PATENT DOCUMENT

Publication Number: US-9351400-B1
Application Number: US-201414185818-A
Country: US
Kind Code: B1

Title: Electrical connections between conductive contacts

Abstract:
Conductive contacts can be disposed on multiple substrates or on different surfaces of a single substrate. Conductive material is disposed over at least a portion of the two conductive contacts to electrically connect the contacts. The conductive material may be disposed over at least one surface between the conductive contacts. One or more conductive borders can be formed on a surface of a conductive layer. The conductive border or borders can improve signal transmission across the surface of the conductive layer.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a first conductive contact disposed on a first surface of a substrate and a second conductive contact disposed on a different second surface of the substrate; and 
 a conductive material disposed on at least a portion of the first and second conductive contacts and on at least a portion of an intervening edge of the substrate between each contact surface of the conductive contacts to electrically connect the first and second conductive contacts, wherein the contact surface of the first conductive contact is oriented in a first direction and the contact surface of the second conductive contact is oriented in a different second direction. 
 
     
     
       2. The electronic device as in  claim 1 , wherein the first direction and the second direction are opposite directions. 
     
     
       3. The electronic device as in  claim 1 , wherein the conductive material comprises one of a metal, silver nanowire, and conductive nanoparticles. 
     
     
       4. An electronic device, comprising:
 a first substrate including a first conductive contact disposed on a surface of the first substrate; a second substrate disposed below the first substrate and including a second conductive contact disposed on a surface of the second substrate; and 
 a conductive material disposed on at least a portion of the first and second conductive contacts and on at least a portion of an intervening edge of at least one of the first or second substrates between each contact surface of the first and second conductive contacts to electrically connect the first and second conductive contacts, wherein a contact surface of the first conductive contact and a contact surface of the second conductive contact are oriented in different directions. 
 
     
     
       5. The electronic device as in  claim 4 , wherein the first conductive contact is disposed on a front surface of the first substrate and the second conductive contact is disposed on a back surface of the second substrate. 
     
     
       6. The electronic device as in  claim 5 , wherein the first substrate comprises a display layer and the second substrate comprises a transparent conductive layer. 
     
     
       7. The electronic device as in  claim 5 , further comprising a flexible cable connected to a flexible cable connector disposed on the front surface of the first substrate. 
     
     
       8. The electronic device as in  claim 4 , wherein the conductive material comprises one of a metal, silver nanowire, and conductive nanoparticles. 
     
     
       9. A method for forming an electrical connection between conductive contacts disposed on different surfaces of one or more substrates, the method comprising forming a conductive material on at least a portion of the conductive contacts and on at least a portion of an intervening edge of at least one of the one or more substrates between each contact surface of the conductive contacts by dipping the conductive contacts and the intervening edge of the at least one of the one or more substrates between the contact surfaces of the conductive contacts into the conductive material. 
     
     
       10. The method as in  claim 9 , further comprising forming insulating material over the conductive material to isolate the electrical connection. 
     
     
       11. The method as in  claim 9 , further comprising forming one or more conductive borders on a portion of a surface of at least one substrate. 
     
     
       12. The method as in  claim 11 , wherein at least one conductive border is formed along a perimeter edge of the at least one substrate. 
     
     
       13. The method as in  claim 9 , wherein one conductive contact is disposed on a front surface of a first substrate and the other conductive contact is disposed on a back surface of the first substrate. 
     
     
       14. An electronic device, comprising:
 a first conductive layer disposed over a display layer; 
 a first conductive contact disposed adjacent an edge of a top surface of the display layer; 
 a second conductive contact disposed adjacent an edge of a bottom surface of the display layer; 
 a conductive material disposed on at least a portion of the first and second conductive contacts and on at least a portion of an intervening edge of the display layer between each contact surface of the first and second conductive contacts to electrically connect the first and second conductive contacts; 
 an electrical connector connected between the first conductive layer and the first conductive contact to electrically connect the first conductive contact to the first conductive layer; and 
 a second conductive layer disposed below the display layer and electrically connected to the second conductive contact, wherein the first conductive layer is electrically connected to the second conductive layer through the electrical connector connected between the first conductive layer and the first conductive contact and the conductive material disposed on at least the portion of the first and second conductive contacts and the intervening edge of the display layer. 
 
     
     
       15. The method as in  claim 14 , further comprising one or more conductive borders formed along a perimeter edge of at least one of the first conductive layer or the second conductive layer. 
     
