Abstract:
A method of and device for making a three dimensional electronic circuit. The method comprises coupling one or more magnet wires with a substrate along a surface contour of the substrate, immobilizing the one or more magnet wires on the substrate, and forming the electronic circuit by electrically coupling the one or more magnet wires with an integrated circuit chip.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of electronic circuitry. More specifically, the present invention relates to electronic circuitry using magnet wires. 
     BACKGROUND OF THE INVENTION 
     Typical circuit traces made by PCB fabrication (printed circuit board) involve using complicated manufacturing process, such as processes of lithography and etching. Another typical circuitry manufacturing process involves using printed conductive inks. The drawbacks of using the printed conductive inks are that the material has high electrical resistance. It is still remaining a great challenge using the typical technologies to fabricate metal traces on a 3D object. Further, the typical mold interconnect device (MID) technology is too complicated and expensive to viably make 3D circuitry. 
     SUMMARY OF THE INVENTION 
     Methods of and devices for making 3D (three dimensional) electronic circuitry using magnet wires are disclosed. Magnetic wires are the thin insulated wires conventionally used as the windings in coils and transformers. The magnet wires can be used to replace metal traces that are fabricated using traditional PCB etching process and can be used to replace the conductive ink. In some embodiments, the magnet wires comprises micro-solid magnet wires coated with a layer of insulating material, such as a polymer (e.g., polyvinyl formal (formvar: thermoplastic resins that are polyvinyl formals, which are polymers formed from polyvinyl alcohol and formaldehyde as copolymers with polyvinyl acetate), polyurethane, polyamide, polyester, polyester-polyimide, polyamide-polyimide, amide-imide resin, polyimide, and teflon). The insulation layer can serve as a flux when it is burnt/burned during soldering. 
     In some embodiments, the micro-solid magnet wires have a size in the range of 1-50 mils (thousandth of an inch). In some embodiments, the micro-solid magnet wires comprise fine line circuitry that can be applied on a 3D object. In some embodiments, the magnet wires are rounded in its cross sectional view. In other embodiments, the magnet wires are rectangular. In some other embodiments, the magnet wires are circular or square. In some embodiments, the size of the magnet wires is ranging from several mils (e.g., 5 mils) to less than 1 mil. 
     The pitch between the magnet wires, which is applied on an object, can range from several mils (such as 3 mils) to less than 1 mil. For example, a magnet wire that is applied on an object have 2 mils in its diameter and 2 mils in space to the next nearest magnet wire. A person of ordinary skill in the art appreciates that any other diameters and pitch spaces are applicable. 
     The wires can be bonded to an integrated circuit chip (hereinafter “chip”) or package pads through micro welding using a laser, a thermosonic bonding process, or a soldering process. The insulation coating on the wire tips can be stripped through applying UV or laser, such that the metal traces can be exposed. Metals used to make the core of the wires include copper, copper alloys, aluminum, silver, or a combination thereof. A person of ordinary skill in the art appreciates that other metals can be used. 
     In an aspect, a method of forming an electronic circuit comprises coupling one or more magnet wires with a substrate along a surface contour of the substrate, immobilizing the one or more magnet wires on the substrate, and forming the electronic circuit by electrically coupling the one or more magnet wires with an electronic component such as an integrated circuit chip. In some embodiments, the contour comprises a non-flat surface. In other embodiments, the method further comprises applying an amount of adhesive on the substrate. In some other embodiments, the method further comprises applying an amount of adhesive on the one or more magnet wires. In some embodiments, the one or more magnet wires comprise a self bonding magnet wire. In some other embodiments, the method further comprises applying an amount of alcohol. In some embodiments, the method further comprises bonding in an oven. In some other embodiments, the method further comprises bonding by generating an electric current. In some embodiments, the method comprises removing a portion of an insulating layer by using a laser pulse. In some other embodiments, the method further comprises covering the portion with an insulating material. 
     In another aspect, an electronic circuit comprises one or more magnet wires couples with an integrated circuit chip on a surface of a substrate. In some embodiments, the surface comprises a non-flat surface. In other embodiments, the surface is a three dimensional surface. In some other embodiments, the one or more magnet wires comprise an aluminium wire. In some embodiments, the one or more magnet wires comprise a silver wire. In some other embodiments, the one or more magnet wires comprise a copper wire. 
     In another aspect, a method of forming a three dimensional electronic circuit comprises shaping a magnet wire according to a surface shape of a substrate, immobilizing the magnet wire on the surface, and coupling the magnet wire with an electronic component. 
