Patent Publication Number: US-2017365569-A1

Title: Contact Bumps and Methods of Making Contact Bumps on Flexible Electronic Devices

Description:
The present application is a continuation-in-part of U.S. application Ser. No. 14/952,958, filed on Nov. 26, 2015, entitled “Contact bumps methods of making contact bumps”; which is a continuation-in-part of U.S. Ser. No. 14/094,714, filed on Dec. 2, 2013, entitled “Contact bumps methods of making contact bumps”, now U.S. Pat. No. 9,215,809 entitled “Contact bumps methods of making contact bumps”; which is a continuation-in-part of PCT patent application PCT/DE2013/000451, filed on Aug. 9, 2013, entitled “Contact bump connection and contact bump and method for producing a contact bump connection”; which claims priority of German patent application 10 2012 015 811.4, filed on Aug. 10, 2012, entitled “Contact bump connection and contact bump and method for producing a contact bump connection”, all of which are hereby incorporated by reference. 
    
    
     FIELD OF TECHNOLOGY 
     This disclosure relates generally to semiconductor manufacturing. Example embodiments may relate to methods, apparatus, and systems wherein contact bumps formed on flexible supporting structures include a rough surface that can mate with the surface of a contact pad material which in one or more embodiments may be flexible. The rough surface can enhance the bonding strength between the contact bumps and the contact pad, for example, against shear and tension forces, especially for flexible electronic devices. In one embodiment, the contact and mating may be formed via roller or other methods. 
     BACKGROUND 
     Contact bumps play an essential role in the field of semiconductor technology for contacting semiconductor devices or chips with other substrates or carriers such as printed circuit boards. 
     Different techniques for forming contact bumps can be used for the connection of pads of semiconductor devices, chips, or substrates. An example is the so-called flip-chip technique, in which the bumps are arranged as connection elements on the chip and are optionally contacted with an additional pressure sensitive adhesive to the connecting pads of a carrier substrate. The quality of the connection established between connection surfaces of the carrier substrate and the bumps plays an essential role in the later use of the components. 
     In the mechanical method, a gold wire can be used, which is shaped at its tip by the action of heat into a ball. The spherical tip of the gold wire is pressed with a suitable tool to a connection surface of the substrate, so that the ball is deformed by the force applied. Then the wire is pinched off, torn or sheared across the globe, so that a bulbous body with a wire remaining on top as bumps or contact bump remains on the substrate. The remaining on the tip of bulbous body is then flattened generally in the same or another tool. This technique is known as mechanical stud bumping and is known for example from U.S. Pat. No. 5,060,843. The connection of the material of the gold bump with metallization of the pad is performed via the pressure applied and the resulting micro-welding between the two boundary surfaces. 
     A general limitation of all know connecting technologies is the limited applicability to flexible electronic components like flexible semiconductors. 
     SUMMARY 
     In some embodiments, the present invention discloses contact bumps and methods of making contact bumps on flexible conductive materials that are configured to form contact with corresponding contact pads. The contact bumps and the corresponding contact pads can be pressed together with a bonding force, which can drive the contact bumps into the material of the contact pads. 
     The contact bumps on flexible conductive materials can include a rough surface that can mate with the material of the contact pads. The material of the contact bump can be harder than the material of the contact pads, thus when pressed, the contact pads can be deformed to flow around the contact bump, forming an improved contact connection. The improved contact connection can include enhanced bonding strength of the contacts, for example, against shear and tension forces, especially for flexible systems such as smart cards. 
     The present invention may then be applied towards completely flexible or semi-flexible systems wherein the flexible conductive and facultatively present intervening layers constitute part of electronic devices originating from conventional or printed Thin Film Technology 
     In some embodiments, an oscillatory force can be used to press the contact bumps into the contact pads. The oscillatory force can include a substantially constant component, such as a pressing force, and an oscillatory component, such as an ultrasonic vibration, to allow for a flowing of the material of the contact pads around the contact bump. 
     In some embodiments processing and manufacturing may also provide for roller elements wherein then a force, such as applied by a roller, may be used such as for instance wherein the roller or rollers assert pressure on a pair of two contact partners to form a galvanic contact such as broadly continuous rolling pressing together may form a flexible device. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         FIGS. 1A-1D  illustrate various prior art contact bumps, which rely on the bonding strength of the contact bump with the contact pad, together with the increase in contact areas. 
         FIGS. 2A-2B  illustrate a contact bump and a corresponding contact bonding process according to some embodiments. 
         FIGS. 3A-3F  illustrate different configurations for the contact bump according to some embodiments. 
         FIGS. 4A-4F  illustrate various configurations for the cross section of the contact bump according to some embodiments. 
         FIGS. 5A-5E  illustrate other configurations for the contact bump according to some embodiments. 
         FIGS. 6A-6F  illustrate other configurations for the contact bump according to some embodiments. 
         FIGS. 7A-7B  illustrate a contact bump configuration according to some embodiments. 
         FIGS. 8A-8B  illustrate flow charts for forming contact bumps according to some embodiments. 
         FIG. 9  illustrates a bonded configuration of a contact bump with a contact pad according to some embodiments. 
         FIGS. 10-11A and 11B  illustrate a process flow for forming the bonded configuration between a contact bump and a contact pad according to some embodiments. 
         FIGS. 12A-12B  illustrate another process flow for forming the bonded configuration between a top contact bump and a bottom contact bump according to some embodiments. 
         FIGS. 13A-13B  illustrate flow charts for forming contact with contact bumps according to some embodiments. 
         FIGS. 14A-14B  illustrate a RFID card having a contact bump bonding according to some embodiments. 
         FIG. 15  illustrates a flow chart for forming flexible element such as a substrate, antenna or device contact with contact bumps according to some embodiments. 
         FIGS. 16A-16D  illustrate contact bump configurations for a rectangular contact pad according to some embodiments. 
         FIGS. 17A-17C  illustrate other configurations for the contact bump according to some embodiments. 
         FIGS. 18A-18B  illustrate flow charts for forming contact connection for a device according to some embodiments. 
         FIGS. 19A-19B  illustrate a contact connection with a contact bump according to some embodiments. 
         FIGS. 20A-20B  illustrate a bonding process between two contact pads according to some embodiments. 
         FIGS. 21A-21C  illustrate bonding configurations according to some embodiments. 
         FIGS. 22A-22B  illustrate flow charts for forming a contact connection according to some embodiments. 
         FIGS. 23A-23C  illustrate contact bump configurations on a flexible substrate. 
         FIGS. 24A-24C  illustrate flow charts for forming a bump for flexible substrates according to some embodiments. 
         FIGS. 25A-25D  illustrate contact bump configurations on a flexible substrate in different configurations and cross sections. 
         FIGS. 26A-26B  illustrate flow charts for forming a bump for flexible substrates according to some embodiments. 
         FIGS. 27A-27C  illustrate forming contact bump configurations on a flexible substrate with rollers. 
         FIGS. 28A-28C  illustrate forming contact bump configurations on a flexible substrate with rollers. 
         FIGS. 29A-29B  illustrate forming contact bump configurations on a flexible substrate with rollers. 
         FIGS. 30A-30B  illustrate flow charts for forming bumps and devices for flexible substrates and devices according to some embodiments. 
         FIG. 31  illustrate flow charts for forming bumps and devices for flexible substrates and devices according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     In some embodiments, the present invention discloses methods and systems for bonding terminal pads of a chip (flexible chip, not crystal) with corresponding contact pads of a substrate, which can be another (device) or a system board. The bonding process can include forming a contact bump on a terminal pad, before bonding the contact bump with a corresponding contact pad. 
     In some embodiments, the contact bump can include an irregular surface, for example, a surface having recesses and protrusions, which can include micro roughness textures of the surface, that are caused by the formation process of the contact bump. The micro roughness textures can include roughness in an order of micrometers, such as less than 30, less than 10, less than 5, less than 1, or less than 0.1 microns. The roughness can be characterized by maximum peak-to-valley height, by the average peak-to-valley height, or by the mean roughness index. 
     In some embodiments, the contact bump can have a hardness higher than the hardness of the corresponding contact pad. Thus, in some cases, during the bonding of the contact bump with the corresponding contact pad, the material of the corresponding contact pad can be deformed, with minimum effect on the contact bump. 
     Further, the structure of the contact bump, e.g., the shapes and sizes of the contact bump, can be such that the material of the corresponding contact pad can be driven away from the contact bump to facilitate a strong surface interaction between the contact bump and the corresponding contact pad. 
     During the bonding of the contact bump with the contact pad, for example, by applying a contact force on the contact bump to drive the contact bump into the contact pad material, the contact pad material can be driven to form intimate mating with the irregular surface, for example, by filling the recesses or flowing around the protrusion. The intimate contact between the contact pads and the irregular surface of the contact bump can significantly improve the bonding strength of the contact bonding, especially enhancing shear and tension bonding characteristics which can be required in flexible substrates such as smart cards. 
     An oscillatory force, such as at an ultrasonic frequency, can be used during the driving of the contact bump to the corresponding contact pad. For example, due to the rough surface of the contact bump, an intermesh effect can be created. And due to the oscillation, a heat can be created for a short time, such as a few milliseconds, which can create an intermetallic connection between the two materials. 
       FIGS. 1A-1D  illustrate various prior art contact bumps, which rely on the bonding strength of the contact bump with the contact pad, together with the increase in contact areas. The contact pads or the contact bump can have pins, which can increase the contact area for improving the bonding strength. 
     In  FIG. 1A , a chip  110  can have a terminal pad  112  disposed on an external surface of the chip. Passivation layer  114  can be included, for example, to isolate the terminal pad  112  from neighbor terminal pads. A layer  116  containing an under-bump material (UBM), such as an alloy of aluminum, nickel and copper, can be formed to facilitate the bonding of the contact bump  120  to the terminal pad  112 . The contact bump  120  can include solder material or palladium material. A substrate  130  having contact pad  132  can be brought to the contact bump  120  for bonding between the contact bump  120  and the contact pad  132 . 
     In  FIG. 1B , pins  164  can be formed on the contact pad  162  of the substrate  160 . The contact between the contact pad  162  and the contact bump  150  can be enhanced by the penetration of pins  164  into the contact bump  150 . In  FIG. 1C , contact bump  180  can be enforced by pins  178 , which can enhance the bonding of the contact bump  180  with the chip  170 . In  FIG. 1D , pins  198  can protrude from the contact bump  196 , which can enhance the bonding of the contact bump  196 , bonding the chip  190  with a contact pad of the substrate. 
