PATENT DOCUMENT

Publication Number: US-8738104-B2
Application Number: US-17207308-A
Country: US
Kind Code: B2

Title: Methods and systems for integrally trapping a glass insert in a metal bezel

Abstract:
Methods and apparatus for creating an overall assembly formed from a transparent member and a metal member are disclosed. According to one aspect of the present invention, a method includes positioning a transparent member in a mold configured for insertion molding, and providing a liquid metal into the mold. The method also includes hardening the liquid metal in the mold. Hardening the liquid metal includes binding the metal to the transparent member to create the integral assembly.

Claims:
What is claimed is: 
     
       1. An apparatus comprising:
 an insert piece, the insert piece including a first channel; 
 a metal member comprising an amorphous alloy, the metal member including a second channel; and 
 a compliant material, the compliant material being arranged in the first channel and the second channel, wherein the compliant material couples the insert piece to the metal member. 
 
     
     
       2. The apparatus of  claim 1  wherein the insert piece comprises glass, ceramic or plastic and the compliant member comprises a material selected from a group including a silicon, a rubber, a thermoplastic elastomer, poron, and any combination thereof. 
     
     
       3. The apparatus of  claim 1 , wherein the amorphous alloy maintains a liquid state at a temperature that is not sufficient to cause significant softening of the insert piece. 
     
     
       4. The apparatus of  claim 1 , wherein the insert piece is transparent. 
     
     
       5. An electronic device comprising:
 an assembly, the assembly comprising a metal member and an insert piece with substantially no voids disposed therebetween, the metal member and the insert piece cooperating to define an exterior portion of the electronic device; and 
 at least one electronic element, the at least one electronic element being arranged to be at least partially covered by the assembly, wherein the metal member comprises an amorphous alloy; and wherein a thermal expansion rate of the metal member is approximately equal to a thermal expansion rate of the insert piece. 
 
     
     
       6. The electronic device of  claim 5  wherein the insert piece comprises glass, ceramic or plastic. 
     
     
       7. The electronic device of  claim 6  wherein the metal member comprises a bezel. 
     
     
       8. The electronic device of  claim 5  wherein the electronic device comprises a cellular phone device. 
     
     
       9. The electronic device of  claim 5 , wherein the metal member forms all or some portion of an entire housing of the electronic device. 
     
     
       10. The electronic device of  claim 5 , wherein the electronic device comprises an electrical and/or communication component. 
     
     
       11. The electronic device of  claim 5 , wherein the amorphous alloy maintains a liquid state at a temperature that is not sufficient to cause significant softening of the insert piece. 
     
     
       12. The electronic device of  claim 5 , further comprising at least one layer of a compliant material at an edge of the insert piece. 
     
     
       13. The electronic device of  claim 12  wherein the insert piece includes a first channel and the metal member includes a second channel, and a gasket is positioned at least partially in the first channel and at least partially in the second channel. 
     
     
       14. The electronic device of  claim 5 , wherein the electronic device comprises a computer, a laptop, a handheld computing device, a media player, a phone, a remote control, or any combination thereof. 
     
     
       15. The electronic device of  claim 5 , wherein the insert piece is transparent. 
     
     
       16. An integral assembly comprising: an insert piece and a metal member; wherein the metal member comprises an amorphous alloy and binds to the insert piece to create the integral assembly; and wherein a thermal expansion rate of the metal member is approximately equal to a thermal expansion rate of the insert piece. 
     
     
       17. The integral assembly of  claim 16 , wherein the insert piece is transparent. 
     
     
       18. An apparatus for forming an integral assembly comprising an insert piece and a metal member; wherein the metal member comprises an amorphous alloy, the apparatus comprising:
 an arm to position the insert piece in a mold; and 
 a metal injector to provide the amorphous alloy around the insert piece in the mold to form the metal member such that the metal member binds to the insert piece to create the integral assembly. 
 
     
     
       19. The apparatus of  claim 18  wherein the apparatus is configured to maintain the amorphous alloy in a liquid state at a temperature that is not sufficient to cause significant softening of the insert piece. 
     
     
       20. The apparatus of  claim 18  wherein the apparatus is configured to center the insert piece relative to the metal member. 
     
     
       21. The apparatus of  claim 18  wherein the apparatus comprises a metal injection molding (MIM) equipment. 
     
     
       22. The apparatus of  claim 21 , wherein the MIM equipment is configured to shrink or bake the amorphous alloy around the insert piece. 
     
