PATENT DOCUMENT

Publication Number: US-8830665-B2
Application Number: US-201213655310-A
Country: US
Kind Code: B2

Title: Attachment features for housings

Abstract:
Methods and apparatus for forming a housing, such as for an electronic device, from multi-layer materials are disclosed. The multi-layer materials include at least two layers. Typically, one or more of the layers are metal. However, different layers of the multi-layer materials can be different metals. In one embodiment, an inner layer of the multi-layer materials can be provided with or form internal features that can be for attaching parts or components to the multi-layer materials. In another embodiment, processing of an inner layer of the multi-layer materials can facilitate part formation with increased curvature and/or internal part clearance. In another embodiment, the multi-layer materials can include an intermediate layer that facilitates creation of internal features that can be for attaching parts or components to the multi-layer materials. In still another embodiment, the multi-layer materials can provide a protective layer that serves to protect an outer surface of the housing during manufacturing and/or assembly.

Claims:
What is claimed is: 
     
       1. A portable electronic device, comprising:
 a multi-layered housing comprising:
 an inner layer having at least one attachment feature used to secure a molded piece such that the molded piece is at least partially molded around the at least one attachment feature, 
 an outer layer having an outer surface corresponding to an exterior surface of the multi-layered housing, and 
 at least one intermediate layer disposed between the inner layer and the outer layer, the intermediate layer having at least one void region associated with a corresponding attachment feature and that exposes a portion of the outer layer. 
 
 
     
     
       2. The portable electronic device of  claim 1 , wherein an internal surface of the inner layer corresponds to an internal surface of the multi-layered housing. 
     
     
       3. The portable electronic device of  claim 1 , wherein the molded piece extends at least partially within the void region. 
     
     
       4. The portable electronic device of  claim 2 , wherein the at least one attachment feature is a manipulated portion of the inner layer proximate the at least one void region. 
     
     
       5. The portable electronic device of  claim 4 , wherein the manipulated portion is a bent portion of the inner layer. 
     
     
       6. The portable electronic device of  claim 1 , wherein the at least one void region is a drilled portion of the intermediate layer. 
     
     
       7. The portable electronic device of  claim 1 , wherein the inner layer and outer layer are comprised of metal. 
     
     
       8. The portable electronic device of  claim 1 , wherein the inner layer and outer layer are comprised of different materials. 
     
     
       9. The portable electronic device of  claim 1 , wherein the intermediate layer is configured to protect the outer layer from damage during processing of the portable electronic device. 
     
     
       10. The portable electronic device of  claim 1 , wherein the intermediate layer is comprised of a material having a higher thermal conductivity than the outer layer. 
     
     
       11. The portable electronic device of  claim 1 , wherein the intermediate layer is comprised of a material having a lower thermal conductivity than the outer layer. 
     
     
       12. A method of forming a multi-layered housing for an electronic device, the method comprising:
 forming an outer layer having an inner surface and an outer surface, the outer surface corresponding to an exterior surface of the housing; 
 forming an intermediate layer on the inner surface of the outer layer, the intermediate layer having at least one void region associated with an attachment feature and that exposes a portion of the outer layer; 
 forming an inner layer on the intermediate layer, the inner layer having the attachment feature; and 
 molding a molded piece at least partially around the attachment feature attaching the molded piece to the multi-layered housing. 
 
     
     
       13. The method of  claim 12 , wherein the intermediate layer protects the outer layer from damage during forming of the inner layer. 
     
     
       14. The method of  claim 12 , further comprising:
 forming the attachment feature by manipulating a portion of the inner layer. 
 
     
     
       15. The method of  claim 14 , wherein manipulating a portion of the inner layer comprises bending a portion of the inner layer. 
     
     
       16. The method of  claim 12 , further comprising:
 forming the attachment feature by separating a portion of the inner layer from the intermediate layer at the void region. 
 
     
     
       17. The method of  claim 16 , wherein the separating comprises drilling a localized region of the intermediate layer. 
     
     
       18. The method of  claim 16 , wherein the separating comprises etching away a localized region of the intermediate layer. 
     
     
       19. The method of  claim 13 , wherein forming the inner layer includes laminating the inner layer on a surface of the intermediate layer. 
     
     
       20. The method of  claim 12 , wherein forming the inner layer comprises a soldering process. 
     
     
       21. A housing for an electronic device, the housing comprising:
 an inner layer having at least one internal feature attached to a molded part such that the molded part is at least partially molded around the at least one internal feature 
 an outer layer having an outer surface corresponding to an exterior surface of the housing; and 
 at least one intermediate layer disposed between the at least one internal feature and the outer layer, the intermediate layer having a pattern which includes at least one void region that exposes a portion of the outer layer. 
 
