WO2010013992A1

WO2010013992A1 - Flexible thin ribbon helical coil

Info

Publication number: WO2010013992A1
Application number: PCT/MY2008/000077
Authority: WO
Inventors: Eng Siang Koh
Original assignee: Eng Siang Koh
Priority date: 2008-07-31
Filing date: 2008-07-31
Publication date: 2010-02-04

Abstract

A flexible helical thin ribbon coil is constructed by winding metallic wire onto the ribbon substrate that is attached to a mandrel. Wire winding process creates hollow space that is eliminated by flattening process. The ribbon coil is thin and flexible. Due to the fact that it is a helical coil, it is a three dimensional coil. However, the thin and flexible characteristic causes the ribbon coil to looks like two-dimensional planer coil. It is miniature but magnetic flux that it generates is much stronger than planer coil. The ribbon coil design concept can be enhanced by many other process and turn it into many other more complicated coils for various application. By having such thin and flexible feature, more rooms of miniaturized wireless device and further miniaturization of various products can be explored.

Description

Descriptions

Title: Flexible Thin Ribbon Helical Coil

TECHNICAL FIELD

This invention relates to a device for transmitting data information through radio frequency in wireless application; magnetic flux generation in confined space; common use in electronic circuitry such as inductor and choke coil.

BACK GROUND ART

The art of coil has been existed for centuries and the interesting part is that as at today, still there are rooms for improvements. Many structures of coils have been developed in the pass centuries to cater for all kinds of needs. Coil carries many names according to its application. Yet, a coil design that can be catered for curve surface shall be demonstrated. In order to achieve this requirement, a simple way is just by means of winding a two-dimensional plane coil and deposits it on a flat surface as in what we could see in RFID label high frequency application that is call an Antenna. The problem exist here is that this design has a set back; that is the inductance value of the coil is easily affected by surrounding material that cause the coil to malfunction. On the other hand, a three-dimensional helical coil provides a more stable and reliable inductance suitable for high and low frequency application. Following the rule of signal transmitting distance is depending on the coil's length over diameter; helical coil is still widely used in such as walkie-talkie antenna. But due to its space requirement; the present helical coil design is only suitable for more bulky device.

For very thin space application, there is a need for a two-dimensional plane coil that can transmit radio frequency as far as possible. A demonstration here is to have a look alike two-dimensional coil and the best part is that it is flexible. The term look alike is mentioned due to the fact that the coil is actually wound in three dimension manner but due to the reason that it is so thin to the extend that at one glance, the first impression is that the coil is two dimensional. By having such a feature, more rooms of miniaturized wireless device can be explored.

At present, more and more superior metallic alloy has been developed and has provides more varieties and advance inductor development. Metallic alloy such as nickel alloy of permalloy for example; and many other alloys such as amorphous and nanocrystalline; all having very superb permeability suitable for inductors and transformers improvement. Such metallic alloy exists in ribbon form that is as thin as 15 micrometer or even lesser. In this new method of inductor and transformer manufacturing process that is going to be demonstrated, powder form and ribbon strip form of the metallic alloy shall be used.

DISCLOSURE OF INVENTION

The following merely illustrates the principles of the invention. All examples and conditional language recited herein are principally intended expressly to be only for pedagogical purpose in aiding the reader to understand the principles of the invention and the concept contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited example and condition. All statements herein reciting principles, aspecta, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalent thereof. In order to demonstrate the design, one of its applications in radio frequency identification (RFID) tag label shall be use as one of the example. Apart of this, other further method of how the design can be used is briefly demonstrated as well.

A thin flexible substrate is needed to hold the wire windings. In this example of coil strip design, a polymer base material is used as the substrate. The strip is a flexible polymer ribbon that is very thin, can be as thin as 15 micrometer or lesser. Copper tracks are printed at one end of the strip. The polymer is then printed with inductive enhancing material such as ferrite or amorphous powder on both sides. Thin layers of varnish are then printed on both sides of the substrate surface. A ribbon of thin flexible substrate is completed and ready for next wire winding process. However, the choice is open as to whether or not the substrate is to be printed with inductive enhancing compound; depending very much on application requirement.