     
       23. The apparatus of  claim 18 , wherein the insert piece is transparent.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority benefit of: (i) U.S. Provisional Patent Application No. 60/949,449, filed Jul. 12, 2007, and entitled “Insert Molding Liquid Metal Around Glass,” which is hereby incorporated herein by reference; and (ii) U.S. Provisional Patent Application No. 61/013,600, filed Dec. 13, 2007, and entitled “Methods and Systems for Integrally Trapping a Glass Insert in a Metal Bezel,” which is hereby incorporated herein by reference 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to methods and systems for creating integral glass and metal parts. 
     2. Description of the Related Art 
     During the manufacture of electronic devices such as cellular telephones, digital music players, and handheld computing devices, transparent components are often held within housings or the like. By way of example, many electronic devices have displays that include glass or plastic windows which are held by a metal housing. Typically, a metal frame or housing is formed, and a glass component or a plastic component is inserted into the formed frame or housing. 
     In order to properly secure a metal frame and a glass component together, the tolerances associated with the fit between the metal frame and the glass component must be strictly maintained. That is, the tolerance matches between the metal frame and the glass component are maintained such that the glass component may be inserted into the metal frame and held in place. An overall assembly that includes a metal frame and a glass component inserted therein may be held together by a press fit, using adhesive materials, and/or using mechanical structures such as screws. If the tolerance matches between the metal frame and the glass component are not strictly maintained, the integrity of the overall assembly may be compromised. For relatively small assemblies, maintaining critical tolerances between metal frames and glass components such that tolerance mismatches are unlikely to occur may be difficult. 
     Therefore, what is needed is a method and an apparatus which allows for the tolerances associated with a metal frame and a glass component, or a metal frame and a plastic component, to be substantially relaxed. 
     SUMMARY OF THE INVENTION 
     The present invention pertains to techniques that enable an assembly that includes a transparent member that is integrally formed with a metal member. 
     The present 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. 
     According to one aspect of the present invention, a method includes positioning a transparent member in a mold configured for insertion molding, and providing a liquid metal into the mold. The method also includes hardening the liquid metal in the mold. Hardening the liquid metal includes binding the metal to the transparent member to create the integral assembly. 
     In accordance with another aspect of the present invention, a method for forming an integral assembly includes positioning a transparent member in a mold and using a metal injection molding (MIM) process to provide metal around the transparent member. The method also includes shrinking the metal at least partially around the transparent member to bind the metal to the transparent member to create the integral assembly. In one embodiment, shrinking the metal includes shrinking the metal by between approximately twenty percent and approximately thirty percent. 
     According to still another aspect of the present invention, a method includes applying at least one layer of a compliant material to an edge of a transparent member. A compliant material is bound to an edge of a metal member arrangement. Binding the compliant material to the edge of the metal member arrangement creates an overall assembly. In one embodiment, the compliant material is a gasket. 
     In accordance with yet another aspect of the present invention, an apparatus includes a transparent member, a metal member, and a compliant member. The transparent member includes a first channel, and the metal member includes a second channel. The compliant material is arranged in the first channel and the second channel such that the complaint material couples the transparent the transparent member to the metal member. 
    
    
     
