Contact module, as for a smart card, and method for making same

A module, such as a contact module for embedding an electronic device into a credit card, smart card, identification tag or other article, comprise a pattern of metal contacts having a first and a second surface and electrically-conductive vias built up on the first surface of the metal contacts. A layer of dielectric adhesive on the first surface of the pattern of metal contacts surrounds the electrically-conductive vias except the ends thereof distal from the metal contacts. An electronic device has electrical contacts connected to the exposed ends of the conductive vias, as by wire bonds or by flip-chip type connections. The module is preferably made by forming a pattern of conductive vias on the first surface of a sheet of electrical contact material, the pattern of vias corresponding to the pattern of contacts of an electronic device; applying dielectric adhesive on the first surface of the sheet of electrical material except in locations corresponding to the vias; patterning the sheet of electrical material to define a pattern of electrical contacts thereon, wherein ones of the electrical contacts are associated with at least corresponding ones of the vias; and attaching the electronic device with the contacts of the electronic device electrically connected to corresponding vias.

The present invention relates to a module and, in particular, to a module
 including an electronic device, and to a method for making same.
 As credit cards, phone cards, identification tags and badges, and other
 forms of identification devices and other commercial objects have become
 more sophisticated to offer greater capabilities and access to more
 services, the need for such objects to include more than just a stripe of
 magnetic material into which information is encoded has been recognized.
 Not only is the need recognized to store more information than can be
 encoded in a magnetic stripe, but also the need to include in the object
 electronic circuitry to receive, process and output information.
 Conventionally, electronic circuitry in the form of semiconductor
 integrated circuits has been embedded into cards, tags and badges to
 receive, process and output information. Typically, the circuitry includes
 a microprocessor or a memory, or both. Information is provided to the card
 and is received from the card in the form of electronic signals by a card
 reader which typically includes electronic circuitry to verify or identify
 the information provided by the card in relation to the information
 provided to the card. For example, where the card is utilized as an access
 badge, the card reader signals the badge to provide identification
 information, and if the information provided matches information stored in
 the card reader to identify an authorized badge, then the card reader
 authorizes access, such as by releasing an electrical lock. In a more
 complex application, a card may be utilized as a substitute for money. The
 card reader, such as a point-of-sale terminal, cash register or automated
 teller machine, first verifies the identity of the money card as
 authorized to conduct a transaction and then queries the card as to the
 value of money it represents. If the card reader determines that the value
 of money represented by the card is sufficient to complete the
 transaction, then the card reader may subtract the value of the
 transaction and transmit to the money card the remaining value which is
 stored in memory in the card. The card reader may also, if the money card
 is a credit card, communicate with the bank or other institution that
 issued the card to make appropriate account entries.
 Irrespective of the details of how a particular card, tag or badge
 functions, information in the form of electrical signals must be
 transmitted between the card, tag or badge and the card reader.
 Conventionally, this is accomplished by electrical contacts in
 predetermined locations on the card coming into electrical contact with
 corresponding contacts in the card reader to complete an electrical
 circuit. Conventional cards, such as card 10 of FIG. 1, are made of a
 plastic material and have a cavity 32 therein into which a module 20
 including the contacts 26 and the electronic circuitry 24 is inserted. The
 module 20 includes a conventional printed wiring circuit board 22 having
 the contacts 26 on one surface thereof and connections 28 to the
 electronic circuitry 24 on the opposite surface thereof. The contacts 26
 are typically formed by etching the copper conductive sheets on the
 opposing surfaces of an insulating substrate 22, such as an FR4 or other
 circuit board material, and forming connections between the opposing
 surfaces by drilling holes through the circuit board substrate and then
 filling the holes with conductive material, such as by plating the holes
 with copper. The individual circuit boards must be separated and cut to
 size, such as by routing, before electronic circuitry 24 is attached
 thereto. Electronic circuitry 24 is attached to circuit board 22 and
 connections 26 thereto are made by wire bonding (as illustrated) or by
 flip-chip interconnections. Finally, a glob of encapsulant 18 is applied
 to cover electronic circuitry 24 and may be ground flat to obtain a
 controlled height dimension with respect to circuit board 22. Thus,
 conventional module 20 requires many separate operations, such as masking,
 etching, drilling, plating, routing, soldering, attaching, wire bonding,
 encapsulating and grinding, each of which adds undesirable processing time
 and cost to the manufacture of module 20. Further, much of the processing
 must be performed on each individual circuit board 22 separately, adding
 further handling and cost.
 Conventionally, module 20 resides in a cavity 32 of a card blank 30.
 Circuit board 22 of conventional module 20 is larger than is the
 electronic circuitry 24 thereon and the cavity 32 in the card blank 30 has
 an opening of like size and shape to that of circuit board 22. The main
 portion 34 of cavity 32 is smaller than the circuit board 22 and larger
 than the electronic circuitry 24 so as to form a shoulder 36 upon which
 circuit board 22 rests to properly position module 20 with respect to card
 10. Module 20 is attached to card blank 30 by adhesive dispensed into
 cavity 32, the amount of which must be precisely controlled to bond to
 encapsulant 18 or to electronic circuitry 24 and circuit board 22, or by
 adhesive dispensed onto shoulder 26 to bond circuit board 22 thereto.
