PATENT DOCUMENT

Publication Number: US-10224661-B2
Application Number: US-201816102529-A
Country: US
Kind Code: B2

Title: Low-profile spring-loaded contacts

Abstract:
Contact structures that are readily manufactured, where contacts in the contact structures provide a sufficient normal force while consuming a minimal amount of surface area, depth, and volume in an electronic device.

Claims:
What is claimed is: 
     
       1. A contact structure comprising:
 a housing having plurality of slots, a top surface, and at least one raised portion extending from the top surface, where the at least one raised portion includes at least one opening; 
 a plurality of contacts, each located in a corresponding one of the plurality of slots, each contact comprising a contacting portion and a midsection portion, wherein the contacting portion of each contact extends through a corresponding opening in the at least one raised portion in the housing; 
 an injection molded portion around the midsection of each contact and adjacent to the housing to secure the plurality of contacts to the housing; and 
 a bottom plate attached to a bottom of the housing. 
 
     
     
       2. The contact structure of  claim 1  wherein the contacting portion of each of the plurality of contacts has a dome shape. 
     
     
       3. The contact structure of  claim 2  wherein each contacting portion is stamped at an end of a contact in the plurality of contacts. 
     
     
       4. The contact structure of  claim 3  wherein each contact in the plurality of contacts comprises a tail portion to attach to a flexible circuit board. 
     
     
       5. The contact structure of  claim 4  wherein the bottom plate is attached to the housing with a first layer of adhesive. 
     
     
       6. The contact structure of  claim 1  wherein the bottom plate is formed of glass. 
     
     
       7. The contact structure of  claim 6  wherein each contact further comprises a flexible arm between the midsection and the contacting portion. 
     
     
       8. The contact structure of  claim 7  wherein for each contact in the plurality of contacts, the flexible arm allows the contacting portion to be depressed towards the bottom plate. 
     
     
       9. The contact structure of  claim 8  further comprising a second layer of adhesive over the top surface of the housing. 
     
     
       10. An electronic device comprising:
 a device enclosure substantially housing the electronic device; 
 a contact structure comprising: 
 a housing having plurality of slots, at least one raised portion, and a top surface, where the at least one raised portion includes at least one opening; 
 a plurality of contacts each located in a corresponding one of the plurality of slots, each contact comprising a contacting portion, a midsection portion, and a tail portion, wherein the contacting portion of each contact extends through a corresponding opening in the at least one raised portion in the housing; 
 an injection molded portion around the midsection of each contact and adjacent to the housing to secure the plurality of contacts to the housing; and 
 a bottom plate attached to the bottom of the housing; and 
 a flexible circuit board coupled to the tail portion of each of the plurality of contacts. 
 
     
     
       11. The contact structure of  claim 10  further comprising a second layer of adhesive between the top surface of the housing and the device enclosure. 
     
     
       12. The contact structure of  claim 10  wherein the contacting portion of each of the plurality of contacts has a dome shape. 
     
     
       13. The contact structure of  claim 12  wherein each contacting portion is stamped at an end of a contact in the plurality of contacts. 
     
     
       14. The contact structure of  claim 13  wherein the bottom plate is attached to the housing with a first layer of adhesive. 
     
     
       15. The contact structure of  claim 14  wherein the bottom plate is formed of glass. 
     
     
       16. A contact structure comprising:
 a housing having plurality of slots, a top surface, and a plurality of raised portions extending from the top surface, where each of the plurality of raised portions includes an opening; 
 a plurality of contacts, each located in a corresponding one of the plurality of slots, each contact comprising a contacting portion and a midsection portion, wherein the contacting portion of each contact extends through a corresponding opening in a corresponding raised portion of the housing; 
 an injection molded portion around the midsection of each contact and adjacent to the housing to secure the plurality of contacts to the housing; and 
 a bottom plate attached to a bottom of the housing. 
 
     
     
       17. The contact structure of  claim 16  wherein the bottom plate is formed of glass. 
     
     
       18. The contact structure of  claim 16  wherein the contacting portion of each of the plurality of contacts has a dome shape. 
     
     
       19. The contact structure of  claim 18  wherein each contacting portion is stamped at an end of a contact in the plurality of contacts. 
     
     
       20. The contact structure of  claim 19  wherein each contact in the plurality of contacts comprises a tail portion to attach to a flexible circuit board.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 15/894,321, filed Feb. 12, 2018, which is a continuation of U.S. patent application Ser. No. 15/138,224, filed Apr. 26, 2016, which is a nonprovisional of U.S. provisional patent application No. 62/215,592, filed Sep. 8, 2015, which are incorporated by reference. 
    
