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Oltin fond 2021, 1-sonBog'liq OLTIN FOND JURNALI 1-SON oxirgi Farhod Sultonov, Farruh Bozorboyev. O\'zbekiston hukmdorlari, 1. Tadbirkorlik turlari va shakllari, yarimo-tkazgichli-lazerlar
2021, 1-son
30
ILM SARCHASHMALARI
DEVELOPMENT AND METHOD FOR RESERVOIR STENCILS
WITH RELIEF AREAS
Dr. Michele Gaddy
The academic director of Karshi Presidential School
Abstract. A stencil comprising two or more layers is described for applying
surface mount materials onto printed circuit boards, flexible circuits, wafers or other
substrates. The stencil can accommodate preexisting surface mount components and
materials. The stencil utilizes material reservoirs, relief areas and delivery apertures
and can be used for depositing surface mount materials such as adhesives, conductive
glues, solder paste and solder balls.
Description. The surface mount technology (SMT) assembly industry requires
the application of surface mount materials such as adhesives and solder onto printed
circuit boards (PCBs), flexible circuits and wafers. Components are glued in place on
the PCB before normally going through a wave solder process to solder the
components to the PCB. One of the methods of depositing glue onto the PCB is with
a glue dispensing machine. This is a sequential process where glue is dispensed
through a fine orifice point by point under control of an X-Y positioning machine.
Glue and solder printing can also be done by stencil printing, which is a parallel
process. Material is applied to a stencil and then forced onto a substrate through
openings in the stencil.
These current techniques generally lack the flexibility to handle the variety of
shapes and heights of glue and solder paste deposits which may be needed due to the
diversity of components that are often used. For example, a 0603 chip component
may require a glue deposit 13 mils wide by 33 mils long by 8 mils high. At the same
time, a plastic leaded chip carrier (PLCC) may require a glue deposit 60 mils wide by
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