WO2007013854A1

WO2007013854A1 - Intelligent card and manufacturing thereof

Info

Publication number: WO2007013854A1
Application number: PCT/SG2005/000255
Authority: WO
Inventors: Vishwanath Lakshmi
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-07-28
Filing date: 2005-07-28
Publication date: 2007-02-01
Anticipated expiration: 2008-01-28

Abstract

A method of manufacturing an intelligent card is disclosed. An electrically conductive substrate (1) is patterned and partially etched and a flip chip (7) attached to it. The assembled flip chip and the substrate are fully molded on the front side and the device fully enclosed by epoxy molding compound or a plastic polymeric substance (9). The portion of the exposed conductive substrate is then removed on the back side to expose the contact terminals of the RF ID module along with a fully molded card. The modules are then separated each to form smart cards.

Description

INTELLIGENT CARD AND MANUFACTURING THEREOF

BACKGROUND

[0001] This invention relates generally to a fully integrated intelligent card and a method of manufacturing such an intelligent and or a smart card. More particularly, this invention relates to a intelligent and or a smart card including at least one integrated circuit die or two or more dies arranged in a single and / or multiple (stacked) configuration so as to have a fully integrated intelligent card with sizes ranging from 1 mm square to 100 cm square and or larger, and to a method of manufacturing such an integrated card.

[0002] With the miniaturization of electronic products, there is a need to also reduce the thickness of the smart cards and increase the functions. The approach is to add more functional features by each IC devices in the smart cards, for example to form a single card that can be used for both contact and contact less applications. A single card that can be used for all communication ports with multi functional integrated circuit chips. And many. [0003] The current available smart cards both contact less and contact type are manufactured in two stages namely a smart card module followed by lamination to produce the respective card forms. The steps for manufacturing the smart card involves manufacturing an organic substrate with respective circuitry, assembling IC device to the same and laminating the arrayed substrate and separation of each card. This method requires precise dimensions of the module, and or chip assemblies to obtain good final lamination yields as any excess module thickness would result in damage to the IC chip and thus yield loss. Also, not every module and or label assemblers are not in a position to laminate the same due to expensive lamination equipment and tools involved. This makes the smart card to be expensive though a number of players out there for module and or label assemblies. SUMMARY [0004] According to an aspect of the present invention, there is provided a method of manufacturing an intelligent card. According to the method, a fully conductive substrate is first provided. Each substrate module includes interconnection pads on a first side of the substrate. Required bond pad patterns are carried out either by subtractive or additive methods. Assembly between substrate pads and the corresponding die bond pads are completed. Molding is done on the first side of the conductive substrate to embed the circuit patterns and the assembled IC chip/s. The un-etched / patterned portion on the 2^nd side of the conductive substrate is removed either by mechanical grinding or by chemical etching to expose the bottom of the circuit pattern on the first side of the substrate. The exposed patterns are finished using appropriate techniques as required thus producing an intelligent card as per the method of invention. [0005] Preferably, the method may further include forming of interconnect pads after the circuitry etching on the first side of the conductive substrate. [0006] Preferably, the circuitry patterns on the first side of the substrates are coated and or plated with corrosion protective thin films. [0007] The method may further include circuitry patterns to sufficient depth in order to obtain high performance electrical inductance / functionality. [0008] Preferably, the method may further include assembly of the IC chip to the first side of the conductive substrate by anisotropic conductive adhesives and or solder materials and or silver filled conductive adhesives. [0009] The method may further include removing the un-etched and or un- patterned material portion on the second side of the conductive substrate by means of mechanical grinding and or chemical mechanical polishing and or chemical wet / dry etching processes.

[0010] The method may further include finishing the exposed circuitry pattern on the second side of the molded substrate with electro less nickel / gold and or tin plating as required. [0011] The method may further include separation of individual smart cards from the matrix array substrate. [0012] Preferably, the method further includes providing at least one IC chip assembled to the conductive substrate.

[0013] Preferably, the smart card may include grinding and polishing of the first side of the card to further reduce the thickness of the smart card. [0014] Preferably, the method further includes providing RF functional chip in the assembly.

[0015] Preferably, the method further includes providing Memory storage chip in the assembly.

[0016] Preferably, the method further includes providing a biometric chip in the assembly.

[0017] Preferably, the method further includes providing a sensor chip in the assembly.