    
     BACKGROUND 
     The number of types of electronic devices that are commercially available has increased tremendously the past few years and the rate of introduction of new devices shows no signs of abating. Devices such as tablets, laptops, netbooks, desktops, all-in-one computers, smart phones, storage devices, portable media players, wearable computing devices, navigation systems, monitors, and others, have become ubiquitous. 
     These electronic devices often include one or more connector receptacles through which they may provide and receive power and data. Power and data may be conveyed over cables that include a connector insert at each end of a cable. The connector inserts may be inserted into receptacles in the communicating electronic devices. In other electronic systems, contacts on a surface of first device may be in direct contact with contacts on a second device without the need for an intervening cable. 
     In systems where contacts on two electronic devices come into direct contact with each other, it may be difficult to generate enough normal force to ensure a good electrical connection between contacts in the two devices. To provide a sufficient normal force, contacts may often have a substantial depth and consume a relatively large volume of space in the electronic device. The loss of this space may mean that the electronic device is either larger or only includes a reduced set of functionality. 
     These electronic devices may be manufactured in large numbers. A corresponding number of contact structures may be manufactured for use in these devices. Any simplification in the manufacturing process of these contact structures may yield tremendous savings in the manufacturing of these electronic devices. 
     Thus, what is needed are contact structures that provide a sufficient normal force while consuming a minimal amount of surface area, depth, and volume in an electronic device and are readily manufactured. 
     SUMMARY 
     Accordingly, embodiments of the present invention may provide contact structures that provide a sufficient normal force while consuming a minimal amount of surface area, depth, and volume in an electronic device and are readily manufactured. 
     An illustrative embodiment of the present invention may provide contact structures having movable contacts at a surface of an electronic device. The contact structures may include a nonconductive housing supporting one, two, three, or more conductive contacts. Each contact may have a contacting portion that may be located at an end of a flexible lever arm, where a remote end of the flexible lever arm may be fixed to the housing. The contacts may have contacting portions that emerge from corresponding openings in the housing. 
     These contact structures may be manufactured in various ways. For example, the contacting portions may be attached to ends of the flexible lever arms by riveting, soldering, or the contacting portions and the flexible lever arms may be formed as a single piece. The contacting portions may be formed of the same or different materials. For example, the contacting portions may be formed of a material that provides a low resistance and low corrosion, while the flexible lever arms may be formed of a material chosen for its flexibility and its ability to withstand fatigue and cold-working. The contacting portion may have a narrowed tail extending from a wider body, where the narrowed tail may be inserted into an opening at an end of the flexible lever arm. The narrowed tail may extend through and beyond the flexible lever arm. Force may be applied to the narrowed tail causing it to expand outward, for example in a riveting process. The contacting portion may be held in place in the opening on the flexible lever arm on one side by the expanded narrowed tail and on the other side by the wider body. Each flexible lever arm may have a surface-mount contacting portion at an end remote from the contacting portion. Each flexible lever arm may further include a barb to be inserted into a notch or groove in the contact structure housing. In other embodiments of the present invention, one or more contacts, such as the center contact, may have the housing insert molded around it such that it does not require a barb. The contacts may be arranged in a line in the housing, though they may be arranged in other patterns. Contacts that are centrally located in the housing may be inserted into the housing from a bottom side and fixed in place by inserting their barbs into slots or grooves in the housing. Again, in other embodiments of the present invention these center contacts may have the housing insert molded around it. Support structures may be placed under the contacting portions of the central and other contacts to limit their travel such that they cannot be pushed all the way into the housing, though these may not be needed when the housing is insert molded around the center contact. Contacts located at the ends may be slid into the housing using slots in the housing. The side contacts may also be fixed in place by inserting their barbs into slots or grooves in the housing. Insulating tape may be used to electrically insulate the housing. A cover having openings for the contacting portions may be fit over the housing. The cover may have a raised portion around the openings for the contacts to fit in an opening of a device enclosure of the electronic device housing the contact structure. 
     Another illustrative embodiment of the present invention may provide contact structures that may provide movable contacts at a surface of an electronic device. The contact structures may include a nonconductive housing having slots for a number of conductive contacts. Each contact may include a contacting portion attached to a flexible lever arm. The flexible lever arm may attach to a contact length that may be located in a slot in the housing. A cover may fit over the housing. The cover may include one or more raised portions having a one or more openings, each opening for a corresponding contacting portion of a contact. The openings may be located in the raised portion. The raised portion may fit in an opening of a device enclosure of the electronic device housing the contact structure. The contact structure may further include a bottom plate. The bottom plate may include side tabs that fit in notches or slots in sides of the housing and cover to fix the cover and housing in place relative to the bottom plate. 
     Another illustrative embodiment of the present invention may provide contact structures that have movable contacts at a surface of an electronic device. This contact structure may include a nonconductive housing supporting one, two, three, or more conductive contacts. Each contact may be a spring-biased contact. The spring-biased contacts may have contacting portions that emerge from corresponding openings in the housing. 
     These contact structures may be manufactured in various ways. For example, the spring-biased contacts may be attached to a flexible circuit board. Terminal contacts on the spring-biased contacts may be soldered into opening in the flexible circuit board. A layer of double-sided adhesive may be used to fix the flexible circuit board to a bracket. Threaded inserts may be placed in one or more openings in the bracket, or the ends of the brackets may include threaded openings. For example, the threaded inserts may be press-fit into openings near ends of the bracket. A cap may be formed where the cap may include openings for contacting portions of the spring-biased contacts. The openings may be located on a raised portion that may be arranged to fit in an opening of a device enclosure of the electronic device housing the contact structure. The cap may include gaskets that form rings around the contacting portions of the spring-biased contacts between the contacting portions and inside edges of the openings in the raised portion of the cap. The cap may be formed as a double-shot injection molded part where the gaskets are the second injection-molded shot. The cap may be fixed to the flexible circuit board using a double-sided adhesive layer. A lid, which may be part of a device enclosure for the device housing the contact structure, may be fixed over the top of the contact structure by screws or other fasteners that may be fit into openings in the lid and inserted into the threaded inserts. The raised portion of the cap may fit into a central opening in the lid. A gasket may be placed around the raised portion of the cap and between the cap and the lid to prevent the ingress of liquid, moisture, debris, or other substances into the electronic device housing the contact structure. 
     The spring-biased contacts may be formed in various ways. For example, a housing have a central hole may be provided. A spring may be fit into the central hole. A contacting portion having a backside opening may be fit over the spring such that one end of the spring is in the central hole of the housing and the other end of the spring is in the backside opening of the contacting portion. A terminal structure may be fit over the contacting portion and top of the housing. A tab on the contacting portion may be under the terminal structure such that the contacting portion is held in place. Tabs on the terminal structure may fit in notches or slots in the housing to secure the terminal structure in place relative to the housing. The terminal structure may include through-hole portions that may be inserted and soldered in place in openings in the flexible circuit board. 