     In some embodiments, the three dimensional electronic circuit is part of a circuit board. In other embodiments, the circuit board is coupled with a microwave oven. In some other embodiments, the circuit board is coupled with an electric motor. 
     Other features and advantages of the present invention will become apparent after reviewing the detailed description of the embodiments set forth below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will now be described by way of examples, with reference to the accompanying drawings which are meant to be exemplary and not limiting. For all figures mentioned herein, like numbered elements refer to like elements throughout. 
         FIGS. 1A and 1B  illustrate an electronic circuitry manufacturing method in accordance with some embodiments of the present invention. 
         FIG. 2  illustrates another electronic circuitry manufacturing method in accordance with some embodiments of the present invention. 
         FIG. 3  illustrates another electronic circuitry manufacturing method in accordance with some embodiments of the present invention. 
         FIG. 4  illustrates another electronic circuitry manufacturing method in accordance with some embodiments of the present invention. 
         FIG. 5  is a flow chart illustrating a magnet wire applying method in accordance with some embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference is made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings. While the invention is described in conjunction with the embodiments below, it is understood that they are not intended to limit the invention to these embodiments and examples. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which can be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to more fully illustrate the present invention. However, it is apparent to one of ordinary skill in the prior art having the benefit of this disclosure that the present invention can be practiced without these specific details. In other instances, well-known methods and procedures, components and processes have not been described in detail so as not to unnecessarily obscure aspects of the present invention. It is, of course, appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer&#39;s specific goals, such as compliance with application and business related constraints, and that these specific goals vary from one implementation to another and from one developer to another. Moreover, it is appreciated that such a development effort can be complex and time-consuming, but is nevertheless a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure. 
       FIGS. 1A and 1B  illustrate an electronic circuitry manufacturing method  100  in accordance with some embodiments of the present invention. At Step  101 , a substrate  102  is prepared. The substrate  102  can be a polymeric three dimensional object. A person of ordinary skill in the art appreciates that the substrate  102  can be any substrates or supporting base. 
     At Step  103 , a computer chip  104  is coupled with the substrate  102 . The coupling of the computer chip  104  and the substrate  102  can be achieved by using a die attaching material  106 , such as a conducting/non-conducting glue. The coupling immobilizes or secures the computer chip  104  on the substrate  102 . Further, an amount of adhesives  112  is applied on the surface of the substrate, such that magnet wires are able to be coupled with/secured on the surface of the substrate  102 . 
     At Step  105 , one or more magnet wires  108  are coupled with the substrate  102 . Heat, a laser beam, UV light, or a combination thereof is applied on the surface of the substrate  102  and wires  108 , such that the wires  108  are secured on the surface of the substrate  102 . 
     At Step  107 , predetermined portions  108 C and  108 D of an insulation layer  108 A of the wires  108  are removed using a laser pulse  130  or any cutting tools, such as any mechanical cutting devices (e.g., scissors, strippers, nips, knifes among others). The predetermined portions  108 C and  108 D of insulation layer  108 A is stripped and the portions  108 B and  108 E of a conducting wire are exposed, which are welded to a pad of the computer chip  104 . A person of ordinary skill in the art appreciates that the predetermined portions  108 C and  108 D can be any length (e.g., 0.2-0.5 cm or the tip of the magnet wires), so long as it is sufficient to be welded/connected with targeting connecting components (such as the pad of the computer chips). 
     At Step  109 , a protective layer  110  is applied to cover/encapsulate the welding/exposed conducting wire portion. The protective layer  110  can be a polymer, such as PE, PP or polyurethane. The protective layer  110  can also be an insulating material, such as an insulating self-adhesive tape. 
       FIG. 2  illustrates another electronic circuitry manufacturing method  200  in accordance with some embodiments of the present invention. At Step  201 , a substrate  202  is manufactured. The substrate  202  can be a polymeric three dimensional object. 
     At Step  203 , a computer chip  204  is coupled with the substrate  202 . The coupling of the computer chip  204  and the subtract  202  can be achieved by using a die attaching material  206 , such as a conducting/non-conducting glue. The coupling immobilizes or secures the computer chip  204  on the substrate  202 . Further, an amount of adhesives  212  is applied on the surface of the substrate, such that magnet wires are able to be coupled with/secured on the surface of the substrate  202 . A person of ordinary skill in the art appreciates that the amount of adhesive  212  can be sufficient to secure the attaching object from falling off. At Step  205 , one or more magnet wires  208  are coupled with the substrate  202  via the attaching force of the adhesive  212 . 