       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. 1  is a process flow diagram which illustrates a method of creating an integral assembly that includes a metal member and a transparent member, e.g., glass, using an insertion molding process in accordance with an embodiment of the present invention. 
         FIG. 2  is a process flow diagram which illustrates one method of forming metal to a transparent member such as a glass plate in accordance with an embodiment of the present invention. 
         FIG. 3  is a process flow diagram which illustrates one method of creating an integral assembly that involves a metal injection molding (MIM) process in accordance with an embodiment of the present invention. 
         FIG. 4A  is a diagrammatic cross-sectional side-view representation of a transparent member that may be included in an integral assembly in which channels have been formed in accordance with an embodiment of the present invention. 
         FIG. 4B  is a diagrammatic perspective representation of a transparent member, e.g., transparent member  404  of  FIG. 4A , in which channels of a first configuration have been formed in accordance with an embodiment of the present invention. 
         FIG. 4C  is a diagrammatic perspective representation of a transparent member, e.g., transparent member  404  of  FIG. 4A , in which channels of a second configuration have been formed in accordance with an embodiment of the present invention. 
         FIG. 4D  is a diagrammatic cross-sectional side-view representation of an integral assembly which includes a transparent member, e.g., transparent member  404  of  FIG. 4A , and a metal member in accordance with an embodiment of the present invention. 
         FIG. 5A  is a diagrammatic cross-sectional side-view representation of a transparent member that may be included in an integral assembly in which bonding features have been formed in accordance with an embodiment of the present invention. 
         FIG. 5B  is a diagrammatic cross-sectional side-view representation of an integral assembly which includes a transparent member, e.g., transparent member  504  of  FIG. 5A , and a metal member in accordance with an embodiment of the present invention. 
         FIG. 6A  is a diagrammatic cross-sectional side-view representation of an assembly in which a transparent member is inserted within an opening in a metal member in accordance with an embodiment of the present invention. 
         FIG. 6B  is a diagrammatic cross-sectional side-view representation of an assembly, e.g., assembly  600  of  FIG. 6A , in which a transparent member is effectively bonded to a metal member in accordance with an embodiment of the present invention. 
         FIG. 7A  is a diagrammatic cross-sectional side-view representation of a transparent member and a metal member prior to a baking or shrinkage step of a MIM process in accordance with an embodiment of the present invention. 
         FIG. 7B  is a diagrammatic cross-sectional side-view representation of a transparent member and a metal member, e.g., transparent member  704  and metal member  708  of  FIG. 7A  after a baking or shrinkage step of a MIM process in accordance with an embodiment of the present invention. 
         FIG. 8A  is a diagrammatic top view representation of a transparent member on which a layer of compliant material has been formed in accordance with an embodiment of the present invention. 
         FIG. 8B  is a diagrammatic cross-sectional side-view representation of an overall assembly that includes a transparent member and a metal member which are in substantial contact through a layer of compliant material in accordance with an embodiment of the present invention. 
         FIG. 8C  is a diagrammatic top view representation of the overall assembly of  FIG. 8B  in accordance with an embodiment of the present invention. 
         FIG. 9  is a process flow diagram which illustrates a method of forming an overall assembly that includes a transparent member and a metal member that are substantially separated by a layer of compliant material in accordance with an embodiment of the present invention. 
         FIG. 10A  is a diagrammatic representation of a first example of an electronic device that includes an assembly that includes a transparent member and a metal member in accordance with an embodiment of the present invention. 
         FIG. 10B  is a diagrammatic representation of a second example of an electronic device that includes an assembly that includes a transparent member and a metal member in accordance with an embodiment of the present invention. 
         FIG. 10C  is a diagrammatic representation of a third example of an electronic device that includes an assembly that includes a transparent member and a metal member in accordance with an embodiment of the present invention. 
         FIG. 11  is a diagrammatic perspective representation of an electronic device that includes a housing that includes an integrally formed glass and metal part in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Example 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. 
     To facilitate the formation of an overall housing of an electronic device, e.g., a cellular telephone or a digital media player, that includes a window or the like, an integral assembly may be formed to include the window. The integral assembly may be an overall housing in that the overall housing may include a glass member, or a plastic member, and a metal member. Alternatively, the integral assembly may be a part that is arranged to be assembled into an overall assembly, and may include a glass member, or a plastic member, and a metal member. When the integral assembly is a part that is arranged to be assembled into the overall assembly, the metal member may effectively be a bezel that is formed around the edge of a glass member. Although such a bezel may be formed from metal, a bezel may generally be formed from substantially any suitable material including, but not limited to including, a compliant material. 
     The overall housing is integral in that a glass member and a metal, or a plastic member and a metal, form a single, unified piece. A single, unified piece that includes a glass member and a metal are typically formed such that there are effectively no voids, gaps, or spaces between the glass member and the metal. The glass member and the metal are substantially directly bonded together. 
     A variety of different methods may be used to form a bezel around a glass member. By way of example, insertion molding methods and metal injection molding (MIM) methods may be used to integrally form a bezel that engages a glass member. Insertion molding refers to an injection molding technique where plastic is injected into a mold in order to surround an insert piece already located in the mold. According to one embodiment, the invention contemplates using the insert molding technique, but rather than injecting plastic around a metal insert, injecting a metal in liquid form around a glass insert. Once hardened, a single part containing a metal member and a glass member is created. The single part may be, in one embodiment, an integral glass and metal assembly or, more generally, an integral assembly. In one example, the metal member may be a portion of a housing of an electronic device and the glass member may be a glass window of an electronic device. The glass window may be a protective shield that covers a display or touch screen, or it may be substantially integral with a display or touch screen. 
     The metal used in an insertion molding process is typically in liquid form. The metal in liquid form may for example correspond to amorphous alloys, which are metals that may behave like plastic, or alloys with liquid atomic structures. LiquidMetal is one suitable example for the metal in liquid form. Substantially any metal or, more generally, material in liquid form which has a thermal expansion rate that is similar to the thermal expansion rate of liquid metal may be used in an insertion molding process. For example, metals which may be used in an insertion molding process generally include metals that may be injection molded such as steel and aluminum. Other materials from which may be used in an insertion molding process, e.g., to form a bezel around a glass window, may include plastics (e.g., polycarbonate, ABS, etc.) and/or ceramics (e.g., alumina, zirconia, etc.). 
