030070131 Mehmet Can Çapar 5th week definitions (Part 4)

4-Laminate (Manufacturing Method)


(Old Answer)
   Laminates used in PCB manufacture,whether rigid or flexible are created in two primary forms:single
clad and double clad laminates.they are also produced in a number of different thicknesses to faciliate the
manufacture of pcb with different thickness requirements and for the construction of multiplayer circuits,the
laminate is commonly referred to as a core material.

            ( Charles A. Harper,Electronic materials and processes handbook,p.13  )    


(New Answer) (Better)


     Multimaterial laminates ususally andicate the lay up of fullu isotropic laminate that
exhibits a concomitant stiffness isotropy or quasihomogeneous anisotropic laminate
that has multifunctional property or identical stiffness anisotropy in extensio,
shear, bending, and twisting. A laminate is a flat plate or curved shell consisting of
two or more plies stacked and bonded as an integral component for multifunctional or
structural applications. Each ply is a uniform-thicknes layer of material. The layup of
a laminate is generally tailored to match the functional or stiffness and strength requ-
irements for loadings from various directions. The constituent material of a uniform-thickness
ply may be homogenous or heterogeneous (including porous material); isotropşc or nonisotropic;
honeycomb-like or otherwise mechanically formed; or of certain combination of the above. However,
the multimaterial not only refers to the variaton of the constituent material property within a ply
in some applications. Laminated plates and shells have found a wide range of applications in
electronic packaging or aerospace structure where, multifunctional properties, high strength-to-weight
and high stiffness-to-weight ratios are desired. Fiber-reinforced composite laminates such as 
graphite/epoxy and Kevlar/epoxy are used to combine with or to replace the conventional aluminum-,
titanium-alloy structural components for weight reduction and other improvements (Wu and WU 1996). 


(Xingcun Colin Tong, Advanced Materials for Thermal Management of Electronic Packaging, pg:153-154)