     
       16. The electronic device as in  claim 14 , wherein the conductive material comprises one of a metal, silver nanowire, and conductive nanoparticles. 
     
     
       17. The electronic device as in  claim 14 , wherein the edge of the display layer is shaped to include a protrusion, and the first conductive contact is disposed on the top surface of the protrusion and the second conductive contact is disposed on the bottom surface of the protrusion.

Description:
TECHNICAL FIELD 
     The present invention relates generally to electronic devices, and more specifically to electrical connections in electronic devices. 
     BACKGROUND 
     Electronic devices, such as smartphones and computers, include devices formed with one or more substrates or layers. For example, a display in a smartphone can include a display stack formed with multiple layers. The layers can include a cover glass, a polarizer, a conductive layer, a color filter, and a display layer. Conductive contacts, such as, for example, contact pads can be used to transmit electrical signals to and from various components on a layer or to a layer itself. 
       FIG. 1  illustrates an electrical connection between conductive contacts on two substrates. A conductive contact  100  is disposed on the front surface of a substrate  102  and another conductive contact  104  is disposed on a back surface of another substrate  106 , although in some situations the contacts may be disposed on the front and back of the same substrate. A flexible cable  108  is used to form an electrical connection between the conductive contacts  100 ,  104 . The flexible cable has a bend radius that limits how sharp the bend in the flexible cable can be between the two conductive contacts  100 ,  104 . Due at least in part to its bend radius, the flexible cable can consume considerable area in an electronic device. The amount of area consumed by the flexible cable can be an issue when the size of the electronic device is small. 
     Additionally, the bend in the flexible cable can produce cracks in one or more conductive traces included in the flexible cable. The cracks can be created when the flexible cable is first bent or the cracks can develop over time. Either way, the cracks in the conductive traces can prevent electrical signals from being transmitted through the entire length of the flexible cable, which can render the electronic device inoperable. 
     SUMMARY 
     In one aspect, an electronic device can include a substrate that has a first conductive contact disposed on a first surface of the substrate and a second conductive contact disposed on a second surface of the substrate. Conductive material is disposed on at least a portion of the first and second conductive contacts to electrically connect the conductive contacts. The conductive material may be disposed over or on at least one surface between the contact surfaces of the conductive contacts. Insulating material can be formed over the conductive material to isolate the electrical connection. 
     In another aspect, an electronic device can include a first substrate having a first conductive contact disposed on a surface of the first substrate and a second substrate having a second conductive contact disposed on a surface of the second substrate. The second substrate may be positioned below the first substrate. Conductive material is disposed on at least a portion of the first and second conductive contacts to electrically connect the conductive contacts. In some embodiments, the conductive material may also be disposed on or over at least one surface between the contact surfaces of the first and second conductive contacts. Insulating material can be formed over the conductive material to isolate the electrical connection. As one example, the first substrate may be a display layer and the second substrate a transparent conductive layer disposed below the display layer. One conductive contact is disposed on a front surface of the display layer and the other conductive contact on a back surface of the transparent conductive layer. The conductive material can be implemented with any suitable conductive material or combination of materials, including, but not limited to, metal, silver nanowire, and conductive nanoparticles. 
     In another aspect, a method for forming an electrical connection between conductive contacts disposed on different surfaces of at least one substrate includes forming a conductive material on at least a portion of the conductive contacts to electrically connect the conductive contacts. The conductive material may be disposed on or over one or more surfaces between the contact surfaces of the conductive contacts. Insulating material can be formed over the conductive material to isolate the electrical connection. 
     In another aspect, a method for forming an electrical connection between a first conductive contact disposed on a front surface of a first substrate and a second conductive contact disposed on a back surface of a second substrate disposed below the first substrate includes forming a conductive material on at least a portion of the conductive contacts to electrically connect the conductive contacts. In some embodiments, the conductive material may be disposed over or on at least one surface between each contact surface of the conductive contacts. Insulating material can be formed over the conductive material to isolate the electrical connection. 