     Although an integral assembly typically includes glass, it should be appreciated that an integral assembly may instead include substantially any suitable transparent material. In general, a suitable transparent material may include any synthetic transparent material, as for example, synthetic sapphire. As previously mentioned, an integral assembly may also include a transparent material such as plastic. 
     The formation of a bezel around a glass member substantially eliminates tolerance issues associated with the bezel and the glass member. Because the material (e.g., metal) used in the bezel is provided in liquid form around the glass member, there is effectively no tolerance that has to be maintained with respect to the bezel. The liquid flows around the edge of the glass member, and when solidified, effectively grabs and adheres to the glass member. 
     In lieu of insertion molding material around a glass insert to form an integral assembly, an integral assembly may instead be formed by effectively trapping a glass insert within a heated metal bezel such that when the metal bezel cools, the metal bezel “grabs” onto the glass insert. That is, a MIM process may be used to mold metal around a glass insert such that the metal forms onto the glass insert, and to bake or sinter the metal such that the metal shrinks and holds the glass insert to form an integral assembly. Put another way, utilizing thermal expansion/contraction, the metal bezel is essentially shrink wrapped about the glass member. 
       FIG. 1  is a process flow diagram which illustrates a method of creating an integral assembly that includes a metal member and a transparent member, e.g., glass, using an insertion molding process in accordance with an embodiment of the present invention. A process  101  of forming an integral assembly that includes metal and a transparent member begins at step  105  in which a transparent member is obtained and prepared. It should be appreciated that although a transparent member is typically glass, substantially any transparent member may be provided in the mold cavity in lieu of a glass member. In other words, the transparent member may be, but is not limited to being, glass. 
     Preparing a transparent member for an insertion molding process may include creating retaining features at the edges of the glass plate member. The retaining features provide areas where metal can be molded relative to the transparent member, thereby increasing the strength of the coupling between the two materials. By way of example, the retaining features may be glass protrusions and/or voids formed in the edges of the transparent member. The protrusions and voids may include undercuts to further aid in coupling by providing features that may be molded around. The retaining features may be widely varied. For instance, the retaining features may be macro or micro, and a variety of techniques may be used to create such macro or micro retaining features. The retaining features may be formed using techniques including, but not limited to including, etching, machining, microperfing, and the like. Examples of retaining features will be discussed below with reference to  FIGS. 4A-D  and  FIGS. 5A-B . It should also be appreciated that retaining features may not be necessary in some situations, as the mold interface and/or the mold around may provide sufficient retention forces. 
     In step  109 , the transparent member is provided to a mold cavity of an overall mold apparatus. The mold is typically configured for an insertion molding process. The transparent member may, for example, be positioned within the mold cavity when the mold is opened such that the transparent member may be accommodated therein. The transparent member may be positioned or otherwise located at its desired position relative to the mold cavity and, thus, relative to the intended location of a metal member, which will couple thereto. The positioning of the transparent member within the mold cavity may be accomplished, for example, with a robot arm. It should be appreciated that providing the transparent member in the mold cavity may include performing additional steps such as preparing the mold cavity and transparent member for subsequent steps by adjusting a temperature within the mold cavity and closing the mold. In one example, if the thermal properties of the transparent material and metal to be insert molded do not substantially match, then providing the transparent member to the mold cavity may include heating the transparent member to a desired temperature. The mold cavity may have a shape that forms the desired or near net shape of the metal member. However, it should be appreciated that post processing steps may be used to clean up and/or substantially change the final shape of the metal member (e.g., machining, polishing, sandblasting, etc.). Generally, the mold cavity is larger than the transparent member at the region where the two members interface (as for example around the edges of the transparent member). 
     From step  109 , process flow moves to step  113  in which liquid metal, or metal in a liquid form, is provided to the mold cavity. Although liquid metal is described, those of skill in the art will understand that substantially any liquid material which is capable of effectively bonding to the transparent material may be provided instead of liquid metal. The transparent member and the liquid metal are typically pre-selected to work together. For example, the transparent member and the liquid metal may be selected such that they have similar rates of thermal expansion. Additionally, the transparent material and liquid metal may be selected such that the temperature at which the transparent material softens is not significantly lower than the temperature at which the liquid metal maintains a liquid state. The transparent material and the liquid metal may be selected such that the temperature to which the transparent material and the liquid metal are heated, as for example to enable the liquid metal to maintain a liquid state, is not sufficient to cause significant softening of the transparent material. In one embodiment, the transparent material may have a softening point that is higher than the softening point of tempered glass. In some cases, the transparent material may be treated to help with this process. 
     After the liquid metal is provided to the mold cavity, a metal on transparent member molding technique is performed in step  117  in order to form a single, integral part. One metal on transparent member molding technique will be described below with reference to  FIG. 2 . When the transparent member is glass, the single, integral assembly may be a single, unified metal/glass part. For example, the glass is inserted into the mold, and then the liquid metal is injected into the mold and allowed to harden around the glass. Typically, molten metal in liquid form is flowed into the mold, allowed to surround the transparent member as appropriate, and cooled. Once solidified, the single, integral assembly that includes metal and transparent components may be ejected from the mold in step  121 . That is, once the metal cools and hardens substantially around the transparent member, the mold may be opened, and ejectors may release the integral assembly from the mold. It should be appreciated that the liquid metal may be molded to all or some portion of the transparent member. It may be molded to a front surface, back surface, and/or side surfaces depending on the needs of the final integral assembly. In one example, the liquid metal is molded to the side of a substantially planar glass member (e.g., to an edge portion). In this example, the liquid metal may substantially only contact the edge portion and/or it may partially wrap around one or both planar surfaces of the transparent member (e.g., front surface and/or back surface). 
     Finishing steps are performed on the single, integral assembly or molded part in step  125 . By way of example, finishing steps may include, but are not limited to including, sandblasting the integral assembly or some portion thereof, grinding the integral assembly or some portion thereof, machining the integral assembly or some portion thereof, polishing the integral assembly or some portion thereof, adding coatings to the integral assembly or some portion thereof, and the like. In general, finishing steps may be performed with respect to the integral assembly such that finishing steps are performed individually on the metal member and on the transparent member, or such that finishing steps may be performed on both the metal member and the transparent member. 