     
     
       22. The housing of  claim 21 , wherein a molded piece is molded around two or more internal features such that the two or more internal features cooperatively engage with the molded piece to secure the molded piece to the housing.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This patent application is a continuation of and takes priority under 35 U.S.C. §120 to pending U.S. application Ser. No. 12/234,437, entitled “METHODS AND SYSTEMS FOR FORMING HOUSINGS FROM MULTI-LAYER MATERIALS” by Stephen B. Lynch et al. and filed Sep. 19, 2008, which claims the benefit of U.S. Provisional Application No. 61/023,375, entitled “METHODS AND SYSTEMS FOR FORMING HOUSINGS FROM MULTI-LAYER MATERIALS,” filed Jan. 24, 2008 and U.S. Provisional Application No. 60/949,780, entitled “METHODS AND SYSTEMS FOR DUAL LAYER HOUSING,” filed Jul. 13, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to forming housing for electronic devices. 
     2. Description of the Related Art 
     The manufacture of devices that include metal parts often includes the formation of features, e.g., complex mechanical structures, on surfaces of the metal parts. In order to ensure the structural integrity of such features, the features are often affixed to the surfaces of the metal parts using an adhesive material. By way of example, an internal feature has been obtained and glued in an appropriate location on a surface of a metal parts or housings. 
     Alternatively, internal features have been welded to the surface of metal parts or housings. Utilizing a welding process to attach internal features to metal parts is limiting in terms of the number and the complexity of the internal features that is possible using a welding technique. Furthermore, the cosmetic quality of a metal part may be degraded as a result of a welding process. For instance, the heat associated with a welding process may alter the shape and/or the color of a metal part. 
     Internal features may also be formed using an injection molding process. When a manufacturing process includes an injection molding process, a through-hole may be formed in a metal part or housing, and a plastic or a resin may be injected through the through-hole. The plastic or resin may form a feature on one side of the metal part, e.g., a metal sheet, while additional plastic or resin may form an undercut on the other side of the metal sheet. The undercut, in cooperation with the plastic or resin that hardens in the through-hole, may effectively serve to anchor or otherwise hold the feature in place. Often, the side of a metal sheet on which an undercut is located may be arranged to be exposed. That is, the side of a metal sheet on which an undercut is located may be an external surface of an apparatus or device. As such, the presence of an undercut on the side of the metal sheet may be aesthetically undesirable, e.g., when the metal sheet is arranged to serve a cosmetic purpose. 
     SUMMARY OF THE INVENTION 
     The invention pertains to forming a housing, such as for an electronic device, from multi-layer materials. The multi-layer materials include at least two layers. Typically, one or more of the layers are metal. However, different layers of the multi-layer materials can be different metals. In one embodiment, an inner layer of the multi-layer materials can be provided with or form internal features that can be for attaching parts or components to the multi-layer materials. In another embodiment, processing of an inner layer of the multi-layer materials can facilitate part formation with increased curvature and/or internal part clearance. In another embodiment, the multi-layer materials can include an intermediate layer that facilitates creation of internal features that can be for attaching parts or components to the multi-layer materials. In still another embodiment, the multi-layer materials can provide a protective layer that serves to protect an outer surface of the housing during manufacturing and/or assembly. 
     The invention may be implemented in numerous ways, including, but not limited to, as a method, system, device, or apparatus. Example embodiments of the present invention are discussed below. 
     As a portable electronic device, one embodiment of the invention includes at least an electronic component and a housing, where the housing includes at least a multi-layer material. The housing can be arranged to substantially house the electronic component. 
     As an assembly, one embodiment of the invention includes at least: a multi-layer metal sheet having at least a first metal layer and a second metal layer; and at least one attachment feature formed in or attached to the first metal layer. 
     As a housing for a portable electronic device, one embodiment of the invention includes at least: a multi-layer material having at least a first metal layer and a second metal layer; and at least one internal feature formed in, attached to, or formed from the first metal layer of the multi-layer material. 
     Various aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, in which: 
         FIG. 1A  is a cross-sectional side-view diagrammatic representation of a housing structure according to one embodiment of the invention. 
         FIG. 1B  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 1C  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 1D  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 2A  is a process flow diagram which illustrates a method of forming a multi-layer structure in accordance with one embodiment of the invention. 
         FIG. 2B  is a process flow diagram which illustrates a method of forming a multi-layer structure in accordance with another embodiment of the invention. 
         FIG. 3A  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 3B  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 4  is a process flow diagram which illustrates a method of forming a multi-layer structure in accordance with another embodiment of the invention. 
         FIG. 5  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 6  is a process flow diagram which illustrates a method of forming a multi-layer structure in accordance with another embodiment of the invention. 
         FIG. 7  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 8  is a process flow diagram which illustrates a method of forming a multi-layer structure in accordance with another embodiment of the invention. 
         FIG. 9A  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 9B  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 9C  is a cross-sectional side-view diagrammatic representation of a housing structure according to another embodiment of the invention. 
         FIG. 10  is a process flow diagram which illustrates a method of forming a multi-layer structure in accordance with another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Exemplary embodiments of the present invention are discussed below with reference to the various figures. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes, as the invention extends beyond these embodiments. 
