Patent Publication Number: US-7900347-B2

Title: Method of making a compliant interconnect assembly

Description:
REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 11/130,494 filed May 17, 2005, issued as U.S. Pat. No. 7,121,839, entitled “Compliant Interconnect Assembly”, which is a continuation of U.S. patent application Ser. No. 10/992,170 filed Nov. 18, 2004, issued as U.S. Pat. No. 7,114,960, entitled “Compliant Interconnect Assembly”, which is a divisional of U.S. patent application Ser. No. 10/453,322 filed Jun. 3, 2003, issued as U.S. Pat. No. 6,957,963, entitled “Compliant Interconnect Assembly”, which is a continuation-in-part application of U.S. patent application Ser. No. 10/169,431 filed Jun. 26, 2002, issued as U.S. Pat. No. 6,939,143, entitled “Flexible Compliant Interconnect Assembly”, which claims priority to PCT/US01/00872 filed Jan. 11, 2001, which claims the benefit of U.S. provisional application Ser. No. 60/177,112 filed Jan. 20, 2000, all of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to a method and apparatus for achieving a compliant, solderless or soldered interconnect between circuit members. 
     BACKGROUND OF THE INVENTION 
     The current trend in connector design for those connectors utilized in the computer field is to provide both high density and high reliability connectors between various circuit devices. High reliability for such connections is essential due to potential system failure caused by misconnection of devices. Further, to assure effective repair, upgrade, testing and/or replacement of various components, such as connectors, cards, chips, boards, and modules, it is highly desirable that such connections be separable and reconnectable in the final product. 
     Pin-type connectors soldered into plated through holes or vias are among the most commonly used in the industry today. Pins on the connector body are inserted through plated holes or vias on a printed circuit board and soldered in place using conventional means. Another connector or a packaged semiconductor device is then inserted and retained by the connector body by mechanical interference or friction. The tin lead alloy solder and associated chemicals used throughout the process of soldering these connectors to the printed circuit board have come under increased scrutiny due to their environmental impact. Additionally, the plastic housings of these connectors undergo a significant amount of thermal activity during the soldering process, which stresses the component and threatens reliability. 
     The soldered contacts on the connector body are typically the means of supporting the device being interfaced by the connector and are subject to fatigue, stress deformation, solder bridging, and co-planarity errors, potentially causing premature failure or loss of continuity. In particular, as the mating connector or semiconductor device is inserted and removed from the present connector, the elastic limit on the contacts soldered to the circuit board may be exceeded causing a loss of continuity. These connectors are typically not reliable for more than a few insertions and removals of devices. These devices also have a relatively long electrical length that can degrade system performance, especially for high frequency or low power components. The pitch or separation between adjacent device leads that can be produced using these connectors is also limited due to the risk of shorting. 
     Another electrical interconnection method is known as wire bonding, which involves the mechanical or thermal compression of a soft metal wire, such as gold, from one circuit to another. Such bonding, however, does not lend itself readily to high-density connections because of possible wire breakage and accompanying mechanical difficulties in wire handling. 
     An alternate electrical interconnection technique involves placement of solder balls or the like between respective circuit elements. The solder is reflown to form the electrical interconnection. While this technique has proven successful in providing high-density interconnections for various structures, this technique does not facilitate separation and subsequent reconnection of the circuit members. 
     An elastomeric material having a plurality of conductive paths has also been used as an interconnection device. The conductive elements embedded in the elastomeric sheet provide an electrical connection between two opposing terminals brought into contact with the elastomeric sheet. The elastomeric material must be compressed to achieve and maintain an electrical connection, requiring a relatively high force per contact to achieve adequate electrical connection, exacerbating non-planarity between mating surfaces. Location of the conductive elements is generally not controllable. Elastomeric connectors may also exhibit a relatively high electrical resistance through the interconnection between the associated circuit elements. The interconnection with the circuit elements can be sensitive to dust, debris, oxidation, temperature fluctuations, vibration, and other environmental elements that may adversely affect the connection. 
     The problems associated with connector design are multiplied when multiple integrated circuit devices are packaged together in functional groups. The traditional way is to solder the components to a printed circuit board, flex circuit, or ceramic substrate in either a bare die silicon integrated circuit form or packaged form. Multi-chip modules, ball grids, array packaging, and chip scale packaging have evolved to allow multiple integrated circuit devices to be interconnected in a group. 