 Conventionally, card blank 30 is formed of at least three layers of plastic
 material laminated together. The first layer 40 has a hole that defines
 the opening into which circuit board 22 is positioned and is of like
 thickness to circuit board 22. The second layer 42 has a hole that defines
 the volume in which electronic circuitry 24 resides, and is at least as
 thick as the maximum height of electronic circuitry 24 and encapsulant 18.
 The third layer 44 forms the bottom of cavity 32 and is of sufficient
 thickness to protect electronic circuitry 24. Each of the many operations,
 the three-layer lamination, adhesive dispensing and module placement, all
 undesirably add to the complexity and cost of card 10.
 Unfortunately, even when conventional card 10 is manufactured using
 automated equipment, the many different operations required each add to
 the cost of card 10 and so it is relatively expensive to manufacture.
 Accordingly, there is a need for a module that is much simpler and less
 costly to manufacture, and it would also be advantageous if the simplified
 module also allowed simplification of the card blank and assembly.
 To this end, the present invention comprises a pattern of metal contacts
 having a first and a second surface, a layer of dielectric adhesive on the
 first surface of the pattern of metal contacts and having at least two
 holes therethrough to the first surface of the metal contacts, at least
 two electrically-conductive vias substantially filling the holes in the
 dielectric adhesive layer and contacting the first surface of the metal
 contacts, each conductive via having an end distal from the first surface
 of the metal contacts, and at least one electronic device having
 electrical contacts connected to the distal end of the conductive vias.
 According to another aspect of the present invention, a method of making a
 module including an electronic device comprises:
 providing a sheet of electrical contact material having first and second
 surfaces;
 providing an electronic device having a pattern of contacts thereon;
 forming a pattern of electrically-conductive vias on the first surface of
 the sheet of electrical contact material, the pattern of
 electrically-conductive vias corresponding to the pattern of contacts of
 the electronic device;
 applying a layer of dielectric adhesive on the first surface of the sheet
 of electrical material except in locations corresponding to the
 electrically-conductive vias;
 patterning the sheet of electrical material to define a pattern of
 electrical contacts thereon, wherein ones of the electrical contacts are
 associated with at least corresponding ones of the electrically-conductive
 vias; and
 attaching the electronic device with the contacts of the electronic device
 electrically connected to corresponding electrically-conductive vias.

DESCRIPTION OF THE PREFERRED EMBODIMENT
 In a contact module 100 according to the present invention, module 100 is
 arranged such that insofar as is practical the steps of the processing
 generally add structure to what has been thus far made and to reduce the
 number of steps in which material is removed. Moreover, the arrangement of
 contact module 100 lends itself to the convenient fabrication of a
 plurality of modules contemporaneously on a single panel, wherein the
 panel need not be separated into individual modules until at or near the
 final operation of the fabrication, thereby to reduce the handling and
 processing of modules individually and to eliminate the cost thereof.
 FIG. 2 is a plan view of a metal layer 110 employed in the module 100 in
 accordance with the present invention. Metal layer 110 is a thin sheet or
 foil of electrically conductive metal, such as a metal foil conventionally
 utilized to form lead frames for semiconductor integrated circuits or
 utilized in laminating printed wiring circuit boards. Suitable materials
 include copper, alloy 42, aluminum, nickel, kovar, and combinations and
 alloys thereof, beryllium copper, brass and other copper-based alloys,
 iron-based alloys, and other suitable metals, and laminates thereof. Metal
 layer 110 is later formed, for example, by photo-etching, to provide the
 external electrical contacts 114 of module 100, as described below, for
 transmitting and receiving electrical signals to and/or from a
 conventional card reader.
 FIG. 3 is a plan view and FIG. 4 is a side cross-sectional view of the
 metal layer 110 on which is applied a layer 120 of a dielectric material
 having suitable electrical insulating (i.e. dielectric) properties and
 suitable mechanical strength, rigidity and stability. Dielectric layer 120
 is preferably a thermoplastic or thermosetting adhesive that is either
 deposited on metal layer 110 as a liquid or paste and is then dried or
 B-staged, i.e. is heated for a period of time to evaporate solvent or to
 form partial polymeric cross-links, or both, or is a sheet of B-staged
 thermoplastic or thermosetting adhesive that is laminated to metal layer
 110. Preferably, dielectric layer 120 is applied by screen printing,
 stenciling, roll coating, mask printing, ink-jet printing, laminating or
 other suitable method. A pattern of via holes 130 in dielectric layer 120
 expose a pattern of sites of metal layer 110 corresponding to contacts to
 be formed therein. Preferably, the pattern of via holes 130 correspond to
 the pattern of contacts 142 of an electronic device 140 that electrically
 connect to the external contacts of module 100 formed of metal layer 110,
 as described below. The via holes 130 may be formed by the screen,
 stencil, mask or other printing device, or may be present in the sheet of
 B-staged adhesive as laminated to metal layer 110, or, alternatively, may
 be subsequently formed, as by laser drilling, plasma etching,
 photo-etching, or other suitable method. While an exemplary pattern of via
 holes 130 and via conductors 132 are illustrated, it is understood that
 other patterns, and greater or lesser numbers of via holes 130 and via
 conductors 132, may also be employed.
 FIG. 5 is a side cross-sectional view further illustrating the fabrication
 of the module 100. Therein, metal is shown plated or otherwise deposited
 onto metal layer 110 through via holes 130 to form via contacts (or via
 conductors) 132, e.g., 132a, 132b, that substantially fill via holes 130,
 and preferably extend slightly beyond the surface of dielectric layer 120.