     The invention pertains to forming a housing, such as for an electronic device, from multi-layer materials. The multi-layer materials include at least two layers. Typically, one or more of the layers are metal. However, different layers of the multi-layer materials can be different metals. In one embodiment, an inner layer of the multi-layer materials can be provided with or form internal features that can be for attaching parts or components to the multi-layer materials. In another embodiment, processing of an inner layer of the multi-layer materials can facilitate part formation with increased curvature and/or internal part clearance. In another embodiment, the multi-layer materials can include an intermediate layer that facilitates creation of internal features that can be for attaching parts or components to the multi-layer materials. In still another embodiment, the multi-layer materials can provide a protective layer that serves to protect an outer surface of the housing during manufacturing and/or assembly. 
     In one embodiment, internal features or complex mechanical structures can be at a surface of a multi-layer material. One or more internal features or complex mechanical structures may be formed or attached to the multi-layer material. Examples of internal features of complex mechanical structures may include, but are not limited to including, structural members, frames, screw bosses, bridges, snaps, flexures, flanges, shelves, tapers, cavities, and/or pockets. 
     In one embodiment, a multi-layer material having at least one metal layer may be a portion or a component of a housing of an electronic device. A multi-layer material that is a portion of a housing of an electronic device may be a bezel section, a front section, and/or a back section of the housing. The multi-layer material may be a laminate combination in which at least one layer is metal and chosen from a wide variety of metals, including, but not limited to including, alloys, stainless steel, and aluminum. 
     In one embodiment, the housing being formed from multi-layer materials can be a metal part, housing, or sheet having multiple layers, where at least one of the layers is metal. The metal part, housing, or sheet may serve a structural and/or a cosmetic purpose. That is, a metal part, housing, or sheet having multiple layers may have a purely structural purpose, a purely aesthetic purpose, or both a structural purpose and an aesthetic purpose. For ease of discussion, a metal part, housing or sheet will generally be described as a housing, although it should be appreciated that a metal element may be substantially any suitable metal component associated with a device or an apparatus, such as a housing, a sheet, or an insert. 
     The invention can be utilized in a variety of different devices (e.g., electronic devices) including, but not limited to including, portable and highly compact electronic devices (i.e., portable electronic devices) with limited dimensions and space. In one embodiment, a device may be a laptop computer, a tablet computer, a media player, a mobile phone (e.g., cellular phone), a personal digital assistant (PDA), substantially any handheld electronic device, a computer mouse, a keyboard, a remote control, substantially any computer accessory, and/or substantially any computer peripheral. Typically, the electronic devices include at least one electrical component inside its housing. The electrical component can, for example, be an integrated circuit or circuit board. Examples of integrated circuits include memory, processor (microprocessor or controller), ASIC, and various others. 
       FIG. 1A  is a cross-sectional side-view diagrammatic representation of a housing structure  100  according to one embodiment of the invention. The housing structure  100  includes a multi-layer material  102 . The multi-layer material  102  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  102  has an outer layer  104  and an inner layer  106 . The outer layer  104  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). The inner layer  106  is normally not visible once the housing and/or electronic device is fabricated. 
     In one embodiment, the outer layer  104  and the inner layer  106  are metal layers that are laminated together, such as in a multi-layer sheet. However, the outer layer  104  and the inner layer  106  can utilize different metals. Since different metals can be used, the properties or characteristics of the different layers  104  and  106  can be advantageously utilized to form housings. For example, with regard to  FIG. 1A , the outer layer  104  can be stainless steel, and the inner layer  106  can be aluminum. The housing structure  100  also includes features  110  that can be attached to a surface  108  of the inner layer  106 . The features  110  can be utilized as binding features or attachment features to assist in the assembly of a housing that utilizes one or more other parts that are to be attached or bounded to the housing structure  100 . As illustrated in  FIG. 1A , the features  110  can be geometrically complex internal features that are suitable for operation as binding features or attachment features. In one embodiment, the features  110  are plastic or resin features that can be molded (e.g., insert-molded, injection-molded) onto the surface  108  of the inner layer  106 . These plastic or resin features can bond themselves to the surface  108 . With the inner layer  106  being aluminum, the plastic or resin features can form stronger bonds than would be available with other metals, such as stainless steel. 
       FIG. 1B  is a cross-sectional side-view diagrammatic representation of a housing structure  120  according to one embodiment of the invention. The housing structure  120  includes a multi-layer material  122 . The multi-layer material  122  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  122  has an outer layer  124  and an inner layer  126 . The outer layer  124  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). In the inner layer  126  is normally not visible once the housing and/or electronic device is fabricated. 