     One of the major issues regarding these technologies is the difficulty in soldering the components, while ensuring that reject conditions do not exist. Many of these devices rely on balls of solder attached to the underside of the integrated circuit device which is then reflown to connect with surface mount pads of the printed circuit board, flex circuit, or ceramic substrate. In some circumstances, these joints are generally not very reliable or easy to inspect for defects. The process to remove and repair a damaged or defective device is costly and many times results in unusable electronic components and damage to other components in the functional group. 
     Many of the problems encountered with connecting integrated circuit devices to larger circuit assemblies are compounded in multi-chip modules. Multi-chip modules have had slow acceptance in the industry due to the lack of large scale known good die for integrated circuits that have been tested and burned-in at the silicon level. These dies are then mounted to a substrate, which interconnect several components. As the number of devices increases, the probability of failure increases dramatically. With the chance of one device failing in some way and effective means of repairing or replacing currently unavailable, yield rates have been low and the manufacturing costs high. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a method and apparatus for achieving a fine pitch interconnect between first and second circuit members. The connection with the first and second circuit members can be soldered or solderless. The circuit members can be printed circuit boards, another flexible circuit, a bare-die device, an integrated circuit device, an organic or inorganic substrate, a rigid circuit and virtually any other type of electrical component. 
     In one embodiment, compliant interconnect assembly include a first dielectric layer having a first major surface and a plurality of through openings. A plurality of electrical traces are positioned against the first major surface of the first dielectric layer. The electric traces include a plurality of conductive compliant members having first distal ends aligned with a plurality of the openings in the first dielectric layer. The first distal ends are adapted to electrically couple with the first circuit member. The second dielectric layer has a first major surface positioned against the electric traces and the first major surface of the first dielectric layer. The second dielectric layer has a plurality of through openings through which the electric traces electrically couple with the second circuit member. 
     In one embodiment, at least a portion of the first distal ends are deformed to project through an opening in the first dielectric layer. In another embodiment, at least a portion of the first distal ends extend above a second major surface of the first dielectric layer. In one embodiment, at least a portion of the first distal ends comprise a plurality of distal ends. In yet another embodiment, at least a portion of the first distal end comprises a curvilinear shape. At least a portion of the conductive compliant members preferably have second distal ends aligned with a plurality of the openings in the second dielectric layer to electrically couple with the second circuit member. 
     The electrical traces can optionally be attached to the first major surface of the first dielectric layer or to a flexible circuit member. In one embodiment, a solder ball is attached to the electrical traces to electrically couple with the second circuit member. 
     In some embodiments, an additional circuitry plane is attached to a second major surface of the second dielectric layer. The additional circuitry plane comprises a plurality of through openings aligned with a plurality of the through openings in the second dielectric layer. The additional circuitry plane can be one of a ground plane, a power plane, or an electrical connection to other circuit members. One or more discrete electrical components are optionally electrically coupled to the electrical traces. 
     The electrical traces are preferably singulated so that a portion of the conductive compliant members are electrically isolated from the electrical traces. In one embodiment, a portion of the conductive compliant members are electrically coupled to form a ground plane or a power plane. 
     The first distal ends of the conductive compliant members are preferably adapted to engage with a connector member selected from the group consisting of a flexible circuit, a ribbon connector, a cable, a printed circuit board, a ball grid array (BGA), a land grid array (LGA), a plastic leaded chip carrier (PLCC), a pin grid array (PGA), a small outline integrated circuit (SOIC), a dual in-line package (DIP), a quad flat package (QFP), a leadless chip carrier (LCC), a chip scale package (CSP), or packaged or unpackaged integrated circuits. 
     In one embodiment, the second dielectric layer is attached to a printed circuit board and a plurality of the conductive compliant members are electrically coupled to contact pads on the printed circuit board through the openings in the second dielectric layer. In another embodiment, a portion of the first electrical traces extend beyond the compliant interconnect assembly to form a stacked configuration other compliant interconnect assemblies. The dielectric layers can be rigid or flexible. 
     In one embodiment, the plurality of electrical traces includes a first set of electrical traces having a plurality of conductive compliant members having first distal ends aligned with a plurality of openings in the first dielectric layer. A second set of electrical traces having a plurality of conductive compliant members having second distal ends are aligned with a plurality of openings in the second dielectric layer. An electrical connection is formed between one or more of the conductive compliant members on the first set of electrical traces and one or more of the conductive compliant members on the second set of electrical traces. 
     A dielectric layer is optionally located between the first and second sets of electrical traces. The electrical connection can be one of solder, a conductive plug, a conductive rivet, conductive adhesive, a heat stake, spot weld, and ultrasonic weld, a compression joint, or electrical plating. An additional circuitry plane is optionally located between the first and second sets of electrical traces. One or more discrete electrical components are optionally located between the first and second sets of electrical traces. 