 Via conductors 132a, 132b are preferably formed of the same metal as is
 metal layer 110. It is noted that the depositing dielectric layer 120 and
 forming via conductors 132a, 132b can be performed in orders other than
 that just described. For example, holes in a patterned photoresist
 deposited on metal layer 110 may be utilized to define the size and
 locations of via conductors 132a, 132b into which metal is then plated or
 otherwise deposited onto metal layer 110 to form via conductors 132a,
 132b. After via conductors 132a, 132b are formed, the photoresist is
 removed and the dielectric layer 120 is applied, in like manner to that
 described above. In any case, dielectric layer 130 provides mechanical
 strength for and supports metal layer 110 and via conductors 132a, 132b.
 Metal layer 110 is patterned to form a pattern of electrical contacts 114,
 e.g., 114a, 114b that are electrically isolated from each other by gaps
 116 and that are electrically connected to at least one of via conductors
 132a, 132b, 134. Patterning of metal layer 110 is preferably by
 conventional photo- or chemical etching as is employed in the manufacture
 of printed wiring circuit boards, for example, or by other suitable
 methods. Where metal layer 110 is of a metal that may oxidize or otherwise
 not maintain good electrical conductivity, such as copper or aluminum, a
 layer of an oxidation resistant metal, such as nickel, tin, silver, gold,
 platinum, palladium, nickel-palladium, nickel-gold or other precious
 metal, or a combination or alloy thereof, is applied as layer 112 on
 contacts 114a, 114b and as layers 134a, 134b on via contacts 132a, 132b,
 respectively.
 FIG. 6 is a side cross-sectional view further illustrating the fabrication
 of the module 100 in accordance with the present invention. An electronic
 device 140, such as a semiconductor die, an integrated circuit or a
 network of resistive, inductive and/or capacitive elements, or the like,
 is attached to metal layer 110 and dielectric layer 120. Preferably,
 electronic device 140 is attached in a flip-chip manner, i.e. a number of
 contact pads 140, e.g., 142a, 142b, thereon are electrically connected to
 corresponding ones of via conductors 132a, 132b. Also preferably, the
 locations of the contact pads 142a, 142b of electronic device 140 and of
 via conductors 132a, 132b correspond so that electrical connections
 therebetween may be made by bumps 144 of a suitable
 electrically-conductive material, for example, solder,
 electrically-conductive adhesive or other electrically-conductive polymer,
 which also mechanically attach electronic device 140 thereto. Preferably,
 the electrically-conductive adhesive is a flexible adhesive, i.e. an
 adhesive having a modulus of elasticity that is less than about 35,000
 kg/cm.sup.2 (about 500,000 psi) or having the ability to withstand at
 least 30% elongation before failure, as may be the dielectric adhesive.
 Where greater mechanical strength or support is desired, a dielectric
 underfill 146, preferably of an electrically-insulating adhesive, may be
 employed. Bumps 144 of electrically-conductive adhesive or solder may be
 deposited onto via conductors 132a, 132b or may be deposited onto the
 contact pads 142a, 142b of electronic device 140, for example, by screen
 printing, mask printing, stencil printing, ink jet printing or other
 suitable manner. Bumps 144 and underfill 146 may be applied as a preformed
 membrane of the insulating underfill 146 material having the desired
 pattern of conductive material 144 formed therein, for example, as
 described in U.S. patent application Ser. No. 09/226,543 entitled
 "Flexible Adhesive Membrane and Electronic Device Employing Same" filed
 Jan. 7, 1999, which is hereby incorporated herein by reference in its
 entirety. Also preferably, contacts 142 of electronic device 140, which
 are often of aluminum, are coated with a layer of an oxidation resistant
 metal, such as nickel, tin, silver, gold, platinum, palladium,
 nickel-palladium, nickel-gold or other precious metal, or a combination or
 alloy thereof.
 FIG. 7 is a side cross-sectional view of an arrangement of module 100 of
 FIG. 6 including an encapsulating material 150. Encapsulating material 150
 surrounds electronic device 140 to seal at least the region in which
 electrical contacts 132a, 132b, 142a, 142b and connections 144 reside,
 thereby to provide resistance to the intrusion of moisture, chemicals and
 other contaminants. Preferably, encapsulating material 150 preferably
 covers electronic device 140 and is a high-flow adhesive that can also
 provide the means for attaching module 100' to a next level article with
 which it is to be assembled for use, such as a "smart card", credit card,
 money card identification tag or badge, or the like. Any adhesive with
 leveling ability to form a flat surface is generally suitable. One
 suitable encapsulating adhesive is a type MB7060 thermoplastic adhesive
 available from AI Technology located in Princeton, N.J., which has the
 beneficial property of a low melt-flow temperature of about 70.degree. C.
 which is compatible with the polyvinyl chloride, polyester and other
 plastic materials of which such next-level articles are typically made.
 Encapsulating adhesive 150 is preferably applied to a panel of a plurality
 of modules 100 before they are singulated or separated into individual
 modules.