     Another illustrative embodiment of the present invention may provide contact structures that may provide movable contacts at a surface of an electronic device. The contact structures may include a nonconductive housing having slots for a number of conductive contacts. Each contact may include a contacting portion attached to a flexible lever arm. The flexible lever arm may attach to a contact length that may be located in a slot in the housing. The housing may include a number of raised portions, each having an opening, each opening for a corresponding contacting portion of a contact. The raised portions may fit in openings of a device enclosure of the electronic device that includes the contact structure. The contact structure may further include a bottom plate. The bottom plate may be attached to the housing by a first adhesive layer. A second adhesive layer may hold the contact structure in place against an inside surface of the device enclosure. 
     Contacts on a surface of a device may be in highly visible location. As such, embodiments of the present invention may provide methods of coating the contacts to have a specific color. The color may be selected to match a color of a portion of a device enclosure for the electronic device housing the contacts. For example, the color of the contacts may be chosen to match a portion of the device enclosure that surrounds or is near the contacts. This may provide an electronic device where the contacts and at least a portion of the device enclosure appear to be made of the same material. This uniform appearance may enhance the perceived quality and value of the electronic device. 
     These and other embodiments of the present invention may instead provide methods of coating contacts to provide a color to contrast with a color of a portion of a device enclosure for the electronic device housing the contacts. This color may be a noticeable color that allows a user to quickly find the contacts for mating with contacts of a second or accessory device. This contrasting color may also be chosen to imply a manufacturing source, or to match other electronic devices, such as a second or accessory device. 
     In these and other embodiments of the present invention, the contacts may have a specific finish, such as a matte or gloss finish. The color may also have a level of transparency. The contacts may also have more than one color. For example, a logo or other fanciful, identifying, or other information may be conveyed by more than one color on a contact. 
     These and other embodiments of the present invention may provide electrical contacts having a low contact resistance. For example, these contacts may have a textured surface having patterns of raised areas or ridges. These raised areas or ridges may provide a large number of contacting points between the contacts and corresponding contacts on a second or accessory device when the contacts are mated with the corresponding contacts. 
     These and other embodiments of the present invention may provide electrical contacts having good corrosion and scratch resistance. For example, a coating to provide color may be placed over a surface of the contact and this additional coating may provide an amount of protection for the contact against corrosion or scratches. 
     These and other embodiments of the present invention may provide contacts having a layer of a silicon based polymer. The silicon based polymer may be dyed to have a specific color, for example a color to match or contrast with at least a portion of an electronic device housing the contacts. Unfortunately, a silicon-based polymer may be a poor conductor. Accordingly, embodiments of the present invention may use this coating only over a portion of a surface of a contact, while the remainder of the surface of the contact may be used to form electrical connections with corresponding contacts on corresponding connectors or devices. In these and other embodiments of the present invention, instead of a silicon-based polymer, a germanium-based polymer may be used. 
     More specifically, in these and other embodiments of the present invention, a plurality of holes may be formed in at least a portion a surface of a contact. These holes may leave a pattern of raised areas or ridges on the surface of the contact. One or more layers may be plated or otherwise formed on at least a portion of the surface of the contact. A layer of silicon-based polymer may be applied as a gel to at least a portion of the surface of the contact. A solvent may then optionally be sprayed or otherwise applied to the gel. The silicon based polymer may be cured such that it contracts into the holes leaving the raised areas or ridges exposed. The optional solvent may help to remove water from the gel during curing to avoid cracking. The exposed areas or ridges may form electrical pathways with a corresponding contact on a corresponding connector or device when the contact and the corresponding contact are mated. 
     In these and other embodiments of the present invention, the holes may be formed in various ways. A substrate of the contact may be formed of copper, copper alloy, or other material. The holes in a surface of a contact may be formed by sandblasting, chemical etching, photolithography, laser etching, stamping, coining, 3-D printing, metal-injection molding, printing, casting, or they may be formed in other ways. To avoid the appearance of lines or other artifacts in the pattern of holes, such as light or dark patches, the location of the holes may be varied or randomized. For example, a laser may have a portion of its position information for some or all of the holes varied or randomized in order to disperse straight lines or other regular or repeating patterns that might otherwise be visible. In these and other embodiments of the present invention, in order to avoid the appearance of lines, light or dark patches, or other artifacts, the depths of the holes may be varied or randomized. In these and other embodiments of the present invention, the diameter of the holes may be varied or randomized. Also, holes may be omitted from areas or regions on contacts where such holes may interfere with the assembly or operation of the contacts. For example, where contacts are located in an injection molded housing, holes may be omitted from areas or regions that are under or near the injection molded housing. 
     In these and other embodiments of the present invention, the holes may have various sizes and spacings. For example, the diameter of the holes may be less than 20 microns, 20-40 microns, 40 microns, 42 microns, 40-45 microns, 45 microns, 48 microns, 55 microns, 52-58 microns, or more than 60 microns. The holes may have a depth of less than 5 microns, 5-10 microns, 8 microns, 10 microns, 10-30 microns, 12 microns, 13 microns, 15 microns, 20 microns, 20-25 microns, or more than 25 microns. The holes may have a center-to-center pitch of less than 20 microns, 20-50 microns, 40 microns, 50 microns, 30-60 microns, 50 microns, 60 microns, 70 microns, 50-70 microns, or more than 70 microns. The holes may have a spacing of less than 5 microns, 5-10 microns, 10 microns, 20 microns, 10-20 microns, 15 microns, 20 microns, 25 microns, 15-25 microns, or more than 25 microns. The spacing or center-to-center pitch of the holes may be varied or randomized to avoid visible patterns formed by the holes. For example, the X and Y coordinates of the holes may be varied in a range such as a plus or minus 3, 4, 5, or more than 5 micron range. These values may be stored in a table and used to modify target information for a laser forming the holes. Light and dark spots may be reduced or removed by adjusting values in the table. 
     After the holes have been formed, one or more plating layers may be applied to the surface of the contact. For example, a top plate may be formed over the contact to provide corrosion and scratch protection. This top plate may be formed of rhodium ruthenium or other material. A barrier layer may be formed over the contact before the top plate is formed to prevent discoloration of the top plate by the copper substrate. The barrier layer may be tin-copper, nickel, palladium, silver, tin-copper-nickel, copper-nickel, tin-nickel, nickel-tungsten, electroless nickel, or other material. One or more adhesion layers may be applied before or after the barrier layer, or both. These adhesion layers may be a gold flash or other layer. Other layers may also be included. For example, a layer of nickel-tungsten alloy, tin-nickel, electroless nickel, copper-nickel, silver, or other material may be plated or formed over the substrate before the barrier layer. Other combinations, such as a top plate of rhodium ruthenium over silver, palladium, nickel, electroless nickel, a nickel-tungsten alloy, tin-nickel, tin-copper, tin-copper-nickel, copper-nickel, tin-nickel, nickel-tungsten, or other nickel alloy may be used, where one or more gold layers may be included. Layers of gold over nickel may also be used in these and other embodiments of the present invention. Additional steps, such as electro-polishing or copper plating may be performed on the substrate after the holes have been formed and before further plating to smooth areas damaged by the laser. In these and other embodiments of the present invention, these layers may be formed by sputtering, vapor deposition, electroplating, or other method. In these and other embodiments of the present invention, the order of these steps may be varied. For example, a substrate may be plated before holes are formed. 
     A dyed silicon-based polymer may then be applied as a gelatinous or viscous solution to one or more surfaces of the contact. The dyed silicon-based polymer may be a sol-gel, formed using a sol-gel process such as the Stöber process. In these and other embodiments of the present invention, tetraethyl orthosilicate (TEOS) may be hydrolyzed to form a silicon oxide network, which may be more generally referred to as sol-gel. In these and other embodiments of the present invention, instead of hydrolyzing, a similar process using a solvent may be employed. The sol-gel may be dyed and applied to one or more surfaces of the contact. A solvent may be applied to the sol-gel. In these and other embodiments of the present invention, both the sol-gel and the solvent may be applied by spraying, printing, or other method. After the sol-gel and optional solvent have been applied, the result may be cured. After curing, the sol-gel may contract to fill the holes, again leaving the surrounding raised portions and ridges exposed. These surrounding raised portions and ridges may then form an electrical connection with a corresponding contact when the contact and the corresponding contact are mated. 