[0018] Preferably, the method further includes providing liquid crystal display and associated functional chips in the assembly. BRIEF DESCRIPTION OF DRAWINGS

[0019] The invention will be better understood with reference to the drawings, in which:

[0020] Figures 1 (a)-1 (o) are sectioned drawings of prior arts for various smart card configurations 2,4,6,8,10,12,18. Figure 1 (a)-1 (o) shows smart cards that use an organic substrate (20) such as printed circuit board or polyester foil and or others for fabrication of the smart cards 2,4,6,8,10,12,18. Single die

(24) and or multi die (24, 26) are assembled on the organic substrate circuitry and laminated with PVC film, depending on requirements. Figure 2 through 15 represent the steps involved in manufacturing an intelligent card as per this method of invention. Fig 2. is a sectioned drawing of a metallic conductive substrate (14), such as Copper / Nickel / Tin / Aluminium / Gold etc (1). The conductive substrate (14) can be a size depending on the number of modules and or cards to be obtained per substrate. Fig 3. is a sectioned drawing of a conductive adhesive and or solder (3) deposited on the conductive substrate (14) to form interconnections with the plurality of bond pads of the integrated circuit chip (A, B) when the later is assembled to tr (14). The patterning of the conductive deposit by numerous methods is well known to those having skill in the art and hence not discussed in this method of invention.

[0021] Fig 4. represents a sectioned drawing of the conductive substrate (14) after etching a^' pattern (5) as required to form a contact smart card module. The process involved in patterning of the module by numerous methods is well known to those having skill in the art and hence not explained in this method of invention. Fig 5. is a sectioned drawing of an assembled integrated circuit chip (7) on the conductive adhesion pads (3) of the conductive substrate (14). The methods involved in assembly of the integrated circuit chip to the substrates is well known to those having skill in the art and hence not explained in this method of invention. Fig 6. is a sectioned drawing showing a molded (9) IC chip (7), where in, the entire conductive substrate (14) portion along with assembled IC chip (7) is molded using plastic molding (9). The plastic and or polymeric and or composite compounds molding of the conductive substrate (14) by numerous methods is very well known to those having skill in the art and hence not explained in this method of invention. Fig 7. is a sectioned drawing of the assembled smart card after the removal of excess un-etched / patterned material on the second side of the conductive substrate to expose the smart card contact terminals (13) on the second side of the substrate (14).

[0022] Fig 8. is a sectioned drawing of the above embodiment with gold / silver and or lead / tin finished leads (15) on the second side of the substrate for long life contact purposes. Fig 9. is a sectioned drawing of another preferred embodiment with multiple die assembly (17. 19) for a one or more applications. Fig 10. is another sectioned drawing of a smart card module (16a) with the above mentioned embodiment of this invention method, that can be used for applications with a pre-formed copper coil antenna. Fig 11. is a sectioned drawing of a smart card module (16b) manufactured with the above mentioned embodiment of this invention method. The module in this drawing represents a multi IC chip that may provide fc less functions. Fig 12. is a sectioned drawing of a smart SIM module (16c) manufactured with the above mentioned embodiment of this invention method that are used in mobile pone communications.

[0023] Fig 13. is a sectioned drawing of another embodiment of this method of invention to produce a smart label (18a) which uses an embedded etched antenna coil (23). Fig 14 is a sectioned drawing of above mentioned embodiment (18b) described in Fig 13, which uses multiple die (25,27) for one or more applications. Fig 15. is a sectioned drawing of above mentioned embodiment (18c) that may provide both contact (through terminals 33,35) and contact less (through antenna 23) functionality. IC chip (31) may serve for contact less functionality where as IC chip (29) may serve for contact iterations purposes.

DETAILED DESCRIPTION OF THE INVENTIVE METHOD [0024] Figure 2 through 15 represents a sequence of steps for manufacturing an intelligent card (14) according to the embodiments of the present invention. The sequence X starts in a PROVIDE SUBSTRATE 1, wherein THE SUBSTRATE IS electrically and thermally conductive in nature. A plurality of IC chip bond pads (3) are fabricated over the first side of the conductive substrate (1) using photo-masking and or printing techniques. Providing the interconnect conductive pads (3) by numerous methods is well known to those having skill in the art such as gold / copper / Al / tin stud bumps, conductive polymer bumps, solder alloy bumps, anisotropic conductive bumps etc, and hence not explained in this method of invention. [0025] The first side of the conductive substrate (1) is then patterned for a smart card module (14) and etched (5) as required. The pattern may be etched to thickness 1 micron meter to 100 micron meter and depending on required application. This method of invention requires the etching of such circuit pattern to be partial across the substrate (1) thickness and hence the selection of substrate thickness may be chosen prior to the fixing the smart card thickness. Forming of such patterns and or circuits for smart card modules (14) assembly is well known to those having skill in the art and hence not explained in this method of invention.