 FIG. 8 is a side cross-sectional view of an alternative embodiment 100' of
 module 100 of FIG. 6 in which electrical connections to electronic device
 140 are made by conventional wire bonds 143a, 143b rather than by
 conductive adhesive bumps 144. Electronic device 140 is attached to metal
 layer 110 and dielectric layer 120 by a conventional die-attach adhesive
 148, typically an electrically-conductive adhesive, with its contact pads
 142a, 142b exposed. Electrical connections between contact pads 142a, 142b
 of electronic device 140 and conductive vias 132a, 132b, respectively, are
 made by conventional wire bonds 143a, 143b formed by wire bonding fine
 wires of gold or aluminum. Electronic device 140 and wire bonds 143a, 143b
 may be encapsulated by conventional glob-top or other molded encapsulating
 dielectric material 152. Optionally, or alternatively, module 100' may be
 encapsulated by a high melt flow encapsulating material 150 of like type
 to that described in relation to FIG. 7, whether or not the conventional
 encapsulation 152 is employed. The total thickness T of module 100 is the
 combination of the thicknesses of the metal layer 110, dielectric layer
 120, electronic device 140 and encapsulating adhesive 150, and is
 typically about 375-625 .mu.m (about 15-25 mils).
 FIGS. 9, 9A, 10, 10A and 11 are plan views illustrating the fabrication of
 a plurality of modules 100 as in FIG. 6 or FIG. 7 as a panel of modules
 100, and the method therefor. In a typical module 100, 100' intended for
 use in a next level article such as a "smart card", credit card, money
 card identification tag or badge, or the like, the materials employed need
 only withstand the temperature range to which such commercial article is
 expected to be exposed, for example, -40.degree. C. to +85.degree. C.
 Thus, the effects of differences in the coefficients of thermal expansion
 of the various materials utilized in such commercial articles is of less
 concern due to the limited temperature range than is the case for articles
 to be exposed to more extreme temperatures, such as the -55.degree. C. to
 +150.degree. C. range specified for certain aerospace and military
 articles.
 As shown if FIG. 9, a sheet 200 of copper foil of about 25-75 .mu.m (about
 1-3 mils) thickness, and of the same type as that used for conventional
 printed circuit board wiring fabricated on conventional FR4 material, is
 typically provided as metal layer 110 for a plurality of modules 100, 100'
 to be formed in an array on a panel 200 of material. Typically, a panel
 200 that is about 25 cm by 25 cm (about 10 inches by 10 inches) may be
 employed to contemporaneously fabricate an 18 by 20 array of 360 modules.
 Other sizes of panels may also be employed, such as an about 25 cm by 50
 cm (about 10 inch by 20 inch) panel, or an about 50 cm by 50 cm (about 20
 inch by 20 inch) panel, as may be convenient. Panel 200 has a set of at
 least two, and preferably more than two, alignment holes 202, for example,
 a set of alignment holes 202a, 202b, 202c, 202d, for registering the
 various layers of material and or masks, screens, stencils and the like
 utilized in the fabrication of modules 100, 100'.
 Dielectric layer 120 is preferably stenciled or screen printed onto the
 metal panel 200, for example, utilizing the stencil or mask panel 300
 shown in FIG. 10 which includes an 18 by 20 array of repeating patterns
 304 of openings 330 corresponding to via holes 130. Dielectric layer 120
 can also be applied by other conventional methods, such as film
 lamination, liquid spinning, paste screening and paste draw down methods.
 Stencil 300 includes a set of relational alignment holes 302, i.e. 302a,
 302b, 302c, 302d, in the exact same pattern as are alignment holes 202 of
 metal panel 200 and a set of fiducial marks 306, i.e. 306a, 306b, 306c,
 for further facilitating alignment of stencil 300. An expanded view of a
 portion of FIG. 10 is shown in FIG. 10A in which ones of the pattern 304
 of openings 330 are visible. The relative positions of the set of
 alignment holes 302, the patterns 304 of openings 330 and the fiducial
 marks 306 are in a predetermined positional relationship.
 Dielectric layer 120 is preferably of a material that is relatively high in
 viscosity and thixotropic index, and should preferably contain at least
 50% solids so that layer 120 may be deposited with suitable thickness. For
 example, dielectric layer 120 typically has a wet thickness of about 150
 .mu.m (about 6 mils) corresponding to a dry thickness after B-staging of
 about 100 .mu.m (about 4 mils). Both thermoplastic and thermosetting
 adhesives may be employed for dielectric layer 120, and should preferably
 have good rigidity and toughness, for example, as exhibited by adhesives
 having a modulus of elasticity over about 35,000 kg/cm.sup.2 (about
 500,000 psi) and an elongation in the range of 3-30% when cured. Suitable
 adhesives will not be adversely affected by exposure to the etching and
 plating chemicals and other chemicals, and to the process environments,
 utilized in processing operations subsequent to application of the
 adhesives, whether the adhesive is in its dried or B-staged state or in
 its cured state at the time of such exposure. Suitable adhesives for
 dielectric layer 130 includes types LESP7670-SC or LESP7450-SC fast-curing
 thermosetting epoxy adhesive in liquid form, available from AI Technology
 located in Princeton, N.J., also available as types ESP7670-SC and
 ESP7450-SC fast-curing thermosetting epoxy adhesives in paste form, and
 types LESP7675 and ESP7675 thermosetting epoxy adhesives.
 Screened dielectric layer 120 is dried (or B-staged) at an elevated
 temperature of about 60-80.degree. C. to remove the solvent from the
 deposited adhesive, and is then cured at an elevated temperature in the
 range of about 80-150.degree. C. Curing is typically performed at a
 temperature of about 100.degree. C. for about 60 minutes, but may be
 performed at a relatively low temperature of about 80.degree. C. for
 several hours, or at a relatively higher temperature of about 150.degree.