     The first and second circuit member can be one of a printed circuit board, a flexible circuit, a bare die device, an integrated circuit device, organic or inorganic substrates, or a rigid circuit. 
     The present invention is also directed to a method of making a compliant interconnect assembly. A plurality of electrical traces are positioned against the first major surface of a first dielectric layer, the electric traces comprising a plurality of conductive compliant members having first distal ends aligned with a plurality of through openings in the first dielectric layer. A first major surface of a second dielectric layer is positioned against the electric traces and the first major surface of the first dielectric layer. The second dielectric layer has a plurality of through openings. The first distal ends are electrically coupled to the first circuit member. The second circuit member is electrically coupled to a second circuit member through the openings in the second dielectric layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a substrate used for making a compliant interconnect in accordance with the present invention. 
         FIG. 2  is a side sectional of the substrate of  FIG. 1  with a masking material applied in accordance with the present invention. 
         FIG. 3  is a side sectional view of the substrate and masking material of  FIG. 2  with an additional hole in accordance with the present invention. 
         FIG. 4  is a side sectional view of a compliant material applied to the substrate of  FIG. 3 . 
         FIG. 5  is a side sectional view of a compliant interconnect assembly in accordance with the present invention. 
         FIG. 6  is a side sectional view of the compliant interconnect assembly of  FIG. 5  in a compressed state in accordance with the present invention. 
         FIGS. 7-9  are side sectional views of an alternate compliant interconnect in accordance with the present invention. 
         FIG. 10A  is a perspective view of a flexible circuit member in accordance with the present invention. 
         FIG. 10B  is a perspective view of an alternate flexible circuit member in accordance with the present invention. 
         FIG. 10C  is a perspective view of another alternate flexible circuit member in accordance with the present invention. 
         FIG. 10D  is a top view of electrical traces of a flexible circuit member prior to singulation. 
         FIG. 10E  is a top view of the flexible circuit member of  FIG. 10D  after singulation. 
         FIG. 10F  is a top view of electrical traces of a flexible circuit member prior to singulation. 
         FIG. 10G  is a top view of electrical traces of a flexible circuit member prior to singulation. 
         FIG. 10H  is a top view of electrical traces of a flexible circuit member prior to singulation. 
         FIG. 10I  is a top view of electrical traces of a flexible circuit member prior to singulation. 
         FIG. 11  is a side sectional view of a compliant interconnect assembly in accordance with the present invention. 
         FIG. 12A  is a side sectional view of an alternate compliant interconnect assembly in a stacked configuration in accordance with the present invention. 
         FIG. 12B  is a side sectional view of an alternate compliant interconnect assembly with a spring member in accordance with the present invention. 
         FIG. 12C  is a side sectional view of an alternate compliant interconnect assembly with a sheet of spring members in accordance with the present invention. 
         FIG. 12D  is a side sectional view of an alternate compliant interconnect assembly using one of the flexible circuit members of  FIGS. 10D-10I . 
         FIG. 13  is a side sectional view of an alternate compliant interconnect assembly with a carrier in accordance with the present invention. 
         FIG. 14A  is a side sectional view of a compliant interconnect assembly on an integrated circuit device in accordance with the present invention. 
         FIG. 14B  is a side sectional view of an alternate compliant interconnect assembly on an integrated circuit device in accordance with the present invention. 
         FIG. 15A  is a side sectional view of a compliant interconnect assembly with a carrier and an integrated circuit device in accordance with the present invention. 
         FIG. 15B  is a side sectional view of a compliant interconnect assembly packaged with an integrated circuit device in accordance with the present invention. 
         FIG. 16  is a replaceable chip module using the compliant interconnect assembly in accordance with the present invention. 
         FIG. 17  is a side sectional view of a plurality of compliant interconnect assemblies in a stacked configuration in accordance with the present invention. 
         FIG. 18  is a top view of a compliant interconnect assembly with the flexible circuit members extending therefrom in accordance with the present invention. 
         FIG. 19  is a side sectional view of a plurality of circuit members in a stacked configuration coupled using a compliant interconnect assembly in accordance with the present invention. 
         FIG. 20  is a side sectional view of various structures on a flexible circuit member for electrically coupling with a circuit member. 
         FIG. 21  is a side sectional view of an alternate compliant interconnect assembly using one of the flexible circuit members of  FIGS. 10D-10I . 
         FIG. 22  is a side sectional view of an alternate compliant interconnect assembly using one of the flexible circuit members of  FIGS. 10F-10I . 