     In some embodiments, the present invention discloses contact bonding processes, and the contact bumps fabricated for the contact bonding processes, that can further include a physical attachment between the contact bump and the contact pad, in addition to the surface chemical bonding. The physical attachment can include multiple protrusions between the contact bump and the contact pad, thus can provide separation resistance. For example, the contact bump can have an irregular surface that includes recesses and protrusions. The irregular surface of the contact bump can be mated to a corresponding surface of the contact pad. The recesses and protrusions at the interface of the bonded surfaces can provide an additional resistance to any separation force in the shear direction. 
       FIGS. 2A-2B  illustrate a contact bump and a corresponding contact bonding process according to some embodiments. A contact bump  220  can be fabricated on a terminal pad  212  of a substrate  210 , such as a semiconductor chip, and of note which may be a flexible chip. The contact bump  220  is shown to be directly formed on the terminal pad  212 , but other configurations can also be used, such as a passivation layer for isolating the contact bump  220  with neighbor contact bumps, or an UBM layer for improving adhesion and contact resistance between the contact bump  220  and the terminal pad  212 . 
     The contact bump  220  can have two facing surfaces  221  and  222 , e.g., inner surfaces of the contact bump. A surface, such as surface  221 , can have irregularities, e.g., a non-smooth surface with recess  240  and/or protrusion  245 , which can provide physical bonding to a bonded contact pad against tensile separation. The irregularities can include recesses and protrusions having dimensions of a few percent of the contact bump dimension, such as greater than about 0.1 micron, greater than 1, 3 or 5 microns, or greater than about 10 microns. The irregularities can include recesses and protrusions having dimensions less than 100 microns, less than 50, 20, 10, 5, 3 microns, or less than about 1 microns. The irregularity can include surface roughness, with peak to valley height in order of a few nanometers to multiple micrometers, such as between about 10 nm and about 100 microns. 
     The two surfaces can be tapered upward, e.g., forming a taper angle  251  with the direction perpendicular to the terminal pad  212 , with the lower opening  250  can be larger than the upper opening  255 . The taper of the surfaces can force the material from the contact pad to rise upward, which can be driven sideway to fill the recess  240  to flow around the protrusion  245 . The taper angle can be greater than zero degree, such as greater than about 10 degrees, or can be greater than about 30 degrees. Other surface configurations can be used, such as curve surfaces. 
     The facing surface, e.g., surface  222 , can form an angle  230  with the direction of the bonding force. Typically, the contact bump can be pressed against a contact pad  260  in a direction perpendicular to the terminal pad  212 . Thus, the surface  222  can form an angle  230  with the normal direction of the terminal pas  212 . When a force is applied to the contact bump for bonding with the contact pad, materials from the contact pad can rise  270  to make contact with the surface  222 . Since the surface  222  forms an angle with the applied force, the normal force at the surface  222  can have a side component  275 , which can direct the material sideway to fill in the recess  245  or to flow around the protrusion. The angle can be greater than zero degree, such as greater than about 10 degrees, or can be greater than about 30 degrees. 
       FIGS. 3A-3F  illustrate different configurations for the contact bump according to some embodiments. A contact bump  320  can be bonded to a terminal pad  312  on a substrate  310 . In  FIG. 3A , a contact bump can have a recess  340  on an inner surface  321 , which forms angle of about 15 degrees with the normal direction of terminal pad  312 . The tips  350  of the contact bump can be flat. The top portion  330  of the inner surface  321  can also be flat when facing with the opposite surface. In  FIG. 3B , the contact bump can have a protrusion  342  on an inner surface. In  FIG. 3C , the contact bump can have a combination of protrusion and recess  344  on an inner surface. Other irregular surfaces can be used, for example, multiple recesses and protrusions on an inner surface of the contact bump. Also, the recesses and protrusions of the irregular surface can be random, generated from a deposition process when forming the contact bump. 
     In  FIG. 3D , the tips  352  of the contact bump can be sharp, which can facilitate the penetration of the contact bump to the contact pad. The top portion  332  of the inner surface can also be sharp. In  FIG. 3E , the tips of the contact bump can have different height. For example, one tip  382  can be shorter than the other tip  380 . The tip  384  can be longer than the other tip  380 . In  FIG. 3F , the surface  370  having the irregularities can be in the normal direction of the terminal pad  312 . The opposite facing surface can form an angle with the normal direction, which can provide a horizontal or side force to drive the excess material to fill in the gaps in the irregular surface  370 . 
     The connection area can be covered the entire surface on the substrate through the layer deposition. The generation of the bump can be in several stages. Adhesion and barrier layer can be deposited by sputtering or evaporation on the connecting metallization and then possibly reinforced by electroplating. For example, Cr, stainless steel, Cu, Ti, Pt, Au, TiW, TiW, Ni, or any alloys or combinations can be used. The contact material can include Au, Cu, Ni, SnPb, AuSn, SnAg, In, or any alloys or combinations, which can be applied by vapor deposition or electrodeposition. For solder bump, SnPb, SnAg and In can be used. For welding, Au and In can be used. Bumps of Au, Ni and Cu may be used by an additional application of adhesive or solder bumps on the substrate or on the side of a solder or adhesive bond. 
     Alternatively, Al or Cu alloy can be used with silicon wafers (flexible electronic devices, build with thin film layers—with vacuum deposition processes or printed layers), which can be deposited without the use of masks, e.g., by an electroless plating, using Ni or Pd on the contact metallization. With Cu and Au, this can normally be strengthened. 
     In some embodiments, the present invention can provide methods to produce contact bumps and bumps which allow the production of an electrical connection of the bump with bond pads, or other connection elements to form a more effective and a higher connection reliability. 
       FIGS. 4A-4E  illustrate various configurations for the cross section of the contact bump according to some embodiments. In  FIG. 4A , a cross section view of the contact bump can show two contact tips  420  and  450  bonded to a terminal pad  410 . Recess  440  can be provided at the contact tip  420 . One recess  440  is shown, but the contact bump can have other irregularities, such as multiple recesses or protrusions, in a surface of one contact tip  420  or  450  or in surfaces of both contact tips  420  and  450 . Cut line A x A x ′ can show different cross section views of the contact bump. 
       FIG. 4B  shows a cross section A 1 A 1 ′ (among the different cross sections A x A x ′ of  FIG. 4A ) of a contact bump as shown in  FIG. 4A , whose cross section can be the cross section C 1 C 1 ′. The contact bump can include two pyramid-like cones  420 B (which can correspond to contact tip  420 ) and  450 B (which can correspond to contact tip  450 ) protruded from the terminal pad  410 B (which can correspond to terminal pad  410 ). Recess  440 B (which can correspond to recess  440 ) can be shown on a surface of cone  420 B. 
       FIG. 4C  shows a cross section A 2 A 2 ′ (among the different cross sections A x A x ′ of  FIG. 4A ) of a contact bump as shown in  FIG. 4A , whose cross section can be the cross section C 2 C 2 ′. The contact bump can include a pyramid-like cone  420 C (which can correspond to contact tip  420 ), together with a half-moon cone  450 C (which can correspond to contact tip  450 ) protruded from the terminal pad  410 C (which can correspond to terminal pad  410 ). Recess  440 C (which can correspond to recess  440 ) can be shown on a surface of cone  420 C. The recess  440 C can be surrounded by a half moon surface of cone  450 C, which can provide horizontal force to the recess at multiple direction, allowing the material from the contact pad to easily fill in the recess. 
       FIG. 4D  shows a cross section A 3 A 3 ′ (among the different cross sections A x A x ′ of  FIG. 4A ) of a contact bump as shown in  FIG. 4A , whose cross section can be the cross section C 3 C 3 ′. The contact bump can include a half moon cone  420 D (which can correspond to contact tip  420 ), together a pyramid-like cone  450 D (which can correspond to contact tip  450 ) protruded from the terminal pad  410 D (which can correspond to terminal pad  410 ). Recess  440 D (which can correspond to recess  440 ) can be shown on a surface of cone  420 D. 
       FIG. 4E  shows a cross section A 4 A 4 ′ (among the different cross sections A x A x ′ of  FIG. 4A ) of a contact bump as shown in  FIG. 4A , whose cross section can be the cross section C 4 C 4 ′. The contact bump can include a circular cone  420 E/ 450 E (which can correspond to contact tips  420 / 450 ) protruded from the terminal pad  410 E (which can correspond to terminal pad  410 ). The circular cone can have the shape of an inverted volcano having a hollow portion in the middle. Recess  440 E (which can correspond to recess  440 ) can be shown on a surface of the circular cone. 
       FIG. 4F  shows a cross section A 5 A 5 ′ (among the different cross sections A x A x ′ of  FIG. 4A ) of a contact bump as shown in  FIG. 4A , whose cross section can be the cross section C 5 C 5 ′. The contact bump can have a shape of a partially surrounding wall, such as a half-moon shape, protruded from the terminal pad  410 F (which can correspond to terminal pad  410 ), with facing surfaces or facing extended portions  420 F (which can correspond to contact tip  420 ) and  450 F (which can correspond to contact tip  450 ). Recess  440 F (which can correspond to recess  440 ) can be shown on a surface of the extended portion  420 F. 
       FIGS. 5A-5E  illustrate other configurations for the contact bump according to some embodiments. In  FIG. 5A , a cross section of a contact bump  515  is shown, which is disposed on a terminal pad  510 . The contact bump  515  shows two tips  520  and  550 , having a mushroom shape. The mushroom shape can include a recess or a protrusion at the end of the tip, or a larger tip portion than a body portion. The mushroom shape  520  can include a protrusion  540 . The mushroom shape  550  can include an angle surface  570 . In  FIG. 5B , the contact bump can include three mushroom tips. In  FIG. 5C , the contact bump can include mushroom tips having irregular patterns.  FIG. 5D  shows a contact bump having contact tips  643  with rough surfaces  673 .  FIG. 5E  shows a contact bump having different contact tips with different rough surfaces. Other shapes can be formed, such as more than three tips, different mushroom shapes, or a combination of mushroom shapes and cone shapes. 
