent years has led to an extensive research in the field to meet the requirements of the industry. Electrolytic copper has been an important technology in the fabrication of PCBs and semiconductors. Aqueous sulfuric acid baths are explored for filling or building up with copper structures like blind micro vias (BMV), trenches, through holes (TH), and pillar bumps. As circuit miniaturization continues, developing a process that simultaneously fills vias and plates TH with various sizes and aspect ratios, while minimizing the surface copper thickness is critical. Filling BMV and plating TH at the same time, presents great difficulties for the PCB manufactures. The conventional copper plating processes that provide good via fill and leveling of the deposit tend to worsen the throwing power (TP) of the electroplating bath. TP is defined as the ratio of the deposit copper thickness in the center of the through hole to its thickness at the surface. In this paper an optimization of recently developed innovative, one step acid copper plating technology for filling vias with a minimal surface thickness and plating through holes is presented.
Industry Directory | Manufacturer
UWELLPCB.com is the PCB supplier. We offer PCB from single side board, double side PCB to 32layer board,including the Rigid PCB, Flex PCB, Rigid-flex PCB,Quick-turn prototype and PCB assembly
Industry Directory | Manufacturer
A global manufacturer of adhesives, conductives and encapsulants. For over 20 years, EMS has formulated state of the art acrylics, epoxies, silicones and urethanes.
Technical Library | 2011-02-17 18:03:21.0
Copper ground pours are created by filling open unused areas with copper generally on the outer layers of the board then connecting the copper fill with stitching vias to ground. Usually, small isolated areas
Technical Library | 2020-07-15 18:29:34.0
In the early 2000s the first fine-pitch ball grid array devices became popular with designers looking to pack as much horsepower into as small a space as possible. "Smaller is better" became the rule and with that the mechanical drilling world became severely impacted by available drill bit sizes, aspect ratios, and plating methodologies. First of all, the diameter of the drill needed to be in the 0.006" or smaller range due to the reduction of pad size and spacing pitch. Secondly, the aspect ratio (depth to diameter) became limited by drill flute length, positional accuracy, rigidity of the tools (to prevent breakage), and the throwing power of acid copper plating systems. And lastly, the plating needed to close up the hole as much as possible, which led to problems with voiding, incomplete fill, and gas/solution entrapment.
Industry News | 2018-02-28 08:22:00.0
Essemtec has been awarded a 2018 NPI Award in the category of Dispensing for its Tarantula – Relentless All Terrain Jet Dispenser. The system features state-of-the-art technology and can be easily integrated in any line. It is designed for a wide range of dispensing applications such as solder paste and SMT glue, LED encapsulation, silver epoxy, dam and fill, underfill, cavity fill, 3D dispensing via laser height mapping and more.
Industry News | 2020-06-11 06:23:00.0
Essemtec announces that its Spider smart-sized high-speed dispenser can be adapted for a wide range of dispensing applications including solder paste and SMT glue, LED encapsulation, silver epoxy, dam and fill, underfill, cavity fill, 3D dispensing via laser height mapping and more.
Technical Library | 2020-10-14 14:33:36.0
Epoxy based adhesives are prevalent interface materials for all levels of electronic packaging. One reason for their widespread success is their ability to accept fillers. Fillers allow the adhesive formulator to tailor the electrical and thermal properties of a given epoxy. Silver flake allow the adhesive to be both electrically conductive and thermally conductive. For potting applications, heat sinking, and general encapsulation where high electrical isolation is required, aluminum oxide has been the filler of choice. Today, advanced Boron Nitride filled epoxies challenge alternative thermal interface materials like silicones, greases, tapes, or pads. The paper discusses key attributes for designing and formulating advanced thermally conductive epoxies. Comparisons to other common fillers used in packaging are made. The filler size, shape and distribution, as well as concentration in the resin, will determine the adhesive viscosity and rheology. Correlation's between Thermal Resistance calculations and adhesive viscosity are made. Examples are shown that determination of thermal conductivity values in "bulk" form, do not translate into actual package thermal resistance. Four commercially available thermally conductive adhesives were obtained for the study. Adhesives were screened by shear strength measurements, Thermal Cycling ( -55 °C to 125 °C ) Resistance, and damp heat ( 85 °C / 85 %RH ) resistance. The results indicate that low modulus Boron Nitride filled epoxies are superior in formulation and design. Careful selection of stress relief agents, filler morphology, and concentration levels are critical choices the skilled formulator must make. The advantages and limitations of each are discussed and demonstrated.
D&H offers an automatic dosing machine for degassing, proportioning, mixing and high precision dosing of two component resins (epoxy, polyurethane, silicone..) in the atmospheric environment. Model:JYPJ-1000 JYPJ-1000 system accurately meters, m
D&H offers an automatic dosing machine for degassing, proportioning, mixing and high precision dosing of two component resins (epoxy, polyurethane, silicone..) in the atmospheric environment. Model:JYPJ-1000 JYPJ-1000 system accurately meters, m
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