Technical Library | 2015-08-25 13:51:27.0
The stencil printing process is one of the most critical processes in the electronic production. Due to the requirement: "faster and smaller" it is necessary to place components with different paste volume close together without regard to solder paste printing. In our days it is no longer possible to control the solder paste volume only by adjustment of the aperture dimensions. The requirements of solder paste volumes for specific components are realized by different thicknesses of metal sheets in one stencil with so called step stencils. The step-down stencil is required when it is desirable to print fine-pitch devices using a thinner stencil foil, but print other devices using a thicker stencil foil. The paper presents the innovative technology of step-up and step-down stencils in a laser cutting and laser welding process. The step-up/step-down stencil is a special development for the adjustment of solder paste quantity, fulfilling the needs of placement and soldering. This includes the laser cutting and laser welding process as well as the resulting stencil characteristics and the potential of the printing process.
Technical Library | 2019-02-05 13:43:14.0
SonoFlux Servo with InSight automated board recognition system helps PCB manufacturers take steps toward greater automation and traceability and the goal of Industry 4.0.
Technical Library | 2011-08-11 20:06:48.0
(Proceedings of the World Congress on Engineering 2011) A Printed Circuit Board (PCB) consists of circuit with electronic components mounted on surface. There are three main steps involved in manufacturing process, where the inspection of PCB is necessar
Sant Longowal Institute of Engineering and Technology (SLIET)
Technical Library | 2016-06-06 05:25:53.0
One of the most important steps in PCB assembly is the need for conformal coating for PCB. The process of choosing a conformal coating spray is a complex one as it involves a number of confusing decisions revolving around selections and compromises.
Technical Library | 1999-05-09 12:51:38.0
This Technical Note outlines, step by step, the easiest ways to remove and replace surface mounted devices, using the lowest possible temperatures. This document discusses the following topics: Removal and replacement of discrete and passive components (capacitors, resistors, SOTs), Removal of two-sided components (SOICs, SOJs, TSOPs), Removal of quad components (PLCCs, QFPs), Replacement of quad components including fine-pitched devices.
Technical Library | 2022-10-31 09:02:58.0
Alias: Feeder Power Board Brand: MITSUBOSHI/Samsung Applicable Machinery: Samsung Placement Machine Selection Principle: Economy, Applicability Warranty: 3 Month Quality: Top Quality High Light: J9060343a, J9060343a Stepping Feeder Board, J9060343a Samsung Board
Technical Library | 2013-01-18 02:42:14.0
ENIG (Electroless Nickel/Immersion Gold) is to deposit nickel gold plating which has good solderability, wear resistance , leveling appearance and small electric resistance. It included 4 steps that are pretreatment, immersion nickel, immersion gold and Post treatment...
Technical Library | 2012-11-29 14:23:58.0
1000 units per day) production environment presents challenging technical, logistic and cost obstacles that are usually more complex than those encountered at the inspection (automated optical inspection) and the manufacturing process test step (in-circuit test).
Technical Library | 2021-04-15 14:49:27.0
In this study, a predefined template-based image processing system is proposed to automatically detect of PCB soldering defects that negatively affect circuit operation. The proposed system consists of a scaled inspection structure, a camera, an image processing algorithm merged with Fuzzy and template guided inspection process. The prototype is produced using a plastic material, depending on the focal length of the camera and the PCB size. Image processing step comprises two steps. Firstly, solder joints are determined and boxed using Fuzzy C-means clustering algorithm.
Technical Library | 2023-07-25 16:25:56.0
This paper address two significant applications of stencils in advance packaging field: 1. Ultra-Thin stencils for miniature component (0201m) assembly; 2. Deep Cavity stencils for embedded (open cavity) packaging. As the world of electronics continues to evolve with focus on smaller, lighter, faster, and feature-enhanced high- performing electronic products, so are the requirement for complex stencils to assemble such components. These stencil thicknesses start from less than 25um with apertures as small as 60um (or less). Step stencils are used when varying stencil thicknesses are required to print into cavities or on elevated surfaces or to provide relief for certain features on a board. In the early days of SMT assembly, step stencils were used to reduce the stencil thickness for 25 mil pitch leaded device apertures. Thick metal stencils that have both relief-etch pockets and reservoir step pockets are very useful for paste reservoir printing. Electroform Step-Up Stencils for ceramic BGA's and RF Shields are a good solution to achieve additional solder paste height on the pads of these components as well as providing exceptional paste transfer for smaller components like uBGAs and 0201s. As the components are getting smaller, for example 0201m, or as the available real estate for component placement on a board is getting smaller – finer is the aperture size and the pitch on the stencils. Aggressive distances from step wall to aperture are also required. Ultra-thin stencils with thicknesses in the order of 15um-40um with steps of 15um are used to obtain desired print volumes. Stencils with thickness to this order can be potential tools even to print for RDLs in the package.