[0026]At least one Integrated Circuit chip (7) with solderable bond pads (A₁B) are aligned with the plurality of the bond pads (3) on the conductive substrate (1) and interconnected using well available interconnect techniques in the field of semiconductor industry. The IC chip (7) to conductive substrate (1) interconnection by numerous methods is well known to those having skill in the art and hence not explained in this method of invention. [0027] The assembled substrate is then molded using injection and or transfer molding methods to completely seal the circuitry patterns (5) and IC chip (7). Plastic / polymeric and or composite materials may be used for molding in this method of invention. The mold thickness may depend on IC chip (7) final thickness and also the desired card thickness. [0028] The un-etched / patterned material is then removed on the second . side of the substrate (1) to expose the bottom of the circuitry pattern, in other words known as contact terminals (13) of the smart cards / modules. The removal of un-etched material and exposure of the contact terminals (13) on the second side of the substrate may be by using well known mechanical grinding and or polishing methods. Also the removal of such material may be carried out by other methods well known to those having skill in the art such as wet chemical etching and or dry etching and hence not discussed in this method of invention.

[0029] The exposed contact terminals (13) on the second side of the conductive substrate are then finished with gold and or silver plating (15) to protect the same from atmospheric moisture and also to provide hard surface finish for long lasting of contact applications.

In another preferred embodiment of this method of invention the steps above mentioned are repeated to obtain an etched antenna coil (23) to enable contact less applications for the smart cards 18a. Single die (21) and or multiple die (25, 27 and or 29, 31) are assembled to this antenna coil (23) for multiple functionality smart cards (18b, 18c). Smart this method of invention provides terminals (33, 35) for contact purposes and antenna (23) for non contact purposes.

Claims

CLAIMSI claim:

1. A method of manufacturing an intelligent card comprising: providing a first conductive substrate including connection pads on a first side of the substrate; the plurality of connection pads corresponding to the bond pads of the Integrated circuit chip; partially removing substrate material from the first side, and or adding required patterns on the first side in order to obtain circuitry and or antenna for smart card applications; the substrate contact pads being electrically connected to the bonding pads of the IC chip on the active side; molding the entire first side of the conductive substrate that includes integrated circuit chip and circuitry for the smart cards; removing the un - disturbed conductive material on the second side of the substrate; exposing the contact terminals of the smart cards on the second side of the molded / first substrate; finishing the contact terminals with protective conductive coatings; separating the modules along the separation zones to produce individualized packaged smart cards, each of which serve as a smart card.

2. A method of forming a smart card and or module according to claim 1, wherein the first conductive substrate is of Copper, Silver, Aluminium, Tin, Nickel and or any other electrically good conductive material, including binary metallic alloys.

3. A method of forming a smart card and or module according to claim 1 , wherein the interconnect pads on the conductive substrate are of copper, tin, nickel, gold, solder alloys, anisotropic conductive films / pastes, conductive polymers.

4. A method of forming a smart card and or module according to claim 3, wherein the interconnect pads on the conductive substrate may be made of electrically conductive alloy formulations from the metals described in the claim 3.

5. A method of forming a smart card and or module according to claim 3 and 4, wherein the interconnect pads are formed by additive methods.

6. A method of forming a smart card and or module according to claim 3 and 4, wherein the interconnect pads are formed by subtractive method.

7. A method of forming a smart card module according to claim 3 and 4, wherein the interconnect pads are coated and or plated with corrosion protective thin films.

8. A method of forming a smart card and or module according to claim 1 , wherein the circuitry patterns are etched to sufficient depth in order to obtain high performance electrical inductance / functionality.

9. A method of forming a smart card and or module according to claim 8, wherein the circuitry patterns are added to sufficient thickness in order to obtain high performance electrical inductance / functionality.