 C. for a few minutes.
 Via holes 130 in dielectric layer 120 typically are of about 50-500 .mu.m
 (about 2-20 mils) diameter, and more usually of about 125-250 .mu.m (about
 5-10 mils) diameter, and are formed in the screen printing of dielectric
 layer 120 or, where layer 120 is laminated to copper layer 110, are formed
 by die cutting, laser drilling photo-etching or other suitable method,
 either before or after the lamination of metal layer 110 and dielectric
 layer 120. A stencil or mask 300 as shown in FIGS. 10 and 10A may be
 utilized in forming dielectric layer 120 either by directly printing
 dielectric adhesive onto metal layer 110 or by printing dielectric
 adhesive onto a sheet of release liner, B-staging the adhesive to dryness,
 and then transferring the sheet of dielectric material 120 and laminating
 it to metal layer 110 in registration predetermined by the positional
 relationship of the alignment holes 202 and 302 of metal sheet 200 and of
 dielectric layer 120, respectively.
 Copper is plated onto the exposed sites on copper layer 110 that are at the
 bottoms of via holes 130 to build up via conductors 132, and copper layer
 110 is patterned to create gaps that define the external contacts 114 of
 module 100, 100'. FIG. 11 shows a mask pattern 400 for an 18 by 20 array
 of repeating patterns 414 of contacts 114, each of which is in
 predetermined positional relationship with alignment holes 402, i.e. 402a,
 402b, 402c, 402d, and fiducial marks 406, i.e. 406a, 406b, 406c. The
 relative positions of the set of alignment holes 402, the patterns 414 of
 contacts 114 and the fiducial marks 406 are in the same predetermined
 positional relationship as are alignment holes 302, patterns 304 and
 fiducial marks 306 of stencil 300. In the expanded view of a portion of
 stencil 300 of FIG. 11A is shown a detail view of the pattern 414 of
 contacts 114. The generally rectangular pattern 414 of ten contacts 114 is
 about 11 mm by 12.5 mm (about 0.435 inch by 0.492 inch) with gaps 116 of
 about 0.25 mm (about 0.01 inch) between the contacts 114, which is the
 pattern of International Standard ISO-7816-2 entitled "Identification
 Cards--Integrated Circuit(s) Cards With Contacts" issued by the
 International Organization for Standardization, and available in the
 United States from the American National Standards Institute (ANSI)
 located in New York, N.Y.
 The panel of modules 100 may now be excised or singulated into individual
 modules 100 of the sort shown in FIG. 6, or may be further processed by
 applying a suitable insulating adhesive 150 to overcoat and/or surround
 electronic device 140 to obtain a panel of modules 100 of the sort shown
 in FIG. 7. Any adhesive having suitable leveling characteristics to
 provide a relatively flat surface may be employed. One suitable adhesive
 is type MB7060 or MB7060-W thermoplastic electrically-insulating adhesive
 available from AI Technology, which has high flow at a melt temperature of
 about 65-75.degree. C. and bonds well to common card materials such as PVC
 with good resistance and insensitivity to moisture. Encapsulating adhesive
 150 may be applied by conventional methods such as roll coating screen
 printing, stenciling and the like, or may be applied by laminating a sheet
 of dried or B-staged adhesive to the panel of modules 100. Typically, the
 thickness of the adhesive layer 150 is about the same as the height of
 electronic device 140, typically about 250-500 .mu.m (about 10-20 mils) to
 form a panel of modules 100 having a slightly greater thickness, typically
 about 350-600 .mu.m (about 14-24 mils). However, a slightly greater yet
 thickness of adhesive 150, typically about 250-500 .mu.m (about 10-20
 mils) thicker than the height of electronic device 140, is desirable so as
 to cover electronic device 140 with encapsulating adhesive 150 where such
 adhesive is to be employed to also secure module 100 into the next level
 article. It is noted that this latter arrangement offers the advantage
 that a simple single-level cavity is suitable to receive and hold module
 100, rather the more complex and more expensive multi-level cavity that is
 required for conventional modules. In addition, although modules 100, 100'
 fabricated as described have a substantially planar adhesive layer 150
 surface that is substantially parallel to the plane in which contacts 114
 lie, modules 100, 100 may be employed even where such planarity and
 parallelism is lacking because the high melt flow characteristic of
 adhesive layer 150 tends to level out imperfections and tolerances when
 modules 100, 100' are inserted into cavities of the next-level articles in
 which they are utilized.
 The panel of modules 100 is singulated into separate individual modules 100
 by any suitable and convenient method, such as die cutting or other
 cutting device, or by laser cutting, stamping and rotary die cutting.
 Where the adhesive employed in layer 120 is a high-strength adhesive, it
 is preferred that the high-strength adhesive be only dried or B-staged
 during the fabrication of the panel and that the panel be singulated into
 individual modules prior to curing the adhesive. This is desirable because
 the adhesive is much easier to cut before curing and is much more
 difficult to cut after curing which increases its strength many times,
 e.g., more than 100 times for a high-strength adhesive such as Al
 Technology type ESP7670-SC or LESP7670-SC. AI Technology types ESP7675 or
 LESP7675 may also be utilized.