         FIG. 23  is a side sectional view of an alternate compliant interconnect assembly using a pair of the flexible circuit members, such as illustrated in  FIGS. 10D-10I , in a back to back configuration. 
         FIG. 24  is a side sectional view of an alternate compliant interconnect assembly using a pair of the flexible circuit members, such as illustrated in  FIGS. 10D-10I , in a back to back configuration. 
         FIG. 25  illustrates an alternate compliant interconnect assembly generally as illustrated in  FIG. 21  with an additional circuitry plane is added to the structure. 
         FIG. 26  illustrates an alternate compliant interconnect assembly generally as illustrated in  FIG. 24  with an additional circuitry plane is added to the structure. 
         FIG. 27  illustrates an alternate compliant interconnect assembly generally as illustrated in  FIG. 21  with an additional circuitry plane is added to the structure. 
         FIGS. 28A-28D  illustrate an alternate compliant interconnect assembly constructed with a plurality of discrete compliant members. 
         FIG. 29  illustrate a variation of the compliant interconnect assembly of  FIG. 28A . 
         FIG. 30  is a top view of a compliant interconnect assembly generally as illustrated in  FIGS. 21-29 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-4  illustrate a method of preparing a compliant interconnect  22  in accordance with the present invention (see  FIG. 5 ). The Figures disclosed herein may or may not be drawn to scale. The substrate  20  is perforated to include one or more through holes  24 . The holes  24  can be formed by a variety of techniques, such as molding, stamping, laser drilling, or mechanical drilling. The holes  24  can be arranged in a variety of configurations, including one or two-dimensional arrays. As will be discussed below, some embodiments do not require the holes  24 . The substrate  20  is typically constructed from a dielectric material, such as plastics, ceramic, or metal with a non-conductive coating. In some of the embodiments discussed below, an electrically active circuit member (see  FIG. 11 ) is substituted for the electrically inactive substrate  20 . 
     As illustrated in  FIG. 2 , the substrate  20  is then flooded with one or more masking materials  26 , such as a solder mask or other materials. Through careful application and/or subsequent processing, such as planarization, the thickness of the masking material at locations  28 ,  30  is closely controlled for reasons that will become clearer below. The additional holes  32  shown in  FIG. 3  are then drilled or perforated in the substrate  20  and masking material  24  at a predetermined distance  36  from the existing through hole  24 . While there is typically a hole  32  adjacent each of the holes  24 , there is not necessarily a one-to-one correlation. The holes  32  can be arranged in a variety of configurations, which may or may not correlate to the one or two-dimensional array of holes  24 . 
     The holes  32  are then filled with a compliant material  38 , as shown in  FIG. 4 . The thickness of the compliant material  38  is typically determined by the thickness of the masking material  26 . Suitable compliant materials include elastomeric materials such as Sylgard™ available from Dow Corning Silicone of Midland, Mich. and MasterSyl &#39;713, available from Master Bond Silicone of Hackensack, N.J. 
     The compliant interconnect  22  of  FIGS. 2-4  can optionally be subjected to a precision grinding operation, which results in very flat surfaces, typically within about 0.0005 inches. The grinding operation can be performed on both sides at the same time using a lapping or double grinding process. In an alternate embodiment, only one surface of the compliant interconnect  22  is subject to the planarization operation. The present method permits the accurate manufacture of raised portions  40  having virtually any height. 
     Once the compliant encapsulant  38  is cured, the masking material  26  is removed to yield the compliant interconnect  22  illustrated in  FIG. 5 . The compliant interconnect  22  illustrated in  FIG. 5  includes the substrate  20 , one or more compliant raised portions  40  of the compliant encapsulant  38  extending above the substrate  20 , and the through holes  24 . The compliant raised portions can be, for example, the non-conductive encapsulant  38  in  FIG. 5  or the conductive member  171 C of  FIG. 12C . The substrate can be a carrier or a circuit member, such as a printed circuit board, a flexible circuit, a bare die device, an integrated circuit device, organic or inorganic substrates, or a rigid circuit. The through holes are optionally added for some applications. 
       FIG. 5  illustrates a compliant interconnect assembly  34  in accordance with the present invention. The compliant interconnect assembly  34  includes the compliant interconnect  22  and one or more flexible circuit members  50 ,  70 . The first flexible circuit member  50  is located along one surface of the compliant interconnect  22 . The first flexible circuit member  50  includes a polymeric sheet  52  and a series of electrical traces  54 . In the embodiment illustrated in  FIG. 5 , the traces  54  terminate at a contact pad  56 . The electrical trace  54  terminates in a solder ball  64 . The contact pad  56  is positioned to engage with a contact pad  60  on a first circuit member  62 . The solder ball  64  is positioned adjacent to through hole  65 . As used herein, “circuit member” refers to a printed circuit board, a flexible circuit, a packaged or unpackaged bare die silicon device, an integrated circuit device, organic or inorganic substrates, a rigid circuit, or a carrier (discussed below). 