     In one embodiment, the outer layer  124  and the inner layer  126  are metal layers that are laminated together, such as in a multi-layer sheet. For example, the layers can be laminated together using cladding. However, the outer layer  124  and the inner layer  126  can utilize different metals. Since different metals can be used, the properties or characteristics of the different layers  124  and  126  can be advantageously utilized to form housings. For example, with regard to  FIG. 1B , the outer layer  124  can be stainless steel, and the inner layer  126  can be brass or copper. The housing structure  120  also includes features  130  that can be attached to a surface  128  of the inner layer  126 . The features  130  can be utilized as binding features or attachment features to assist in the assembly of a housing that utilizes one or more other parts that are to be attached or bounded to the housing structure  120 . As illustrated in  FIG. 1B , the features  130  can be geometrically complex internal features that are suitable for operation as binding features or attachment features. In one embodiment, the features  130  are metal (e.g., brass, copper) features that can be manufactured and attached to the surface  128  of the inner layer  126  by way of soldering or brazing. With the inner layer  126  being brass or cooper, the brass or copper features can be easily soldered or brazed together, whereas soldering or brazing with some metals, such as stainless steel, is more difficult. 
       FIG. 10  is a cross-sectional side-view diagrammatic representation of a housing structure  140  according to one embodiment of the invention. The housing structure  140  is similar to the housing structure  100  illustrated in  FIG. 1A  with the addition of an additional piece  142  bound to the multi-layer material  102 . The additional piece  142  is adhered to the multi-layer material  122  through use of the features  110 . The additional piece  142  can be attached to, or effectively molded around, the features  110 . The additional piece  142  may, in one embodiment, be arranged to include complex mechanical features (not shown) which can be complementary to the features  110 . 
       FIG. 1D  is a cross-sectional side-view diagrammatic representation of a housing structure  160  according to one embodiment of the invention. The housing structure  160  is similar to the housing structure  120  illustrated in  FIG. 1B  with the addition of an additional piece  162  bound to the multi-layer material  122 . The additional piece  162  is adhered to the multi-layer material  122  through use of the features  130 . The additional piece  162  can be attached to, or effectively molded around, the features  130 . The additional piece  162  may, in one embodiment, be arranged to include complex mechanical features (not shown) which can be complementary to the features  130 . 
       FIG. 2A  is a process flow diagram which illustrates a method  200  of forming a multi-layer structure in accordance with one embodiment of the invention. The multi-layer structure can be used as part of an overall assembly that is suitable for use in an electronic device. The multi-layer structure is a multiple layer metal part with a molded piece adhered thereto. For example, the multi-layer structure can, for example, be the housing structure  100  illustrated in  FIG. 1A . 
     According to the method  200 , a multi-layer metal substrate is obtained  202 . For example, the multi-layer metal substrate is a substrate having two or more layers of metal. Typically, the multi-layer metal substrate includes layers of different metals. Next, a surface treatment is performed  204  on an inner surface of the inner layer of the multi-layer metal substrate. The surface treatment can, for example, be mechanical or chemical-based. For example, the inner surface of the inner layer of the multi-layer of metal substrate could be etched or chemically treated as a surface treatment. Thereafter, attachment features can be molded  206  onto the surface of the inner layer. The surface treatment operates allow the attachment features to securely bond to the inner surface of the inner layer. As a result, the inner layer of the multi-layer metal substrate can be chosen to provide strong bonding characteristics with respect to the attachment features, whereas the outer layer of the multi-layer metal substrate can be chosen for structural properties as well as outward appearance (e.g., cosmetic reasons). 
       FIG. 2B  is a process flow diagram which illustrates a method  250  of forming a multi-layer structure in accordance with another embodiment of the invention. The multi-layer structure can be used as part of an overall assembly that is suitable for use in an electronic device. The multi-layer structure is a multiple layer metal part with a metal piece adhered thereto. For example, the multi-layer structure can, for example, be the housing structure  120  illustrated in  FIG. 1B . 
     According to the method  250 , a multi-layer metal substrate is obtained  202 . For example, the multi-layer metal substrate is a substrate having two or more layers of metal. Typically, the multi-layer metal substrate includes layers of different metals. Next, metal attachment features can be obtained  254 . For example, the metal attachment features can be geometrically complex shapes. Thereafter, the metal attachment features can be attached  256  onto the surface of the inner layer. For example, the metal attachment features can be attached through brazing or soldering. The metal attachment features operate to facilitate attachment of another part to the multi-layer metal substrate. As a result, the inner layer of the multi-layer metal substrate can be chosen to provide good brazing or soldering capabilities with respect to the metal attachment features, whereas the outer layer of the multi-layer metal substrate can be chosen for structural properties as well as outward appearance (e.g., cosmetic reasons). In one implementation, the metal attachment features are brass or cooper, the inner layer of the multi-layer metal substrate is brass or cooper, and the outer layer of the multi-layer metal substrate is stainless steel. 
       FIG. 3A  is a cross-sectional side-view diagrammatic representation of a housing structure  300  according to one embodiment of the invention. The housing structure  300  includes a multi-layer material  302 . The multi-layer material  302  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  302  has an outer layer  304  and an inner layer  306 . The outer layer  304  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). The inner layer  306  is normally not visible once the housing and/or electronic device is fabricated. 
     In one embodiment, the outer layer  304  and the inner layer  306  are metal layers that are laminated together, such as in a multi-layer sheet. For example, the layers can be laminated together using cladding. However, the outer layer  304  and the inner layer  306  can utilize different metals. Since different metals can be used, the properties or characteristics of the different layers  304  and  306  can be advantageously utilized to form housings. For example, with regard to  FIG. 3A , the outer layer  304  can be aluminum, and the inner layer  306  can be stainless steel. The housing structure  300  also includes features  310  that can be attached to a surface  308  of the inner layer  306 . The features  310  can be utilized as binding features or attachment features to assist in the assembly of a housing that utilizes one or more other parts that are to be attached or bounded to the housing structure  300 . As illustrated in  FIG. 3A , the features  310  can be geometrically complex internal features that are suitable for operation as binding features or attachment features. In one embodiment, the features  310  are metal (e.g., stainless steel) features that can be manufactured and attached to the surface  308  of the inner layer  306  by way of welding (e.g., laser-spot welding). When the inner layer  306  and the features  310  are stainless steel, the stainless steel features can be easily welded to the surface  308  of the inner layer  306 , whereas welding stainless steel to aluminum is not practical. 