     The sol-gel coated contacts may be cured or dried at room or a higher temperature. The die particles in the sol-gel may begin to aggregate as the sol-gel is cured or dried. As the curing process continues, the sol-gel may become more gelatinous and the aggregations of dyed particles may begin to themselves aggregate. The sol-gel may then become a solid as it contracts into the holes and pulls back from the raised portions and ridges. The optional solvent may help to prevent cracking and other damage to the sol-gel by removing water from the sol-gel during curing. The dried sol-gel may consume as little as eight percent of the original volume of the sol-gel. 
     In these and other embodiments of the present invention, instead of using a sol-gel, other materials, such as conductive ink or other types of ink may be used. In these and other embodiments of the present invention, paint may be used. For example, a polymeric paint, such as a polytetrafluoroethylene (PTFE) based paint, may be used. These inks or paints may be applied using pad printing, ink-jet printing, 3-D printing, aerosol jet printing, or other types of printing. In these and other embodiments of the present invention, the formation of holes may be optional. 
     Embodiments of the present invention may provide contact structures that may be located in various types of devices, such as portable computing devices, tablet computers, desktop computers, laptops, all-in-one computers, wearable computing devices, cell phones, smart phones, media phones, storage devices, keyboards, covers, cases, portable media players, navigation systems, monitors, power supplies, adapters, remote control devices, chargers, and other devices. These contact structures may provide pathways for signals and power compliant with various standards such as one of the Universal Serial Bus (USB) standards including USB Type-C, High-Definition Multimedia Interface® (HDMI), Digital Visual Interface (DVI), Ethernet, DisplayPort, Thunderbolt™, Lightning™, Joint Test Action Group (JTAG), test-access-port (TAP), Directed Automated Random Testing (DART), universal asynchronous receiver/transmitters (UARTs), clock signals, power signals, and other types of standard, non-standard, and proprietary interfaces and combinations thereof that have been developed, are being developed, or will be developed in the future. In one example, the contact structures may be used to convey a data signal, a power supply, and ground. In various embodiments of the present invention, the data signal may be unidirectional or bidirectional and the power supply may be unidirectional or bidirectional. 
     Various embodiments of the present invention may incorporate one or more of these and the other features described herein. A better understanding of the nature and advantages of the present invention may be gained by reference to the following detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an electronic system according to an embodiment of the present invention; 
         FIG. 2  illustrates a contact structure in a device enclosure according to an embodiment of the present invention; 
         FIG. 3  illustrates a portion of an electronic device according to an embodiment of the present invention; 
         FIG. 4  illustrates a side view of a contact structure according to an embodiment of the present invention; 
         FIGS. 5-11  illustrate a method of assembling a contact structure according to an embodiment of the present invention; 
         FIG. 12  illustrates another contact structure in a device enclosure according to an embodiment of the present invention; 
         FIG. 13  illustrates a contact structure according to an embodiment of the present invention; 
         FIG. 14  illustrates a contact structure in a device enclosure according to an embodiment of the present invention; 
         FIG. 15  is an exploded view of a contact structure according to an embodiment of the present invention; 
         FIG. 16  illustrates a spring-biased contact according to an embodiment of the present invention; 
         FIG. 17  is an exploded view of a spring-biased contact of  FIG. 16 ; 
         FIG. 18  illustrates another contact assembly according to an embodiment of the present invention; 
         FIG. 19  illustrates a housing and contacts for a contact assembly according to an embodiment of the present invention; 
         FIG. 20  illustrates a bottom plate an adhesive layer according to an embodiment of the present invention; 
         FIG. 21  illustrates a layer of adhesive that may be used to attach a contact structure to an inside surface of a device enclosure according to an embodiment of the present invention; 
         FIG. 22  is a side view of the contact assembly of  FIG. 18 ; 
         FIGS. 23-31  illustrate methods of manufacturing contacts according to embodiments of the present invention; and 
         FIG. 32  illustrates a method of manufacturing a dome shaped contact according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       FIG. 1  illustrates an electronic system according to an embodiment of the present invention. This figure, as with the other included figures, is shown for illustrative purposes and does not limit either the possible embodiments of the present invention or the claims. 
     In this example, host device  110  may be connected to accessory device  120  in order to share data, power, or both. Specifically, contacts  112  on host device  110  may be electrically connected to contacts  220  on accessory device  120 . Contacts  112  on host device  110  may be electrically connected to contacts  220  on accessory device  120  via cable  130 . In other embodiments of the present invention, contacts  112  on host device  110  may be directly and electrically connected to contacts  220  on accessory device  120 . 
     To facilitate a direction connection between contacts  112  on host device  110  and contacts  220  on accessory device  120 , contacts  220  may be part of a surface-mount contact structure. An example of a surface-mount contact structure that may include contacts  220  is shown in the following figures. 
       FIG. 2  illustrates a contact structure in a device enclosure according to an embodiment of the present invention. In this example, a raised portion  212  of a contact structure may be placed in an opening in device enclosure  230 . The raised portion  212  of the contact structure may include openings for a number of contacts  220 . 
     Contacts  220  may be low-profile contacts. Such contacts may allow a contact structure to provide contacts for a connector without consuming a large volume in the electronic device housed by device enclosure  230 . In various embodiments the present invention, contacts  220  may be spring-biased contacts. For example, contacts  220  may be biased by a spring, flexible arm, or other flexible structure such that they may be pushed or depressed and may return to their original position once released. Spring-biased contacts may provide an amount of compliance with contacts in a corresponding connector, thereby assisting in forming electrical connections between multiple contacts  220  and corresponding contacts of a second connector on a second device (not shown.) 
     Accordingly, embodiments of the present invention may provide contact structures having low-profile, spring-biased contacts. An example is shown in the following figure. 
       FIG. 3  illustrates a portion of an electronic device according to an embodiment of the present invention. This figure illustrates a contact structure  300  having a raised portion  212  on a cover  210  that is fit on a top side of housing  310 . Raised portion  212  may be arranged to fit an opening  232  in device enclosure  230 . Contact structure  300  and may support a number of contacts  220  each in openings in raised portion  212 . Contacts  220  may emerge from bottom of housing  310  and be connected to interconnect  320 . 
     In this example, contact structure  300  may include three contacts  220 . In other embodiments of the present invention, contact structure  300  may include one, two, or more than three contacts  220 . Also, while in this example each of the contacts  220  are located in a single raised portion  212 , in other embodiments of the present invention, more than one raised portion  212  may be employed, and one or more contact  220  may be located in portions of contact structure  300  other than the one or more raised portions  212 . Also, while the three contacts  220  are shown as being in a line, in other embodiments of the present invention, contacts  220  may be arranged in other patterns. 
       FIG. 4  illustrates a side view of a contact structure according to an embodiment of the present invention. Contact structure  300  may be located in an electronic device having device enclosure  230 . As before, raised portion  212  of cover  210  of contact structure  300  may be located in an opening in device enclosure  230 . Housing  310  of contact structure  300  may support contacts having contacting portions  221 ,  222 , and  223 . These contacting portions  221 ,  222 , and  223  may be attached to ends of flexible lever arms  420 ,  424 , and  428 . Each flexible arm may terminate in a second end and may include a barb, which may be inserted into notches or grooves in housing  310 . Specifically, flexible lever arm  420  may include barb  421 , flexible lever arm  424  may include barb  425 , and flexible lever arm  428  may include barb  429 . In other embodiments of the present invention, the center contact may have housing  310  insert molded around it and barb  425  may not be needed. 