     The region of the polymeric sheet  52  adjacent to the contact pad  56  includes singulation  58 . The singulation  58  is a complete or partial separation of the terminal from the sheet  52  that does not disrupt the electrical integrity of the conductive trace  54 . In the illustrated embodiment, the singulation  58  is a slit surrounding a portion of the contact pad  56 . The slit may be located adjacent to the perimeter of the contact pad  56  or offset therefrom. The singulated flexible circuit members  50 ,  70  control the amount of force, the range of motion, and assist with creating a more evenly distributed force vs. deflection profile across the array. 
     As used herein, a singulation can be a complete or partial separation or a perforation in the polymeric sheet and/or the electrical traces. Alternatively, singulation may include a thinning or location of weakness of the polymeric sheet along the edge of, or directly behind, the contact pad. The singulation releases or separates the contact pad from the polymeric sheet, while maintaining the interconnecting circuit traces. 
     The singulations can be formed at the time of manufacture of the polymeric sheet or can be subsequently patterned by mechanical methods such as stamping or cutting, chemical methods such as photolithography, electrical methods such as excess current to break a connection, a laser, or a variety of other techniques. In one embodiment, a laser system, such as Excimer, CO 2 , or YAG, creates the singulation. This structure is advantageous in several ways, where the force of movement is greatly reduced since the flexible circuit member is no longer a continuous membrane, but a series of flaps or bond sites with a living hinge and bonded contact (see for example  FIG. 10 ). 
     The second flexible circuit member  70  is likewise positioned on the opposite side of the compliant interconnect  22 . Electrical trace  72  is electrically coupled to contact pad  74  positioned to engage with a contact pad  76  on a second circuit member  78 . Solder ball  80  is located on the opposite end of the electrical trace  72 . Polymeric sheet  82  of the second flexible circuit member  70  also includes a singulation  84  adjacent to the contact pad  74 . 
     The contact pads  56 ,  74  can be part of the base laminate of the flexible circuit members  50 ,  70 , respectively. Alternatively, discrete contact pads  56 ,  74  can be formed separate from the flexible circuit members  50 ,  70  and subsequently laminated or bonded in place. For example, an array of contact pads  56 ,  74  can be formed on a separate sheet and laminated to the flexible circuit members  50 ,  70 . The laminated contact pads  56 ,  74  can be subsequently processed to add structures (see  FIG. 20 ) and/or singulated. 
     The contact pads  60 ,  76  may be a variety of structures such as, for example, a ball grid array, a land grid array, a pin grid array, contact points on a bare die device, etc. The contact pads  60 ,  76  can be electrically coupled with the compliant interconnect assembly  34  by compressing the components  62 ,  78 ,  34  together (solderless), by reflowing solder or solder paste at the electrical interface, by conductive adhesive at the electrical interface, or a combination thereof. 
     As illustrated in  FIG. 6 , the first and second flexible circuit members  50 ,  70  are compressed against the compliant interconnect assembly  34 . The solder balls  64 ,  80  are reflown and create an electrical connection between the first and second flexible circuit members  50 ,  70 , generally within through hole  65 . Adhesive  90  may optionally be used to retain the first and second flexible circuit members  50 ,  70  to the substrate  20 . Contact pads  56 ,  74  are abutted against raised portion  40  of the compliant material  38 . 
     The singulations  58 ,  84  permit the raised portions  40  to push the contact pads  56 ,  74  above the surface of the substrate  20 , without damaging the first and second flexible circuit members  50 ,  70 , respectively. The raised portion  40  also deforms outward due to being compressed. The contact pads  56 ,  74  may optionally be bonded to the raised compliant material  40 . The raised compliant material  40  supports the flexible circuit members  50 ,  70 , and provides a contact force that presses the contact pads  56 ,  74  against the contact pads  60 ,  76  as the first and second circuit members  62 ,  78 , respectively are compressed against the compliant interconnect assembly  34 . The movement of the contact pads  56 ,  74  is controlled by the raised portion  40  of the compliant material  38  and the resiliency of the flexible circuit members  50 ,  70 . These components are engineered to provide a desired level of compliance. The raised portions  40  provide a relatively large range of compliance of the contact pads  56 ,  74 . The nature of the flexible circuit members  50 ,  70  allow fine pitch interconnect and signal escape routing, but also inherently provides a mechanism for compliance. 