       FIGS. 6A-6F  illustrate other configurations for the contact bump according to some embodiments. In  FIG. 6A , a cross section of a contact bump  615  is shown, which is disposed on a terminal pad  610 . The cross section view of the contact bump  615  shows three tips  620 ,  650  and  660 . Multiple recesses and protrusions  640  can be formed on the inner surfaces of the tips.  FIG. 6B  shows the cross section view of cut line BB′, with the tips  620  and  650  having a volcano shape and the tip  660  a cone shape in the middle of the volcano.  FIG. 6A  can be a cross section view of cut line DD′ of  FIG. 6B . Other cross section views of cut line BB′ can be used, such as multiple pyramid-like cones (similar to that of  FIG. 4B ), one or two pyramid-like cones with one or two half-moon cones (similar to that of  FIGS. 4C and 4D ), multiple circular cones (similar to that of  FIG. 4E ), multiple partially surrounding walls (similar to that of  FIG. 4F ). 
       FIGS. 6C-6F  show other cross section configurations of the contact bump, which can be viewed at a same direction as that of  FIG. 6A . The different cross section configurations of the contact bump as shown in  FIGS. 6C-6F  can have the cross section view of cut line BB′ as shown in  FIG. 6B , or can have different cross section views as discussed above. 
     In  FIG. 6C , the middle tip  662  can be shorter than the surrounding tips  622  and  652 . In  FIG. 6D , the middle tip  664  can be longer than the surrounding tips  624  and  654 . In  FIG. 6E , the surrounding tips  626  and  656  can have vertical surfaces, e.g., planes parallel to the normal direction of the terminal pad or perpendicular to the plane of the terminal pad. The middle tip  666  can have slant surface for assist in filling the recesses and protrusions. In  FIG. 6F , the middle tip  668  can have vertical surfaces. The surrounding tips  628  and  658  can have slant surface for assist in filling the recesses and protrusions. 
       FIGS. 7A-7B  illustrate a contact bump configuration according to some embodiments.  FIG. 7A  shows a cross section view of the contact configuration  10 .  FIG. 7B  shows a cut view II-II. A contact bump configuration  10  can include a contact bump  14  formed on a terminal pad  11  of a semiconductor chip  12 . Passivation layer  13  can be used to isolate the neighbor contact bumps. The contact bump  14  can have the shape of surrounding walls  15  and a middle cone  16  raised from the floor  17 . The surrounding walls  15  can form a hollow chamber  18  with opening  19 . The inner surfaces of the surrounding walls  15  can have multiple recesses and protrusions  20 ,  21 ,  22 , and  23 . 
     In some embodiments, the present invention discloses a contact bump with improve contact bonding with a contact pad. The improved contact bonding can include physical attachments between the surfaces of the contact bump and the surfaces of the contact pad. The physical attachments can include irregular interfaces with recesses and protrusions, which can enhance the separation resistance of the contact bump from the contact pad, especially for tensile and shear stresses. 
     In some embodiments, the contact bumps can include a non-smooth surface, e.g., a surface having irregularities, and another facing surface. The two surfaces can be tapered toward the terminal pad, e.g., the contact bump has a larger opening at the end of the bump (e.g., away from the terminal pad) as compared to a smaller opening nearer the terminal pad. The facing surface can form an angle with the normal direction of the terminal pad. 
     In some embodiments, the contact bump can include a wall surrounding a cone. The wall can have sharp ends for ease of penetration to the contact pad. The inner surfaces of the wall or the surfaces of the cone can be non-smooth, e.g., having irregularities such as recesses and protrusions. 
     In some embodiments, the contact bump can be formed by a deposition process, such as an electroless plating process. The contact bump can also be formed by a photolithography process, together with other processes such as deposition and etching. The contact bump can include palladium or palladium alloy materials. 
       FIGS. 8A-8B  illustrate flow charts for forming contact bumps according to some embodiments. In  FIG. 8A , operation  800  prepares a terminal pad. The terminal pad can be formed on a substrate or on a semiconductor chip. Operation  810  deposits a conductive material on the terminal pad to form a contact bump. The contact bump can have an irregular surface with recesses and/or protrusions. The recesses and protrusions can be disposed on an inner surface of the contact bump, meaning a surface of the contact bump facing another surface of the contact bump. The irregular surface can include rough surfaces, e.g., the peaks and valleys of the rough surface can be considered as the recesses and protrusions, which can assist in securing the contact bonding of the bump connectors, one with contact bumps, to the corresponding contact pads. For example, during the contact bump formation process, such as an electroless deposition of the contact bump, the deposition can precipitate as spherical conglomerates, forming a micro roughness surface, which can be characterized as the recesses and protrusions of the contact bump surfaces. The conductive material can include palladium, such as palladium element or a palladium alloy. 
     In  FIG. 8B , operation  830  prepares a terminal pad. The terminal pad can be formed on a substrate or on a semiconductor chip. Operation  840  deposits a conductive material on the terminal pad to form a contact bump. The contact bump can have two facing surfaces, with at least a surface having irregularities of recesses and/or protrusion, and a surface forming an angle with the normal direction of the terminal pad. The conductive material can include palladium, such as palladium element or a palladium alloy. 
       FIG. 9  illustrates a bonded configuration of a contact bump with a contact pad according to some embodiments. A bonded configuration  24  can include a top substrate  12  having a contact bump  10 , and a bottom substrate  26  having a contact pad  27  on layer  28 . The contact bump  10  can penetrate the contact pad  27  from the contact surface  32 , with mating surfaces  30  between the contact bump  10  and the contact pad  27 . The mating surfaces contain irregularities, such as recesses and protrusions, which can enhance the bonding between the contact bump and the contact pad. The irregularities can form physical attachments which can be effective against tensile force. For example, raised portions  31  and  33  from the contact pad  27  can enhance the contact surface between the bump  10  and the contact pad  27 . 
       FIGS. 10-11A and 11B  illustrate a process flow for forming the bonded configuration between a contact bump and a contact pad according to some embodiments. In  FIG. 10 , a contact bump  10  is brought into contact with a contact pad  25 . The tips of the contact bump are shown to touch the surface  32  of the contact pad  25 . The contact bump can form a chamber  19 , surrounded by the walls of the contact bump. A middle cone  18  of the contact bump is disposed in the chamber  19 . 
     In  FIG. 11A , a force is applied to the contact bump to drive the contact bump into the contact pad. The walls of the contact bump can penetrate the contact pad surface, and can drive the material  34  of the contact pad inward (as shown by force Fa). As shown, the material  29  is outside the bump  10  and thus is not subjected to the force Fa. In  FIG. 11B , the contact bump is further driven into the contact pad. The surrounding walls and the middle cone of the contact bump can penetrate the material of the contact pad, and can push the material inward for filling the recesses and irregularities of the inner surfaces of the contact bump. For example, forces Fa and Fi can push on the material of the contact pad to fill the hollow area  35  in the contact bump. Heating and agitation process can be added to assist in the flow of material to the surface irregularities. A vibration process, such as an ultrasonic vibration, can be used during the pressing of the contact bump into the contact pad. The vibration can be in a direction transverse to the pressing direction  36 . Alternatively, or additionally, the vibration can be in the direction of the pressing direction  36 . 
       FIGS. 12A-12B  illustrate another process flow for forming the bonded configuration between a top contact bump and a bottom contact bump according to some embodiments. A top contact bump  1222  having surface irregularities can be brought into contact with a bottom contact bump  1220 . The top contact bump can penetrate the bottom contact bump, with the surface irregularities providing additional bonding strength for the bonded configuration. 
       FIGS. 13A-13B  illustrate flow charts for forming contact with contact bumps according to some embodiments. In  FIG. 13A , operation  1300  approaches, by a first layer having a contact bump, to a second layer. The contact bump can have an irregular surface with recesses and/or protrusions. The recesses and protrusions can be disposed on an inner surface of the contact bump, meaning a surface of the contact bump facing another surface of the contact bump. The conductive material can include palladium, such as palladium element or a palladium alloy. The contact bump and/or the contact pad surfaces can be optionally coated with an adhesion layer. Operation  1310  applies pressure to the first layer to drive the contact bump into the second layer. The surface irregularities of the contact bump can be filled with the material from the second layer, which can strengthen the bond between the first and second layers. 
     In  FIG. 13B , operation  1330  approaches, by a first layer having a contact bump, to a second layer. The contact bump can have an irregular surface with recesses and/or protrusions. The recesses and protrusions can be disposed on an inner surface of the contact bump, meaning a surface of the contact bump facing another surface of the contact bump. The conductive material can include palladium, such as palladium element or a palladium alloy. The contact bump and/or the contact pad surfaces can be optionally coated with an adhesion layer. Operation  1340  brings two layers together, wherein the configuration of the contact bump allows the material of the second layer to fill the surface irregularities. 
     In some embodiments, the bonded configurations with the contact bumps can be used for radio frequency identification (RFID) devices. The contact bump can be fabricated on the RFID chip, and the contact pads can be fabricated on a flexible element such as a substrate, antenna or device. The RFID chip can be bonded to the flexible element such as a substrate, antenna or device, forming a complete RFID device or RFID-Chip connected to the antenna creating a RFID device or product. 
     It is noted that the RFID device (or chip) may be flexible in some embodiments. 
     In some embodiments, the RFID device can be used on a card, e.g., a flexible surface. The enhanced bonding of the contact bonding between the RFID chip and the flexible element such as a substrate, antenna or device can significantly improve the reliability of the RFID card, for example, against bending during everyday usage. 
       FIGS. 14A-14B  illustrate a RFID card having a contact bump bonding according to some embodiments. A card  1410  can have a flexible element such as a substrate, antenna or device  1420  fabricated thereon. A chip  1430  having contact bumps  1440  can be bonded to the contact pads of the flexible element such as a substrate, antenna or device. The contact bumps can have surface irregularities, which can form intimate contact with the contact pads for better bonding strength. 