     Once finishing steps are performed on the integral assembly, the integral assembly is assembled into an electronic device in step  129 . In one example, the metal member is a housing component of the electronic device, while the transparent member is arranged to form a window or a screen of the electronic device. The process of forming an integral assembly is essentially completed once the integral assembly is assembled into an electronic device. The metal member may form all or some portion of the entire housing of the electronic device (e.g., all or some portion of a bezel). The metal member may include retention features for attachment to other portions of a housing of the electronic device. These retention features may include, but are not limited to including, snap features, fasteners, or the like. The retention features may be molded during step  113 , or they may be formed in post processing steps, as for example through machining the metal member or welding or otherwise attaching the features to the metal member. 
     In one embodiment, a transparent member is a glass plate, and the mold cavity forms the shape of a housing component of an electronic device. The mold cavity may instead form the shape of a bezel that effectively holds a glass plate is arranged to be incorporated into a housing of an electronic device. An electronic device into which an integral assembly that includes a transparent member and a metal member may include, but is not limited to including, substantially any electronic device that includes a glass window as for example computers, laptops, and handheld computing devices such as media players, phones, remote controls, and the like. In one example, the bezel surrounds the entire edge of the glass plate. It should be appreciated, however, that this is not a limitation and that the bezel may only cover a portion of the edge in either a continuous manner or a discrete points or lengths about the edge depending on the needs of the device. It should also be appreciated that the edge is not a limitation and that the bezel may cover other areas of the glass plate including, for example, the front and back surfaces. 
       FIG. 2  is a process flow diagram which illustrates one method of forming metal to a transparent member such as a glass plate in accordance with an embodiment of the present invention. A process  201  of forming a metal on transparent member assembly begins at step  205  in which parameters for a metal to transparent member insertion molding process are selected. The parameters may include mold parameters, parameters associated with the transparent member and metal parameters associated with a molding process. The parameters may also include mold configuration parameters, glass properties, and metal properties. It should be appreciated that parameters associated with the properties of a transparent member and properties of a metal member often selected prior to the transparent member being positioned in a mold cavity. 
     In one embodiment, selecting parameters may include substantially matching a thermal expansion rate of the transparent member to a thermal expansion rate of the metal. In the event that the thermal expansion rates of the transparent member and the metal do not substantially match, selecting parameters may include determining whether the transparent member should be heated or cooled differently than the metal to effectively compensate for dissimilar thermal expansion rates. The selection of parameters may further include selecting temperatures associated with the insertion molding process. Selecting temperatures may include selecting an appropriate temperature at which the insertion molding process occurs such that the transparent member is not significantly softened, while the metal flows in a liquid form. 
     Once parameters are selected in step  205 , process flow moves to step  209  in which metal in liquid form is injected into the mold cavity. The metal in liquid form may, for example, be a molten metal alloy. One suitable example for the metal in liquid form is LiquidMetal, although it should be appreciated that LiquidMetal is but one example of a metal in liquid form that may be suitable for use in an insertion molding process. 
     In step  213 , the metal in liquid form is allowed to flow, harden and attach to the transparent member inside the mold cavity. For example, the metal in liquid form may flow within the mold cavity and come into contact with one or more edges of the transparent member. It should be appreciated that relatively complex metal shapes may be molded around the transparent member. By way of example, the metal in liquid form may be configured to substantially surround all the edges of the transparent member to thereby effectively trap or otherwise integrally engage the transparent member within the confines of a metal member formed from the metal in liquid form. Upon allowing the metal to attach to the transparent member, the process of forming a metal on transparent member assembly is completed. 
     As previously mentioned, a MIM process may be used to form an integral assembly that includes a transparent member and a metal member. With reference to  FIG. 3 , a method of creating an integral assembly that involves a MIM process will be described in accordance with an embodiment of the present invention. A process  301  of forming an integral assembly that includes metal and a transparent member begins at step  305  in which a transparent member is obtained and prepared. Preparing a transparent member for a MIM process may include creating retaining features at the edges of the glass plate member. 
     The transparent member is provided to a mold cavity of an overall mold apparatus in step  305 . Then, in step  313 , a MIM process is used to provide metal substantially around the transparent member, as will be discussed below with reference to  FIG. 7A . The metal may be provided as metal powder that is mixed with a binder. After the metal is provided, the MIM process is used to center the transparent member as appropriate relative to the metal in step  317 . In one embodiment, centering may include positioning the transparent material such that when the metal adheres to the transparent material and subsequently shrinks, the metal forms a bezel or housing around the transparent material. 
     In one embodiment, centering may occur at a temperature of approximately two thousand degrees Fahrenheit, although the temperature may vary depending upon the materials which are actually used. Hence, the transparent material may be selected such that its softening point is not significantly lower than the temperature at which centering may occur. Additionally, the transparent material and the metal may be selected such that their coefficients of thermal expansion are relatively close. Selecting a transparent material with a coefficient of thermal expansion that is relatively close to the coefficient of thermal expansion of the metal typically reduces internal stresses associated with an integral assembly that is subsequently formed from the transparent material and the metal. 
     From step  317 , process flow moves to step  321  in which the MIM process is used to shrink or bake the metal around the transparent material. In general, the metal may shrink between approximately twenty percent and approximately thirty percent. Once the metal shrinks, an integral assembly that includes a transparent member and a metal member is formed. The integral assembly may be ejected from the mold in step  325 . Ejecting the integral assembly may include opening the mold, and ejecting the integral assembly from the mold. 
     Finishing steps are performed on the single, integral assembly or molded part in step  329 . By way of example, finishing steps may include, but are not limited to including, machining the integral assembly, polishing the integral assembly, adding coatings to the integral assembly, and the like. After finishing steps are performed on the integral assembly, the integral assembly is assembled into an electronic device in step  333 , and the process of forming an integral assembly is essentially completed. 