 In the example of FIGS. 9-11, an exemplary pattern of eight via holes 130
 and via conductors 132 arranged in two rows of four via holes 130 each are
 shown, and an exemplary pattern 414 of ten contacts 114 are shown, only
 eight of which contacts 114 have via conductors 132 associated therewith,
 i.e. the eight via conductors 132 are associated with the two rows of four
 contacts 114 along the longer edges of pattern 414 and the two central
 contacts 414 along the shorter edges thereof are not connected in this
 example. It is understood that greater and lesser numbers of contacts and
 other patterns of contacts, and greater or lesser numbers of via holes 130
 and via conductors 132 and other patterns thereof, may also be employed.
 In addition, panels of modules 100 may be processed in continuous fashion
 by abutting the panels and providing sprocket drive holes therein and a
 sprocket drive mechanism or by forming modules 100 on a continuous web or
 strip of dielectric substrate 120 material or metal foil 200. In such
 case, dielectric adhesive is applied, electroplating and photo-etching is
 performed, conductive adhesive is deposited continuously as the panels,
 web or strip, as the case may be, passes respective stations performing
 such operations.
 Any of the following three processes may be utilized to the end of making a
 circuit substrate of module 100, 100'. In a first of the processes, a
 first photoresist or other suitable masking resin is applied, selectively
 exposed as through a mask to form selective cross-links, and developed to
 define the pattern of contact pads 114 of the individual modules for
 subsequent metallization. A layer 112 of nickel, or other suitable
 passivating metal, is deposited onto contacts 114 and onto the via sites
 at the bottoms of via holes 130, typically to a thickness of a few microns
 (i.e. micrometers) such as by electrolytic or electroless plating. In
 addition, the plating of the nickel onto the via sites should be of
 sufficient thickness to fill via holes 130 with metal so as to be at or
 slightly above the surface of dielectric layer 120, thereby forming via
 conductors 132. This may be by plating nickel to the necessary thickness,
 or by plating copper onto the via sites, such as by electrolytic plating,
 to fill via holes 130 with metal to form via conductors 132 and then
 plating a layer 134 of nickel thereon. Preferably the nickel layers 112,
 134 on contacts 114 and via conductors 132 are finished with a flash or
 electroplate of gold or palladium or other precious metal for reduced
 electrical resistance, unless satisfactory electrical contact can be
 obtained and maintained with the nickel layer 112, 134 alone. The first
 photoresist is then stripped away and a second photoresist is applied to
 metal layer 110 to cover the contacts 114, and is exposed and developed to
 define the areas of metal layer 110 to be etched away to provide gaps 116
 between contacts 114. The exposed vias 132, 134 extending from dielectric
 layer 130 may also be masked. Metal layer 110 is then etched or stripped
 chemically to leave the pattern of contacts 114. Alternatively, the first
 photoresist may be left in place until after the photo-etching of metal
 layer 110, and then both the first and second photoresists maybe removed.
 Thus, a module 100, 100' circuit substrate of metal layer 110 and
 dielectric layer 120 having larger contacts 114 on one side thereof for
 making contact with a card reader and having smaller contacts 132, 134 on
 the other side thereof for making connection to an electronic device 140
 is provided.
 In a second of the processes, a photoresist is applied to metal layer 110
 to cover the areas of metal layer 110 that will be contacts 114, and is
 exposed and developed to define the metal to be etched away to provide
 gaps 116 between contacts 114. The exposed via holes 130 in dielectric
 layer 130 may also be masked to prevent etching of the via sites at the
 bottom thereof on metal layer 110. After the photoresist is exposed and
 developed, metal layer 110 is then etched or stripped chemically to leave
 the pattern of contacts 114 and then the photoresist is stripped away. A
 layer 112 of nickel, or other suitable passivating metal, is deposited
 onto contacts 114 and onto the via sites at the bottoms of via holes 130,
 typically to a thickness of a few microns (i.e. micrometers) such as by
 electrolytic or electroless plating. In addition, the plating of the
 nickel onto the via sites should be of sufficient thickness to fill via
 holes 130 with metal so as to be at or slightly above the surface of
 dielectric layer 120, thereby forming via conductors 132. This may be by
 plating nickel to the necessary thickness, or by plating copper onto the
 via sites, such as by electrolytic plating, to fill via holes 130 with
 metal forming via conductors 132 and then plating a layer 134 of nickel
 thereon. Preferably the nickel layers 112, 134 on contacts 114 and via
 conductors 132 are finished with a flash of gold or palladium or other
 precious metal for reduced electrical resistance, unless satisfactory
 electrical contact can be obtained and maintained with the nickel layer
 112, 134 alone. It is noted that where via conductors 132 are built up of
 deposited copper, the nickel finish 112, 134 on contacts 114 and on via
 contacts 132 may be deposited at the same time and after the copper is
 deposited. Thus, a module 100, 100' circuit substrate of metal layer 110
 and dielectric layer 120 having larger contacts 114 on one side thereof
 for making contact with a card reader and having smaller contacts 132, 134
 on the other side thereof for making connection to an electronic device
 140 is provided.