       FIG. 15  illustrates a flow chart for forming a flexible element such as a substrate, antenna or device contact with contact bumps according to some embodiments. Operation  1500  provides a flexible substrate having contact layer or antenna having contact pads. The flexible element such as a substrate, antenna or device can be fabricated on a card, such as a smart card, a label, a ticket. Operation  1510  provides a chip, such as an RFID chip, having contact bumps. The contact bump can have an irregular surface with recesses and/or protrusions. The recesses and protrusions can be disposed on an inner surface of the contact bump, meaning a surface of the contact bump facing another surface of the contact bump. The conductive material can include palladium, such as palladium element or a palladium alloy. The contact bump and/or the contact pad surfaces can be optionally coated with an adhesion layer. Operation  1520  applies pressure to the first layer to drive the contact bump into the second layer. The surface irregularities of the contact bump can be filled with the material from the second layer, which can strengthen the bond between the chip and the flexible element such as a substrate, antenna or device. The contact bonding process can also include vibrating the components, in a direction transverse and/or along the direction of the pressing force. Thermal energy can also be provided. 
     In some embodiments, an adhesion layer can be provided on the contact bump before contacting the contact bump with the substrate. 
     In some embodiments, the present invention discloses a bump connection between a contact bump and contact pad on substrates or electronic components. The bump connection can include a conductive bump, which can electrically connect the contact pad and thus the substrates or electronic components. The contact bump or contact pad can be connected to a terminal of an electronic component, such as a radio frequency identification (RFID) chip. The substrate can include a contact bump or contact pad of another electronic component, or a terminal of a flexible element such as a substrate, antenna or device, which can be configured for coupling to the RFID chip. 
     The bump connection can include a contact pad, which has a lateral surface, which can be configure for bonding to a terminal of an electronic component, such as a device or a flexible element such as a substrate, antenna or device. The bump connection can include a contact bump. The contact bump can be coupled to the lateral surface. The contact bump can include a first surface and a second surface. The first surface can face the second surface. The first surface can include a recess or a protrusion. The second surface can form an angle with a direction perpendicular to the lateral surface. 
     In some embodiments, the first surface can surround the second surface. The second surface can surround the first surface. The contact bump can include at least a first and a second extended portions, the first extended portion can include the first surface, and the second extended portion can include the second surface. The second extended portion can form a hollow chamber which can surround the first portion. The first extended portion can surround the second extended portion. The second extended portion can surround the first extended portion. The first extended portion can be disposed next to the second portion. The second surface can include a recess or a protrusion. The first surface can form an angle with the perpendicular direction. The second surface can be operable to exert a force in a direction parallel to the lateral surface when the contact bump can be pushed against an object surface in a direction perpendicular to the lateral surface. The contact pad can be connected to a terminal of an electronic component. The bump connector can be configured to form a hollow chamber and a middle portion disposed in the hollow chamber. The hollow chamber and the middle portion can include the first and second surfaces. The first extended portion can be disposed in the hollow chamber. The material in the substrate can be configured to be mated with the recess or protrusion. The material in the substrate can be configured to be interlocked with the recess or protrusion. The second extended portion can surround the first extended portion. The first extended portion can be shorter than the second extended portion. The substrate can include a terminal end of a flexible element such as a substrate, antenna or device. The first extended portion can include a sharp tip. The second extended portion can include a sharp tip. The first and second extended portions can form a mushroom shape. The bump connection can be formed in an RFID device between a chip and a flexible element such as a substrate, antenna or device. 
     In some embodiments, the present invention discloses a bump connection. The bump connection can include a contact pad, a substrate, and a bump connector electrically connecting the contact pad and the substrate. The contact pad can include a lateral surface. The bump connector can be coupled to the lateral surface of the contact pad. The bump connector can include a first extended portion and a second extended portion. The first and second extended portions are at least partially embedded in the substrate. The second extended portion at least partially can surround the first extended portion. The first or the second extended portion can include a recess or a protrusion. The first and second extended portions are at least partially embedded in the substrate passing the recess or the protrusion. The first or the second extended portion facing the recess or the protrusion can form an angle with a direction perpendicular to the lateral surface, which can be operable to push the material of the substrate to mate with the recess or protrusion. 
     In some embodiments, the contact pad can be connected to a terminal of an electronic component. The bump connector can be configured to form a hollow chamber. The first extended portion can be disposed in the hollow chamber. The second extended portion can form a hollow chamber which can surround the first portion. The material in the substrate can be displaced to be mated with the recess or protrusion. The material in the substrate can be displaced to be interlocked with the recess or protrusion. The second extended portion completely can surround the first extended portion. The first extended portion can be shorter than the second extended portion. The substrate can include a terminal end of a flexible element such as a substrate, antenna or device. The first extended portion can include a sharp tip. The second extended portion can include a sharp tip. The first and second extended portions form a mushroom shape. 
     In some embodiments, the present invention discloses a method for forming a bump interconnect between a first contact pad and a substrate. The method can include pressing a bump connector on the substrate. The bump connector can be coupled to a lateral surface of the first contact pad. The bump connector can include a first extended portion having a first surface and a second extended portion having a second surface. The first surface can face the second surface. The first surface can include a recess or a protrusion. The second surface can form an angle with a direction perpendicular to the lateral surface. The pressing can be operable to displace the material in the substrate to interlock with the recess or protrusion of the bump connector. The method can include vibrating the bump connector during the pressing. 
     The material of the contact pad can flow in a lateral direction to fill the recess or a space above the protrusion. The vibration can be in a direction parallel to the lateral surface. 
     In some embodiments, the method can include forming an electronic component. The electronic component can include the first bump connector. The first bump connector can include the contact bump. The method can include forming a second component. The second component can include a second bump connector. The second bump connector can include a contact pad. The contact bump can be pressed on the contact pad of the second bump connector. The method can include forming an RFID chip. The RFID chip can include the first bump connector. It is also noted in other embodiments, the RFID chip can include the second bump connector. The method then can include forming the bump connector coupled to the lateral surface of a contact pad. The method can include forming a flexible element such as a substrate, antenna or device. The bump connector with contact bump can be pressed on a bump connector with contact pad of the flexible element such as a substrate, antenna or device. 
     In some embodiments, the present invention discloses contact bumps having rough surfaces, which can provide a physical locking with a corresponding substrate, e.g., a terminal pad, a contact pad or a bond pad of a separate component. For example, a first component, such as a bump connector of an RFID device, can have a contact bump with rough surfaces. The contact bump can be disposed on the contact pad of the RFID device. The RFID device can have one or more contact pads, such as two contact pads for externally bonding with two terminal pads of a flexible element such as a substrate, antenna or device. 
     When bonded with a second component, such as a contact pad of a flexible element such as a substrate, antenna or device, the contact bump can press on the contact pad, driving away the material in the terminal pad to form an improved electrical connection between the contact pads of the RFID device with the terminal pad of the flexible element such as a substrate, antenna or device. The improved electrical connection can include a physical locking feature, for example, due to the materials in the terminal pad flowing around the rough surface and securing the bond pad with the terminal pad to prevent connection loosening, for example, due to vibration. 
     The rough surface can be submicron or micron roughness, meaning a surface can be characterized as rough, e.g., having micro roughness, by having a height variation greater than 0.1, 0.2, 0.5, or 1 microns, or by having a minimum peak-to-valley height of 0.1, 0.2, 0.5, or 1 microns, and having a maximum peak-to-valley height of 10, 50, or 100 microns. For example, the peak-to-valley height of a rough surface can be between 0.1 to 100 microns, between 0.2 to 100 microns, or between 0.5 to 50 microns. The peak-to-valley height of the rough surface can be a minimum peak-to-valley height, a maximum peak-to-valley height, an average peak-to-valley height, or an average peak-to-valley height for a selected range (such as an average with a maximum and a minimum section removed, or an average with the outlier values, e.g., too small values or too large values out of range, removed). 
     In some embodiments, the surface can be characterized as rough by having a height variation greater than 0.5% or 1% of a dimension of the contact bump. For example, a contact bump can have a dimension of 50 microns, then the surface of the contact bump can be considered rough if the height variation of the contact bump is greater than 0.25 micron. 
     The rough surface can be formed during the formation of the contact bump, such as due to the formation of irregularities on the surface of the contact bump caused by a deposition process. For example, the contact bump can be formed by an electroless deposition of palladium, which can conglomerate or precipitate as spherical conglomerates. 
     In some embodiments, the contact bump can be disposed on a surface of bump connector. The contact pad can have a square shape, a polygon shape, such as an octagon, or a curve, such as circular or oval, shape. The contact bump can be formed in different configurations on the surface of the bump connector. For example, the contact bump can be formed on a periphery of the bump connector. The contact bump can also be formed on the interior of the bump connector. For example, the contact bump can be formed on a periphery and in the middle, e.g., inside the periphery. The contact bump can be formed randomly on the bump connector. 
     In addition, the contact bump can have one or more protuberances distributed on the surface. The protuberances can be discrete protuberances, e.g., forming multiple bumps that are separate from each other. The protuberances can be continuous protuberances, e.g., forming a wall of protrusions, with the top portion of the wall having similar or different height. The continuous protuberances can include a line of protrusions connected by a high ground, a series of more or less connected protrusions ranged in a line, or a group of protrusions located close to each other. The continuous protuberances can be similar to a mountain range. The contact bump can include discrete protuberances and continuous protuberances, e.g., there can be some protuberances standing separate from others, and some protuberances located close to each other with some overlapped at the bases of the protuberances. 
     The protuberances can have different sizes and shapes. For example, discrete protuberances can include large protuberances and small protuberances. In bump connector, large protuberances can be formed at a periphery of the connector, such as forming discrete protuberances at corners, forming discrete protuberances along a portion of a periphery, or forming a wall of protuberances along a portion of a periphery. Smaller protuberances can be formed in the middle. Continuous protuberances can include large protuberances located close to small protuberances, with overlapping bases. 
     In some embodiments, the contact bump can form a ring-like protuberance with hollow spaces in between. The ring-like protuberances can include continuous protuberances or discrete protuberances forming along a periphery of a bump connector. The ring-like protuberances can form a close ring configuration, e.g., the protuberances can surround the contact pad along the periphery or the protuberances can fill the periphery of the bump connector without gaps or with only small gaps in between. The ring-like protuberances can form an open ring configuration, e.g., the protuberances can be distributed along the periphery or the protuberances with large gaps in between. 