     During assembly, the central contact including contact portion  222  may be inserted through an opening in a bottom of housing  310 . Without more, contacting portion  222  could be pushed deep into housing  310 . In some instances, contacting portion  222  could be pushed below cover  210 . If contacting portion  222  were to be laterally offset at this time, contacting portion  222  may not emerge from its opening in cover  210 . Accordingly, a bottom stop portion  430  may be located under contacting portion  222 . Bottom stop portion  430  may limit a depth to which contacting portion  222  may be depressed, thereby preventing possible damage to contact structure  300 . In other embodiments of the present invention, the center contact may have housing  310  insert molded around it such that bottom stop portion  430  may not be needed. 
     Contacts structure  300  may be formed in various ways. An example is shown in the following figure. 
       FIGS. 5-11  illustrate a method of assembling a contact structure according to an embodiment of the present invention. In  FIG. 5 , contacts for a contact structure according to an embodiment of the present invention, such as contact structure  300 , may be formed. These contacts may include contacting portions  221 ,  222 , and  223 . Ends of contacting portions  221 ,  222 , and  223  may be attached to flexible lever arms  420 ,  424 , and  428 . Flexible lever arm  420  may terminate in a first barb  421  and include a surface-mount contact portion  520 . Flexible lever arm  424  may include barb  425  and may terminate in surface-mount contacting portion  521 . Flexible lever arm  428  may include barb  429  and may terminate in surface-mount contacting portion  522 . In other embodiments of the present invention, the center contact may have housing  310  insert molded around it and barb  425  may not be needed. 
     Contacting portions  221 ,  222 , and  223  may be riveted to flexible lever arms  420 ,  424 , and  428 . Specifically, contacting portion  221  may include a narrowed tail portion  228  below ledge  227 . Narrowed end or tail portion  228  may be inserted into opening  236  in flexible lever arm  420 . Ledge  227  may rest on a top surface of flexible lever arm  420  around opening  226 . Narrowed end or tail portion  228  may have a force applied such that it widens, for example, by riveting. In this way, contacting portion  221  may be secured to flexible lever arm  420  by ledge  427  and the widened portion of narrowed tail portion  228 . When contacting structure  300  is mounted on a board or other appropriate substrate, surface-mount contacting portions  520 ,  521 , and  522  may be soldered to contacts on the board thereby forming interconnect path from contacting portions  221 ,  222 , and  223  to interconnect traces on the board. 
     In  FIG. 6 , a central contact including contacting portion  221  may be inserted through an opening in a bottom of housing  310 . At least some of contacting portion  221  may emerge from a top surface of housing  310 . In other embodiments, housing  310  may be insert molded around the central contact. 
     In  FIG. 7 , central contact  220  is inserted through a bottom opening in housing  310 . Since central contact  220  is inserted through a bottom opening in housing  310 , central contacting portion  221  could inadvertently be pushed all the way to the bottom of housing  310 . To prevent this, embodiments of the present invention may attach a bottom stop portion  430  to a bottom of housing  310 . Bottom stop portion  430  may include a raised portion  710  below contacting portion  221 . This raised portion  710  may restrict the travel range of contacting portion  221 . This may prevent contacting portion  221  be pushed all the way into housing  310 , thereby damaging contacting structure  300 . In other embodiments of the present invention, the center contact may have housing  310  insert molded around it and bottom stop portion  430  may not be needed. 
     In  FIG. 8 , side contacts including contacting portions  221  and  223  may be inserted into housing  310  using slots  810  and  812 . Flexible lever arm  420  may be pushed into housing  310  until barb  421  is inserted into a groove or notch in housing  310 . Similarly, flexible lever arm  428  may be pushed into housing  310  until barb  429  is inserted into a groove or notch in housing  310 . 
     In  FIG. 9 , a piece of insulating tape  910  may be wrapped around a portion of the top, sides, and bottom of housing  310 . Insulating tape  910  may include openings  912  for surface-mount contacting portions  520 ,  521 , and  522  of the contacts in housing  310 . Insulating tape  910  may include top surface tabs  914 . Top surface tabs  914  may be sandwiched between cover  210  and housing  310 , thereby helping to maintain insulating tape  910  in place. In various embodiments of the present invention, insulating tape  910  may be Mylar tape or other type of tape or insulating layer. 
     In  FIG. 10 , a cover  210  may be placed over housing  310 . Again, top surface tabs  914  of insulating tape  910  may be placed between cover  210  and housing  310 , thereby holding insulating tape  910  in place. Cover  210  may include a raised portion  212  having openings  213  for contacts  220 . 
       FIG. 11  illustrates a completed contact structure  300  according to an embodiment of the present invention. 
     In various embodiments of the present invention, different portions of contact structure  300  and other contact structures may be formed of various materials. For example, housing  310  and cover  210  may be formed of the same or different materials, such as plastic, LPS, or other non-conductive material. Contacting portions  221 ,  222 , and  223 , may be formed of noncorrosive materials, such as gold, gold plated copper, gold plated nickel, gold-nickel alloy, and other materials. Flexible lever arms  420 ,  444 , and  428  may be formed of spring metal, sheet-metal, copper alloy, or other complaint material. 
     In various embodiments of the present invention, different portions of contact structure  300  and other contact structures may be formed in various ways. For example, housing  310  and cover  210  may be formed using injection or other molding, printing, or other technique. Contact portions  221 ,  222 , and  223  and flexible lever arms  420 ,  424 , and  428  may be machined, stamped, coined, forged, printed, or formed in different ways. Contact portions  221 ,  222 , and  223  may be attached to flexible lever arms  420 ,  424 , and  428  by riveting, soldering, spot-welding, or other technique, or they may be formed as a single unit. Housing  310  and cover  210  may be formed around contacts  220  using injection molding. 
       FIG. 12  illustrates another contact structure in a device enclosure according to an embodiment of the present invention. In this example, a raised portion  1210  of a contact structure may be fit in an opening in device enclosure  1200 . Raised portion  1210  may include contacting portions  1220  each surrounded by an individual raised portion  1212 . 
     Contacting portions  1220  may be low-profile contacts. Such contacts may allow a contact structure to provide contacts for a connector without consuming a large volume in the electronic device housed by device enclosure  1200 . In various embodiments the present invention, contacting portions  1220  may be contacting portions for spring-biased contacts. For example, contacting portions  1220  may be biased by a spring, flexible arm, or other flexible structure such that they may be pushed or depressed and may return to their original position once released. Spring-biased contacts may provide an amount of compliance with contacts in a corresponding connector, thereby assisting in forming electrical connections between multiple contacting portions  1220  and corresponding contacts of a second connector on a second device (not shown.) 
     Accordingly, embodiments of the present invention may provide contact structures having low-profile, spring-biased contacts. An example is shown in the following figure. 
       FIG. 13  illustrates a contact structure according to an embodiment of the present invention. This contact structure may include housing  1320  having a number of slots for contact portions  1222 . Contact portions  1222  may connect to contacting portions  1220  via flexible lever arms  1224 . 
     This contact structure may further include a top plate or cover  1310  having a raised portion  1210 . Raised portion  1210  may include further raised portions  1212  around each opening  1213 . Each opening  1213  may allow a connection to be made to contacting portion  1220 . 
     This contact structure may further include a bottom plate  1330 . Bottom plate  1330  may include tabs  1350  to fit in notch  1352  in top plate or cover  1310  and notch  1354  in housing  1320  to secure top plate or cover  1310 , housing  1320 , and bottom plate  1330  together as a unit. 
     In various embodiments of the present invention, different portions of this contact structure and other contact structures may be formed of various materials. For example, housing  1320 , cover  1310 , and bottom plate  1330  may be formed of the same or different materials, such as plastic, LPS, or other non-conductive material. Contacting portions  1220  may be formed of noncorrosive materials, such as gold, gold plated copper, gold plated nickel, gold-nickel alloy, and other materials. Flexible lever arms  1224  and contact portions  1222  may be formed of spring metal, sheet-metal, copper alloy, or other complaint material. 