     A transparent member, e.g., a glass member, that is a part of an integral assembly may include attachment features as mentioned above. For instance, the retaining features may be protrusions and/or voids formed in the edges of the transparent member. The protrusions and voids may include undercuts to further aid in coupling.  FIG. 4A  is a diagrammatic cross-sectional side-view representation of a transparent member which includes undercuts in accordance with an embodiment of the present invention. A transparent member  404  includes a at least one channel  412  on edges of transparent member  404  which are arranged or configured to come into contact with a metal member (not shown). Each channel  412  channel is dimensioned for receiving liquid metal. As shown in  FIG. 4B , channels  412 ′ may be continuous channels formed in transparent member  404 ′. Alternatively, as shown in  FIG. 4C , channels  412 ″ may be segmented on each edge of transparent member  404 ″ that is configured to come into contact with metal. In another embodiment, a transparent member may include a plurality of discrete cavities such as dimples along each edge in contact with metal. The channels and cavities may be evenly spaced or placed asymmetrical locations relative to each other. The location of such channels and/or cavities generally depends on the desired needs of the interface between a transparent member and metal. 
     The channels and cavities can be formed in a variety of ways. In one example, channels and cavities are formed via machining or cutting operations. Alternatively, they may be formed with a cutting beam such as a laser or water jet stream. It should be noted that the invention is not limited to using cavities or channels to facilitate the bonding of a transparent member to a metal member. For example, the transparent member may include pegs or dovetails that are embedded in the edge of the transparent member. Alternatively, an intermediate member can be attached to the edge of the transparent member. For example, a metal to glass adhesion layer may be applied to the edge of a glass member. In one example, a material such as COVAR manufactured by Corning may be used. The channels may also be formed via chemical processes such as etching. 
       FIG. 4D  shows an integral assembly that includes transparent member  404  of  FIG. 4A  and a metal member in accordance with an embodiment of the present invention. Integral assembly  400  includes a metal member  408  that is effectively molded into channels  412  of transparent member  404 . Metal member  408  is bonded to edges of transparent member  404  and in channels  412 . Channels  412  lock metal member  408  into place with respect to transparent member  404  in multiple directions, thereby significantly securing metal member  408  to transparent member  404 . For an embodiment in which metal member  408  is shrink wrapped to transparent member  404 , channels  412  may further provide a aligning effect, which helps center metal member  408  with respect to transparent member  404 . 
     The shape of channels  412  may be widely varied. A channel  412  may be rectilinear, thereby having angled, chamfered and/or straight, perpendicular side walls. A channel  412  may also be curvilinear, thereby having curved contoured walls (as shown). In one embodiment, a channel  412  may have inwardly tapering walls that narrow relative to depth (whether rectilinear or curved), and may provide ease of flow during the molding processes. It should be appreciated, however, that outwardly tapering walls that spread out relative to depth (whether rectilinear or curved) may also be used. Such an implementation may provide better retention forces between metal member  408  and transparent member  404 . It should also be noted that a combination of rectilinear and curvilinear channels  412  may be used. In addition, it should further be noted that channels  412  may be formed as various complex grooves such as reverse T shapes (small upper channel, larger lower channel), or vice versa. The exact configuration of channels  412  may depend on the characteristics and attributes of metal member  408  and transparent member  404 . In the illustrated embodiment, channels  412  are substantially curves that taper inwardly from at least two opposing sides, while the other opposing sides of the channels are effectively straight walls. 
     In another embodiment, the edge of a transparent member may include a protrusion that extends away from the edge and is arranged to be molded over.  FIG. 5A  is a diagrammatic cross-sectional side-view representation of a transparent member that may be included in an integral assembly in which bonding features such as a protrusion have been formed in accordance with an embodiment of the present invention. A transparent member  504  includes protrusion  514  that are arranged to be molded over. As shown in  FIG. 5B , protrusion  514  may be molded over by a metal member  508  such that an integral assembly  500  is formed. 
     Like the channels described above, the shape of protrusion  514  may be widely varied. Protrusion  514  may be rectilinear having angled, chamfered and/or straight perpendicular side walls. Protrusion  514  may also be curvilinear having curved contoured walls (as shown). Inwardly tapering walls that narrow relative to depth (whether rectilinear or curved) may provide ease of flow during the molding processes. It should be appreciated, however, that outwardly tapering walls that spread out relative to depth (whether rectilinear or curved) may also be used (reverse trapezoid). Such an implementation may provide better retention forces between metal member  508  and transparent member  504 . It should also be noted that a combination of rectilinear and curvilinear shapes may be used. Further, it should also be noted that protrusion  514  may be formed as various complex dovetails such as T shapes (small lower channel, larger upper channel) or vice versa. The exact configuration may depend on the characteristics and attributes of metal member  508  and transparent member  514 . 
     In the illustrated embodiment, protrusions  514  are chamfers that taper inwardly from at least two opposing edges of transparent member  504 . In the illustrated example, the tapered portions meet at a point. It should be appreciated, however, that the tapered portions may instead meet at a plateau region that is substantially flat. 
     It should be appreciated that retaining features are not limited to protrusions or channels, and may be a combination of the two embodiments. For example, a first set of opposing edges may include protrusions while a second set of opposing edges may include channels. In another example, each edge may include a combination of protrusions and channels. For example, an edge may include alternating discrete regions dedicated to channels and protrusions. 
       FIGS. 6A and 6B  show an alternate embodiment for positioning a glass plate member within an opening in a metal member in accordance with the present invention. In this embodiment, as shown in  FIG. 6A , a gasket  620  is placed at the interface between the edge of a metal member  608  and a transparent member  604 . In general, transparent member  604  is positioned within an opening in metal member  608 . For example, the outer shape of transparent member  604  may generally coincide with the inner shape of metal member  608  (minus some small tolerance, which allows transparent member  604  to be fit therein). For example, metal  608  member may be in the form of a ring which may have a rectilinear shape, curvilinear shape or both, and transparent member  608  may be a platform that has an outer shape that is substantially the same as the open area of the ring. In this embodiment, metal member  608  includes a channel or cut-out  612   b  and transparent member  604  includes a channel or cut-out  612   a  that are arranged to accommodate gasket  620 . Gasket  620  is configured to have two states. The first state for gasket  620  is shown in  FIG. 6A , while the second state for gasket  620  is shown in  FIG. 6B . The shape of gasket  620  in the second state may be configured to substantially conform to the shape of the cut-outs  612   a ,  612   b.    
     In the first state, a cross section of gasket  620  is reduced or shrunk within cut-out portions  612   a ,  612   b . In the second state, as shown in  FIG. 6B , the cross section of gasket  620 ′ is substantially expanded within cut-out portions  612   a ,  612   b . Because of its expanded state, gasket  620 ′ provides a biasing force between metal member  608  and transparent member  604  from opposing edges that helps trap or otherwise secure transparent member  604  within the opening in metal member  608 . In essence, gasket  620  is an expandable continuous biscuits joiner. In one embodiment, gasket  620  changes form the first state to the second state based on a reaction parameter such as heat or chemicals. For example, heat may be applied to a cooled reduced gasket  620  in order for it to expand into expanded gasket  620 ′. Once in the expanded state, the expanded form of gasket  620 ′ may be substantially permanent, or may be arranged to be transitioned back to a reduced state if another reaction is performed, e.g., if cold is applied. Gasket  620  may also be configured to react to other parameters such as electrical stimulus, magnetism and the like. In one example, a stimulus such as heat or electricity may be applied through metal member  608 . 