     At Step  207 , an external force/pressure is applied on the wires  208 , such that the wires  208  are firmly coupled with the substrate  202 . The force/pressure can be generated by a mechanical device  214 , such as a pressing roller. Next, a laser  216  is used to melt a polymer skin/insulation coating that wraps a conductive wire of the wires  208 . The polymer skin/insulation coating solidifies when it cools down below its melting point. The melting and solidification processes form a new protecting layer over the wires  208  on the substrate  202 . As shown in a cross sectional view  207 A, the insulating coating  208 B of the wires  208  melts and forms a new protecting layer  208 C over the conducting wire  208 A of the wires  208 . 
     At Step  209 , predetermined portions  208 C and  208 D of an insulation layer  208 A of the wires  208  are cut using a laser device  230  or any cutting tools, such as any mechanical cutting devices (e.g., scissors, strippers, nips, knifes among others). The predetermined portions  208 C and  208 D of insulation layer  208 A are stripped and the portions  208 B and  208 E of a conducting wire are exposed, which are welded to a pad of the computer chip  204 . A person of ordinary skill in the art appreciates that the predetermined portions  208 C and  208 D can be any length (e.g., 0.2-0.5 cm or the tip of the magnet wires), so long as it is sufficient to be welded/connected with targeting connecting components (such as the pad of the computer chips). 
     At Step  211 , a protective layer  210  is applied to cover/encapsulate the welding/exposed conducting wire portion. The protective layer  210  can be a polymer, such as PE, PP or polyurethane. The protective layer  210  can also be an insulating material, such as an insulating self-adhesive tape. 
       FIG. 3  illustrates another electronic circuitry manufacturing method  300  in accordance with some embodiments of the present invention. At Step  301 , a substrate  302  is manufactured. The substrate  302  can be a polymeric three dimensional object. 
     At Step  303 , a computer chip  304  is coupled with the substrate  302 . The coupling of the computer chip  304  and the substrate  302  can be achieved by using a die attaching material  306 , such as a conducting/non-conducting glue. The coupling immobilizes or secures the computer chip  304  on the substrate  302 . 
     At Step  305 , one or more self bonding magnet wires  308  are coupled with the substrate  302  via the attaching force of the adhesive/enamel  312  on the self bonding magnet wires  308 . The enamel  312  can couple the self bonding magnet wires  308  with the substrate  302  using an activating liquid (such as an organic solvent; e.g., alcohol/ethanol/propanol) or a predetermined temperature. Three exemplary self-bonding enamel wire fusing methods are provided, including an alcohol bonding method, an oven bonding method, and a resistance heating method. 
     In the alcohol bonding method, an amount of alcohol is applied onto wires immediately before or sometime before coil winding or the wires are soaked into alcohol after the winding process. After the application of the alcohol, heating is performed to enhance an adhesive strength. The alcohol bonding method can be used in making electrical equipment, such as brushless motors. 
     In the oven bonding method, heat-sealing coils are heated in a heat chamber. The oven bonding method can be used for fusing narrow wires that cannot be electrified due to excessively high resistance or thick wire coils that require a large current. The oven bonding method can be used to make microwave ovens. 
     In the resistance heating method, electric current is used to melt and fuse bonding films by generating Joule heat. In this method, the temperature is determined on the radiation effect, which is affected by the conductor diameter, film thickness, wire turns, coil shape, and surrounding environment. The resistance heating method can be used to make microwave ovens. 
     At Step  307 , predetermined portions  308 C and  308 D of an insulation layer  308 A of the wires  308  are cut using a laser device  330  or any cutting tools, such as any mechanical cutting devices (e.g., scissors, strippers, nips, knifes among others). The predetermined portions  308 C and  308 D of insulation layer  308 A are stripped and the portions  308 B and  308 E of a conducting wire are exposed, which are welded to a pad of the computer chip  304 . A person of ordinary skill in the art appreciates that the predetermined portions  308 C and  308 D can be any length (e.g., 0.2-1.5 cm or the tip of the magnet wires), so long as it is sufficient to be welded/connected with targeting connecting components (such as the pad of the computer chips). 
     At Step  309 , a protective layer  310  is applied to cover/encapsulate the welding/exposed conducting wire portion. The protective layer  310  can be a polymer, such as PE, PP or polyurethane. The protective layer  310  can also be an insulating material, such as an insulating self-adhesive tape. 