     In various embodiments of the present invention, different portions of this contact structure and other contact structures may be formed in various ways. For example, housing  1320 , cover  1310 , and bottom plate  1330  may be formed using injection or other molding, printing, or other technique. Contacting portions  1220 , flexible lever arms  1224 , and contact portions  1222  may be machined, stamped, coined, forged, printed, or formed in different ways. Contact portions  1220  may be attached to flexible lever arms  1224  by riveting, soldering, spot-welding, or other technique, or they may be formed as a single unit. Housing  1320 , cover  1310 , and bottom plate  1330  may be formed around contacting portions  1220  using injection molding. 
       FIG. 14  illustrates a contact structure in a device enclosure according to an embodiment of the present invention. In this example, a raised portion of a cap  1410  of a contact structure may be fit in an opening in a device enclosure. A raised portion of cap  1410  may include contacts  1420 . This contact structure may include bracket  1430 . Bracket  1430  may be fixed to a lid, device enclosure, or other structure by inserting fasteners into threaded inserts  1432 . 
     Contacts  1420  may be low-profile contacts. Such contacts may allow a contact structure to provide contacts for a connector without consuming a great deal of volume in the electronic device housed by the enclosure. In various embodiments the present invention, contacts  1420  may be spring-biased contacts. For example, contacts  1420  may be biased by a spring, flexible arm, or other flexible structure such that they may be pushed or depressed and may return to their original position once released. Spring-biased contacts may provide an amount of compliance with contacts in a corresponding connector, thereby assisting in forming electrical connections between multiple contacts  1420  and corresponding contacts of a second connector on a second device (not shown.) 
     This contact structure may be assembled in various ways. An example is shown in the following figure. 
       FIG. 15  is an exploded view of a contact structure according to an embodiment of the present invention. In this example, a flexible circuit board  1550  may include a number of openings for terminals of spring-biased contacts  1420 . Spring-biased contacts  1420  may be attached to flexible circuit board  1550  by inserting terminals of spring-biased contacts  1420  into the openings in flexible circuit board  1550  and soldering. A cap  1410  having openings for contacts  1420  may be placed over contacts  1420 . Cap  1410  may further include gaskets  1520  in openings in cap  1410 . An additional gasket  1530  may be placed or formed between contacts  1420  and inside edges of openings in cap  1410 . Gaskets  1520  and  1530  may be formed of silicone or other sealing material. Cap  1410  may be formed as a two shot injection molded process, where the main part of cap  1410  is formed in a first shot and gaskets  1520  are formed in a second shot. Cap  1410  may be attached to flexible circuit board  1550  using a double-sided adhesive layer  1540 . Adhesive layer  1540  may be a heat activated film or adhesive layer. Bracket  1430  may be attached using a second adhesive layer  1560  to a bottom of flexible circuit board  1550 . Adhesive layer  1560  may also be a heat activated film or adhesive layer. Lid  1510  may be placed over cap  1410 . Lid  1510  may be a portion of a device enclosure for a device housing this contact structure. The enclosure may be conducive or nonconductive. Gasket  1530  may be placed around a raised surface of cap  1410  and be located between cap  1410  and lid  1510 . Threaded inserts  1432  may be press-fit into openings at ends of bracket  1430 . Fasteners, such as screws  1512 , may be inserted into openings at ends of lid  1510  and screwed into threaded inserts  1432  in bracket  1430 . In other embodiments of the present invention, the threaded inserts may be replaced by threaded opening in bracket  1430 . 
     In this example, the contact structure may include three contacts  1420 . In other embodiments of the present invention, the contact structure may include one, two, or more than three contacts  1420 . Also, while in this example each of the contacts  1420  are located in a single raised portion, in other embodiments of the present invention, more than one raised portion may be employed, and one or more contact  1420  may be located in portions of the contact structure other than the one or more raised portions. Also, while the three contacts  1420  are shown as being in a line, in other embodiments of the present invention, contacts  1420  may be arranged in other patterns. 
     Various spring-biased contacts  1420  may be used in contacting structures according to embodiments of the present invention. An example is shown in the following figures. 
       FIG. 16  illustrates a spring-biased contact according to an embodiment of the present invention. This spring-biased contact may include a contacting portion  1420  supported by housing  1610 . Terminal structure  1620  may include legs that may be inserted into openings in a flexible circuit board, printed circuit board, or other appropriate substrate. 
       FIG. 17  is an exploded view of a spring-biased contact of  FIG. 16 . In this example, housing  1610  may include a central opening  1612 . A first end of spring  1710  may be inserted into central opening  1612 . Housing  1610  may further include notches  1616  and  1618 , as well as corner notches  1614 . 
     A contacting portion  1420  may have a backside cavity (not shown.) A second end of spring  1710  may be inserted into the backside cavity of contacting portion  1420 . 
     Terminal structure  1620  may be fit over contacting portion  1420  such that contacting portion  1420  passes through central opening  1622  of terminal structure  1620 . Terminal structure  1620  may include legs which may fit in corner notches  1614 . Tabs  1628  and  1626  may fit in notches  1618  and  1616  in housing  1610  to secure terminal structure  1620  in place relative to housing  1610 . Contacting portion  1420  may include tabs  1422 , which may fit under terminal structure  1620  near portion  1624  to hold contacting portion  1420  in place. Tabs  1628  may include raised portions  1629 , which may fit in the back side cavity of contacting portion  1420 . Tabs  1629  may help to ensure that electrical contact remains between contacting portion  1420  and terminal  1620  as the contacting portion  1420  is depressed towards housing  1610 . 
       FIG. 18  illustrates another contact assembly according to an embodiment of the present invention. This example illustrates contact assembly  1800  having a housing  1810  supporting a number of contacts  1820 . Contacts  1820  may be located in slots  1815  of housing  1810 . Contacts  1820  may include contacting portions  1822  which may extend through openings  1813  in raised portions  1812 . In this example, individual raised portions  1812  may partially surround each contacting portion  1822 , though in other embodiments of the present invention, raised portions  1812  may be combined into a single raised portion. A portion of contacts  1820  may be encased in injection molding  1830 , which may be formed adjacent to housing  1810  in order to secure contacts  1820  to housing  1810 . Contact assembly  1800  may attach and be electrically connected to traces of flexible circuit board  2220  (shown in  FIG. 22 ). Specifically, tail portions  1824  of contacts  1820  may be soldered to traces or contacts on flexible circuit board  2220 . Posts  1834  may be used to align the flexible circuit board  2220  to contact assembly  1800 . 
       FIG. 19  illustrates a housing and contacts for a contact assembly according to an embodiment of the present invention. Housing  1810  may include raised portions  1812  having openings  1813 . Slots  1815  may be available for contacts  1820 . Openings  1817  in housing  1810  may be used as an opening to inject injection molding  1830  (shown in  FIG. 18 ) during assembly. Contacts  1820  may include a midsection  1826  that may be encased by injection molding  1830 , as shown in  FIG. 18 . Contacts  1820  may further include a flexible arm  1828 . Flexible arm  1828  may be able to deflect in a downward direction (into housing  1810 ) when contacting portion  1822  is mated with a corresponding contact on a second device. Contacting portion  1822  may be stamped at an end of flexible arm  1828  or it may be a separate structure attached to flexible arm  1828 . For example, contacting portion  1822  may be a separate piece that is riveted to flexible arm  1828 , as described above in  FIG. 5  and related figures. The flexible arm  1828  may be pre-biased to hold contacting portions  1822  in position extending through raised portions  1812  of housing  1810 . 
     Contact assembly  1800  may further include a bottom plate. This bottom plate may be formed of glass or other material that is thin and provides minimal thickness, high stiffness and rigidity, and good insulation. An example is shown in the following figure. 
       FIG. 20  illustrates a bottom plate and an adhesive layer according to an embodiment of the present invention. Bottom plate  2010  may be attached to an underside of housing  1810  (shown in  FIG. 19 ) by adhesive layer  2000 . Adhesive layer  2000  may include openings  2002  to prevent flexible arms  1828  of contacts  1820  (shown in  FIG. 19 ) from becoming fixed to adhesive layer  2000 . In these and other embodiments of the present invention, adhesive layer  2000  may be a pressure-sensitive adhesive. Bottom plate  2010  may be glass or other composite material to provide minimal thickness, high stiffness and rigidity, and good insulation. 
     Contact assembly  1800  may be fixed to an inside surface of a device enclosure (not shown.) The low-profile of contact assembly  1800  may allow its use in devices having a thin device enclosure  2210  (shown in  FIG. 22 .) Contact assembly  1800  may be fixed to the inside surface of device enclosure  2210  (shown in  FIG. 22 ) using a layer of adhesive. An example is shown in the following figure. 