     In another aspect, one or more conductive borders can be formed on at least a portion of a surface of a conductive layer. The conductive border(s) can improve signal transmission across the surface of the conductive layer. In one embodiment, at least one conductive border may be formed along a perimeter edge of the conductive layer. The conductive border or borders can be formed using any suitable fabrication method and any suitable material or combination of materials, can be opaque or transparent, and can be formed into any desired shape or shapes. In one embodiment, at least one conductive border can have a lower impedance than the material(s) used to form the conductive layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other. Identical reference numerals have been used, where possible, to designate identical features that are common to the figures. 
         FIG. 1  illustrates an electrical connection between conductive contacts on two substrates in accordance with the prior art; 
         FIG. 2  depicts a perspective view of one example of an electronic device; 
         FIG. 3  illustrates a simplified cross-sectional view of the display  104  taken along line  3 - 3  in  FIG. 2 ; 
         FIG. 4  depicts a top view of the display layer  310  shown in  FIG. 3  and one example of an electrical connection to the electrical contact  316 ; 
         FIG. 5  illustrates a cross-sectional view of the substrate and electrical connection taken along line  5 - 5  in  FIG. 4 ; 
         FIG. 6  depicts an example of a substrate with conductive contacts on different surfaces; 
         FIG. 7  illustrates an example of a bottom surface of a conductive layer; 
         FIG. 8  depicts a cross-sectional view of another example of electrical connections; 
         FIG. 9  illustrates a top view of the electrical connections shown in  FIG. 8 ; 
         FIG. 10  depicts a top view of an example of conductive contacts on a substrate; 
         FIG. 11  illustrates a cross-sectional view of an example of electrical connections for the embodiment shown in  FIG. 10 ; 
         FIG. 12  depicts a cross-sectional view of another example of electrical connections for the embodiment shown in  FIG. 10 ; 
         FIG. 13  illustrates a top view of an example of conductive contacts on a substrate; 
         FIG. 14  depicts a cross-sectional view of an example of electrical connections for the embodiment shown in  FIG. 13 ; 
         FIG. 15  illustrates a top view of a substrate and electrical connections; and 
         FIG. 16  is a flowchart of one example of a method for forming one or more electrical connections or conductive borders. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments described herein may provide an electrical connection between conductive contacts disposed on two different surfaces of a single substrate or on two or more substrates. As one example, first and second conductive contacts may be located on opposite sides of a substrate and connected to one another, in full or in part, by a conductive material. A conductive material may be disposed over at least portions of the conductive contacts to electrically connect the conductive contacts. In some embodiments, the conductive material also overlies, contacts, or is otherwise adjacent to an intervening edge of the substrate between the two contacts. The conductive material may be formed from metal, a conductive polymer, a mesh or nanowire, a ceramic, an impregnated resin and the like. The conductive contacts can be used to transmit a signal or signals to components disposed on or in a substrate, to conductive layers disposed over different surfaces of a single substrate, or to conductive layers disposed on two or more substrates. Additionally, a signal can be transmitted around one or more edges of the conductive layer using conductive material disposed along the edge or edges of the substrate. A substrate can be any type of substrate, including, but not limited to, a glass, plastic, printed circuit board, or flexible cable. 
     Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The meaning of “a”, “an”, and “the” includes plural reference, the meaning of “in” includes “in” and “on”. The term “connected” means either a direct physical and/or electrical connection between the items connected or an indirect connection through one or more passive or active intermediary devices. The term “circuit” means either a single component or a multiplicity of components, either active or passive, that are connected together to provide a desired function. The term “signal” means at least one current, voltage, or data signal. 
     Additionally, directional terminology, such as “top”, “bottom”, “front”, “back”, “leading”, “trailing”, etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments described herein can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration only and is in no way limiting. 
     When used in conjunction with a substrate, a layer, substrates, or layers in an electrical device, such as the layers in a display stack included in an electronic device, the directional terminology is intended to be construed broadly, and therefore should not be interpreted to preclude the presence of one or more intervening layers or other intervening device features or elements. Thus, a given substrate or layer that is described herein as being formed on, formed over, disposed on, or disposed over another layer may be separated from the latter layer by one or more additional layers. 
     Further, the term “electronic device” is to be understood as any type of electronic device, including, but not limited to, a cell phone or smart phone, a tablet, a computing device, an integrated circuit, and a printed circuit board or boards. 
     Referring now to  FIG. 2 , there is shown one example of an electronic device. In the illustrated embodiment, the electronic device  200  is implemented as a smart telephone. Other embodiments can implement the electronic device differently, such as, for example, as a computer, a tablet computing device, and an integrated circuit. 