One could find to wind conductive wire in a helical manner directly on a substrate that is thin and flimsy is truly difficult especially for example: on a 15 micrometer thin flexible polymer ribbon. Therefore, an intermediate stage is necessary. To wind an air coil is easy for thick wire as it can maintain its shape after exit from winding machine mandrel. However, winding an air coil of ultra fine wire is no easy task. A method is to wind an air coil with hollow internal space, attached to substrate on one side of the internal wall. Hollow internal space was created due to mandrel effect just like common air coil of large wire diameter. In this winding process, it is important to bond the wire winding to substrate before the wire winding exiting the mandrel. The bonding process of wire to the substrate is achieved by heating up the varnish on the substrate and or the wire and then cooling it down. Alternatively, it could be cured by alcohol provided that the varnish coated on the wire and or the substrate is an alcohol-cured material. After The winding and the substrate exits from the mandrel, the opposite side of the coil wall that is not attached to the substrate is then press flat onto the substrate; and a second curing process is carried out. This flattening process causes the wire to be slanting (113). This laying flatten of wire winding process complete a first stage coil strip ribbon design (as in Fig. 2b); that is suitable for various kind of application.

The second curing process of flattening of wire is unique from conventional winding process on rigid core material that does not have a second curing process. Conventional method winds the metallic wire directly to the final shape tightly against the bobbin or core; but can only be done if the core is bulky and rigid.

Such a coil strip is on its own, already able to function as an inductor, an antenna for radio frequency signal transmission. (Fig. 2b), a mini low profile transformer given that a few coil strips are coupled together to form primary coil set and secondary coil set and so on. In the case of mini transformer application, the substrate is preferred to be printed with inductive enhancing compound such as ferrite powder compound of manganese zinc or nickel zinc; amorphous metallic alloy powder and nanocrystalline metallic alloy powder. If metallic ribbon strip is to be the substrate such as nanocrystalline alloy ribbon strip, then it is necessary to insulate the substrate by flexible non conductive material such as polymer base encapsulation for protection on wire.

In this example of the coil strip application on RFID tag, a single coil strip is sufficient to act as the antenna. However, helical shape may have its disadvantage. The north and south pole of the antenna is rather weak in signal transmission. In the occasion that a counter measure for this disadvantage is necessary, then a second coil strip ribbon or plurality of coil strips ribbon are placed perpendicular to the first coil strip or any other most suitable orientation such as a right angle L or T; Start and Delta combination. The terminals of the coil strips are then interconnected in series, in parallel; or in a connection that form a center tap terminal with other two end terminals in a form of like a primary and secondary looping. As an example, two substrates are aligned in series on the winding machine mandrel. After winding process, the substrates are inside one single air coil; leaving a larger winding pitch at the center where the substrates are joined and after completing pressing flat and the second curing process, the two substrate are then split and laid perpendicularly or any other suitable orientation. Here it is similar to having two coil strips connected in series and the joining terminal wires of the two ribbon coils may become a center tap terminal. It is not limited to only two coil strips placement; a plurality of coil strips may be used to form various orientations that are necessary to obtain optimal performance. The substrate is preferred to have inductive enhancing compound printed on it or a nanocrystalline alloy flexible metallic base ribbon; and the substrates are laid with ends overlapping one to the other.

A substrate or one of the substrates shall have a space allocated for integrated circuitry die attachment (120). Chip on board process of RFID chip die attachment together with wire bonding is then completed with epoxy moulding protection on the RFID chip. The plurality of coil strips are then lay onto adhesive thin label. Another thin layer of polymer is applied with adhesive is laid to cover the plurality antenna strips for protection purpose; follow by a layer of anti-stick paper laid to protect the exposed adhesive. This completes the whole design of RFID tag label sticker. By peeling off this anti-stick paper, the RFID tag sticker can be stick onto any clean surface.