       FIGS. 16A-16D  illustrate contact bump configurations for a rectangular contact pad according to some embodiments. The contact pad shown is rectangular, but other shapes can also be used, such as square, polygon, or curve shapes.  FIG. 16A  shows 2 configurations of the contact bump. In  FIG. 16A  (a), the contact bump  1600  can include multiple protuberances  1610  disposed along a periphery of the bump connector. The surface of the protuberances  1610  can be rough, due to the deposition process when forming the contact bump. The area  1620  in the middle can be empty, e.g., there is no protuberance in the middle of the bump connector. The surface of the middle area  1620  can be rough, due to the deposition process when forming the contact bump. In  FIG. 16A  (b), the contact bump  1605  can include multiple protuberances  1615  disposed along a periphery of the bump connector. The area  1625  in the middle can include some additional protuberances  1645 . The surfaces of the protuberances  1615  and  1645  can be rough, due to the deposition process when forming the contact bump. 
       FIG. 16B  shows different configurations for the cross-section GG′ along a portion of the contact bump  1600 . The contact bump can form a continuous wall  1610 A, e.g., a solid wall with flat top ( FIG. 16B  (a)). The surface of the contact bump can be rough, e.g., having peak-to-valley height  1650  or  1655 . The roughness can be micro-roughness, meaning the peak-to-valley height  1650  or  1655  can be between 0.1 and 100 microns. 
     In  FIG. 16B  (b), the contact bump can form discrete protuberances  1610 B along a peripheral or a wall of the contact pad, including gaps  1611  between nearby protuberances. As shown, the discrete protuberances can have an overlapping base portion  1612 . Alternatively, the discrete protuberances can be completely separated. 
     In  FIG. 16B  (c), the contact bump can form continuous protuberances  1610 C along a peripheral or a wall of the contact pad, having small gaps  1614  between nearby protuberances. As shown, the discrete protuberances can have an overlapping base portion  1613 . The continuous protuberances  1610 C can also be considered as discrete protuberances with overlapping portions  1613 . 
       FIG. 16C  shows configurations for a portion of the top view of the contact bump. The protuberances  1610 A can be continuous with no gap in between ( FIG. 16C  (a)). The protuberances  1610 A can be discrete, forming separate peaks  1610 B ( FIG. 16C  (b)). 
       FIG. 16D  shows configurations for the cross-section FF′ along a portion of the contact bump  1600 , and for the cross section HH′ along a portion of the contact bump  1605 . The cross-section FF′ in  FIG. 16D  (a) shows the protuberances  1610  at a periphery of the bump connector with rough surfaces. There is no protuberance in the middle  1620  of the contact pad. The cross section HH′ in  FIG. 16D  (b) shows the protuberances  1615  at a periphery of the connector with rough surfaces. There is some smaller protuberance  1645  in the middle portion  1625  of the contact pad. 
       FIGS. 17A-17C  illustrate other configurations for the contact bump according to some embodiments. The contact bump can include multiple protuberances having rough surfaces, such as micro-roughness surfaces. In  FIG. 17A , a contact bump  1700  can include multiple discrete protuberances  1710  disposed on a square or rectangular bump connector  1680 . The discrete protuberances can form a ring-like along a periphery of the bump connector, leaving hollow space  1720  in the middle. The ring-like configuration can be a close ring, e.g., the protuberances can be close to each other with a small gap  1711  in between. 
     In  FIG. 17B , a contact bump  1705  can include multiple discrete protuberances  1715  disposed on a square or rectangular bump connector. The discrete protuberances can form a ring-like along a periphery of the connector. A protuberance  1745  can be formed in the space in the middle. There are some hollow spaces  1725  between the protuberances  1715  and  1745 . The ring-like configuration can be a close ring, e.g., the protuberances can be close to each other with a small gap  1712  in between. 
       FIG. 17C  shows other configurations for the contact bump. In  FIG. 17C  (a), the contact bump can have multiple protuberances  1716  forming along a periphery of a bump connector, leaving a middle hollow space  1726  and gap  1713 . In  FIG. 17C  (b), the contact bump can have multiple protuberances  1717  forming along a periphery of a bump connector, together with a protuberance  1747  in a middle hollow space  1727 . There can be large gaps  1714  in the periphery, between the protuberances  1717 . In  FIG. 17C  (c), the contact bump can have multiple protuberances  1718  forming an open ring-like configuration along a periphery of a bump connector, leaving a middle hollow space  1728 , and an opening  1724  in the ring-like configuration of protuberances  1718 . 
       FIGS. 18A-18B  illustrate flow charts for forming contact connection for a device according to some embodiments. In  FIG. 18A , contact bump can be formed on a surface, such as the surface of a bump connector of a device. The contact bump can be used as a contact connection with another bump connector and contact pad of another device. Operation  1800  provides a surface, such as the surface of a bump connector of a device. For example, a device can be formed having input or output connections. Bump connectors can be formed, electrically coupled to the input or output connections. 
     Operation  1810  forms a contact bump on the surface. The contact bump can include a rough surface, such as a surface having micro-roughness, e.g., having a peak-to-valley height between 0.1 and 100 microns. The contact bump can include one or more protuberances arranged in a ring-like configuration. The ring-like configuration can be a close ring configuration, meaning the protuberances can be placed next to each other without any large gaps. For example, the protuberances can form a circle or can be placed along a complete periphery of a polygon surface. The ring-like configuration can be an open ring configuration, meaning there can be a large gap between the protuberances. For example, the protuberances can form a half moon circle or can be placed on only a portion of a periphery of a polygon surface. 
     In addition, the protuberances can form a solid wall, e.g., the protuberances can have a length similar to the length of a side or a periphery of the bump connector. The protuberances can be discrete or can be continuous, e.g., having overlapping bases. 
     The surface of the protuberances can be rough, for example, due to the deposition process during the formation of the contact bump. 
     In  FIG. 18B , a deposition can be performed on a surface, such as the surface of a bump connector of a device. The deposition process can be configured to form one or more protuberances on the surface of the connector. The protuberances can form a contact bump, which can be used as a contact connection with another contact pad of another device. Operation  1830  provides a surface, such as the surface of a bump connector of a device. Operation  1840  deposits a material on the surface. The deposition can include electroless deposition (or other form of deposition such as electroplating or vapor deposition, e.g., physical or chemical vapor deposition). The deposition can form protuberances, which can be arranged in a ring-like configuration along a periphery of the bump connector, such as close ring or open ring configuration, together with optionally forming protuberances in the middle area of the ring-like configuration. The protuberances can have a rough surface, such as a micro roughness surface. The rough surface can be the result of the conglomeration of the deposited material. For example, during an electroless deposition of palladium, palladium can precipitate as spherical conglomerates, forming rough protuberances. 
     In some embodiments, the present invention discloses a contact connection between two substrates, such as between the bond pads or bump connectors of two separate device components. For example, a device can have one or more bond pads, which are configured to bond with corresponding bond pads of another device, with corresponding bond pads of a component, or with corresponding bond pads of a substrate. 
     The contact connection can include a bump connector with contact bump. The contact bump can be pressed on the other corresponding bump connector such as a bond pad or contact pad, to form an improved contact connection, for example, by having a physical locking feature due to the rough surface of the contact bump. The contact bump has been discussed above, and can include protuberances having micro roughness surfaces. Further, the structure of the contact bump, including the protuberances, can be configured to drive away material from the corresponding contact pad to facilitate strong surface interaction between the two bump connectors, with respectively contact bump and contact pads or bond pads. 
     In some embodiments, the hardness of the material of the contact bump can be higher than that of the corresponding bond pad or contact pad. For example, the contact bump can include palladium or palladium alloy, and the corresponding bond pad can include aluminum, gold, silver or copper. The difference in hardness values can allow the corresponding bond pad or contact pad to be deformed to the shape of the contact bump, and thus forming a contact connection with a high surface area and a physical locking feature due to the rough surface. 
       FIGS. 19A-19B  illustrate a contact connection with a contact bump according to some embodiments. In  FIG. 19A , a contact connection  1900  can include a first bump connector  1930 , disposed on an external surface of a first device or component  1940 , such as an RFID device. In the figure, a portion of the first device or component  1940  having the first bump connector  1930  is shown. The first device or component  1940  can extend beyond the picture frame. 
     A contact bump  1910  can be formed on the bump connector  1930 . The contact bump  1910  can have a rough surface, for example, due to the deposition process, such as a precipitation as spherical conglomeration of the material during an electroless deposition. The contact bump can be pressed on a contact pad  1950  of a second device or component, such as the terminal pads or contact pads of a flexible element such as a substrate, antenna or device for the RFID device. 
       FIG. 19B  shows a flow chart for the formation of a contact connection. Operation  1990  forms a first device having a first bump connector wherein comprises a contact bump. Operation  1991  then forms a second device having a second bump connector with a contact pad, wherein the hardiness of the material of the contact bump is higher than that of the contact pad. Operation  1992  than has the pressing of the first bump connector with contact bump on the second bump connector with contact pad to embed at least a portion of the contact bum in the contact pad. The first device can have one or more first bump connectors. Each of the first bump connectors can include a contact bump. The contact bump can have a rough surface. The first device can include an RFID device. The second device can have one or more second contact pads. The second device can include a flexible element such as a substrate, antenna or device for the RFID device. The rough surface of the contact bump can secure a good contact with the second contact pad, for example, by providing higher surface area, and a physical locking feature through the material in the second contact pad flowing out from the peaks and entering the valleys of the contact bump rough surface. 
     In some embodiments, the present invention discloses methods to form contact connection between two bump connectors, with one connector having a contact bump. A vibration or an oscillatory force can be included in driving the contact bump onto the opposite contact pad, for example, to assist in forming an improved contact connection. 
     In some embodiments, the contact bump can have a rough surface, e.g., protruding peaks and recessed valleys from the surface of the contact bump. The material from the opposite contact pad can flow around the rough surface, such as moving from the protruded peaks to the recessed valleys. The material flow can form a physical locking configuration, such as an intermesh between the contact bump and the opposite contact surface, which can assist in securing the contact connection between the two contact pads. The material of the contact bump can be harder, e.g., having a higher hardness value, than the material of the opposite contact pad, thus allowing the opposite contact pad to be deformed and flowed around the rough surface of the contact bump. 
     In some embodiments, the vibration or an oscillatory force, such as an ultrasonic pulsing, can assist in flowing the material from the opposite contact pad around the contact bump, together with forming an intermetallic connection between the materials of the contact bump and of the opposite contact pad. The ultrasonic pulsing can be applied to the contact bump, together with a force driving the contact bump into the opposite contact pad. The vibration of the contact bump can create a thermal energy, for example, at the frictional contact of the rough surface of the contact bump with the opposite contact pad. The thermal energy can heat up the contact surface for a short time, such as a few milliseconds. The thermal energy can soften the material of the opposite contact pad, helping the material to flow around the contact bump. Further, due to the heat, an intermetallic connection between the contact bump and the opposite contact pad can be created. 