     Gasket  620  may be formed from a flexible or rigid material. Additionally, it may be a soft or hard material or configuration. In one example, gasket  620  is formed from a shape memory material or shape changing material. 
     The gasket concept, or an embodiment which includes a gasket such as gasket  620 , may be utilized with molding or MIM concepts. In fact, the heat supplied by these processes via a metal member may provide the state changing stimulus. 
     When a MIM process is used to form an integral assembly, a metal member may be sized such that when the metal member shrinks, the metal member engages a transparent member.  FIG. 7A  is a diagrammatic cross-sectional side-view representation of a transparent member and a metal member prior to a baking or shrinkage step of a MIM process in accordance with an embodiment of the present invention. A transparent member  704  is positioned with respect to a metal member  708  such that when metal member  708  shrinks, metal member  708  may engage transparent member  704 . As shown in  FIG. 7B , when metal member  708 ′ shrinks or is baked, metal member  708 ′ shrinks and engages transparent member  704  to form integral assembly  700 . 
     The interface between the metal member  708 ′ and transparent member  704  may be widely varied. Transparent member  704  and metal member  708 ′ may include any combination of protrusions and channels to help lock the two members together. Such protrusions and channels may be similarly configured to any of those embodiments described above. For sake of brevity, these embodiments will not be described again. In the illustrated embodiment, however, transparent member  704  includes a protrusion and metal member  708 ′ includes a channel that receives the protrusion when metal member  708 ′ shrinks or wraps itself about transparent member  704 . The shape of the protrusion may correspond to the shape of the channel. It should also be appreciated that the embodiment shown in  FIGS. 6A and 6B  may also be utilized in the embodiment of  FIGS. 7A and 7B . In one example, a gasket does not provide two states, but rather relies on the two states of a metal member to trap and hold the gasket between the metal member and a transparent member. 
     In one embodiment, an interface may be formed between a transparent member and a metal member, e.g., a bezel, of an overall assembly. Such an interface may be arranged to prevent a transparent member from coming into contact with a metal member when the transparent member is effectively supported by the metal member, e.g., when a glass window is support by a bezel or housing in an overall assembly. An interface may also be arranged to serve as a shock absorbing layer in the vent that a device that includes an overall assembly is dropped. 
     An interface between a transparent member and a metal member may be formed from any suitable compliant material. The compliant material may be applied to the edges of a transparent member and/or appropriate areas on a metal member. Compliant materials include, but are not limited to including, silicon, rubber, thermoplastic elastomers (TPEs), and poron. An interface may be a form, e.g., a form made from foam, that is placed around the edges of the transparent member. Referring next to  FIG. 8A , a transparent member on which a layer of compliant material has been formed will be described in accordance with an embodiment of the present invention. A transparent member  804 , which may be a glass window, includes at least one layer of compliant material  804  that is applied to the edges of member  804 . The amount of compliant material that is applied, and the area of member  804  that is covered by compliant material  810 , may vary widely. By way of example, compliant material  810  may be applied at specific areas along the edge of member  804 . Complaint material  810  may include, but is not limited to including, rubber, silicon, plastic, springs, and the like. 
     Compliant material  810  may be printed onto edges of member  804 , as for example using a Tampa printing technique. Depending upon the thickness desired for compliant material  810 , multiple layers of compliant material  810  may be printed or otherwise applied to member  804 . Once the desired thickness of compliant material  810  is achieved, member  804  may be inserted into an opening in a metal member, e.g., a bezel or a housing. 
       FIG. 8B  is a diagrammatic cross-sectional side-view representation of an overall assembly that includes transparent member  804  and a metal member in accordance with an embodiment of the present invention, and  FIG. 8C  is a diagrammatic top view representation of the overall assembly. A metal member  808  is arranged to adhere or otherwise bond to compliant material  810  such that transparent member  804  may effectively be held by metal member  808  without metal member  808  coming into substantially direct contact with transparent member  804 . By way of example, compliant material  810  may substantially prevent glass to metal contact when transparent member  804  is a glass member. 
     It should be appreciated that in lieu of being applied to edges of a transparent member, a compliant material may instead be applied to areas along the top of a transparent material. Further, the transparent member may include chamfered edges that correspond to chamfered edge portions of an opening in a metal member. 
       FIG. 9  is a process flow diagram which illustrates a method of forming an overall assembly that includes a transparent member and a metal member that are substantially separated by a layer of compliant material in accordance with an embodiment of the present invention. A process  901  forming an overall assembly begins at step  905  in which a transparent member is obtained and prepared. In one embodiment, preparing the transparent member may include chamfering the edges of the transparent member. In step  909 , a metal member is obtained and prepared. Although a metal member is described, it should be appreciated that a metal member is one example of a suitable member which may, together with a transparent member, form an overall assembly. 
     Once the transparent member and the metal member are obtained and prepared, at least one layer of a compliant material is provided on the transparent member and/or the metal member in step  913 . In other words, compliant material may be applied to the transparent member, the metal member, or both. Any suitable method may be used to apply a compliant material including, but not limited to including, printing or screening the compliant material onto the surface of a transparent member and/or a metal member. 
     After the compliant material is applied, the metal member and the transparent member are coupled through the compliant material in step  917 . The coupling may be facilitated through the use of an adhesive material, e.g., a liquid adhesive, and/or a press fit. Then, in step  921 , finishing steps are performed on the overall assembly. Finally, an electronic device is assembled using the overall assembly in step  925 , and the process of forming an overall assembly is completed. 
     As previously discussed, integral assemblies may be assembled into electronic devices, e.g., handheld electronic devices. A handheld electronic device may, for example, be a media player, phone, internet browser, email unit or some combination of two or more of such. A handheld electronic device generally includes a housing and a display area. With reference to  FIGS. 10A-C , electronic devices into which assemblies which include transparent members and metal members, e.g., an integral assembly formed using an insertion molding process, may be assembled will be described in accordance with an embodiment of the present invention. For ease of discussion, the transparent members will be described as glass plate windows, although it should be appreciated that transparent members may be formed from materials other than glass. 