This design differentiated itself from existing RFID tag label by allowing much longer wire to be laid. It is therefore suitable for low frequency application such as 125kHz RFID application. In the past, 125kHz RFID tag can be some what solid and bulky, now we can have a small and flexible thin label just like the 13.56MHz RFID tag label.

Apart from the example application above as an antenna, a wide range of applications can be achieved as well by adding in further necessary process. In the application of mini transformer; plurality of high permeability ribbon substrates layers is added to enhance its magnetic flux generation. A further demonstration is by having plurality substrate layers in the middle of the air coil before the flattening process. In this case, the wire winding shall have a primary winding and plurality secondary windings as in Fig. 4a. After wire winding being lay flattening and completion of second curing process; both surface of the coil strips are laid with one piece of polymer insulation each one on top and bottom to protect the wire winding. Additional stack of substrates on top and bottom are laid with half the number of the center substrate ribbon layers (129, 130); on each side of the flat surface of coil ribbon strips. These three stacks of flexible substrate ribbons are clamp together and bonded to hold all three parts together at the two ends of the substrate ribbons. If there is a need to allow the mini transformer to be bendable, then the bonding material must be good in elongation property such as polyurethane base adhesive or a shrinkable tube to wrap the two ends of the three stacks of substrate. More detail illustration is demonstrated in Fig. 4 and Fig. 5. Both structures are a super low profile, flexible thin ribbon transformer. This design structure is more robust as the transformer is more resistance to drop breakage. The conventional type low profile is usually built with soft ferrite core and it has the limitation to the core thickness. The Ferrite core is not able to withstand drop impact. It breaks easily.

A better method to construct a miniaturize transformer can also be achieved without external two stacks of ribbon substrates layers (129, 130) as demonstrated above. It is achieved by means of forming a complete looping shape core of ribbon substrates. In this method, the ribbon substrates layers are laid in the zigzag manner in air coil. The ribbon substrates could be arranged zigzag in every alternate ribbon substrate or every plurality of ribbon substrates of equal number (139, 140, 141 & 142) as in Fig. 6a. It is possible to have a single thin ribbon substrate provided that the substrate has very good permeability. The beauty of this design is that the wire winding process is linear whereby the winding process is much faster than conventional toroidal winding process. After lay flattening of wire winding and second curing process, the ribbon substrates that have flexibility property are bended into including but not limited to a round, a square or a rectangular shape; joining up the two zigzag ends of the ribbon substrates. The joint location (144) is then bonded together by adhesive or epoxy compound. The joining point may not be necessary in zigzag mannered, it could be in a simple two steps (139, 140) only. The air gap (144) is drawn just for demonstration of joining point. In transformer application, it would be best not to have air gap and that the substrate ends are touching each other. To achieve this, the length of every piece of the substrates is slightly different. The one that is located at the inner circle will be shortest and the outer circle is the longest piece of substrate. In reality, there will exist a very thin air gap, but the weak point can be overcome by placing additional small pieces of substrate (145, 146) attached to the sides of joint location 144. This substrate provide additional path for enhancing the magnetic flux flow. The whole assembly is then coated with flexible polymer material such as including and not limited to polyurethane or synthetic rubber.

This miniature transformer design differentiate itself from common toroidal transformer is that the traditional method will have to form a round multi-layer ring coiling of a single long strip of substrate and follows with a slow wire winding process. Machine winding is difficult on traditional method when the toroidal core inner diameter is very small, in most case slow wire winding has to be done manually when the inner diameter of the core does not has enough space to accommodate the machine winding ring. The new method of production process does not face this limitation. This new design provides a way to mass production of the miniature transformer or in another word: a miniature voltage converter.

In this method, the miniature transformer is lesser flexible as the ribbon has been jointed up to form a ring. However, it stills carry a little features of flexibility, due to the fact that the original substrate is flexible. The shape can be changed to suit its environment to certain extend such as square and rectangular shape.