     In a preferred embodiment, the present invention may provide then a contact connection, comprising at least a contact pad, wherein the contact pad may comprise of a pad surface and a contact bump wherein the contact bump may be coupled to a flexible electronic device, wherein the contact bump comprises a rough surface, and wherein the contact bump comprises one or more protuberances arranged along a periphery of the surface. The contact bump may then be connected to the contact pad. Additionally, the contact pad and contact bump form a contact connection between a flexible chip, element or device and the contact pad on a flexible substrate. 
     It may be noted that the flexible electronic device may be produced via thin-film technology, and/or by vacuum deposition. The device may also be a chip with a non-crystal structure. It may be also noted the rough surface may comprise a roughness having a peak-to-valley height greater than 0.01 microns and smaller than 5 microns and wherein the rough surface may be comprised of a deposited material during formation of the contact bump such as wherein the rough surface may be comprised of an electroless deposited material during a formation of the contact bump. This formation may be completed, such as wherein the contact bump may be connected to the contact pad by means of a press connection and wherein the press connection may be achieved by applying a supplemental vibrational force such as with a roller. 
     Additionally, a preferred method may be such that a user may form a connection comprising at least wherein the used provides a contact pad with pad surface and then may form a contact bump, wherein the contact bump is provided including a connection to a flexible electronic device. The user may provide depositing a material during the formation of the contact bump, wherein the material may form a rough surface wherein the rough surface comprises a roughness having a peak-to-valley height greater than 0.01 microns and smaller than 5 microns, wherein there may be one or more protuberances arranged along a periphery of the surface connecting the contact bump to the contact pad, and wherein the rough surface may be comprised of an electroless deposited material 
     It may be noted that the user may produce the flexible device via thin-film technology or via vacuum deposition and wherein the electronic device may be a chip with non-crystal structure. 
     It may be noted that the flexible substrate as mentioned, or element, or device, may be any type of element including complete devices or a component of a larger or other device or element, and as such may be for instance a flexible electronic element, such as an substrate, chip, device, semiconductor or display element including for instance, an electronic chip. In some embodiments then wherein the contact pad is on a flexible substrate, among any other permutation wherein the device or element is flexible, as mentioned. For instance the mentioned, device, substrate or other terms can be replaced by the above, or any other device. 
     It also may be noted that the user may form the connection between the contact bump and contact pad is provided by press connecting the contact bump and contact pad, wherein providing a supplemental vibrational force while press connecting and providing the pressing force with a roller. 
     The vibrational assisted bonding process can be highly cost effective, for example, the process can have lower operating cost than a standard thermo-compressing bonding with anisotropic conductive paste or non-conductive paste. Throughput can be enhanced, since the bonding time can be in order of seconds (or milliseconds). For example, the bonding heat, e.g., the thermal energy created to bond the contact bump with the opposite contact pad, can be generated in order of milliseconds, in contrast to a standard thermo-compressing bonding of between 6 and 9 seconds. The short heating time can prevent the contact connection from undergoing any distortion. Further, the high heat can form a chemical bonding, such as intermetallic connection between metal-based contact bumps and metal-based contact pads. Smooth bonding can be achieved using the vibrational assisted bonding process. 
     In addition, multiple bonding can be performed in parallel, e.g., a vibrational assembly can be used to process multiple contact connections, leading to a less number of bond heads. Thus, high throughput can be achieved, such as throughput of higher than 50,000 units per hour. This can provide a significant advantage over thermo-compressing bonding, since a high number, e.g., greater than 150, of thermal-compressing bond heads can be difficult to control, align and handle. 
       FIGS. 20A-20B  illustrate a bonding process between two bump connectors according to some embodiments. A vibration or oscillatory force, such as an ultrasonic system, can be used to bond the two connectors. 
     A device, such as an RFID device, can have a bump connector  2011  for external connections. The connector  2011  can have a contact bump  2010  having a rough surface. A portion of the device  2012  is shown, showing one contact bump  2010  coupled to one connector  2011 . In the figures, one bump connector  2011  is shown, but the device can have more than one. Further, the drawing is not to scale, for example, the contact bump  2010  is shown not proportional with the device. 
     The device portion  2012  can be placed on another device or component  2022 , such as a flexible element such as a substrate, antenna or device. In some embodiments, the component  2022  can include a bond pad or contact pad  2020 . In general, a bond pad or a contact pad is a component for forming an external connection, e.g., for forming an electrical connection with another component. The bond pad or contact pad can sometimes called a terminal pad or a connection pad. The contact pad  2011  and the bond pad  2020  can be aligned, e.g., the contact bump  2010  can be placed on the contact pad  2020 . 
     The figures show the intrusion of one contact bump  2010  into one bond pad  2020 , but the device  2012  can have multiple contact bumps connecting with multiple bond pads. The multiple bond pads can be from a same component  2022 . For example, an RFID device can have two contact bumps, for coupling with two terminals of a flexible element such as a substrate, antenna or device. The multiple bond pads can be different components. For example, a device can be electrically connected to two different components. The device can have a first contact bump coupling with a bond pad of a first component, and a second contact bump coupling with a bond pad of a second component. 
     The figures also the component  2022  to be a separate element from the bond pad  2020 . In some embodiments, the bond pad  2020  can include the same material as the component  2022 . 
     In some embodiments, the component  2022  can function as a bond pad, e.g., the contact bump can be bonded directly to the component  2022 , without the need for a bond pad. For example, the component  2022  can include a thin layer of material, and having a portion to act as a bond pad, e.g., so that the contact bump can penetrate and form an electrical connection. The portion act as the bond pad can be thicker than the rest of the component, for example, to accommodate the contact bump. 
     The bond pad  2020 , e.g., a separate bond pad having a different material than that of the component  2022 , a separate bond pad having the same material as that of the component  2022 , or a portion of the component  2022  acting as a bond pad, can be made of a material that is softer than the material of the contact bump  2010 . Thus, during the formation of the connection, e.g., the pressing of the contact bump  2010  into the bond pad  2020 , the contact bump can be embedded in the bond pad without or with minimum distortion. 
     In some embodiments, an optional support  2030  can be used to support the component  2022 . The support  2030  can include a substrate, which can support individual components, or can support multiple components. For example, multiple components can be disposed on a support. Different devices can be placed on corresponding components, and then bonded to the components through the contact bumps embedded in the component materials. 
     In some embodiments, supportless components, such as pure metal foils for flexible element such as a substrate, antenna or device materials, can be used. The devices can be placed directly on the supportless components, and bonded to the components through the connection between the contact bumps and the bond pad of the component, or between the contact bumps and the component. 
     A vibrational assembly  2040  can be provided. For example, an ultrasonic assembly  2060 , which can include a piezo electric component, can be coupled to the assembly  2040  to generate an oscillatory action. The vibrational assembly  2040  can be pushed on the device  2012 , e.g., a pressing force  2050  can be applied to the vibrational assembly  2040  to press the device  2012  on the component  2022 . The vibrational assembly  2040  can drive the contact bump  2010  into the bond pad  2020  during the pressing force  2050  applied to the vibrational assembly  2040 . The vibrational assembly  2040  can be moved in a direction perpendicular or substantially perpendicular to the contact pads. 
     The vibration force can improve the bonding between the contact pad  2011  and the bond pad  2020 . For example, the vibration can help forming an intermesh between the rough surfaces of the contact bump with the bond pad  2020 . The vibration can heat up the contact surface between the contact bump  2010  and the bond pad  2020 , leading to a formation of intermetallic connection between the metallic contact bump  2020  and the metallic bond pad  2020 . 
     Other configurations can also be used, such as a vibrational assembly can be coupled to the support  2030 , instead of or in addition to the vibrational assembly coupled to the device  2012 . Also, the vibrational assembly can be used to simultaneously drive multiple contact connections. Multiple components can be arranged for a same height bonding process, and can be bonded using one vibrational assembly. Multiple components can be placed next to each other, for a total size of about the size of the vibrational assembly. 
     In some embodiments, the vibration or oscillatory force can have a component in the direction of the pressing force, e.g., parallel to the pressing force. For example, the vibration or oscillatory force can be applied in a same direction as the pressing force. Alternatively, the vibration or oscillatory force can form an angle with the pressing force, and can be decomposed to include a parallel component and a perpendicular component. Thus, the pressing force can vary, for example, from a maximum value to a minimum value, together with an optional sideway vibration. 
     In some embodiments, the vibration or oscillatory force can be periodic, with a frequency of greater than about 10 kHz, preferred greater than 60 kHz. The amplitude of the vibration or oscillatory force can be greater than 1 micron. The amplitude of the vibration or oscillatory force can be smaller than 100 microns. In some embodiments, the amplitude can be greater than the spacing of the rough surface of the contact bump, such as greater than the average spacing of the peaks and valleys of the rough surface. The amplitude can be smaller than the thickness of the contact bump, such as less than 50 or 10% of the height of the contact bump. 
     In some embodiments, the pressing force can be large enough to drive the contact bump  2010  into the opposite contact pad  2020 . For example, the pressing force can be greater than 0.1, 0.5 or 10N. The pressing force can be smaller than the fracture resistance of the contact connection assembly. In some embodiments, the time for bonding can be greater than a few milliseconds, such as greater than 20 or 100 ms. 
     In some embodiments, the vibrational assembly can be coupled to the contact pads with a high vibrational transmission from the vibrational assembly to the contact pads. A clean contact of the vibrational assembly to the device can be used, for example, to facilitate the vibrational transmission. 
     In some embodiments, a cleaning process can be applied to the vibrational assembly and/or the devices, for example, to increase the vibrational energy transmission. The cleaning process can remove contaminants, such as debris and adhered particles, from the contact surfaces  2070  of the vibrational assembly and/or the devices. For example, a cleaning device, such as a laser cleaning assembly, can be used to clean the surfaces of the vibrational assembly and/or the surfaces of the devices, such as by vaporizing the contaminants on the surfaces. The cleaning process can be performed before the vibrational assembly is in contact with the devices. In some embodiments, the cleaning time can be less than 1 minute, or less than 1 second. 