       FIG. 21  illustrates a layer of adhesive that may be used to attach a contact structure to an inside surface of a device enclosure according to an embodiment of the present invention. In this example, contact assembly  1800  may include a top surface  2120 . Adhesive layer  2100  may be attached to top surface  2120  in order to secure contact assembly  1800  to an inside surface of device enclosure  2210 . Adhesive layer  2100  may include openings  2102 . Openings  2102  may help to prevent flexible arms  8028  from becoming fixed to adhesive layer  2100 . In these and other embodiments of the present invention, adhesive layer  2100  may be a pressure-sensitive adhesive. Adhesive layer  2100  may stop at backside  1832 , or it may continue over a portion of flexible circuit board  2220  (shown in  FIG. 22 ) to secure a portion of flexible circuit board  2220  between tail portions  1824  of contacts  1820  and device enclosure  2210  (shown in  FIG. 22 .) 
       FIG. 22  is a side view of the contact assembly of  FIG. 18 . In this example, contacts  1820  may be located in housing  1810 . Injection molding  1830  may be formed around and midsections  1826  of contacts  1820  to secure contacts  1820  to housing  1810 . Contacts  1820  may include flexible arm  1828 , which may terminate in contacting portion  1822 . Flexible arm  1828  may allow contacting portion  1822  to be depressed in a downward direction towards bottom plate  2010 . Contacts  1820  may further include tail portions  1824  for connecting with flexible circuit board  2220 . This flexible circuit board  2220  may be flush with a backside  1832  of injection molding  1830 . Flexible circuit board  2220  may have a similar height and may form a coplanar surface with top surfaces  2120  of housing  1810 . In this way, contact assembly  1800  and a flexible circuit board may reside against an inside surface of device enclosure  2210  Bottom plate  2010  may be fixed to housing  1810  with a first layer of adhesive  200  (shown in  FIG. 20 .) A second adhesive layer  2100  (shown in  FIG. 21 ) may be applied to top surfaces  2120 , which may fix contact assembly  1800  to the inside surface of device enclosure  2210 . 
     Embodiments of the present invention may provide methods of coating contacts to provide a specific color. The color may be selected to match a color of a portion of a device enclosure for the electronic device housing the contacts. For example, the color of the contacts may be chosen to match a portion of the device enclosure that surrounds or is near the contacts. This may provide an electronic device where the contacts and at least a portion of the device enclosure appear to be made of the same material. This uniform appearance may enhance the perceived quality and value of the electronic device. 
     These and other embodiments of the present invention may instead provide methods of coating contacts to provide a color to contrast with a color of a portion of a device enclosure for the electronic device housing the contacts. This color may be a noticeable color that allows a user to find the contacts quickly for mating with contacts of a second or accessory device. This contrasting color may also be chosen to imply a manufacturing source, or to match other electronic devices, such as a second or accessory device. 
     In these and other embodiments of the present invention, the contacts may have a specific finish, such as a matte or gloss finish. The color may also have a level of transparency. The contacts may also have more than one color. For example, a logo or other fanciful, identifying, or other information may be conveyed by more than one color on a contact. 
     These and other embodiments of the present invention may provide electrical contacts having a low contact resistance. For example, these contacts may have a textured surface having patterns of raised areas or ridges. These raised areas or ridges may provide a large number of contacting points between the contacts and corresponding contacts on a second or accessory device when the contacts are mated with the corresponding contacts. 
     These and other embodiments of the present invention may provide electrical contacts having good corrosion and scratch resistance. For example, a coating to provide color may be placed over a surface of the contact and this additional coating may provide an amount of protection for the contact against corrosion or scratches. Examples are shown in the following figures. 
       FIGS. 23-31  illustrate methods of manufacturing contacts according to embodiments of the present invention. In  FIG. 23 , a substrate  2300  for contact  112  may be received. The substrate  2300  may be for a contact  220 , or other contact in other devices. The substrate  2300  of contact  112  may be formed of copper, copper alloy, or other material. A number of holes  2310  may be formed in at least a portion of one or more surfaces of contact  112 . These holes  2310  may be formed in substrate  2300  of contact  112  in various ways. Holes  2310  may be sandblasted, chemically etched, formed using photolithography, laser etched, stamped, coined, 3-D printed, metal-injection molded, printed, cast, or they may be formed in other ways. To avoid the appearance of lines or other artifacts in the pattern of holes, the location of the holes may be varied or randomized. For example, a laser may have a portion of its position information for some or all of the holes varied or randomized in order to disperse straight lines or other regular patterns that might otherwise be visible. 
     In these and other embodiments of the present invention, the holes may have various sizes or diameters  2380  and spacings  2382 . For example, the diameter  2380  of holes  2310  may be less than 20 microns, 20-40 microns, 40 microns, 42 microns, 40-45 microns, 45 microns, 48 microns, 55 microns, 52-58 microns, or more than 60 microns. Holes  2310  may have a depth  2384  of less than 5 microns, 5-10 microns, 8 microns, 10 microns, 10-30 microns, 12 microns, 13 microns, 15 microns, 20 microns, 20-25 microns, or more than 25 microns. Holes may have a center-to-center pitch  2386  of less than 20 microns, 20-50 microns, 40 microns, 50 microns, 30-60 microns, 50 microns, 60 microns, 70 microns, 50-70 microns, or more than 70 microns. Holes  2310  may have a spacing  2382  of less than 5 microns, 5-10 microns, 10 microns, 20 microns, 10-20 microns, 15 microns, 20 microns, 25 microns, 15-25 microns, or more than 25 microns. The spacing  2382  or center-to-center pitch  2386  of holes  2310  may be varied or randomized to avoid visible patterns formed by the holes. For example, the X and Y coordinates of holes  2310  may be varied in a range such as a plus or minus 3, 4, 5, or more than 5 micron range. These values may be stored in a table and used to vary a target for a laser forming the holes. Light and dark spots may be reduced or removed by adjusting values in the table. 
     In  FIG. 24 , holes  2310  in substrate  2300  of contact  112  may be plated with one or more plating layers  2400 . These layers may include a top plate that may be formed over contact  112  to provide corrosion and scratch protection. This top plate may be formed of rhodium ruthenium or other material. A barrier layer may be formed over contact  112  before the top plate is formed to prevent discoloration of the top plate by the copper substrate  2300 . The barrier layer may be tin-copper, nickel, palladium, silver, tin-copper-nickel, copper-nickel, tin-nickel, nickel-tungsten, electroless nickel, or other material. One or more adhesion layers may be applied before or after the barrier layer, or both. These adhesion layers may be a gold flash or other layer. Other layers may also be included. For example, a layer of nickel-tungsten alloy, tin-nickel, electroless nickel, copper-nickel, silver, or other material may be plated or formed over the substrate before the barrier layer. Other combinations, such as a top plate of rhodium ruthenium over silver, palladium, nickel, electroless nickel, a nickel-tungsten alloy, tin-nickel, tin-copper, tin-copper-nickel, copper-nickel, tin-nickel, nickel-tungsten, or other nickel alloy may be used, where one or more gold layers may be included. Layers of gold over nickel may be used in these and other embodiments of the present invention. Additional steps, such as electro-polishing or copper plating may be performed on the substrate after the holes have been formed and before plating to smooth areas damaged by the laser. In these and other embodiments of the present invention, these layers may be formed by sputtering, vapor deposition, electroplating, or other method. In these and other embodiments of the present invention, the order of these steps may be varied. For example, a substrate  2300  may be plated before holes  2310  are formed. 
     In  FIG. 25 , a dyed silicon-based polymer  2500  may be applied as a gelatinous or viscous solution to one or more surfaces of contact  112 . The dyed silicon-based polymer  2500  may be a sol-gel formed using a sol-gel process such as the Stöber process. In these and other embodiments of the present invention, tetraethyl orthosilicate (TEOS) may be hydrolyzed to form a silicon oxide network, which may be more generally referred to as a sol-gel. In these and other embodiments of the present invention, instead of hydrolyzing, a similar process using a solvent may be employed. The sol-gel may be dyed and applied to at least a portion of one or more surfaces of contact  112 . A solvent may then be applied to the sol-gel. Both the sol-gel and the solvent may be applied by spraying, printing, or by other method. The sol-gel may then be dried or cured. The drying or curing may take place at room or an elevated temperature. The die particles in the sol-gel may begin to aggregate as the sol-gel is dried and cured. As the curing process continues, the sol-gel may become more gelatinous and the aggregations of dyed particles may begin to themselves aggregate. The sol-gel may then become a solid as it contracts into the holes and pulls back from the raised portions and ridges. The optional solvent may help to prevent cracking and other damage to the sol-gel by removing water from the sol-gel during curing. The dried sol-gel may consume as little as eight percent of the original volume of the hydrolyzed sol-gel. In these and other embodiments of the present invention, instead of a silicon-based polymer, a germanium-based polymer may be used. 