 In a third of the processes, a photoresist or other suitable masking resin
 is applied to exposed metal layer 110, but is not exposed or developed at
 this time. Copper is then plated onto the via sites at the bottom of via
 holes 130 of sufficient thickness to fill via holes 130 with copper so as
 to be at or slightly above the surface of dielectric layer 120, thereby
 forming via conductors 132. The photoresist is then exposed and developed
 to define the pattern of contact pads 114 of an individual module, i.e. to
 define the areas of metal layer 110 that will remain to provide contacts
 114. A layer 112, 134 of nickel, or other suitable passivating metal, is
 deposited onto contacts 114 and onto via conductors 132, typically to a
 thickness of a few microns (i.e. micrometers) such as by electrolytic or
 electroless plating. Preferably the nickel layers 112, 134 on contacts 114
 and via conductors 132 are finished with a flash or electroplate of gold
 or palladium or other precious metal for reduced electrical resistance,
 unless satisfactory electrical contact can be obtained and maintained with
 the nickel layer alone. The photoresist is then stripped away and a
 suitable solution is applied to preferentially etch metal layer 110
 chemically to remove the uncovered copper areas, but leave the pattern of
 contacts 114 which are protected by the nickel or nickel/gold layers that
 are unaffected by the preferential etching solution. Alternatively, a
 second photoresist can be applied, exposed and developed to protect
 contacts 114 and via conductors 132, 134 against etching. Thus, a module
 100, 100' circuit substrate of metal layer 110 and dielectric layer 120
 having larger contacts 114 on one side thereof for making contact with a
 card reader and having smaller contacts 132, 134 on the other side thereof
 for making connection to an electronic device 140 is provided.
 Alternatively, via conductors 132, 134 may be built up of an
 electrically-conductive adhesive deposited onto metal layer 110,
 preferably over a thin layer of nickel, gold or other suitable passivating
 metal deposited on the via sites on metal layer 110, for example, at the
 bottoms of via holes 130.
 Connecting bumps 144 are preferably directly deposited as by screen or mask
 printing onto the contact pads 142 of electronic device 140 or onto the
 contacts 114 of the circuit substrate of module 100, 100'. The preferred
 material is a flexible electrically-conductive adhesive having a high
 thixotropic index which facilitates precise deposition. Suitable
 electrically-conductive adhesives include types PSS8090 and PSS8150
 thermoplastic polymer adhesives and type ESS8450 thermosetting polymer
 adhesives in paste form, also available from AI Technology. Connecting
 adhesive bumps 144 are printed with a wet thickness of about 50-100 .mu.m
 (about 2-4 mils), and electronic device 140 may be attached thereto while
 the adhesive is still wet. The adhesive is then dried at an elevated
 temperature of about 60-80.degree. C. for about 30-60 minutes to form a
 satisfactory electrical and mechanical connection and bond between
 contacts 142 of electronic device 140 and via contacts 132, 134 of module
 100, 100'. Alternatively, bumps 144 may be solder bumps. To further
 strengthen the attachment of electronic device 140, an underfill of a low
 viscosity, non-thixotropic, and therefore, high flow, adhesive may be
 employed. Suitable underfill adhesives include type MEE7650 flexible
 thermosetting insulating adhesive and type MEE7660 high-strength
 thermosetting adhesive available from AI Technology, which are cured at a
 temperature of about 80-150.degree. C. similar to the type LESP7675
 adhesive employed in dielectric layer 120 as described above.
 It is noted that module 100, 100' is suitable for utilization in many
 different kinds and types of next-level articles, such as smart cards,
 identification tags, credit and money cards and the like made by
 conventional and new methods. Such suitable articles include, for example,
 those described in U.S. patent application Ser. No. 09/412,058 entitled
 ""Article Having An Embedded Electronic Device, And Method Of Making Same"
 and in U.S. patent application Ser. No. 09/411,849 entitled "Wireless
 Article Including A Plural-Turn Antenna" both of which being filed by
 Kevin K-T Chung on even date herewith, which applications are hereby
 incorporated herein by reference in their entireties.
 Completed modules 100, 100' may, for convenience, be stored in a waffle
 package 500 shown in FIG. 12 which has an 18 by 20 array of receptacles
 504 each of a size to receive a module 100, 100'. For facilitating
 automated operations, such as pick-and-place equipment picking modules
 100, 100' from receptacles 504 of waffle package 500 and placing them into
 proper position on cards, tags or other next-level articles, package 500
 includes a set of relational alignment holes 502, preferably in like
 positional relationship to the alignment holes 202, 302 and 402 of metal
 panel 200, via stencil 300 and contact stencil 400, respectively.
 FIG. 13 is a side cross-sectional view of a module 100" including plural
 electronic devices 140, 170, 180, 190 connected by conductors 160, but
 otherwise similar to contact module 100 of FIG. 6 in construction and
 materials, in accordance with the present invention. Electronic devices
 140, 170, 180, 190 may be integrated circuits, diodes, transistors,
 resistors, capacitors, inductors, or networks of such components, or any
 combination thereof. Contacts 114a, 114b, dielectric layer 120, conductive
 vias 142a, 142b and electronic device 140 are as described above. In like
 manner to conductive vias 142a, 142b, conductive vias 147, 147 and 149 are
 built up on the metal layer 110 by depositing electrically-conductive
 adhesive (e.g., types ESS8450 and PSS8150 available from AI Technology) or
 building up metal (e.g., copper, nickel or aluminum) thereon and are
 provided for connecting electronic devices 170, 180, 190, respectively, in
 circuit, and are fabricated substantially contemporaneously with
 conductive vias 142a, 142b. When metal layer 110 is removed as by
 photo-etching to leave the pattern of contacts 114a, 114b, the metal of
 layer 110 proximate conductive vias 147, 148, 149 is substantially removed
 leaving conductive vias 147, 148, 149 flush with the surface of dielectric
 layer 120 or projecting slightly therefrom. A layer of oxidation-resistant
 nickel-gold is deposited relatively heavily on the exposed portions of
 contacts 114a, 114b, and relatively lightly on the exposed portions of
 conductive vias 132a, 132b, 147. 148, 149.
