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High reliability in multilayer circuit boards:
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High elongation at elevated temperature prevents foil cracking.
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Handles as easily as standard copper foil.
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Standard profile for conventional multilayer/mass lamination applications.
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Low profile for high density multilayer boards.
Overview
The growth of multilayer laminates has placed much more emphasis on printed circuit board
reliability. This emphasis has been compounded by the direction of the industry to fabricate
smaller, denser PCB packages. As the number of layers increased, additional concerns towards
maintaining reliability were raised. These concerns involve the Z-Axis expansion or strain of
the PCB raw materials. It has been well documented that the raw materials expand under thermal
conditions such as PCB soldering processes. PCB reliability after this expansion is especially
critical since the manufacturer cannot test the package until the latter stages of the process.
Gould developed JTCS foil
, which exhibits excellent ductility at elevated temperature and, therefore, withstands the
stress caused by thermal Z-Axis expansion of the laminate. In addition to meeting IPC-4562
requirements and the qualities exhibited by standard Gould foils, JTCS foil withstands the
stresses near the edge of plated thru holes without cracking. JTCS copper is produced in a
unique manner so there is no sacrifice in handleability, lamination or PCB processing.
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Copper foil with aluminium or steel separator sheet.
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Easy use of free-standing thin foils 5 and 9 micron for high end multilayers.
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Less material handling and reduced operator labour costs.
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Improved yield by elimination of airborne particles and resin dust.
Overview
Copper-Aluminium-Copper (CAC) and Copper-Steel-Copper (CSC) offer an aluminium or steel separator
with an impressive difference. It is sandwiched between two sheets of copper foil, which pre-seals
the critical copper shiny surfaces from exposure to airborne particles and resin dust. During
multilayer lamination, the copper foil releases from the aluminium/steel separator sheet and
becomes the outer layer foil for the printed circuit board, above and below.
GOULD's proprietary process ensures that hte copper surfaces are free of any particles or dents
5 micron or larger. The net result is consistently higher yields on high density, fine line and
gold feature circuit boards. Costly manual handling and cleaning steps are eliminated, which reduces
labour costs and improves cycle time and throughput during the lay-up process.
CAC/CSC is also the best and most economical solution for using difficult-to-handle free-standing
thin foils like 5 and 9 micron (laser drillable) on high end multilayers.
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