     The electronic device  200  includes an enclosure  202  surrounding a display  204  and one or more buttons  206  or input devices. The enclosure  202  can form an outer surface or partial outer surface and protective case for the internal components of the electronic device  200 , and may at least partially surround the display  204 . The enclosure  202  can be formed of one or more components operably connected together, such as a front piece and a back piece. Alternatively, the enclosure  202  can be formed of a single piece operably connected to the display  204 . 
     The display  204  can be implemented with any suitable display, including, but not limited to, a multi-touch capacitive sensing touchscreen device that uses liquid crystal display (LCD) technology, organic light-emitting display (OLED) technology, or organic electro luminescence (OEL) technology. The button  206  can take the form of a home button, which may be a mechanical button, a soft button (e.g., a button that does not physically move but still accepts inputs), an icon or image on a display, and so on. Further, in some embodiments, the button  206  can be integrated as part of a cover glass of the electronic device. 
       FIG. 3  illustrates a cross-section view of the display taken along line  3 - 3  in  FIG. 2 . The layers of a display stack  300  include the layers that constitute the display  204 . For example, a top layer in the display stack  300  can be a cover glass (not shown) that is disposed over a front polarizer  304 . The front polarizer  304  is disposed over a front transparent conductive layer  306 , such as, for example, an ITO layer. The front transparent conductive layer  306  is disposed over a color filter layer  308  that is disposed over a display layer  310 . The front transparent conductive layer  306  may, for example, provide electrostatic protection to prevent electrical discharge into the display. 
     The display layer  310  may take a variety of forms, including a LCD, a LED display, and an OLED display. In many embodiments, the display layer may be formed from glass or have a glass substrate. A back transparent conductive layer  312  is below the display layer  310 . The back transparent conductive layer  312  is disposed over a back polarizer  314 . The back transparent conductive layer may serve to prevent noise from entering the system through the display stack and thus may function as an isolation plane. In alternative embodiments, one or both of the conductive layers may have other functions and/or other layers, elements and the like, and may be part of the display stack  300 . 
     Since certain layers, elements or the like located on one or both sides of the display layer  310  may require an electrical signal (or the same electrical signal), it may be useful to place electrical contacts in close proximity to one another but on opposing sides of a substrate. In order to do so, front and back conductive contacts  316 ,  318  may be provided. The front conductive contact  316  is disposed on a front surface of the display layer  310  and a back conductive contact  318  is disposed on an opposing back surface of the display layer  310 . The conductive contacts  316 ,  318  can be implemented with any suitable conductive material and formation, including, but not limited to, contact pads, flexible cable connectors, and conductive traces. 
     An electrical connector  320  may electrically connect the front transparent conductive layer  306  to the front conductive contact  316 . The back transparent conductive layer  312  may be electrically connected to the back conductive contact  318  in the illustrated embodiment. Embodiments described herein may provide structures and methods for electrically connecting the back conductive contact  318  to the front conductive contact  316 , thereby allowing a signal or signals to be transmitted to or from the back conductive contact  318  using the front conductive contact  316 . In the illustrated embodiment, a signal or signals transmitted to the front conductive contact  316  can be transmitted to the front and back transparent conductive layers  306 ,  312  because the front conductive layer  306  is electrically connected to the front conductive contact  316  using electrical connector  320  and the back conductive contact  318  is electrically connected to the front conductive contact  316  using the techniques and methods described in more detail herein. It should be appreciated that the front and back conductive contacts  316 ,  318  may likewise provide electrical connections to additional layers or elements of the electronic device, or may provide such connections instead of providing connections to either of the conductive layers  306 ,  312 . 
     Those skilled in the art will recognize that other components or devices can be disposed on the display layer  310 . By way of example only, one or more integrated circuits (not shown) can be disposed on the display layer  310 . In some embodiments, the other components, including the conductive contacts, can be disposed in an area on the display layer  310  that extends into a region that is not visible by a user viewing the display of the electronic device. For example, when the electronic device is a smartphone or a tablet computing device, the other components and the conductive contacts are disposed on the display layer in an area that is covered by a black mask layer. 
     The front and back polarizers  304 ,  314  can be implemented in any suitable form and can include polarizers that are known and used in the art. Additionally, the color filter layer  308  can be implemented in any suitable form and can include a color filter layer that is known and used in the art. 