Given that if the joining location (144) in Fig. 6b is not arranged in zigzag mannered at all; and the spacing being maintained by none ferrous base metallic material or non metallic material; without patch up substrate 146 & 146; and provided that the gap between the substrate ends is sufficient to prevent current saturation, then the coil design is suitable to be used as fluorescent lamp ballast. In this application as ballast choke coil, given that silicon steel is used as the substrate, in most cases, the plate would be thicker and the size of the coil is no longer miniature. It would probably ends up more bulky. However, the size of the coil will be smaller than the common resistance type fluorescent lamp ballast. This is the result of a round loop design. And in this design, less silicon steel and copper wire is needed to produce a same capacity compare to a common resistance type ballast choke coil. Silicon steel has to be replaced by such as nanocrystalline substrate strips of higher permeability if the size of the choke coil has to be made miniature. Other application of a choke coil that is available at the moment is a design of a coil constructed by a solid amorphous core cast in one single piece; with a slot cut on the core to create an air gap. However, due to the same fact that it is a toroidal core, the winding process has limitation on the inner core diameter that only allow certain size of toroidal winding ring that can be used; thus limit the wire size as well. The new method of producing this type of coil that is explained does not have such limitation. The high permeability flexible ribbon substrate opens up a new production method; that has break free from the boundaries that existed in the conventional choke coil production method. One additional important advantage of this design is that the choke coil noise is minimized. This is due to the reason that the original substrate is straight; when it is purposely bend, the inner ring will have a natural force pushing the next outer ring and so on. Therefore, every piece of the substrate in a way is automatically tightly packed as long as the most outer ring of the substrate is held in shape by a housing or collar such as 163, 164 in Fig. 7.

DESCRIPTION OF DRAWING FOR CARRYING OUT THE DESIGN

Note that all ribbon substrate in the figure are drawn not proportion to its actual thickness. The substrates are draw purposely thicker for demonstration purpose.

Fig. 1 illustrates a simple construction of a piece of ribbon substrate. 101 being the thin ribbon polymer; 102, 103, 104, 105 & 106 are groves for hooking wire during winding. 107 is inductance enhancing compound printing on top and 108 is inductance enhancing compound printing at the bottom surface of the substrate 109, 110 are preprinted solder pad.

Fig. 2 illustrates a wire winding method on flexible thin ribbon substrate from Fig. 1.

In Fig. 2a, metallic wire is soldered on pad 109 and hook to grove 111 and continues to grove 103 (in Fig. 1). Wire windings on a substrate create hollow space

115 during winding process on winding mandrel. Wire winding exits grove 112 and soldered to pad 110.

Fig. 2b shows a view of wire windings being press down flattened in slanting manner and bonded onto the substrate.

Fig. 3 illustrates a further variation from Fig. 2 design. It demonstrates two substrates in one winding process that construct a RFID strip.

Fig. 3a illustrates two pieces of substrates 117, 118; aligned in series leaving a gap 119 such that the wire excess is longer at this position. Track 121, 122 links the solder pads to RFID chip die (120) soldering point that is embedded in the epoxy that protect the RPID chip die. Enameled wire 123 laid inside of the wire windings.

Fig. 3b illustrates a possible orientation of two substrates with one substrate end overlapping the other. Wire .124 being the bent shape of wire 123, hooked onto the groove of the first substrate.

Fig. 4 illustrates a method of constructing a flexible low profile miniature transformer.

Fig. 4a shows four pieces of flexible ribbon nanocrystalline substrate (125) insulated with a shrinkable tube, polymer tape or flexible epoxy coating (126); wound with wire also created hollow space due to mandrel effect. A few center taps of wire CAi, CA2 up to CAN are pulled out for multi-steps of voltage tapping. Fig. 4b shows hollow space being eliminated by pressing flat the wire winding in slanting manner and bonded the wire to the substrate. Two pieces of polymer insulation (127, 128) each one on top and bottom is laid to protect the wire winding. Fig. 4c shows additional two pieces of nanocrystalline substrates stacks on top (129) and another two pieces at the bottom (130); both bend at location 131, 132 and 134, 134 respectively for wire and insulation clearance. Two ends of the substrates are being held together by shrinkable tube collars (135, 136).