     In  FIG. 26 , after curing, the sol-gel may contract to fill holes  2310 , leaving the surrounding raised portions and ridges  2600  exposed. That is, the surface tension of the sol-gel may pull the sol-gel away from raised portions and ridges  2600  and into holes  2310 . These surrounding raised portions and ridges  2600  may then form an electrical connection with a corresponding contact when contact  112  and the corresponding contact are mated. 
     In these and other embodiments of the present invention, instead of using a sol-gel, other materials, such as conductive ink or other types of ink may be used. In these and other embodiments of the present invention, paint may be used. For example, a polymeric paint, such as a polytetrafluoroethylene (PTFE) based paint, may be used. These inks or paints may be applied using pad printing, ink-jet printing, 3-D printing, aerosol jet printing, or other types of printing. In these and other embodiments of the present invention, the formation of holes may be optional. 
       FIG. 27  is a top view of a portion of contact  112  having holes  2310  filled with dried sol-gel (dyed silicon-based polymer  2500 ) to expose surrounding raised portions and ridges  2600  of plating layers  2400 . The pattern of holes  2310  may be a regular, repeating pattern of holes that may form lines of raised portions and ridges  2600  that may be visible.  FIG. 28  illustrates lines  2800  that may be visible in a pattern of raised portions and ridges  2600  formed by holes  2310 . 
     Accordingly, in  FIG. 29  the X and Y coordinates of each hole  2310  may be varied or randomized to reduce or eliminate lines  2800 . That is, the X and Y coordinates for each hole may be varied from the regular, repeating pattern in  FIGS. 6 and 7 . For example, the X and Y coordinates of each hole may be modified by a value of −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5 microns, where the value is read from a table stored in memory and used to vary a position of a laser forming holes  2310 . In this way, a laser may have a portion of its position information for some or all of holes  2310  varied in order to disperse straight lines or other regular or repeating patterns that might otherwise be visible. These tables may be arranged to reduce or eliminate local light and dark regions as well. An example of such as table is shown in  FIG. 30 . In this table, a variance in what would otherwise be a regular, repeating pattern or array of holes is provided by X and Y values for each point. That is, each point may be a location for a hole in a regular, repeating pattern of holes. This regular, repeating pattern may be varied by moving each hole in an X direction by an amount listed in a corresponding X entry in the X column of the table and by moving each hole in a Y direction by an amount listed in a corresponding Y entry in the Y column of the table. Using these variations, a resulting pattern of holes may appear to be randomized and may have a reduced incidence of regular or repeating lines, patterns, or light or dark areas that may be observable. In these and other embodiments of the present invention, in order to avoid the appearance of lines, light or dark patches, or other artifacts, the depths of the holes may be varied or randomized. In these and other embodiments of the present invention, the diameter of the holes may be varied or randomized. Also, holes may be omitted from areas or regions on contacts where such holes may interfere with further assembly or operation of the contacts. For example, where contacts are located in an injection molded housing, holes may be omitted from areas or regions that are under or near the injection molded housing. 
     To further reduce reflections from raised portions and ridges  2600 , the edges of the raised portions and ridges  2600  may be smoothed or rounded off. For example, after holes  2310  are formed in substrate  2300  of contact  112 , substrate  2300  of contact  112  may be etched, polished, or otherwise rounded off before being plated with plating layers  2400 . In  FIG. 31 , surface  3100  has been rounded off. Holes  2310  may have similar depths  2384 , diameters  2380 , and center-to-center pitches  2386  a shown above. 
     The methods shown in the above figures may be applied to contacts having surfaces of various contours. For example, it may be applied to contacts having a flat surface. They may also be applied to contacts having curved, round, dome shaped, or other shaped contacting portions. An example is shown in the following figure. 
       FIG. 32  illustrates a method of manufacturing a dome shaped contact according to an embodiment of the present invention. As shown in  FIG. 19  and repeated here, contacts  1820  may include contacting portions  1822 . It may be difficult to form holes in a surface of contacting portions  1822  due to its domed or curved shape. Accordingly, embodiments of the present invention may form holes in a top portion of the contacting portion  1822 . For example, holes may be formed in areas  3200 , while holes are not formed in areas  3210 . The sol-gel and other layers may be applied to both surface portions. In these and various embodiments of the present invention, sol-gel may be applied to area  3210  and  3200  of contacting portions  1822 . Area  3210  may have a diameter  3232 . Holes may be generated in area  3200 , which may have a smaller diameter  3230 . In other embodiments of the present invention, contacting portions  1822  may be rotated in one or more dimensions to increase an area where holes may be formed. 
     In various embodiments of the present invention, different portions of this contact structure and other contact structures may be formed of various materials. For example, cap  1410  and gaskets  1520  may be formed of the same or different materials, such as plastic, LPS, or other non-conductive material. Contacting portions of spring-biased contacts  1420  may be formed of noncorrosive materials, such as gold, gold plated copper, gold plated nickel, gold-nickel alloy, and other materials. Bracket  1430  may be formed of sheet metal or other material. 
     In various embodiments of the present invention, different portions of this contact structure and other contact structures may be formed in various ways. For example, cap  1410  and gaskets  1520  may be formed using injection or other molding, printing, or other technique. Contact portions and other conductive portions of contacts  1420  may be machined, stamped, coined, forged, printed, or formed in different ways. 
     Embodiments of the present invention may provide contact structures that may be located in various types of devices, such as portable computing devices, tablet computers, desktop computers, laptops, all-in-one computers, wearable computing devices, cell phones, smart phones, media phones, storage devices, keyboards, covers, cases, portable media players, navigation systems, monitors, power supplies, adapters, remote control devices, chargers, and other devices. These devices may include contact structures that may provide pathways for signals and power compliant with various standards such as one of the Universal Serial Bus (USB) standards including USB Type-C, HDMI, DVI, Ethernet, DisplayPort, Thunderbolt, Lightning, JTAG, TAP, DART, UARTs, clock signals, power signals, and other types of standard, non-standard, and proprietary interfaces and combinations thereof that have been developed, are being developed, or will be developed in the future. In one example, the contact structures may be used to convey a data signal, a power supply, and ground. In various embodiments of the present invention, the data signal may be unidirectional or bidirectional and the power supply may be unidirectional or bidirectional. 
     The above description of embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Thus, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.

Metadata:
Filing Date: 20180813
Publication Date: 20190305
Grant Date: 20190305
Priority Date: 20150908
Inventors: WAGMAN, Daniel C.
AMINI, Mahmoud
JOL, ERIC S.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01R13/2478", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/2421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/2442", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R13/41", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/428", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R43/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R43/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/2471", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/405", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/405", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/2478", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/2442", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R43/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R43/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/428", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/41", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/2478", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/2471", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/2442", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R13/2421", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 64693574