     In the illustrated embodiment, the electric trace  54  extends between solder ball  64  and contact pad  56 . Similarly, the electric trace  72  extends between the solder ball  80  and the contact pad  74 . Consequently, the compliant interconnect assembly  34  operates as a pass-through connector between the contact pad  60  on the first circuit member  62  and the contact pad  76  on the second circuit member  78 . 
       FIG. 7  illustrates an alternate substrate  100  with an array of through holes  102 . In the illustrated embodiment, masking material  104  is applied to only one surface of the substrate  100  and the through hole  102 . Additional holes  106  are prepared in the masking material  104  and substrate  100  a fixed distance  108  from the hole  102 , as illustrated in  FIG. 8 . The hole  106  is only drilled partially into the substrate  100 . A compliant material  110  is then deposited in the hole  106 . After the masking material  104  is removed, the resulting compliant interconnect  112  includes a raised compliant material only on one surface (see generally  FIG. 11 ). 
       FIG. 10A  is a perspective view of a flexible circuit member  120 A suitable for use in the present invention. The flexible circuit member  120 A includes a series of electrical traces  122 A deposited on a polymeric sheet  124 A and terminating at an array of contact pads or terminals  126 A. As used herein “terminal” refers to an electrical contact location or contact pad. In the illustrated embodiment, the terminals  126 A include a singulation  128 A. The degree of singulation  128 A can vary depending upon the application. For example, in some embodiments the flexible circuit member  120 A stretches in order to comply with the raised portions. In other embodiments a greater degree of singulation minimizes or eliminates stretching of the flexible circuit member  120 A due to engagement with the raised portions. 
     In some embodiments, the terminals  126 A include one or more locations of weakness  130 A. As used herein, “locations of weakness” include cuts, slits, perforations or frangible portions, typically formed in the polymeric sheet  124 A and/or a portion of the electrical trace  122 A forming the terminal  126 A. The locations of weakness facilitate interengagement of an electrical contact, such as a ball contact on a BGA device, with the terminal  126 A (see  FIG. 19 ). The terminals  126 A can optionally include an aperture  132 A to further facilitate engagement with an electrical contact. In another embodiment, a portion  134 A of the trace  122 A protrudes into the aperture  132 A to enhance electrical engagement with the electrical contact. 
     In other embodiments, a compliant raise portion is attached to the rear of the flexible circuit member  120 A opposite the terminal  126 A (see  FIG. 11 ). When the flexible circuit member  120 A is pressed against a surface (such as a printed circuit board), the raised compliant material lifts the singulated terminal  126 A away from the surface. 
       FIG. 10B  is a top plan view of an alternate flexible circuit member  120 B with an elongated singulation  128 B. Contact pads  126 B are located on the top of the polymeric sheeting  124 B and the solder ball bonding sites  125 B are located on the bottom. The contact pads  126 B are offset from the solder ball-bonding site  125 B by the portion  127 B of the polymeric sheeting  124 B. An electrical trace can optionally connect the contact pads  125 B with the contact pads  126 B along the portion  127 B. The portion  127 B permits the contact pads  126 B to be raised up or deflected from the flexible circuit member  120 B in order to comply with the motion of the flexure (see for example  FIGS. 11-15 ) with minimal or no deformation or stretching of the surrounding polymeric sheeting  124 B. The contact pads  126 B can optionally include locations of weakness. 
       FIG. 10C  is a top plan view of an alternate flexible circuit member  120 C with an irregularly shaped singulation  128 C. Contact pads  126 C are located on the top of the polymeric sheeting  124 C and the solder ball bonding sites  125 C are located on the bottom. The contact pads  126 C are offset from the solder ball-bonding site  125 C by the irregularly shaped portion  127 C of the polymeric sheeting  124 C. The shape of the portion  127 C determines the force required to raise up or deflect the contact pads  126 C from the flexible circuit member  120 C in order to comply with the motion of the flexure (see for example  FIGS. 11-15 ). Again, minimal or no deformation or stretching of the surrounding polymeric sheeting  124 C is experienced. An electrical trace  121 C can optionally connect some of the contact pads  125 C with the contact pads  126 C along the portion  127 C. Additionally, trace  129 C can connect two or more contact pads  125 C, such as for a common ground plane. 