10. A method of forming a smart card and or module according to claim 1 , wherein the IC chip is interconnected to the first side of the conductive substrate by anisotropic conductive adhesives and or solder materials and or silver filled conductive adhesives.

11. A method of forming a smart card and or module according to claim 10, wherein the IC chip is interconnected to the first side of the conductive substrate by solder reflow methods.

12. A method of forming a smart card and or module according to claim 1, wherein the encapsulation method comprises of injection molding.

13. A method of forming a smart card and or module according to claim 1, wherein the encapsulation method comprises of transfer molding.

14. A method of forming a smart card and or module according to claim 1, wherein the encapsulation method comprises of casting of plastic compound.

15. A method of forming a smart card and or module according to claim 1, wherein the un-etched and or un-patterned material portion on the second side of the conductive substrate is removed by mechanical grinding.

16. A method of forming a smart card and or module according to claim 15, wherein the un-etched and or un-patterned material portion on the second side of the conductive substrate is removed by chemical wet etching.

17. A method of forming a smart card and or module according to claim 16, wherein the un-etched and or un-patterned material portion on the second side of the conductive substrate is removed by deep reactive ion etching (DRIE).

18. A method of forming a smart card and or module according to claim 17, wherein the un-etched and or un-patterned material portion on the second side of the conductive substrate is removed by room temperature plasma etching.

19. A method of forming a smart card and or module according to claim 18, wherein the un-etched and or un-patterned material portion on the second side of the conductive substrate is finished by chemical and mechanical polishing process.

20. A method of forming a smart card and or module according to claim 15 through 18, wherein the exposed circuitry pattern on the second side of the molded conductive substrate is finished with protective electro-less nickel / gold and or tin plating thin films.

21. A method of forming a smart card and or module according to claim 1, wherein the molded matrix arrayed substrate are processed for separation of individual smart cards.

22.A method of forming a smart card and or module according to claim 1, wherein the smart card module to include at least one IC chip assembled to the first side of the conductive substrate.

23.A method of forming a smart card and or module according to claim 20, wherein the smart card may include further grinding and polishing of the first side to further reduce the thickness of the smart card.

24.A method of forming a smart card and or module according to claim 22, wherein the smart card system may provide a RF functional chip in the assembly.

25.A method of forming a smart card and or module according to claim 22, wherein the smart card system may provide a memory storage chip in the assembly.

26.A method of forming a smart card and or module according to claim 22, wherein the smart card system may provide a biometric chip in the assembly.

27.A method of forming a smart card and or module according to claim 22, wherein the smart card system may provide a sensor chip in the assembly.

28.A method of forming a smart card and or module according to claim 22, wherein the smart card system may provide a liquid crystal display and associated integrated chip in the assembly.

29.A method of forming a smart card and or module according to claim 22, wherein the smart card system may provide one or multiple integrated chips on a single layer for the first conductive substrate.

30. A method of forming a smart card and or module according to claim 22, wherein the smart card system may provide one or multiple integrated chips on a multiple layers arranged in stack formation.

31. A method of forming a smart card and or module according to claim 1, wherein the mold resin material consists of different colours to obtain different colour codes of smart cards for specific applications / standards

32.A method of forming a smart card and or module according to claim 1, wherein the smart cards / modules may be printed using laser printing.

33.A method of forming a smart card and or module according to claim 1, wherein the smart cards / modules may be printed using label printing.

34.A method of forming a smart card and or module according to claim 1, wherein the smart cards / modules may be printed using off-set printing.

35.A method of forming a smart card and or module according to claim 1, wherein the smart cards / modules may be printed using roller printing.

36.A method of forming a smart card and or module according to claim 1, wherein the smart modules may be printed with pre-formed antenna coils.

37.A method of forming a smart cards and or modules according to claim 1, wherein the manufacturing process flow be used for processing smart labels.

38.A method of forming a smart label according to claim 37, wherein the label be embedded in plastic structures and containers.

39.A method of forming a smart label according to claim 37, wherein the label be embedded in metallic structures and containers.

40. A method of forming a smart label according to claim 37, wherein the label be embedded in concrete structures and containers.

41. A method of forming a smart label according to claim 37, wherein the label be embedded in composite structures and containers.

42.A method of forming a smart card and or label according to claim 1 offers a low cost solution for intelligent card communication applications.