       FIG. 3B  is a cross-sectional side-view diagrammatic representation of a housing structure  350  according to one embodiment of the invention. The housing structure  350  includes a multi-layer material  352 . The multi-layer material  352  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  352  has an outer layer  354 , an inner layer  356 , and an intermediate layer  358 . The outer layer  354  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). The inner layer  356  is normally not visible once the housing and/or electronic device is fabricated. The intermediate layer  358  can operate as a protective layer, such as to protect the outer layer  354  from damage during processing or assembly of either the housing structure  350  or a housing of an electronic device making use of the housing structure  350 . 
     In one embodiment, the outer layer  354  and the inner layer  356  are metal layers. In one implementation, the intermediate layer  358  is also metal. In another implementation, the intermediate layer  358  is not metal. In some embodiments, it is advantageous for the intermediate layer  358  to have high thermal conductivity, such as copper. In other embodiments, it is advantageous for the intermediate layer  358  to have low thermal conductivity, such as stainless steel (or a non-metal). In still other embodiment, it is advantageous for the intermediate layer  358  to have anisotropic thermal conductivity. The outer layer  354 , the inner layer  356  and the intermediate layer  358  can be laminated together, such as in a multi-layer sheet. For example, the layers can be laminated together using cladding. The outer layer  354  and the inner layer  356  can utilize different metals. Since different metals are used, the properties or characteristics of the different layers  354  and  356  can be advantageously utilized to form housings. In one example, the outer layer  354  can be aluminum and the inner layer  356  can be stainless steel. In another example, the outer layer  354  can be stainless steel and the inner layer  356  can be aluminum. In still another example, the outer layer  354  and the inner layer  356  can be stainless steel. 
     The housing structure  350  illustrated in  FIG. 3B  can also include features  362  that can be attached to a surface  360  of the inner layer  356 . The features  362  can be utilized as binding features or attachment features to assist in the assembly of a housing that utilizes one or more other parts that are to be attached or bounded to the housing structure  350 . As illustrated in  FIG. 3B , the features  362  can be geometrically complex internal features that are suitable for operation as binding features or attachment features. In one embodiment, the features  362  are metal (e.g., stainless steel) features that can be manufactured and attached to the surface  360  of the inner layer  356  by way of welding (e.g., laser-spot welding). With the inner layer  356  being stainless steel (or other compatible metal), the stainless steel features can be easily welded to the surface  360  of the inner layer  356 . During the welding of the features  362  to the surface  360  of the inner layer  356 , the outer layer  354  is protected by the intermediate layer  358 . For example, the welding of the features  362  requires a significant amount of heating of the features  362  as well as the surface  360 , and such generated heat can cause localized damage to portions of the outer layer  354 . For example, when an intermediate layer is not used, localized damage from welding can cause undesired color or shape changes to the outer layer  354 . Advantageously, however, when the intermediate layer  358  is provided between the outer layer  354  and the inner layer  356  of the multi-layer material  352 , the intermediate layer  358  can serve to protect the generated heat during the welding from damaging to the outer layer  354 . 
     Additionally, when an outer layer (e.g., outer layer  354 ) is a polished surface, such as polished stainless steel, assembly (when using a welding process to attach internal features) conventionally dictates that polishing of a stainless steel outer layer be performed after the welding process of the features. However, in accordance with one embodiment of the invention illustrated in  FIG. 3B , the polishing of the stainless steel outer layer can be performed in advance of the welding process. Indeed, the polishing of the stainless steel outer layer can be performed while in the multi-layer material  352  is in a sheet form as opposed to later when the housing for an electronic device is partially assembled. Hence, it is more efficient to polish the stainless steel in a sheet form then it is to later polish assembled or partially assembled housings. The use of an intermediate layer (e.g., intermediate layer  358 ) to provide a thermal barrier protects the outer layer from thermal damage. In this embodiment, the thermal damage being presented is with regard to heat induced during a weld process; therefore, the intermediate layer can also be referred to as a weld barrier. 
       FIG. 4  is a process flow diagram which illustrates a method  400  of forming a multi-layer structure in accordance with another embodiment of the invention. The multi-layer structure can be used as part of an overall assembly that is suitable for use in an electronic device. The multi-layer structure is a multiple layer metal part with a metal piece adhered thereto. For example, the multi-layer structure can, for example, be the housing structure  350  illustrated in  FIG. 3B . 
     According to the method  400 , a multi-layer metal substrate is obtained  402 . For example, the multi-layer metal substrate is a substrate having two or more layers of metal as well as a thermal barrier layer. The thermal barrier layer can be, in one embodiment, a high thermal conductivity material. As an example, the thermal barrier layer can be a metal, such as copper that has high thermal conductivity. In an alternative embodiment, the thermal barrier can be a low thermal conductivity material. As an example, the thermal barrier layer can be a metal, such as stainless steel that has low thermal conductivity, or a non-metal, which tends to have even lower thermal conductivity. In still another embodiment, the thermal barrier layer is a material that has an anisotropic thermal conductivity, e.g., high thermal conductivity in the plane of the substrate (e.g., sheet) and low thermal conductivity orthogonal to the plane of the substrate (e.g., in the direction of attachment). 