       FIG. 10D  is a top plan view of a pattern of electrical traces  122 D of a flexible circuit member  120 D prior to singulation. In the embodiment of  FIG. 10D , the electrical traces  122 D include tie bars  124 D interconnecting a plurality of compliant members  126 D. As will be discussed below, distal ends  128 D of the compliant members  126 D can be easily deformed out of the plane of the tie bars  124 D to electrically couple with other circuit members. For example, the distal ends  128 D are configured to electrically couple with contact pads on an LGA device, while proximal ends  130 D can electrically couple with a BGA device. Although the distal end  128 D is generally linear, it can be configured with a variety of non-linear features, such as curvilinear or serpentine portions (see e.g.,  FIGS. 10F-10I ). The electrical traces  122 D are preferably constructed from a copper alloy formed by chemical etching, laser ablation, mechanical stamping or a variety of other techniques. 
     The electrical traces  122 D can optionally be attached to a polymeric sheet, such as illustrated in  FIGS. 10A-10C . In another embodiment, the electrical traces  122 D are attached to a carrier, such as illustrated in  FIG. 12C . The carrier can be rigid, semi-rigid, or flexible. The electrical traces  122 D can be attached to a carrier using a variety of techniques, such as lamination with or without adhesives, over molding, insert molding, and a variety of other techniques. In some embodiments, portions of the electrical traces  122 D are sufficiently thick to operate as freestanding compliant members, such as illustrated in  FIG. 12B . 
     In the preferred embodiment, the electrical traces  122 D are supported by a carrier that maintains the relative position of the individual compliant members  126 D after singulation. Singulation is typically accomplished by cutting or removing selected tie bars  124 D using chemical etching, laser ablation or mechanical processes. One advantage of the present embodiment is the ability to process an entire field of compliant members  126 D as a group. Many different geometries of electrical traces  122 D are possible and are shaped based upon the type of terminal to which it must connect. 
       FIG. 10E  is a top plan view of a pattern of electrical traces  122 D of a flexible circuit member  120 D of  FIG. 10D  after singulation. The electrical traces  122 D are attached to a carrier (see e.g.  FIG. 21 ) so that the relative position of the compliant members  126 D remains substantially unchanged even if all tie bars  124 D are removed during singulation. In the embodiment illustrated in  FIG. 10E , selected tie bars  124 D are removed by chemical etching or laser ablation. The compliant members  132 D connected by tie bars  124 D form a ground plane or power plane. The compliant members  134 D that are disconnected from the electrical traces  122 D (i.e., discrete compliant members) typically carry electrical signals between the first and second circuit members (see  FIG. 21 ). 
       FIG. 10F  is a top plan view of a pattern of electrical traces  122 F of a flexible circuit member  120 F prior to singulation. The electrical traces  122 F include tie bars  124 F interconnecting a plurality of compliant members  126 F. In the embodiment of  FIG. 10F , each compliant member  126 F includes a pair of distal ends  128 F,  130 F. The distal ends  128 F,  130 F of the compliant members  126 F can be easily deformed out of the plane of the tie bars  124 F to electrically couple with other circuit members. The distal ends  128 F,  130 F can be deformed in the same or different directions, depending upon the application (see e.g.,  FIG. 22 ). The curved portions  132 F,  134 F of the distal ends  128 F,  130 F are particularly well suited to electrically couple with a BGA device. The curved portions  132 F,  134 F are adapted to create a snap-fit attachment to a ball on BGA circuit member. Members  136 F,  138 F on the inside edge of the curved portions  132 F,  134 F facilitate electrical coupling to a BGA device. 
       FIG. 10G  is a top plan view of a pattern of electrical traces  122 G of a flexible circuit member  120 G prior to singulation. Each compliant member  126 G includes a pair of distal ends  128 G,  130 G. The distal ends  128 G,  130 G of the compliant members  126 G can be easily deformed out of the plane of the tie bars  124 G to electrically couple with other circuit members. 
       FIG. 10H  similarly shows a top plan view of a pattern of electrical traces  122 H of a flexible circuit member  120 H prior to singulation. Each compliant member  126 H includes a pair of distal ends  128 H,  130 H. 
       FIG. 10I  is a top plan view of a pattern of electrical traces  122 I where each compliant member  126 I includes a pair of curved distal ends  128 I,  130 I. The curved portions  132 I,  134 I of the distal ends  128 I,  130 I are particularly well suited to electrically couple with a BGA device. The curved portions  132 I,  134 I are adapted to create a snap-fit attachment to a ball on BGA circuit member. 