     In some embodiments, an optional adhesive layer can be used. The adhesive layer can be used to keep the components in position. e.g., keeping the contact bump  2010  aligned on the opposite contact pad  2020 , before the final bonding process, e.g., before the contact bump can be pressed in the opposite contact pad. The adhesive layer can also be used for encapsulating the components, e.g., covering the contact connection between the contact bump and the contact pad. 
     The adhesive can be dispensed on the surfaces of the contact pads, such as on the surface  2075  of the contact bump and/or on the surface  2076  of the opposite contact pad  2020  or between or around contact pads. The adhesive can be brushed or sprayed. For example, multiple components, in a field of ca. 4 mm square, can be arranged next to each other, and an adhesive coating can be applied, for example, by spraying. 
     In some embodiments, the adhesive can be applied and then cured. For example, a layer of adhesive can be coated on the surfaces, and ultraviolet radiation can be used to cure the adhesive layer. The equipment for the adhesive dispensing and the adhesive curing can be located close to each other, and the components can be transported from the adhesive dispensing equipment to the adhesive curing equipment. 
       FIGS. 21A-21C  illustrate bonding configurations according to some embodiments. In  FIG. 21A , a device  2130 , such as an RFID device, can have multiple bump connectors  2120  for external connections. The connectors  2120  can each have a contact bump  2110  having a rough surface. As shown, the device  2130  has two connectors  2120 . In some embodiments, the device  2130  can have more than two contact pads, such as 4 contact pads. 
     The device  2130  can be placed on another device or component  2140 , such as a flexible element such as a substrate, antenna or device. The component  2140  can be constructed so that the material of the component  2140  can be softer than the material of the contact bump. Thus, the component  2140  can act as a bond pad. For example, the contact bumps  2110  can be pressed into the component  2140 , to form electrical connection between the device  2130  and the component  2140 . The component  2140  can be placed on a support  2150 , for example, to support the component  2140  against the pressing force acting on the device  2130 . The pressing force can include a vibratory component, which can include a component in the direction perpendicular to a surface of the device  2130 . 
     As shown, the support  2150  is used to support the component  2140 . Alternatively, the support  2150  can be used to support the device  2130 , with a pressing force acting on the component  2140 . 
     In  FIG. 21B , a device  2132 , such as an RFID device, can have multiple bump connectors  2122  for external connections. The connectors  2122  can each have a contact bump  2112  having a rough surface. The device  2132  can be placed on another device or component  2142 , such as a flexible element such as a substrate, antenna or device. The component  2142  can be constructed so that the material of the component  2142  can be softer than the material of the contact bump. Thus, the component  2142  can act as a bond pad. For example, the contact bumps  2112  can be pressed into the component  2142 , to form electrical connection between the device  2132  and the component  2142 . The component  2142  can be without a support, such as a foil substrate which can be used as the component. 
     In  FIG. 21C , a device  2134 , such as an RFID device, can have multiple bump connectors  2124  for external connections. The connectors  2124  can each have a contact bump  2114  having a rough surface. The device  2134  can be placed on another device or component  2144 , such as a flexible element such as a substrate, antenna or device. The component  2144  can be constructed to have a portion  2146  having a thicker material at the area of contact with the contact bumps, to accommodate for the pressing of the contact bumps  2114  into the component  2144 . 
       FIGS. 22A-22B  illustrate flow charts for forming a contact connection according to some embodiments. A force that forms the contact connection can have an oscillatory component, such as an ultrasonic vibration, added to a linear force component pushing the contact pads together. In  FIG. 22A , operation  2200  applies a force on a contact connection. The contact connection can include a first bump connector disposed on a second bump connector. The first connector can have a contact bump having a rough surface. The second connector can have a contact pad which can have a material that is softer than the material of the contact bump. The force can include an oscillation component. For example, the force can include a compression force, pressing the first bump connector, and contact bump, to the second connector with contact pad. The force can include an oscillatory component in the direction of the compression force, thus can vibrate the two-contact pad in the direction of the compression force. 
     The oscillatory component can include an ultrasonic vibration, which is added to the compression force in a general direction, such as perpendicular, parallel, or form an angle with the direction of the compression force. 
     In  FIG. 22B , operation  2220  places a first bump connector on a second bump connector. The first bump connector can include a contact bump having a rough surface. The second contact bump connector can have a contact pad with material that is softer than the material of the contact bump. 
     Operation  2230  applies a force on the first bump connector. The force can include an oscillation component. For example, the force can include a pressing force, together with an ultrasonic vibration. The ultrasonic vibration can be applied to the pressing force in a general direction, such as perpendicular, parallel, or form an angle with the direction of the pressing force. 
     In some embodiments, a cleaning process, such as a laser cleaning process, can be used to clean the contact surface of the object that provides the pressing force for the first and second contact pads. A layer of adhesive can also be applied to the contact pad surfaces, such as to the top surface of the second contact pad, or to the surface of the contact bump of the first contact pad. An optional ultraviolet radiation curing can be used to cure the adhesive layer, before bonding the first and second contact pads. 
     In some embodiments, the present invention discloses a contact connection, for example, between two components, such as between two active devices, between an active device and a passive device, or between two passive devices. The contact connection can be performed between two bond pads, e.g., between a first bond pad of a first component, and a second bond pad of a second component. 
     One bump connector can have a contact bump, e.g., protuberances protruded from a surface of the bond pad. The other connector can have a bond pad can include a flat surface, having a material that is softer, e.g., having lower hardness, than the material of the contact bump. 
     In some embodiments, the bump connector can have a surface, on which a contact bump is formed. The contact bump can have a rough surface. The contact bump can include one or more protuberances arranged along a periphery of the surface. The protuberances may be highest on the periphery of a surface, or in a given pattern, such as the periphery ring of a circle may have higher protuberances than the interior circle. In other embodiments, the interior of a pattern or shape, such as the inner circle may have higher protuberances than a ring around the outside. The protuberance area may be any width, shape or pattern, and may have any cross-sectional height and difference between the high and low areas. 
     The rough surface can include a roughness having a peak-to-valley height greater than 0.1 microns and smaller than 100 microns, or greater than 1 microns and smaller than 20 microns. In other embodiments, the roughness may have any peak-to valley height difference. 
     A deposition process can be used to deposit a material on the surface of the bump connector. The deposition process can be under conditions so that the deposited material can form a contact bump, e.g., forming the one or more protuberances protruded from the surface of the bump connector. The deposition can include physical vapor deposition, chemical vapor deposition, electroplating, or electroless plating. For example, the rough surface can include a conglomeration of the material of the contact bump, a precipitation of a deposited material during a formation of the contact bump, or irregularities of a deposited material during a formation of the contact bump, which can be resulted by an electroless deposition process. 
     In some embodiments, the protuberances can form a continuous wall around the periphery of the surface of the bump connector. The protuberances can include distinct protuberances around the periphery. The distinct protuberances can have overlapping bases around the periphery. The protuberances can form an open ring or a close ring around the periphery. The contact bump can include a protuberance inside the periphery. 
     The other bump connector can be a contact pad or bond pad and can include a flat surface, having a material that is softer, e.g., having lower hardness, than the material of the contact bump. Thus, when bonded, for example, under a pressing force, the contact bump, e.g., the protuberances, can be at least partially embedded in the flat surface of the bond pad. In some embodiments, the contact bump can include structures configured to drive away materials in the second substrate to facilitate a strong surface interaction. For example, the structure can include protuberances having larger base portion than top portion, and protuberances having rough surfaces. 
     In some embodiments, the present invention discloses methods to form a contact connection, using a vibratory action to form an improved bond between a contact bump and a bond pad. The vibratory action can include an ultrasonic vibration, for example, formed by a piezo electric assembly, for vibrating the contact bump or the bond pad when the contact bump is pressed into the bond pad. 
     The contact bump can be pressed into the bond pad by a force that includes a pressing component and a vibratory component. The pressing component can be a substantially constant force, pressing the contact bump into the contact pad. The vibratory component can be an oscillatory force, such as an ultrasonic vibration, having a small vibration magnitude, e.g., smaller than a dimension of the contact bump or bond pad, such as less than 100 microns, or less than 25 microns. 
     For example, a vibrational assembly can be used for pressing the contact bump into the bond pad. The pressing component can include the pressing force acting on the vibrational assembly. The vibrationary assembly can provide the vibratory component, for example, the vibrational assembly can include an oscillatory component such as an ultrasonic vibration. Thus, by pressing the vibrational assembly on the contact bump on the bond pad, a combination force can be generated, which includes the pressing component and the vibratory component. 
     The vibrational assembly and/or the contact surface between the vibrational assembly and the components can be cleaned, for example, by a laser radiation, before pressing on the components. 
     In some embodiments, the method and device comprises wherein electroless, such as a process without the use of an electric current, chemically generated Pd bump forming precipitates (some in the form of amorphous protuberances, some in the form of crystals) selectively grown on flexible conductive material ( 212 ,  312 , etc.). 
     In some embodiments, the present invention “broccoli” Pd bumps as mentioned the contact bumps, which allow superior contacting of flexible antenna materials, to the thin-film based electronic components (diodes, LEDs, chips, etc.), to allow improved contacting of flexible or solid contact partners as mentioned. 
     In some embodiments, a method to form a contact connection can include placing a contact bump facing a contact pad, and then applying a force on the contact bump or on the contact pad. Placing a contact bump facing a contact pad can include placing a contact bump on a contact pad, or placing a contact bump under a contact pad, or placing a contact pad under a contact bump, or placing a contact pad on a contact bump. The contact bump can include a rough surface. The material of the contact bump may have a higher hardness than the material of the contact pad. The force can include a substantially constant component and an oscillatory component. 
     In some embodiments, an adhesive layer can be applied on a surface of the contact pad or on a surface of the contact bump. The adhesive layer can undergo an ultraviolet radiation for curing or may be cured for instance by heat or exposure to ambient or the materials within the contact bump and contact pad, etc. 
     In some additional embodiments, the present invention may teach to Pd bumps on flexible chips. These may or may not be have a crystal structure. These may be formed or built by vacuum deposition processes and other common art practices of which for instance may be similar to thin film technology. In additional embodiments processes, such as printing processes allow electrical functionality besides silicon crystal devices and may ease in production of the devices. It is noted that some embodiment may include then wherein the structure is not a crystal structure but may be then a deposited structure or printed structure which may aid in flexibility and adherence. 