     The two or more layers of metal for the multi-layer metal substrate can be the same metal or can be different metals. Next, metal attachment features can be obtained  404 . For example, the metal attachment features can be geometrically complex shapes that are used to adhere other parts to the multi-layer metal substrate. Thereafter, the metal attachment features can be attached  406  onto the surface of the inner layer. The metal attachment features operate to facilitate attachment of another part to the multi-layer metal substrate. As a result, the inner layer of the multi-layer metal substrate can be chosen to provide welding (or brazing or soldering) capabilities with respect to the metal attachment features, whereas the outer layer of the multi-layer metal substrate can be chosen for structural properties as well as outward appearance (e.g., cosmetic reasons). In one implementation, the metal attachment features are aluminum or stainless steel, the inner layer of the multi-layer metal substrate is aluminum or stainless steel, and the intermediate layer is copper. 
       FIG. 5  is a cross-sectional side-view diagrammatic representation of a housing structure  500  according to one embodiment of the invention. The housing structure  500  includes a multi-layer material  502 . The multi-layer material  502  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  502  has an outer layer  504  and an inner layer  506 . The outer layer  504  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). In the inner layer  506  is normally not visible once the housing and/or electronic device is fabricated. 
     In one embodiment, the outer layer  504  and the inner layer  506  are metal layers that are laminated together, such as in a multi-layer sheet. For example, the layers can be laminated together using cladding. However, the outer layer  504  and the inner layer  506  can utilize different metals. Since different metals can be used, the properties or characteristics of the different layers  504  and  506  can be advantageously utilized to form housings. For example, with regard to  FIG. 5 , the outer layer  504  can be stainless steel, and the inner layer  506  can be aluminum. The housing structure  500  also has features  510  formed into a surface  508  of the inner layer  506 . Such features  510  can be referred to as internal features. The features  510  can be utilized to assist in the assembly of a housing that utilizes one or more other parts that are to be attached or bounded to the housing structure  500 . Alternatively, the features  510  can be utilized to provide recesses or regions of additional clearance as may be needed for counterpart parts for which the multi-layer material  500  abuts against or is adhered to during further assembly of a housing or other part. In one embodiment, the inner layer  506  utilizes a metal that can be machined without difficulty. For example, the inner layer  506  can be aluminum or brass, while the outer layer  504  can be stainless steel. 
       FIG. 6  is a process flow diagram which illustrates a method  600  of forming a multi-layer structure in accordance with another embodiment of the invention. The multi-layer structure can be used as part of an overall assembly that is suitable for use in an electronic device. The multi-layer structure is a multiple layer metal part with machined regions to facilitate attachment and/or clearance. For example, the multi-layer structure can, for example, be the housing structure  500  illustrated in  FIG. 5 . 
     According to the method  600 , a multi-layer metal substrate is obtained  602 . For example, the multi-layer metal substrate is a substrate having two or more layers of metal. Typically, the multi-layer metal substrate includes layers of different metals. Next, internal features can be machined  604  into an inner layer of the multi-layer metal substrate. The internal features can facilitate attachment of another part to the multi-layer metal substrate. The internal features can also serve to provide additional clearance to components internal to a housing that is formed from the multi-layer metal substrate. As a result, the inner layer of the multi-layer metal substrate can be chosen to provide good machining characteristics, whereas the outer layer of the multi-layer metal substrate can be chosen for structural properties as well as outward appearance (e.g., cosmetic reasons). In one implementation, the inner layer of the multi-layer metal substrate is aluminum or brass, and the outer layer of the multi-layer metal substrate is stainless steel. 
     Besides attachment or clearance (as noted above with respect to  FIGS. 5 and 6 ), it should be noted that internal features being machined into an inner layer of a multi-layer metal substrate can additionally or alternatively be used for alignment purposes when assembling a multi-part structure, such as a housing. In addition, machining of portions of an inner layer can also facilitate increased bending ability for the multi-layer material. For example, a curvature radius for corners that can be formed from a metal sheet is limited depending upon the thickness of the metal sheet. Hence, by machining away portions of the inner layer of the multi-layer material, the thickness of the multi-layer material can be reduced. As a result, a greater degree of curvature can be provided such that tight corners and/or sharp angles can be utilized when forming structures, such as housings for electronic devices. 
       FIG. 7  is a cross-sectional side-view diagrammatic representation of a housing structure  700  according to one embodiment of the invention. The housing structure  700  includes a multi-layer material  702 . The multi-layer material  702  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. In this embodiment, the multi-layer material  702  includes a primary layer  704  and an outer protective layer  706 . The primary layer  704  can serve as the housing. In an alternative embodiment, the primary layer  704  can itself be a multi-layer material. The outer protective layer  706  serves to protect the primary layer  704  during fabrication and/or assembly of the housing. In one embodiment, the primary layer  704  and the outer protective layer  706  are metal layers that are laminated together, such as in a multi-layer sheet. The primary layer  704  and the outer protective layer  706  can, in such an embodiment, utilize different metals. Since different metals are used, the properties or characteristics of the different layers  704  and  706  can be utilized to form housings. For example, with regard to  FIG. 7 , the primary layer  704  can be stainless steel, such as pre-polished stainless steel, and the outer protective layer  706  can be any suitable material capable of protecting the primary layer  704  while also being removable following fabrication or assembly. As an example, the outer protective layer  706  can be a thin metal layer that can be subsequently removed by an etch process. Once the outer protective layer  706  has been removed, the primary layer  704  can be exposed and serve as a surface for the housing. In one implementation, it may be advantageous to provide a non-metal layer between the primary layer  704  and the outer protective layer  706 . The non-metal layer may be able to better protect the primary layer  704  and may be able to be removed following fabrication and assembly with less damage or degradation to the resulting exposed surface of the primary layer  704 . 
