Technical Library | 2024-04-08 15:46:36.0
A designed experiment evaluated the influence of several variables on appearance and strength of Pb-free solder joints. Components, with leads finished with nickel-palladium-gold (NiPdAu), were used from Texas Instruments (TI) and two other integrated circuit suppliers. Pb-free solder paste used was tin-silver-copper (SnAgCu) alloy. Variables were printed wiring board (PWB) pad size/stencil aperture (the pad finish was consistent; electrolysis Ni/immersion Au), reflow atmosphere, reflow temperature, Pd thickness in the NiPdAu finish, and thermal aging. Height of solder wetting to component lead sides was measured for both ceramic plate and PWB soldering. A third response was solder joint strength; a "lead pull" test determined the maximum force needed to pull the component lead from the PWB. This paper presents a statistical analysis of the designed experiment. Reflow atmosphere and pad size/stencil aperture have the greatest contribution to the height of lead side wetting. Reflow temperature, palladium thickness, and preconditioning had very little impact on side-wetting height. For lead pull, variance in the data was relatively small and the factors tested had little impact.
Precision Fine Pitch Aperture Cleaners Thousands of dollars less than fully-automatic cleaners Low solvent usage and running costs Fast cleaning time of 1-3 minutes Minimal waste disposal Portable unit can be used directly on the screen printe
Career Center | Lumberton, New Jersey USA | Engineering
Reports to: Cad/Laser Manager Department: Cad Location: Lumberton Phone: 609-261-2670 Ask for Greg Starrett Email: Send resume as a word document or PDF to greg@metassocs.com Job Summary: Under the general supervision of the Cad Manager
New Equipment | Solder Paste Stencils
Stentech produces mini stencils; small stencils that are used mainly for BGA re-work. Mini stencils are designed to deposit precise amounts of solder paste for single BGA footprints on loaded PCBs. These precision stencils mimic the footprint and ape
New Equipment | Cleaning Equipment
The Sawa Eco-Roll eliminates waste and saves money by reusing wiper rolls for printing machines. The SC-ER360 cleans wiper rolls in just 20 minutes and measures W900 x D850 x H1200 mm. Sawa Stencil Cleaners are widely used in the Japanese electronic
New Equipment | Cleaning Agents
AQUANOX A8830 cleans solder paste from stencil apertures in ultrasonic immersion cleaning tanks. A typical wash cycle using a 10% solution of A8830 at room temperature typically requires less than a 4-minute wash cycle and easily rinses with water, l
Technical Library | 2008-01-16 18:25:55.0
The consumer's interest for smaller, lighter and higher performance electronics products has increased the use of ultra fine pitch packages, such as Flip Chips and Chip Scale Packages, in printed circuit board (PCB) assembly. The assembly processes for these ultra fine pitch packages are extremely complex and each step in the assembly process influences the assembly yield and reliability.
ALPHA® TETRABOND™ is the culmination of "frameless" stencil development; an elegantly simple system designed to enhance the rigidity of the foil, making safe mounting and demounting an easier proposition. Innovatively encompassed in a thin, one piece
Technical Library | 2023-06-12 19:00:21.0
The SMT print process is now very mature and well understood. However as consumers continually push for new electronic products, with increased functionality and smaller form factor, the boundaries of the whole assembly process are continually being challenged. Miniaturisation raises a number of issues for the stencil printing process. How small can we print? What are the tightest pitches? Can we print small deposits next too large for high mix technology assemblies? How closely can we place components for high density products? ...And then on top of this, how can we satisfy some of the cost pressures through the whole supply chain and improve yield in the production process! Today we are operating close to the limits of the stencil printing process. The area ratio rule (the relationship between stencil aperture opening and aperture surface area) fundamentally dictates what can and cannot be achieved in a print process. For next generation components and assembly processes these established rules need to be broken! New stencil printing techniques are becoming available which address some of these challenges. Active squeegees have been shown to push area ratio limits to new boundaries, permitting printing for next generation 0.3CSP technology. Results also indicate there are potential yield benefits for today's leading edge components as well. Stencil coatings are also showing promise. In tests performed to date it is becoming apparent that certain coatings can provide higher yield processing by extending the number of prints that can be performed in-between stencil cleans during a print process. Preliminary test results relating to the stencil coating technology and how they impact miniaturisation and high yield processing will be presented.
New Equipment | Cleaning Equipment
The Low-cost / Compact Stencil Cleaners Heated wash for cleaning lead-free solder paste, pallets and adhesives 100% Stainless steel construction Two model sizes to conserve energy, use less chemistry and generate less waste Install i
