Thinwall composites for electronic enclosures

Abstract

A housing for an electronic device comprising: a core layer comprising a first thermoplastic material; a first skin layer comprising a second thermoplastic material located on a first side of the core layer; a second skin layer comprising the second thermoplastic material located on a second side of the core layer opposite the first side; wherein the core layer comprises a foam structure, a honeycomb structure, or combinations thereof; and wherein the thickness of the core layer is 30% to 75% of the total thickness of the housing.

1 . A housing for an electronic device comprising:
 a core layer comprising a first thermoplastic material;   a first skin layer comprising a second thermoplastic material located on a first side of the core layer;   a second skin layer comprising the second thermoplastic material located on a second side of the core layer opposite the first side;   wherein the core layer comprises a foam structure, a honeycomb structure, or combinations thereof;   wherein the thickness of the core layer is 30% to 75% of the total thickness of the housing, and wherein at least one of the following the core layer comprises 0 vol. % to 35 vol. % of a reinforcing material and 100 vol. % to 65 vol. % of the first thermoplastic material, based upon the total volume of the core layer; and   the first skin layer has a different viscosity, different molecular weight, different reinforcement loading, or combinations thereof, as compared to the second skin layer.   
     
     
         2 . A housing for an electronic device comprising:
 a core layer comprising a first thermoplastic material;   a first skin layer comprising a second thermoplastic material located on a first side of the core layer;   a second skin layer comprising the second thermoplastic material located on a second side of the core layer opposite the first side;   wherein the core layer comprises a foam structure, a honeycomb structure, or combinations thereof;   wherein the thickness of the core layer is 30% to 75% of the total thickness of the housing, and wherein at least one of the following   the core layer comprises 0 vol. % to 35 vol. % of a reinforcing material and 100 vol. % to 65 vol. % of the first thermoplastic material, based upon the total volume of the core layer; and   the first skin layer has a different viscosity, different molecular weight, different reinforcement loading, or combinations thereof, as compared to the second skin layer.   
     
     
         3 . The housing of  claim 1 , further comprising a frame connected to at least a portion of the core layer. 
     
     
         4 . The housing of  claim 1 , wherein the total thickness of the housing is 0.5 millimeters to 1.5 millimeters. 
     
     
         5 . The housing of  claim 1 , wherein the thickness of the core layer is 55% to 70% of the total thickness of the housing. 
     
     
         6 . The housing of  claim 1 , wherein the first thermoplastic material comprises polycarbonate. 
     
     
         7 . The housing of  claim 1 , wherein first thermoplastic material comprises 20% to 50% by weight glass fiber or wherein first thermoplastic material comprises 10% to 30% by weight short carbon filler. 
     
     
         8 . The housing of  claim 1 , wherein the second thermoplastic material comprises inorganic fabric reinforced thermoplastic material. 
     
     
         9 . The housing of  claim 1 , wherein the second thermoplastic material comprises inorganic fabric reinforced polypropylene, polyamide, polycarbonate, polyphenylene sulfide, polyetherimide, polyetheretherketone, and the like. 
     
     
         10 . The housing of  claim 3 , wherein the coefficient of thermal expansion of the core layer differs from the coefficient of expansion of the frame by less than 10%. 
     
     
         11 . The housing of  claim 1 , wherein the coefficient of thermal expansion of the core layer differs from the coefficient of expansion of the frame by less than 20%. 
     
     
         12 . The housing of  claim 1 , wherein the core layer comprises a thermal conductivity of less than or equal to 0.02 W/mK. 
     
     
         13 . A method for making an electronic device housing comprising:
 locating a first skin layer on a first side of an injection mold;   locating a second skin layer on a second side of an injection mold;   closing the mold;   injecting a first thermoplastic material between the first skin layer and the second skin layer to form a core layer;   opening the mold and removing a housing comprising the first skin layer, core layer, and second skin layer;   wherein the core layer comprises a foam structure, a honeycomb structure, or combinations thereof;   wherein the thickness of the core layer is 30% to 75% of the total thickness of the housing, and wherein at least one of the following   the core layer comprises 0 vol. % to 35 vol. % of a reinforcing material and 100 vol. % to 65 vol. % of the first thermoplastic material, based upon the total volume of the core layer; and   the first skin layer has a different viscosity, different molecular weight, different reinforcement loading, or combinations thereof, as compared to the second skin layer.   
     
     
         14 . The method of  claim 13 , wherein the core further comprises a frame extending beyond the first skin layer and second skin layer, wherein the frame comprises the first thermoplastic material. 
     
     
         15 . The method of  claim 13 , wherein first skin layer and the second skin layer comprise a second thermoplastic material. 
     
     
         16 . The method of  claim 13 , wherein the total thickness of the housing is 0.5 millimeters to 1.5 millimeters. 
     
     
         17 . The method of  claim 13 , comprising:
 locating the housing in an injection mold;
 wherein the core layer has a through plane thermal conductivity of less than equal to 0.02 W/mK; 
 wherein the thickness of the core layer is 30% to 75% of the total thickness of 
   the housing;   closing the mold;   injecting a thermoplastic material around the housing to form a frame attached to the housing; and   opening the mold and removing the framed housing.   
     
     
         18 . The method of  claim 17 , wherein the thickness of the core layer is 55% to 70% of the total thickness of the housing. 
     
     
         19 . The method of  claim 17 , wherein the total thickness of the housing is 0.5 millimeters to 1.5 millimeters. 
     
     
         20 . The method of  claim 17 , wherein the first thermoplastic material comprises polycarbonate; and wherein first thermoplastic material comprises 20% to 50% by weight glass fiber and/or 10% to 30% by weight short carbon filler.