       FIG. 8  is a process flow diagram which illustrates a method  800  of forming a multi-layer structure in accordance with another embodiment of the invention. The multi-layer structure can be used as part of an overall assembly that is suitable for use in an electronic device. The multi-layer structure having one or more metal layers along with a protective layer. For example, the multi-layer structure can, for example, be the housing structure  700  illustrated in  FIG. 7 . 
     According to the method  800 , a multi-layer substrate having a protective layer is obtained  802 . For example, the multi-layer substrate is a substrate having one or more layers of metal as well as a protective layer. As an example, the protective layer can be a metal. Once the multi-layer substrate has been obtained  802 , one or more structures can be formed  804  using the multi-layer substrate. As an example, one structure that can be formed using the multi-layer substrate is a housing for an electronic device. Subsequently, the protective layer can be removed  806 , thereby exposing the underlying metal layer of the multi-layer substrate. 
       FIG. 9A  is a cross-sectional side-view diagrammatic representation of a housing structure  900  according to one embodiment of the invention. The housing structure  900  includes a multi-layer material  902 . The multi-layer material  902  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  902  has an outer layer  904 , an inner layer  906 , and an intermediate layer  908 . The outer layer  904  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). The inner layer  906  is normally not visible once the housing and/or electronic device is fabricated. The intermediate layer  908  can operate to facilitate formation of internal features using portions of the inner layer  906 . The intermediate layer  908  can also be referred to as a filler layer. 
     In one embodiment, the outer layer  904  and the inner layer  906  are metal layers. In one implementation, the intermediate layer  908  is also metal. In another implementation, the intermediate layer  908  is not metal. The outer layer  904 , the inner layer  906  and the intermediate layer  908  can be laminated together, such as in a multi-layer sheet. The outer layer  904  and the inner layer  906  can utilize different metals. If different metals are used, the properties or characteristics of the different layers  904  and  906  can be advantageously utilized to form housings. In one example, the outer layer  904 , the inner layer  906  and the intermediate layer  908  can be stainless steel. 
       FIG. 9B  is a cross-sectional side-view diagrammatic representation of a housing structure  920  according to one embodiment of the invention. The housing structure  920  includes a multi-layer material  922 . The multi-layer material  922  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  922  shown in  FIG. 9B  represents one embodiment of the multi-layer material  902  after internal features have been formed. The multi-layer material  922  has an outer layer  924 , an inner layer  926 , and an intermediate layer  928 . The outer layer  924  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). The inner layer  926  is normally not visible once the housing and/or electronic device is fabricated. The intermediate layer  928  can operate to facilitate formation of internal features using portions of the inner layer  926 . The intermediate layer  928  can also be referred to as a filler layer. 
     To facilitate formation of the features using the inner layer  926 , the intermediate layer  928  can have a pre-formed pattern. In one embodiment, the pre-formed pattern can be provided to the intermediate layer  928  prior to formation of the multi-layer material  922 . For example, the pre-formed pattern can include a number of void regions where the intermediate layer  928  has a void or opening. Alternatively, instead of having a pre-formed pattern, the intermediate layer  928  can be processed to separate the inner layer  926  from the intermediate layer  928  (and correspondingly also separate from the outer layer  924 ) at selected regions. For example, such processing to separate the inner layer  926  from the intermediate layer  928  could, for example, drill or etch away localized regions of the intermediate layer  928 . In any case, through use of the pre-formed pattern or processing, selected portions of the inner layer  926  can be formed into internal features. As illustrated in  FIG. 9B , selected portions of the inner layer  926  can be physically manipulated, such as through bending, to form internal features  930 . The internal features  930  can be utilized as binding features or attachment features to assist in the assembly of a housing that utilizes one or more other parts that are to be attached or bounded to the housing structure  920 . As illustrated in  FIG. 9B , the internal features  930  can be geometrically complex internal features that are suitable for operation as binding features or attachment features. 
       FIG. 9C  is a cross-sectional side-view diagrammatic representation of a housing structure  940  according to one embodiment of the invention. The housing structure  940  includes a multi-layer material  942 . The multi-layer material  942  can, for example, represent a material utilized as a housing, such as a housing of an electronic device. The multi-layer material  942  shown in  FIG. 9C  represents one embodiment of the multi-layer material  942  after internal features have been formed. The multi-layer material  942  has an outer layer  944 , an inner layer  946 , and an intermediate layer  948 . The outer layer  944  can serve as the outer surface of the housing and can be referred to as a cosmetic layer (or cosmetic surface). The inner layer  946  is normally not visible once the housing and/or electronic device is fabricated. The intermediate layer  948  can operate to facilitate formation of internal features using portions of the inner layer  946 . The intermediate layer  948  can also be referred to as a filler layer. 