       FIG. 10A  is a diagrammatic representation of a first example of an electronic device that includes a glass/metal assembly in accordance with an embodiment of the present invention. An electronic device  1100 , which may include internal electrical and/or communications components, includes a bezel or housing  1104  and a glass window  1108 . In one embodiment, glass window  108  is integrally formed with bezel or housing  1104 . Housing  1104  may include a bezel portion or, alternatively, housing  1104  may be a bezel. 
     Alternatively, glass window  1108  may be positioned within bezel or housing  1104  of electronic device  1100  such that a layers of a compliant material that are adhered to glass window  1108  and/or bezel or housing  1104  effectively serve as cushioning layers between bezel or housing  1104  and glass window  1108 . 
     Glass window  1108  may generally be arranged or embodied in a variety of ways. By way of example, glass window  1108  may be configured as a protective glass piece that is positioned over an underlying display such as a flat panel display (LCD) or touch screen display (LCD and a touch layer). Alternatively, glass window  1108  may effectively be integrated with a display, i.e., glass window  108  may be formed as at least a portion of a display. Additionally, glass window  1108  may be substantially integrated with a touch sensing device such as a touch layer associated with a touch screen. In some cases, glass window  108  acts as the outer most layer of the display area. 
       FIG. 10B  is a diagrammatic representation of a second example of an electronic device that with a glass/metal part in accordance with an embodiment of the present invention. An electronic device  1100 ′ includes a bezel or housing  1104 ′ and a glass window  1108 ′. In one embodiment, glass window  1108 ′ and bezel or housing  1104 ′ form an integral assembly, i.e., a glass/metal part, that is created by either an insertion molding process or a MIM process. Alternatively, glass window  1108 ′ may be positioned within bezel or housing  1104 ′ of electronic device  1100 ′ such that a layers of a compliant material that are adhered to glass window  1108 ′ and/or bezel or housing  1104 ′ effectively serves as a cushioning layer between bezel or housing  1104 ″ and glass window  1108 ″. As a front surface of electronic device  1100 ′ also includes a click wheel control  1112 , glass window  1108 ′ does not cover the entire front surface of electronic device  1100 ′ Electronic device  11100 ′ essentially includes a partial display area that covers a portion of the front surface. 
       FIG. 10C  is a diagrammatic representation of a third example of an electronic device that includes a glass/metal part in accordance with an embodiment of the present invention. An electronic device  1100 ″ includes a bezel or housing  1104 ″ and a glass window  1108 ″ that substantially fills the entire top surface of electronic device  1100 ″. In one embodiment, glass window  1108 ″ may be positioned within bezel or housing  1104 ″ of electronic device  1100 ″ such that a compliant material effectively serves as a “boundary layer” between bezel or housing  1104 ″ and glass window  1108 ″. In another embodiment, glass window  1108 ″ and bezel or housing  1104 ″ are an integral assembly formed from a process such as insertion molding or MIM. When glass window  1108 ″ and bezel or housing  1104 ″ are an integral assembly, a bond between glass window  1108 ″ and bezel or housing  1104 ″ are directly bonded with substantially no voids or gaps formed therebetween. Housing  1104 ″ may include openings through which a speaker/receiver and/or buttons may be accessed. Housing  1104 ″ may also include an opening or recess within which a display and/or touch screen  1116  is positioned. 
       FIG. 11  is a diagrammatic perspective representation of an electronic device that includes an integrally formed glass and metal part, e.g., a glass and metal part in which the glass and metal components are substantially bonded with no gaps or voids therebetween, in accordance with an embodiment of the present invention. An electronic device  1200  includes a front housing  1204   a  and a back housing  1204   b  that are attached to form an enclosure of electronic device  1200 . Front housing  1204   b  may, for example, include a bezel portion  1206  that surrounds a window  1216  that defines a display region of electronic device  1200 . 
     Front housing  1204   a  and back housing  1204   b  may be formed from similar or dissimilar materials. Examples of materials used in front housing  1204   a  and back housing  1204   b  include, but are not limited to including, plastics, metals, ceramics, glass, and the like. In one embodiment, front housing  1204   a  is formed from at least a first material, and back housing  1204   b  is formed from at least a second material that is different than the first material. For example, front housing  1204   a  may be formed from a first metal such as steel, and back housing  1204   b  may be formed from a second metal such as aluminum. In addition, front housing  1204   a  may be formed from a metal (e.g., steel), and back housing  1204   b  may be formed either substantially entirely or partially with a plastic material (e.g., polycarbonate). Front housing  1204   a  and back housing  1204   b  work together to surround and protect the internal components of electronic device  1200 . Front housing  1204   a  and back housing  1204   b  also form the ornamental shape of electronic device  1200  (e.g., help define the look and feel). Housing parts  1204   a ,  1204   b  may be attached in a variety of ways including, for example, using snaps, screws, adhesives and similar attachment means. 
     Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or the scope of the present invention. By way of example, the steps associated with the methods of the present invention may vary widely. Steps may be added, removed, altered, combined, and reordered without departing from the spirit of the scope of the present invention. 
     The techniques describe herein may be applied to a variety of electronic devices including but not limited handheld electronic devices, portable electronic devices and substantially stationary electronic devices. Examples of these include any known consumer electronic device that includes a display. By way of example, and not by way of limitation, the electronic device may correspond to media players, cellular phones, PDAs, remote controls, notebooks, tablet PCs, monitors, all in one computers and the like. 
     An interface between a metal member, e.g., a metal housing, and a transparent member, e.g., a glass window, may be formed using a variety of different methods. For instance, methods used to provide a material which may be used to effectively fill appropriate channels as discussed above with respect to  FIGS. 6A and 6B  may vary. In one embodiment, a material may be injected into such channels through local holes or openings formed in a metal housing. Such a material may be a plastic, glue, epoxy, silicon, or TPE, although it should be understood that substantially any suitable material may be used. 
     In general, an integral assembly may be used in substantially any electronic device which includes glass members. While mobile telephones such as the iPhone™ available commercially from Apple Inc. of Cupertino, Calif. and digital media players such as the iPod™ available commercially from Apple Inc. have been described, the electronic devices which utilize an integral assembly are not limited to those devices described. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.

Metadata:
Filing Date: 20080711
Publication Date: 20140527
Grant Date: 20140527
Priority Date: 20070712
Inventors: YEATES KYLE H.
Assignee: APPLE INC
CPC Classifications: [{"code": "Y10T29/49826", "inventive": false, "first": false, "tree": "[]"}, {"code": "B22D19/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K7/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T428/2457", "inventive": false, "first": false, "tree": "[]"}, {"code": "B22D19/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "C03C27/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49826", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "C03C27/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B22D19/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T428/2457", "inventive": false, "first": false, "tree": "[]"}, {"code": "B22D19/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "B22D19/04", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 39887443