For protection and easy mounting purpose, the assembly can be seated on the polymer casing ready with plurality of pin terminals for soldering. Assembly of Fig. 4c may be encased by a metal case; whereby the two ends shrinkable tube (135 & 136) may not be needed anymore. However, doing so will result in the low profile transformer to lose its flexibility.

Fig. 5 illustrates alternative method of thin flexible profile transformer design making use of part of design structure in Fig. 4a; resulted in extra low profile design.

Fig. 5a illustrates the external square collar substrates. 171 being part of design in Fig. 4a which is already flattened the wire; being inserted into collar substrate 172. Air Gap 173 & 174 has to be minimized. The gap 173 & 174 between the substrate ribbon is filled up with flexible adhesive such as polyurethane adhesive or synthetic rubber adhesive mixed with inductive enhancing compound.

Fig. 5b illustrates 4 pieces of substrate strip 175, 176, 177, 178 guiding the assembly in place to enhance magnetic flux flow; and shrinkable tube collar 179 & 180 aligning and holding the thin and flexible assembly. Fig. 5 c illustrates structure of polymer case ready with solder pin pad CBi₅ CB2 up to CBN. The solder pin pad is a C cap; 177 demonstrate the shape before the protruding bottom portion of the C cap is bent in as show by the arrow to form into the shape of pad CBi, CB2 up to CBN.

The assembly illustrated in Fig. 5b by itself is a complete miniature transformer; or it could be fitted onto the polymer case of Fig. 5 c for easy soldering onto printed circuit board. Alternatively structure Fig. 5b could be embedded in an end product casing even if the end product casing shape is curvy, leaving the terminals wires protruding out of the casing for soldering onto the printed circuit board.

Fig. 6 illustrates another method of constructing a complete looping miniature transformer. Fig. 6a shows four stacks of substrates (139, 140, 141, 142), with two pieces of substrates per stack. In actual fact, more pieces of substrate can be packed in every stack as each piece of the substrate is a very thin ribbon as thin as less than 15 micrometer. Stacks of substrate are insulated by shrinkable tube, polymer tape or flexible epoxy coating (143) to form a multi-layer substrates core. The core is wound with wire also created hollow space due to mandrel effect. A few center taps of wire CCi, CC2 up to CCN are pulled out for multi-steps of output voltage tapping.

Fig. 6b shows after the wire winding is flattened slanting and bonded to the substrate; the core is bent round to joint the two ends of the substrate as in joint 144. For protection and easy mounting purpose, the assembly can be seated on the polymer casing ready with plurality of pin terminals for soldering and the epoxy encapsulation is applied to fill up the cavity just like a common current sense coil.

Fig. 7 illustrates a method to make used of the design illustrated in Fig. 5 to produce a choke coil.

Fig. 7a illustrates 2 similar packs of substrate stacks 150, 151 but arranged in two steps. Insulation 153 is completed at the center by shrinkable tube, flexible epoxy coating or polymer adhesive tape. Plurality of bobbin or bobbin-less coils (example: two units as in drawing) are inserted. Both ends bend upward as in 157, 158 creating curve shape at 153. The curve-shape 159; is maintained by a metal or polymer collar such as item 164 that is illustrated in Fig. 6c. The two ends of the substrates are than insulated by shrinkable tube, flexible epoxy coating or polymer adhesive tape. After which, the two ends are bend either to form circle shape as in Fig. 7b or 7c; depending on the original length of the substrate and its arrangement. '

Fig. 7b illustrates a bent result from the substrate stacks different length of arrangement 150, 151 in Fig. 6a. The two bent ends merged in to eliminate air gap. A similar collar 164 shape will be needed to hold the two ends in shape. Adhesive or flexible epoxy is applied on the matching ends of the substrates to hold the substrate to the collar.