     To facilitate formation of the features using the inner layer  946 , the intermediate layer  948  can have a pre-formed pattern. In one embodiment, the pre-formed pattern can be provided to the intermediate layer  948  prior to formation of the multi-layer material  942 . For example, the pre-formed pattern can include a number of void regions where the intermediate layer  948  has a void or opening. Alternatively, instead of having a pre-formed pattern, the intermediate layer  948  can be processed to separate the inner layer  946  from the intermediate layer  948  (and correspondingly also separate from the outer layer  944 ) at selected regions. For example, such processing to separate the inner layer  946  from the intermediate layer  948  could, for example, drill or etch away localized regions of the intermediate layer  948 . In any case, through use of the pre-formed pattern or processing, selected portions of the inner layer  946  can be formed into internal features. As illustrated in  FIG. 9C , selected portions of the inner layer  946  can be physically manipulated, such as through hydro-formation, to form internal features  950 . For example, hydro-formation at the selected portion of the inner layer  946  can be physically altered to form internal ribs or other shapes. The internal features  950  can be utilized as binding features or attachment features to assist in the assembly of a housing that utilizes one or more other parts that are to be attached or bounded to the housing structure  940 . As illustrated in  FIG. 9C , the internal features  950  can be geometrically complex internal features that are suitable for operation as binding features or attachment features. 
       FIG. 10  is a process flow diagram which illustrates a method  1000  of forming a multi-layer structure in accordance with another embodiment of the invention. The multi-layer structure can be used as part of an overall assembly that is suitable for use in an electronic device. The multi-layer structure is a multiple layer metal part with an intermediate layer provided between inner and outer metal layers. For example, the multi-layer structure can, for example, be the housing structure  900  illustrated in  FIG. 9A . 
     According to the method  1000 , a multi-layer metal substrate is obtained  1002 . For example, the multi-layer metal substrate is a substrate having two or more layers of metal (e.g., an inner layer and an outer layer) as well as an intermediate layer. Next, the multi-layer metal substrate can be processed  1004  to facilitate internal features. In this regard, depending upon the intermediate layer, processing  1004  can be utilized to separate regions of the inner layer of the multi-layer metal substrate from the intermediate layer as well as the outer layer of the multi-layer metal substrate. For example, if the intermediate layer is pre-punched, the processing  1004  may not be required since upon formation of the multi-layer metal substrate, regions where the inner layer is already separated from the intermediate layer (and outer layer). However, in the case in which the intermediate layer is not pre-punched, the processing  1004  can drill or etch way localized regions of the intermediate layer so as to separate the inner layer from the outer layer at such regions. Following the processing  1004 , if any, internal features can be formed  1006  from the inner layer. Here, the internal features are formed  1006  from the inner layer at the regions where the inner layer is or has been separated from the outer layer (and intermediate layer). As an example, following the formation of  1006  of the internal features, the multi-layer metal substrate can correspond to the housing structure  920  illustrated in  FIG. 9B  or the housing structure  940  illustrated in  FIG. 9C . 
     Additional information on housings having multiple layers can be found in: (i) U.S. patent application Ser. No. 11/964,652, filed on Dec. 26, 2007, entitled “Methods and Systems for Forming a Dual Layer Housing”, which is incorporated herein by reference for all purposes; and (ii) U.S. Provisional Patent Application No. 60/949,780, filed on Jul. 13, 2007, entitled “Dual Layer Housing”, which is incorporated herein by reference for all purposes. 
     The many features and advantages of the present invention are apparent from the written description. Further, since numerous modifications and changes will readily occur to those skilled in the art, the invention should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.

Metadata:
Filing Date: 20121018
Publication Date: 20140909
Grant Date: 20140909
Priority Date: 20080124
Inventors: LYNCH STEPHEN B.
FILSON JOHN B.
ZADESKY STEPHEN P.
WEBER DOUGLAS J.
Assignee: APPLE INC
CPC Classifications: [{"code": "B32B7/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T156/1028", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B3/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B15/043", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2307/304", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T156/1041", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B15/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/12347", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B3/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/5313", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2457/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B15/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/12493", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T428/12347", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T428/12201", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B15/043", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B15/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/5313", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2307/304", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K5/0086", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B2307/734", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T428/12271", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B15/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B3/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B7/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T156/1028", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T428/12271", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/53174", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T428/12493", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B3/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/53174", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K7/1401", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T428/12201", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2307/734", "inventive": false, "first": false, "tree": "[]"}, {"code": "B32B2457/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T156/1041", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 40898985