     Referring now to  FIG. 4 , there is shown a top view of the display layer  310  shown in  FIG. 3  and one example of an electrical connection to the front conductive contact  316 . Display layer  310  includes the front conductive contact  316 , a flexible cable connector  400 , and one or more integrated circuits  402 . A conductive material  404  is disposed on at least a portion of the front conductive contact  316 . The conductive material can be implemented with any suitable conductive material or combination of materials, including, but not limited to, metal, silver nanowire, and conductive nanoparticles. 
       FIG. 5  illustrates a cross-section view of the display layer  310  and the electrical connection taken along line  5 - 5  in  FIG. 4 . The front polarizer  304  is not shown for simplicity. The conductive material  404  is disposed over at least a portion of the front surface  500  of the front conductive contact  316  and the back surface  502  of the back conductive contact  318 . The conductive material is also disposed over the surfaces  504  between the front and back surfaces  500 ,  502  of the front and back conductive contacts  316 ,  318 . 
     The surfaces of the conductive contacts in which the conductive material is disposed over are called contact surfaces. When the conductive material  404  is disposed over the front surface  500  of the front conductive contact  316  and the back surface  502  of the back conductive contact  318  when an electrical connection is formed, some of the contact surfaces (i.e.,  500 ,  502 ) are oriented in opposite directions and the other contact surfaces are oriented in the same direction. In other embodiments, all or some of the contact surfaces can be oriented in the same directions or in different (opposite and non-opposite) directions.  FIG. 6  depicts an example of a substrate  600  with two conductive contacts  602 ,  604  on different surfaces. The conductive material  606  is disposed over multiple contact surfaces with all of the contact surfaces of the conductive contacts oriented in different directions. 
     Returning to  FIG. 5 , since the back transparent conductive layer  312  is electrically connected to the back conductive contact  318 , the back transparent conductive layer  312  is also electrically connected to the front conductive contact  316  through the conductive material  404 . A signal can be transmitted to or from the back transparent conductive layer  312  using the front conductive contact  316 , the conductive material  404 , and the back conductive contact  318 . For example, unused existing electrical connections to front conductive contact  316  can be used to transmit a signal to the back transparent conductive layer  312  using conductive material  404  and back conductive contact  318 . Alternatively, a new electrical connection to the front conductive contact  316  can be added to the device and used to transmit a signal to or from the back transparent conductive layer  312  using conductive material  404  and back conductive contact  318 . 
     The conductive material  404  can be configured or shaped into any desired shape or thickness. For example, the conductive material  404  can be formed at a thickness or a shape that results in the conductive material consuming less area in an electronic device compared to the flexible cable  108  in  FIG. 1 . Flexible cables may come in different thicknesses and widths, but flexible cables are substantially fixed in a shape and limited in part by a bend radius when connected to the conductive contacts  100 ,  104 . 
     In some embodiments, the back transparent conductive layer  312  can be implemented with a material, or combination of materials, that has a higher than desired impedance. For example, when the back transparent conductive layer  312  is formed with ITO, the impedance across the surface of the layer  312  can be an issue when biasing the back transparent conductive layer  312 . The resistance to the center of the layer  312  generally is higher than the resistance at an edge of the back transparent conductive layer  312 , which can result in signal non-uniformity across the surface of the layer  312 . 
       FIG. 7  illustrates one implementation for improving signal transmission across the surface of the back transparent conductive layer  312  in certain embodiments. A back surface  700  of the back transparent conductive layer  312  is shown in  FIG. 7 . Conductive borders  702 ,  704 ,  706 ,  708  are disposed on the perimeter edges of the back surface of the back transparent conductive layer  312 . The conductive borders  702 ,  704 ,  706 ,  708  cooperate to form a conductive frame around the perimeter edges of the layer  312  in the illustrated embodiment. The conductive frame transmits the signal around the perimeter edges to improve signal uniformity across the surface of the back transparent conductive layer  312 . 
     The conductive border or borders can be formed using any suitable material or combination of materials that has a lower impedance than the material(s) used to form the transparent back conductive layer  312 . A conductive border or borders can be opaque or transparent. A conductive border or borders can be formed prior to forming the back transparent conductive layer  312 . Alternatively, a conductive border or borders can be formed after the formation of the back transparent conductive layer  312 . 
     The conductive border or borders can be formed on the back transparent conductive layer  312  using any suitable fabrication method. By way of example only, the conductive border(s) can be deposited on the surface of the back transparent conductive layer  312 . The conductive border(s) can be deposited using, for example, photolithography or screen printing. A mask can be used to mask off areas of the surface where the conductive border(s) is not to be formed. A conductive border can be used with, or in place of, the conductive material  404 . 