Fig. 7c illustrates a bent result of single substrate stack 150 and the two ends are purposely maintains a sufficient air gap (162) to cater for current saturation effect. If necessary, the two ends of the substrates are cut such that the edges are even flatness. A collar as in item 163 shape is used to maintain the curvy shape and air gap. Similarly adhesive or flexible epoxy is applied on the near-matching ends of the substrates with ^"an air gap to hold the substrate to the collar. Collar 164 is used to shape the other ends. And in the case of no air gap, then 2 units of collar 164 are used to maintain the bent shape of the substrates. The collar 163 & 164 is used to maintain the bent shape of the substrate in Fig. 6b as well; whereas in this case, the collars may be touching each other and can be bonded together or a mould part of feature 163 and 164 or 2 units of 164 being mould into a single piece.

Fig. 8a illustrate the structure 181 (design as in Fig. 5b) with tapped out wires of CAi, CA2 up to CAN soldered to terminals of a metal stamping parts such as lead frame 182. Note that structure in Fig. 5b may be replaced by structure Fig. 4c.

Lead frame 182 is a thin stamped metal pre-tinted for improving solder ability; consist of plurality of cut pin strips of 183, 184 and 186 to 194. Structure 181 is place on two individual short pin strips 183 and 184. Pin strips 183 & 184 are bent a groove at the bottom to evade shrinkable tube such that both 183 & 184 touches the flexible ribbon strip of assembly 181 (substrate of 171 & 172 of Fig. 5a). 183 & 184 are bonded to the assembly 181 with heat conductive adhesive. Epoxy 185 is applied to bond the pin strip 184 to the structure 181; and another epoxy is applied to bond the pin strip 183 to structure 181. All terminal wires are pre-soldered, then hooked onto the pin strips 186 to 194, and soldered.

Fig. 8b illustrates the moulded product of miniature low profile transformer in the form of a module package just like a normal integrated circuitry chip. The assembly structure of lead frame 182 and structure 181 is moulded with polymer compound in the injection mould machine. Excess strip of 183, 184 are cut off after moulded as shown by 197. The terminal pin strips 186 to 194 are cut and bent as shown by 198, a cut terminal pin and 199 shows the next process of bending. Bottom part of the pins 186 to 194 are exposed, suitable for soldering the terminals to the printed circuit board. Excessive lead frame strip 183 & 184 (as in 197 shape) can be soldered to printed circuit board for dissipating heat from the miniature transformer.

Claims

1. A thin flexible coil strip as in Fig. 2b consists of helical wire winding on flexible thin substrate including but not limited to structure as shown in Fig. 1.

2. Plurality of coil strip ribbons as in claim 1 being arranged in various formations on a tag label such as including but not limited to a) double coil strips as in combination of including but not limited to T shape and L shape as in Fig. 3. b) triple coil strips as in combination of including but not limited to Star shape and triangular delta shape c) quadruple coil strips as in combination of including but not limited to square and rectangular shape and d) more numbers of coil strips to form many other shapes.

3. Gap (119) and excess wire (124) allow for series arrangement of plurality of ribbon strip substrates to be separated and orientated in various orientations.

4. Wire windings as in claim 1 is a thin flexible-helical flatten coil.

5. Thin flexible-helical flatten coil as in claim 4 has plurality of center taps windings as in included but not limited to Fig. 4, Fig 5, Fig 6 & Fig. 7.

6. Wire as in claim 4 is an enameled conductive metallic material such as including but not limited to copper, aluminum and brass.

7. Staging of many thin layers of single layer of winding into multi-layers of winding coil and interconnecting of wire terminals in series to form multilayers coil to increase inductive value.

8. First bonding of wire to substrate by varnish by the method of including but not limited to high temperature curing of varnish; by applying alcohol liquid or alternatively by mean of adhesive.

9. Bonding process as in claim 8 bonds one side of the substrate to one side of the coil winding and created hollow space in the internal part of the coil.

10. Flattening and second bonding process cause wire winding to rest in slanting manner (113) as in Fig. 2b.

11. Substrate is a plurality of including but not limited to a thin polymer or organic film, coated with inductance enhancing compound.

12. Substrate is a plurality of including but not limited to thin polymer or organic flexible film printed with inductance enhancing compound and coated with heat or alcohol cured varnish.

