Technical Library | 2023-06-12 18:52:18.0
This paper will review stencil design requirements for printing solder paste around and in through-hole pads / openings. There is much interest in this procedure since full implementation allows the placement of both through-hole components as well as SMD's and the subsequent reflow of both simultaneously. This in turn eliminates the need to wave solder or hand solder through-hole components.
Technical Library | 2015-06-30 22:02:41.0
This paper describes the losses from defects at the placement process in the SMT line. Two case studies of European and Taiwanese SMT manufacturers illustrate the actual losses from their defects. An evaluation method to select a pre-reflow AOI system maximizing the return on investment (ROI) is introduced. In the end, ROIs of three commercial pre-reflow AOI systems are compared to demonstrate the importance of selecting an appropriate AOI system. This paper will increase the probability that anyone installing an AOI system during the pre-reflow process will obtain a successful gain with short payback period.
Technical Library | 2009-07-15 12:14:31.0
The increasing demand for smaller & smaller portable electrical devices is leading to the increasing usage of extremely small components in the SMT assembly lines. With the introduction of 01005 packages in mass production, all the different stages of the line are facing new challenges: from board design, through component placement to reflow process. Each stage introduces some specific types of defect which are considered impossible to repair due to the small size of the package. AOI has become an essential tool to enable good yield in the assembly of 01005.
Technical Library | 2024-06-23 22:03:59.0
The melting temperatures of most lead-free solder alloys are somewhat higher than that of eutectic Sn/Pb solder, and many of the alloys tend to wet typical contact pads less readily. This tends to narrow down the fluxing and mass reflow process windows for assembly onto typical organic substrates and may enhance requirements on placement accuracy. Flip chip assembly here poses some unique challenges. The small dimensions provide for particular sensitivities to wetting and solder joint collapse, and underfilling does not reduce the demands on the intermetallic bond strength. Rather, the need to underfill lead to additional concerns in terms of underfill process control and reliability. Relatively little can here be learned from work on regular SMT components, BGAs or CSPs.
Technical Library | 2007-08-09 12:23:10.0
Recent developments in No Flow-Fluxing Underfill (NFFUF) products have demonstrated their utility to enhance the reliability of flip chip assemblies with reduced processing steps over conventional capillary flow methods. This basic work considered processing conditions such as dispensed volume and placement force, speed and dwell time. Further evaluations of these new products on a variety of flip chip assembly configurations manufactured by various processes have been undertaken to provide further evidence of their suitability and potential in high volume electronic manufacturing. This paper summarizes the recent evaluations and discusses new studies of additional assembly configurations, which include higher input/output (l/O) counts up to full arrays in excess of 1200 l/Os.
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.
Main Products: 1. Original new and Original Used SMT/AI Spare Parts. 2. SMT Equipments And Related Machine( SMT Calibration, SMT Feeder Carts,Conveyer etc.) 3. Maintenace and Repair Service Pre-Sales Service Provide details ab
Manufacturer's Representative / Manufacturer / Equipment Dealer / Broker / Auctions / Consultant / Service Provider
Building A, Jiepeng Square, Fuyong
Shenzhen, 30 China
Phone: 0755-33578694
.jpg)