     Additionally, those skilled in the art will recognize that other embodiments are not limited to the conductive frame. One or more conductive borders, of any given design or shape, can be formed on the back transparent conductive layer. Additionally, one or more conductive borders or shapes do not have to be continuous and unbroken. A conductive border can be formed in any suitable shape or configuration. 
     Although the embodiment described in conjunction with  FIGS. 3-7  describes a display layer and a back transparent conductive layer, other embodiments are not limited to this construction. Any type of substrate, such as glass, plastic, printed circuit board, or flexible cable, can be used in place of the display layer and the back transparent conductive layer. Various embodiments can include an electrical connection between two conductive contacts on a single substrate or an electrical connection between two conductive contacts on different substrates. The contact surfaces of the conductive contacts can be oriented in different directions or in the same direction. The different directions can assume any difference in direction. By way of example only, the different directions can be opposite (180 degrees), at an acute angle with respect to each other, or at an obtuse or reflex angle with respect to each other. 
     Referring now to  FIG. 8 , there is shown a cross-sectional view of another example of electrical connections.  FIG. 9  depicts a top view of the electrical connections shown in  FIG. 8 . The conductive material  404  is disposed on at least a portion of the front conductive contact  316  and the back conductive contact  318  and, optionally, the surfaces between the conductive contacts. A first flexible cable connector  800  is disposed on the front surface of a substrate  802  and a second flexible cable  804  is connected to the first cable connector  800 . The substrate  802  can be made of any suitable material or combination of materials including, but not limited to, glass, plastic, and flexible cable. The flexible cable  804  can be implemented with any suitable flexible cable, including, but not limited to, ribbon cable, flexible flat cable, flat panel cable, and flexible printed circuit. In other embodiments, the flexible cable  804  can be connected to the front conductive contact  316 . 
     Referring now to  FIG. 10 , there is shown a top view of an example of conductive contacts on a substrate. The substrate  1000  can be made of any suitable material or combination of materials including, but not limited to, glass, plastic, and flexible cable. Conductive contacts  1002 ,  1004 ,  1006 ,  1008  are disposed on the front surface  1010  of the substrate  1000 . 
       FIG. 11  depicts a cross-sectional view of an example of electrical connections for the embodiment shown in  FIG. 10 . Conductive material  1100  electrically connects the conductive contact  1002  on the front surface  1010  of the substrate  1000  to a conductive contact  1102  on a back surface  1104  of the substrate  1000 . Insulating material  1106  surrounds the conductive material  1100  to electrically isolate the electrical connection between the front and back conductive contacts  1002 ,  1102 . 
     Conductive material  1108  electrically connects the conductive contact  1004  on the front surface  1010  of the substrate  1000  to a conductive contact  1110  on the back surface  1104  of the substrate  1000 . Insulating material  1112  surrounds the conductive material  1108  to electrically isolate the electrical connection between the front and back conductive contacts  1004 ,  1110 . 
     Conductive material  1114  electrically connects the conductive contact  1006  on the front surface  1010  of the substrate  1000  to a conductive contact  1116  on the back surface  1104  of the substrate  1000 . Insulating material  1118  surrounds the conductive material  1114  to electrically isolate the electrical connection between the front and back conductive contacts  1006 ,  1116 . 
     Conductive material  1120  electrically connects the conductive contact  1008  on the front surface  1010  of the substrate  1000  to a conductive contact  1122  on the back surface  1104  of the substrate  1000 . Insulating material  1124  surrounds the conductive material  1120  to electrically isolate the electrical connection between the front and back conductive contacts  1008 ,  1122 . Outer insulating material  1124  is optional and is not included in some embodiments in accordance with the invention. For example, a device can omit the outer insulating material  1124  when the electrical connection between front and back conductive contacts  1008 ,  1122  is connected to ground for electrostatic discharge (ESD) protection. 
     In the illustrated embodiment, the conductive material  1100 ,  1108 ,  1114 ,  1120  extends partially over the conductive contacts. In other embodiments, the conductive material can extend completely over the conductive contacts. Additionally, a different conductive material can be used to form each electrical connection or one or more electrical connections. For example, the conductive material  1114  can by of a different type than the other conductive materials  1100 ,  1108 , and  1120 . A different insulating material can also be used to isolate one or more electrical connections. 
     The electrical connections formed in the embodiment shown in  FIG. 11  can be appropriate when only contact  1102  is near an edge of the substrate  1000  and the other conductive contacts  1110 ,  1116 ,  1122  are positioned closer and closer to the middle of the substrate  1000 . 
