High precision transfer lamination mandrel

Abstract

A high precision transfer lamination plate/mandrel is fabricated in a sanch construction design wherein an inner core is constructed of a low coefficient of thermal expansion (CTE) comprised of an iron-nickel alloy core member (e.g., Kovar or Invar) with stainless steel cladding on each side of the core member. The stainless steel is selected from AISI type 302, 304, or 316. The stainless steel cladding outer surface of the top and bottom plate to which an electroplated copper foil circuitry is applied must be free of pits, scratches, and defects so as to yield a continuous circuitry satisfactory for military electronics. A matched (CTE) of the transfer lamination plate/mandrel with a composite material to which the electronic circuitry is transferred results in adherence of the copper circuitry minimally to the plate/mandrel to avoid blistering and enables the transfer to be achieved without distortion of circuitry features due to CTE mismatch. The composite material to which the electronic circuitry is laminated is an aramid/epoxy prepreg fabric (e.g., Kevlar/epoxy prepreg fabric).

I claim: 
     
       1. A high precision transfer lamination plate/mandrel fabricated in a sandwich construction and method coefficient of thermal expansion with a composite material to which an electronic circuitry is transfer laminated, said high precision transfer lamination plate/mandrel comprising: P1 (i) an iron-nickel allow core member having a low coefficient of thermal expansion in the form of a plate; and P1 (ii) heat-resisting stainless steel cladding plates free of pits, scratches, and defects positioned in intimate contact on a top surface and a bottom surface of said core member to form said high precision transfer lamination plate/mandrel having a matched coefficient of thermal expansion with a composite material to which an electronic circuitry is transfer laminated. 
     
     
       2. The high precision transfer lamination plate/mandrel as defined in claim 1 wherein said iron-nickel alloy core member is selected from an iron-base alloy comprised of 28-30% nickel, 15-18% cobalt, fractional percentages of manganese, and balance iron and an iron-nickel alloy comprised of 63.8% iron, 36% nickel, and 0.2% carbon, and wherein said heat-resisting stainless steel cladding plates are selected from a stainless steel defined by austenitic steels having AISI number 301, 304, and 316 as specifically defined in Table I set forth below as follows:                                     TABLE I                                 
__________________________________________________________________________
ELEMENT NOMINAL COMPOSITION, PERCENT                                      
AISI Type                                                                 
      C    Mn, max                                                        
                Si, max                                                   
                    Cr    Ni    Other.sup.a                               
__________________________________________________________________________
301   0.15 max                                                            
           2.00 1.00                                                      
                    16.00-18.00                                           
                          6.00-8.00                                       
304   0.08 max                                                            
           2.00 1.00                                                      
                    18.00-20.00                                           
                           8.00-12.00                                     
316   0.08 max                                                            
           2.00 1.00                                                      
                    16.00-18.00                                           
                          10.00-14.00                                     
                                2.00-3.00 Mo                              
__________________________________________________________________________
 .sup.a phosphorus is 0.045 percent maximum; sulphur is 0.030 percent     
 maximum; and balance of steel, iron.