       FIG. 4  illustrates another electronic circuitry manufacturing method  400  in accordance with some embodiments of the present invention. At Step  401 , a substrate  402  is manufactured. The substrate  402  can be a polymeric three dimensional object. 
     At Step  403 , a computer chip  404  is coupled with the substrate  402 . The coupling of the computer chip  404  and the substrate  402  can be achieved by using a die attaching material  406 , such as a conducting/non-conducting glue. The coupling immobilizes or secures the computer chip  404  on the substrate  402 . Further, an amount of adhesives  412  are applied on the surface of the substrate, such that magnet wires are able to be coupled with/secured on the surface of the substrate  402 . A person of ordinary skill in the art appreciates that the amount of adhesive  412  can be sufficient to secure the attaching object from falling off. At Step  405 , one or more magnet wires  408  are coupled with the substrate  402  via the attaching force of the adhesive  412 . 
     At Step  407 , an external force/pressure is applied on the wires  408 , such that the wires  408  are firmly coupled with the substrate  402 . The force/pressure can be generated by a mechanical device  414 , such as a pressing roller. Next, a laser  416  is used to melt a polymer skin/insulation coating that wraps a conductive wire of the wires  408 . The polymer skin/insulation coating solidifies when it cools down below its melting point. The melting and solidification processes form a new protecting layer over the wires  408  on the substrate  402 . 
     At Step  409 , solders  420  are used to connect the exposed wires  433  to the chip  404 . During the soldering process, the insulation layer of the wires  408  acts as a flux, which avoids a step of stripping the insulation layer while making the electrical connections. 
     At Step  411 , a protective layer  410  is applied to cover/encapsulate the welding/exposed conducting wire portion. The protective layer  410  can be a polymer, such as PE, PP or polyurethane. The protective layer  410  can also be an insulating material, such as an insulating self-adhesive tape. 
       FIG. 5  is a flow chart illustrating a magnet wire applying method  500  in accordance with some embodiments of the present invention. At step  502 , one or more computer chips are attached to a substrate. At Step  504 , the routes/paths/distribution of the wires are determined. The determination can be done by referencing to a circuit blue print. At Step  506 , the magnet wires are attached to the substrate. At Step  508 , connections between the conductive portion of the magnet wires and the computer chip are made. At Step  510 , protective layers are applied to prevent the exposure of the conducting portion of the magnet wires. The method  500  can stop at Step  512 . 
     Magnet wires used as conductive wires provide many superior features in the industrial applications and uses. For example, some of the magnet wires are commercially available with various diameters, such as 1 mil or 0.1-2 mils. Some of the magnet wires are coated with insulating materials, such that shorting can be prevented between wires. The magnet wires can be embedded on or in polymer substrate as circuit traces without going through complicated PCB fabrication process. Furthermore, magnet wire has better electrical conductivity when compared with printed circuits on PCB, thereby the magnet wire is able to endure higher current and voltage. Moreover, the magnet wire can be embedded on a surface of a 3D object, which are difficult to be achieved by typical processes. 
     The methods and devices disclosed here can be utilized in making electronic connections for consumer electronics, such as transformers, inductors, motors, speakers, hard disk head actuators, and other applications that use tight coils of wire. The wires are able to be fully annealed and electrolytically refined copper. 
     In some embodiments, the magnet wire used herein comprises four layers of insulation. Two of the four layers can comprise different compositions for providing a tough and continuous insulating layers for structure integrity. The chemicals for the polymer layers can be selected with a high (e.g., 250° C.) or low melting temperature. In some embodiments, the insulation layer of the wires can be Telfon, fiberglass yarn with vanish, aramid paper, kraft paper, mica, and polyester. The polymers used can be determined by their breakdown voltage. 
     The magnet wires or enameled wires used herein can be copper, silver, gold, or aluminum wire coated with a thin layer of insulation. The magnet wires chosen can be in a temperature class of 105° C., 130° C., 155° C., 180° C., and 220° C., which indicates the temperature of wire when it has a 20,000 hour service life. 
     In operation, the method of applying the magnet wires including holding the wire in place using a tool (like capillary for wire bonding) and pushing the wire against a polymer substrate based on the circuitry design. An amount of adhesive can be pre-applied on the surface of the substrate. While the wire is pushed onto the substrate, an amount of UV or heat is applied locally to cure the adhesive. Accordingly, the wires can be placed, attached, and secured to the substrate when the adhesive is cured or dried. 
     The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It is readily apparent to one skilled in the art that other various modifications can be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention as defined by the claims.