       FIG. 12  illustrates a cross-sectional view of another example of electrical connections for the embodiment shown in  FIG. 10 . Only conductive contacts  1002 ,  1004 , and  1006  are shown in  FIG. 12  for simplicity. Conductive material  1100  electrically connects the conductive contact  1002  on the front surface  1010  of the substrate  1000  to the conductive contact  1102  on the back surface  1104  of the substrate  1000 . Insulating material  1106  surrounds the conductive material  1100  to electrically isolate the electrical connection between the front and back conductive contacts  1002 ,  1102 . 
     Conductive material  1200  electrically connects the conductive contact  1004  on the front surface  1010  of the substrate  1000  to a conductive contact  1202  on a back surface  1204  of another substrate  1206 . The substrate  1206  is disposed below the substrate  1000 . Insulating material  1208  surrounds the conductive material  1200  to electrically isolate the electrical connection between the front and back conductive contacts  1004 ,  1202 . 
     Conductive material  1210  electrically connects the conductive contact  1006  on the front surface  1010  of the substrate  1000  to a conductive contact  1212  on a back surface  1214  of a substrate  1216 . The substrate  1216  is disposed below the substrate  1206 . Insulating material  1218  surrounds the conductive material  1210  to electrically isolate the electrical connection between the front and back conductive contacts  1006 ,  1212 . 
     The conductive contact  1008  (not shown) can be electrically connected to a conductive contact on the back surface  1214  of the substrate  1216 , or to a conductive contact on another substrate (not shown) that is disposed below the substrate  1216 . The electrical connections formed in the embodiment shown in  FIG. 12  can be appropriate when conductive contacts  1102 ,  1202 , and  1212  are near an edge of each substrate. As discussed, the conductive contact  1008  can be electrically connected to a conductive contact positioned closer to the middle of the substrate  1216  or to a conductive contact positioned near an edge on a separate substrate disposed below the substrate  1216 . 
     Referring now to  FIG. 13 , there is shown a top view of an example of conductive contacts on a substrate. The substrate  1300  can be made of any suitable material or combination of materials including, but not limited to, glass, plastic, and flexible cable. Conductive contacts  1302 ,  1304 ,  1306 ,  1308  are disposed on the front surface  1310  of the substrate  1300 . A flexible cable  1312  is connected to the conductive contact  1306 . The conductive contact  1306  can be implemented, for example, as a cable connector or a conductive contact pad. 
       FIG. 14  depicts a cross-sectional view of an example of electrical connections for the embodiment shown in  FIG. 13 . Conductive material  1400  electrically connects the conductive contact  1302  on the front surface  1310  of the substrate  1300  to a conductive contact  1402  on a back surface  1404  of the substrate  1300 . Insulating material  1406  surrounds the conductive material  1400  to electrically isolate the electrical connection between the front and back conductive contacts  1302 ,  1402 . 
     Conductive material  1408  electrically connects the conductive contact  1304  on the front surface  1310  of the substrate  1300  to a conductive contact  1410  on the back surface  1404  of the substrate  1300 . Insulating material  1412  surrounds the conductive material  1408  to electrically isolate the electrical connection between the front and back conductive contacts  1304 ,  1410 . Insulating material  1412  also electrically isolates the electrical connection between the flexible cable  1312  and the conductive contact  1413 . 
     Conductive material  1414  electrically connects the conductive contact  1308  on the front surface  1310  of the substrate  1300  to a conductive contact  1416  on the back surface  1404  of the substrate  1300 . Insulating material  1418  surrounds the conductive material  1414  to electrically isolate the electrical connection between the front and back conductive contacts  1308 ,  1416 . Outer insulating material  1418  is optional and is not included in some embodiments. 
       FIG. 15  illustrates a top view of a substrate and electrical connections. The substrate  1500  can be fabricated in any shape or design. In the illustrated embodiment, the substrate  1500  has trenches  1502 ,  1504 ,  1506 . The trenches produce substrate fingers or protrusions, and conductive contacts  1508 ,  1510 ,  1512 ,  1514  are disposed on the substrate fingers. Conductive material  1516 ,  1518 ,  1520 ,  1522  is disposed on at least a portion of a respective conductive contact. 
     Those skilled in the art will recognize that a substrate can be fabricated in any given shape. Shaping the substrate can result in an easier fabrication process for the conductive contacts or electrical connections. By way of example only, if the substrate fingers are dipped in a conductive material, the substrate fingers can reduce the likelihood that conductive material will be formed on the non-finger portion of the substrate. 
     Additionally, shaping the substrate can allow for different conductive materials to be used to form one or more electrical connections. The conductive contacts  1508 ,  1510 ,  1512 ,  1514  can be electrically connected to conductive contacts on multiple substrates or on a single substrate. 