 Conductors 160 are preferably conductive adhesive (such as type PSS8150 or
 type ESS8450) deposited on dielectric layer 120 (such as type ESP7450
 insulating adhesive) and contacting conductive vias 132a, 132b, 147, 148,
 149 for connecting them in circuit. The respective contacts of electronic
 devices 140, 170, 180, 190 are attached to conductive vias 132a, 132b,
 147, 148, 149 by bumps 144, 174, 184, 194 of conductive material such as
 solder and electrically-conductive adhesive, which may be applied either
 to the ends of vias 123a, 132b, 147, 148, 149 or to the contacts of
 electronic devices 140, 170, 180, 190. It is noted that either solder
 bumps or conductive adhesive bumps, or both, may be employed on a given
 module 100", and in fact it may be preferable to employ flexible
 conductive adhesive bumps for connecting an integrated circuit device and
 solder bumps for connecting resistors, capacitors, and the like.
 Conductive bumps 144, 174, 184, 194 may be about 70 .mu.m (about 3 mils)
 diameter, or other suitable size. Suitable underfill may be utilized
 between devices 140, 170, 180, 190, if desired, to increase the strength
 of the bonding of devices 140, 170, 180, 190 to dielectric layer 120.
 It is further noted that solder bumps can be employed with conductive vias
 and conductors formed of electrically-conductive adhesive that have been
 plated with a suitable metal, such as nickel, gold, nickel-gold and the
 like, as well as with metal conductive vias. Further, suitable insulating
 underfill may be utilized to strengthen the attachment of one or more of
 electronic devices 140, 170, 180, 190 as desired.
 FIG. 14 is an exploded side cross-sectional view of the contact module 100"
 of FIG. 13 included in an article 600. Module 100" is laminated between
 two card blanks 610, 620 where article 600 is to be utilized as a credit
 card, debit card, smart card or the like, and may be laminated only to
 card blank 610 where it is to be utilized as an identification tag or the
 like. In either case, card blank 610 includes a thin layer 612 of high
 melt-flowable adhesive (e.g., an about 25 .mu.m thick (about 1 mil thick)
 layer of type MB7060 or type MB7100 adhesive) that serves to bond card
 blank 610 to module 100". Card blank 610 is of like thickness to contacts
 114a, 114b, for example, about 75 .mu.m (about 3 mils) each, and has an
 aperture 614 therethrough into which contacts 114a, 114b fit so as to be
 exposed and substantially flush with or extending slightly above the
 surface of card blank 610. Dielectric layer 120 is preferably also of like
 thickness thereto. Module 100" is coated with a layer 150 of high
 melt-flowable adhesive (e.g., also of type MB7060 or type MB7100 adhesive)
 that is of sufficient thickness to encapsulate electronic devices 140,
 170, 180, 190 to dielectric substrate 120 and also serves to attach card
 blank 620 to module 100". Card blank 620 is typically of like thickness to
 card blank 610 and contacts 114a, 114b, for example, about 75 .mu.m (about
 3 mils). Card blanks 610, 620 are of conventional materials, for example,
 of PVC or polyester, and the like.
 The thickness of adhesive layer 150 is selected not only to cover
 electronic devices 140, 170, 180, 190, but to establish the overall
 thickness of article 600 at a desired dimension, such as the 0.785 mm
 (about 31 mil) thickness of standard credit cards, smart cards and the
 like. Thus an about 535 .mu.m (about 21-mil) thick layer 150 combines with
 the three 75-.mu.m (3-mil) thicknesses of card blanks 610, 620 and of
 dielectric layer 120, plus the 25-.mu.m (1-mil) thick adhesive layer 612,
 for an overall thickness of about 0.785 mm (about 31 mils). Conveniently,
 these thicknesses are compatible with the height of electronic devices
 140. 170, 180, 190, which are about 500 .mu.m (about 20 mils) or less. The
 mounted height of each device should preferably be about 400-450 .mu.m
 (about 16-18 mils) or less when connected by solder bumps and about
 450-500 .mu.m (about 18-20 mils) when connected by conductive adhesive
 bumps, which bumps are typically of 70-.mu.m (3-mil) diameter. For
 example, a typical 405-.mu.m (16-mil) thick electronic device attached by
 75-.mu.m (3-mil) conductive bumps has a height of about 480 .mu.m (19
 mils).
 While the present invention has been described in terms of the foregoing
 exemplary embodiments, variations within the scope and spirit of the
 present invention as defined by the claims following will be apparent to
 those skilled in the art. For example, conductive vias could be formed by
 depositing a pattern of electrically-conductive adhesive onto metal
 contacts 114, either before or after dielectric adhesive layer 120 is
 deposited thereon, as by screen printing, stencil printing, mask printing
 or other suitable method. In addition, although electroless and
 electrolytic plating (electroplating) is preferred, other deposition
 methods such as chemical plating, immersion coating and the like may be
 utilized.