13. Inductive enhancing compound as in claim 11 and 12 include but not limited to ferrite powder compound of manganese zinc or nickel zinc; amorphous metallic alloy powder and nanocrystalline metallic alloy powder.

14. Substrate is flexible thin metallic alloy film of including but not limited to amorphous metallic alloy ribbon and nanocrystalline metallic alloy ribbon; coated with polyurethane or any other insulation method; with additional coat of adhesive or varnish layer that is cured by heat or alcohol.

15. Parallel arrangement of plurality of substrates allow for ribbon strip substrates having a choice of bending the substrate and joint up the two end to form a close loop of substrates or not completely close by having an air gap; and bending of the substrate is done after wire winding process.

16. With a close loop substrate (Fig. 6b & 7b) as in claim 15, the coil is use in application of including but not limited to electricity current sensing, common mode choke coil; filter coil and miniature transformer.

17. The substrate as in claim 15 with an almost close loop but a small air gap 162; joint gap 144 with substrate not zigzag mannered and without substrate 145 & 146 as a counter measure for current saturation; the coil is use in application of including but not limited to ballast coil for fluorescent lamp.

18. The coil strip as in claim 1, low profile miniature transformer as in Fig. 4 and extra low profile miniature transformer as in Fig. 5b, being mould into casing cover of various end products, accommodating it self even in curvature shape.

19. Application field of coils strip (as in claim 1) in wireless devices in radio frequency transmission ranging from very low frequency range in only a few kilohertz up to ultra high frequency range in term if gigahertz.

20. Application field of coils strip (as in claim 1 & 16) in charging DC power dry cell at a near filed environment without direct contact to AC power source; of including but not limited to capacitor and battery.

21. Application in generating magnetic flux including but not limited to inducing neighbor coil to response as in the mode of remote switch and inducing miniature speaker's diagram to vibrate.

22. Application in generating magnetic flux including but not limited to inducing neighbor coil to self-coil-charging in busting current energy or voltage to create bursting current for stepping up radio frequency transmission energy that is powered by including but not limited to miniature DC current source such as button cell battery.

23. Wireless device as in claim 19 is including but not limited to a Radio Frequency Identification (RFID) Tag, RFID reader antenna, and mobile telecommunication device.

24. RFID tag as in claim 23 is in the shape of including but not limited to single antenna strip, rectangular or square sheet of label consists of plurality of coil antenna strips in the structure of flexible thin coil strip ribbons.

25. Plurality of ribbon strips as in claim 11, 12, 13 and 14 are arranged in series or parallel during winding process depend on design requirement.

26. Miniature transformer as in claim 16 build from flexible thin ribbon substrate including but not limited to design structure as in Fig. 4, Fig. 5, Fig. 6, Fig 7b and chipset module 200 as in Fig. 8.

27. Miniature transformer of design structure including but not limited to Fig.6 & Fig.7b, is produce by winding process followed by bending of substrates.

28. Substrate stacks 139, 140, 141, 142 of miniature transformer as in claim 26 of Fig. 6 is insulated by shrinkable tube or other mean of polymer insulation cover all stacks into one.

29. Plurality of individual packs of substrates 139, 140, 141 & 142 as in claim 28 are insulated by shrinkable tube or other mean of polymer insulation covering each stacks separately.

30. Plurality of patch up substrate 145 & 146 to increase magnetic flux flow path due to poor matching point of the bend circle of miniature transformer.

31. Miniature transformer sub-assembly as in Fig. 5b from claim 26 functions as an extra low profile bendable transformer.

32. Metallic or polymer collar in the shape of including but not limited to 163 and 164 individually or simultaneously guiding substrates in bent shape.

33. Chip set module miniature transformer as in claim 26 consist of solder terminals of structure 199 as a finish shape of cut lead frame terminal pin strips of 186 to 190.

34. Heat dissipation pin strips of structure 197 on chip set module as in claim 33 are final shape of cut lead frame pin strips of 183 and 184.