     Referring now to  FIG. 16 , there is shown a flowchart of one example of a method for forming one or more electrical connections or conductive borders. Initially, a determination is made at block  1600  as to whether one or more masks is needed prior to forming a conductive border or borders on a surface of one or more substrates, or prior to forming an electrical connection or connections between conductive contacts. The mask(s) can be used to mask off previously formed components on or in a substrate, or areas of a surface or surfaces where an electrical connection or a conductive border(s) is not to be formed. 
     If one or more masks are needed, the method passes to block  1602  where the mask or masks are formed on the surface or surfaces of one or more substrates. The mask can be formed on the substrate(s) using any suitable fabrication method. The mask can include masks that are known and used in the art. 
     Next, as shown in block  1604 , one or more electrical connections or conductive borders are formed. The electrical connection(s) or conductive border(s) can be formed, for example, by dipping the substrate or substrates in a conductive material. Alternatively, the one or more conductive borders or electrical connections can be formed by depositing conductive material on a surface or conductive contact. Examples of conductive materials include, but are not limited to, metal, organic materials, nanoparticles, or combinations thereof. By way of example only, a conductive border or electrical connection can be deposited using a chemical vapor deposition process or a physical vapor deposition process, such as sputtering. 
     The mask or masks can then be removed (block  1606 ) and a determination made at block  1608  as to whether insulating material is to be formed over the electrical connection(s). If so, the insulating material is formed over the electrical connection using any suitable method (block  1610 ). By way of example only, the insulating material can be deposited over the conductive material that forms the electrical connection. 
     It should be noted that a mask or masks can be used in conjunction with forming the insulating material over the electrical connection. The mask(s) is formed on the substrate prior to forming the insulating layer. The mask(s) can be used to mask off previously formed components on or in a substrate, or areas of a surface or surfaces where the insulating material is not to be formed. The mask(s) can be removed after the insulating layer has been formed. 
     A determination is then made at block  1612  as to whether another electrical connection or conductive border is to be formed. Another electrical connection can be formed between different conductive contacts on a single substrate, between different conductive contacts on multiple substrates, or a different type of electrical connection can be formed, such as, for example, a connection using flexible cable. If another electrical connection or conductive border is to be formed, the process returns to block  1600 . 
     If a mask is not needed at block  1600 , the process passes to block  1614  where a conductive border or borders, or an electrical connection(s) is formed. The electrical connection(s) or conductive border(s) can be formed, for example, by dipping the substrate or substrates in a conductive material. Alternatively, the one or more conductive borders or electrical connections can be formed by depositing conductive material on a surface or conductive contact. Examples of conductive materials include, but are not limited to, metal, organic materials, nanoparticles, or combinations thereof. The method then passes to block  1608 . 
     Various embodiments have been described in detail with particular reference to certain features thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the disclosure. For example, the embodiments described in conjunction with  FIGS. 3-9  are not limited to a display layer and a back transparent conductive layer. Electrical connections between two conductive contacts having contact surfaces that are oriented in different directions and disposed on any substrate or substrates, including, but not limited to, metal, plastic, glass, or printed circuit boards, can use embodiments described herein. Additionally or alternatively, embodiments can have or form an electrical connection between three or more conductive contacts. 
     And even though specific embodiments have been described herein, it should be noted that the application is not limited to these embodiments. In particular, any features described with respect to one embodiment may also be used in other embodiments, where compatible. Likewise, the features of the different embodiments may be exchanged, where compatible.

Metadata:
Filing Date: 20140220
Publication Date: 20160524
Grant Date: 20160524
Priority Date: 20130221
Inventors: SUNG KUO-HUA
GRESPAN SILVIO
SHADLE BRIAN
TEIL ROMAIN A.
WITTENBERG MICHAEL B.
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K3/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/09", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/11", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K3/403", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/11", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K2201/09172", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09172", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2203/1361", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/11", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K2203/1476", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2203/1361", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/403", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2203/1476", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 55969910