     In some additional embodiments, the construction of the flexible chips consists of a thin isolating substrate with added conductive and nonconductive structures to create micro electrical devices. Because the substrate and elements are flexible, then this may create then some embodiments wherein the chips/devices are thin and flexible. This may be made from such as palladium and may be formed for instance using a known electroless bumping process. 
     In some embodiments, the outer bump shape can be modified. In some embodiments contact bumps may be made such that connection pads of flexible electronic devices. The bumps may be made in any form by photo masking. This may also be possible on silicon crystals and any other substrates or materials. 
     When forming, the bumps may be forms such that the bumps may be in a specific area of a substrate such as on a ring around the exterior of a given surface or within the interior of a given shape. 
     In some embodiments, the present invention may provide wherein there may be an interconnection between two flexible components such as specific substrates. These may then also be flexible substrates and materials. 
     In some embodiments, the present invention bumps and substrates may be formed without ultrasonic methods of which may degrade the substrates and devices. 
     In some embodiments, the present invention may provide wherein the connection may be made wherein by winding and pressure force, where the rough surface provides a connection to the substrate terminals. 
     In some embodiments, the winding force can be part of the roll to roll process described, wherein when unwinding for instance a roll or strand of printed elements such as antennas with contact pads are sourced from a roll. Wherein then correspondingly, for instance chips with bumps, are rolled or dispended on the contact pads and wherein then the strand of elements together with the dispended electronic elements is upwound to form the outgoing roll. The upwinding exerts a winding force that contacts the pieces to each other and completes the marriage. In other words, this winding force leads to the mating of the rough bump surface into the flexible antenna material wherein the winding of the respective rollers mates and pressures the contact pad and contact bump together. 
       FIGS. 23A-23C  illustrate contact bump configurations on a flexible substrate. 
       FIG. 23A  shows a single layer of an electronic device  2320  of which can be formed on the substrate  2360  of which may be bonded to a layer  2310  of which may be any material and of which may include bond layer  2370  of any material, glue or attachment method. There then may be cover layer  2380  which may protect the device  2320  and of which may then include bump  2350  of which sits in a cut out of layer  2380 . 
       FIG. 23B  shows wherein a transistor  2321  can be formed on the substrate  2361 . Gate  2323  can be formed on substrate  2361 . An amorphous silicon layer  2326  can be deposited on the gate  2323 , and then laser annealed to form a polycrystalline silicon layer. Source and drain  2324  and  2325  can be formed on the polycrystalline silicon layer, for example, by ion implantation. Via connection  2327  can be formed to connect the drain  2325 . Bond pad  2328  can be connected to via  2327 . The bump connector  2328  which then may be within a cover layer  2381  wherein then bump  2351  may extrude such that the bumps may be useable. Additionally, the above may then be adhered to a layer  2311  of which may include flexible materials to then provide the elements into a single flexible device. 
       FIG. 23C  shows a similar bump on an RFID device on a flexible substrate such that a transistor  2322  can be formed on the substrate  2362  of which may be bonded to a layer  2312  of which may be any material and of which may include bond layer  2372  of any material, glue or attachment method. There then may be cover layer  2332  which may protect the transistor  2320  and of which may then include bump  2352  on the exterior of the layer. 
       FIGS. 24A-24C  illustrate flow charts for forming a bump for flexible substrates according to some embodiments. 
       FIG. 24A  displays at least process  2400  wherein providing a flexible substrate, Process  2410  wherein forming a device on the flexible substrate, wherein the device comprises a bump connector and Process  2420  wherein forming a bump having a rough surface on the bump connector 
       FIG. 24B  displays at least process  2440  wherein forming a bump having a rough surface on the bump connector, wherein the bump connector is connected to an RFID device, wherein the RFID device is formed on a flexible substrate. 
       FIG. 24C  displays at least process  2460  wherein forming a bump having a rough surface on a flexible element such as a substrate, antenna or device, wherein the flexible element such as a substrate, antenna or device is formed on a flexible substrate. 
       FIGS. 25A-25D  illustrate contact bump configurations on a flexible substrate in different configurations and cross sections. 
       FIG. 25A  shows a device  2500  wherein a substrate  2530  will form bumps wherein there may be corner or exterior bumps, to a specific area such as a cross section high bump profile  2510  and lower bump profile  2520 . 
       FIG. 25B  shows then the above wherein there may be a device  540  wherein then the cross section across A to A′ is seen to then include the higher bump or protrusion area  2541  and lower bumper or protrusion area  2542 . 
     It is understood that the exterior being higher protrusion or bumper and interior lower protrusion is only for example and it can be seen any combination, pattern or area may be made. The patterns may be a byproduct of the shape, geometry or orientation of the object, such as due to surface area or other reasons during formation, or may be purposefully deposited or placed. 
       FIG. 25C  shows then a device  2550  with corners  2560  wherein then bumps may exist and radiate or be made at the corners such as corner  2570  having bumps  2575  radiating and corner  2550  having bumper radiating  2551  wherein then a center lower bump area  2552  exists wherein when looked by cross section from B to B′. It is noted that the bumps may be such that the corners or areas of intersection, etc. may also be formulated to have the lower bumps. 
     It is noted in a preferred embodiment the corners seed the bumps for higher cross section area of bumps which may be beneficial to element use in that the corners or edges of may be necessitated for higher contact surface area, etc. 
       FIG. 25D  shows an irregular shape wherein then a device  2560  forms bumper wherein a high bump area  2561  exists and a low bump section  2562  as seen from cross-section about C to C′ 
       FIGS. 26A-26B  illustrate flow charts for forming a bump for flexible substrates according to some embodiments. 
       FIG. 26A  teaches to at least Process  2600  determining a base structure for a bump connection, wherein the bump connection comprises a rough surface and process  2610  designing a shape of a seed layer which is configured to form the bump connection, wherein a corner of the shape corresponds to a formation of a bump. 
       FIG. 26B  teaches to at least Process  2620  Determining a base structure for a bump connection, wherein the bump connection comprises a rough surface, process  2621  forming a seed layer on a substrate, wherein the shape of the seed layer is configured to form the bump connection and process  2622  Forming the bump connection on the seed layer such as by using electroless for plating of Pd or other elements or substances. 
       FIGS. 27A-27C  illustrate forming contact bump configurations on a flexible substrate with rollers. 
       FIG. 27A  shows a preprocessed or diced substrate roll  2712  of which may be flexible with embedded or otherwise formed device elements  2716  wherein a bump connection having a rough surface and contact bump or bumps. 
       FIG. 27B  shows a preprocessed or diced substrate roll  2714  of which may be flexible with embedded or otherwise formed bump connector  2718  wherein the bump connector has bond pad comprises a material having lower hardness than the material forming the contact bump above. 
       FIG. 27C  then shows using a roller or rollers  2722  wherein the elements  2712  and  2714  may then press the bump into the soft material of the bond pad of corresponding device, such as a roll to roll or reel to reel process to form devices with bump connections. This may allow for quick manufacturing and possible manufacturing on flexible devices. 
       FIGS. 28A-28C  illustrate forming contact bump configurations on a flexible substrate with rollers. 
       FIG. 28A  then shows a roll as described in  FIG. 23A  wherein then substrate roll  2812  of which may be flexible with embedded or otherwise formed device elements wherein a bump connector comprises a bump connection having a rough surface with contact bumps. 
       FIG. 28B  then shows a preprocessed or diced substrate roll  2814  of which may be flexible with embedded or otherwise formed bump pad wherein the bond pad comprises a material having lower hardness than the material forming the bump connection. 
       FIG. 28C  then shows the two  2812  and  2814  rolled or pressed by roller  2822  such that the bumps contact and form a uniform device after rolling. 
       FIGS. 29A-29B  illustrate forming contact bump configurations on a flexible substrate with rollers. 
       FIG. 29A  shows then the two rolls  2912  and  2914  as previously described in  FIGS. 23A, 23B, 28A and 28B  wherein rolled as seen in  28 C and within  FIG. 29B , wherein the bumps press into the softer material such as  2970  and  2971 . It is shown that the vertical or horizontal orientation of the soft pad can be vice versa and any orientation.  FIG. 29B  then provides the two rolls  2912  and  2914  press by roller  2922 . 
       FIGS. 30A-30B  illustrate flow charts for forming bumps and devices for flexible substrates and devices according to some embodiments. 
       FIG. 30A  provides at least process  3000  wherein at least providing a flexible substrate, process  3010  wherein at least forming a device on the flexible substrate, wherein the device comprises a bump connector, and process  3020  wherein at least forming at least one contact bump such that the bump connector having a rough surface. 
       FIG. 30B  provides at least process  3040  providing a first device on a first flexible substrate, wherein the first device comprises a bump connector, wherein the first connector comprises a bump connection having a rough surface disposed thereon, at least process  3050  wherein at least providing a second device on a second flexible substrate, wherein the second device comprises a second connector, wherein the second connector comprises a contact pad or bond pad comprises a material having lower hardness than the material forming the bump connection and process  3060  wherein at least supplying the first substrate and the second substrate to a roller assembly, wherein the first and second substrates are configured so that the first bond pad is aligned with the second bond pad, wherein the roller assembly is configured to form a secure connection between the first and second bond pads. 
       FIG. 31  illustrate flow charts for forming bumps and devices for flexible substrates and devices according to some embodiments. 
       FIG. 31  provides at least process  3100  forming an array of first devices on a first rollable substrate, wherein the first devices comprise first bump connectors, wherein the first bump connectors comprise bump connections having rough surfaces disposed thereon with contact bumps, at least process  3110  providing an array of second devices on a second rollable substrate, wherein the second devices comprise second bump connectors with contact pads or bond pads, wherein the second bond pads comprise a material having lower hardness than the material forming the contact bumps, at least process  3120  processing the first and second rollable substrates in a reel-to-reel assembly, wherein the first and second substrates are configured so that the first bond pads are aligned with the second bond pads, wherein the reel-to-reel assembly is configured to form a secure connection between the first and second bump connectors, at least process  3130  wherein the first devices comprise RFID devices and the second devices comprise flexible element such as a substrate, antenna or device structures, at least process  3140  optionally heating the first and second substrates or the reel-to-reel assembly when forming the secure connection and at least process  3150  Optionally vibrating the first and second substrates or the reel-to-reel assembly when forming the secure connection.