       FIG. 11  is a sectional view of an alternate compliant interconnect assembly  140  in accordance with the present invention. The raised compliant material  142  is formed directly on second circuit member  144 , which in the embodiment of  FIG. 11  is a printed circuit board. In an alternate embodiment, the raised compliant material  142  are formed separate from the second circuit member  144  and subsequently bonded thereto using a suitable adhesive or other bonding technique. In another embodiment, the raised portion  142  is formed on, or bonded to, the rear of flexible circuit member  146 . In the illustrated embodiment, the printed circuit board  144  serves the function of both the substrate  20  and the second circuit member  78  illustrated in  FIG. 5 . The embodiment of  FIG. 11  does not require through holes in the circuit member  144 . 
     Flexible circuit member  146  includes a solder ball  148  that is typically reflown to electrically couple bonding pad  150  to the contact pad  152  on the circuit board  144 . Alternatively, solder paste can be applied to both the bonding pad  150  and the contact pad  152 . Electrical trace  154  electrically couples the solder bonding pad  150  to contact pad  156 . Contact pad  156  may optionally include a rough surface to enhance the electrical coupling with the contact pad  160  on the first circuit member  162 . The flexible circuit member  146  is singulated so that the raised compliant material  142  lifts the contact pad  156  away from the circuit member  144 . When the circuit member  162  is compressed against the compliant interconnect assembly  140 , the raised compliant material  142  biases the contact pad  156  against the first circuit member  162 . In the compressed state, the compliant interconnect assembly  140  can have a height of about 0.3 millimeters or less. Alternatively, the contact pad  160  can be electrically coupled with the contact pad  156  by reflowing solder or solder paste at the electrical interface, by conductive adhesive at the electrical interface, or either of the above in combination with compression. 
     The raised compliant material  142  can optionally be doped or filled with rigid or semi-rigid materials to enhance the integrity of the electrical contact created with the contact pad  160  on the first circuit member  162 . Bonding layer  164  is optionally provided to retain the contact pad  156  to the raised compliant material  142 . 
       FIG. 12A  illustrates an alternate compliant interconnect assembly  170  using a compliant interconnect generally as illustrated in  FIGS. 7-9 . Raised compliant material  172  is attached to a carrier  174  that is interposed between first and second circuit members  176 ,  178 . The carrier  174  can be rigid or flexible. An additional support layer  182  can optionally be added to the carrier  174  to increase rigidity and/or compliance. In one embodiment, the raised compliant material  172  has a first modulus of elasticity and the additional support layer  182  has a second modulus of elasticity different from the first modulus of elasticity. In another embodiment, the raised compliant material  172  is attached to the rear surface of flexible circuit member  184 . 
     Flexible circuit member  184  is electrically coupled to the contact pad  186  on second circuit member  178  by solder ball or solder paste  188 . When the first circuit member  176  is compressively engaged with the compliant interconnect assembly  170 , raised compliant material  172  biases contact pad  190  on the flexible circuit member  184  against contact pad  192  on the first circuit member  176 . In an embodiment where the carrier  174  has compliant properties, the combined compliant properties of the carrier  174  and raised compliant material  172  provides the bias force. 
     In another embodiment, the flexible circuit member  184  extends to a second interconnect assembly  170 A. Any of the interconnect assemblies disclosed herein can be used as the interconnect assembly  170 A. In the illustrated embodiment, raised compliant material  172 A is attached to a carrier  174 A that is interposed between first circuit members  176  and a third circuit member  194 . The carrier  174 A can be rigid or flexible. An additional support layer  182 A can optionally be added to the carrier  174 A to increase rigidity and/or compliance. The third circuit member  194  can be an integrated circuit device, such as the LGA device illustrated in  FIG. 12A , a PCB or a variety of other devices. The entire assembly of circuit members  176 ,  178 ,  194  can be stacked together and the solder then mass reflowed during final assembly. 
       FIG. 12B  illustrates an alternate compliant interconnect assembly  170 B generally as illustrated in  FIG. 12A , except that the raised compliant material  172 B attached to a carrier  174 B is an elongated compliant member  171 B. The compliant member  171 B can be spring member or a rigid member attached to a compliant carrier  174 B, such as a beryllium copper spring. An additional support layer  182 B can optionally be added to the carrier  174 B to increase rigidity and/or compliance. The compliant members  171 B provide reactive support to urge the contact pad  190 B on the flexible circuit member  184 B against the contact pad  192 B on the first circuit member  176 B. The compliant member  171 B can be formed in the carrier  174 B or formed separately and attached thereto. The compliant member  171 B can alternatively be a coil spring or a variety of other structures. 
       FIG. 12C  illustrates another alternate compliant interconnect assembly  170 C generally as illustrated in  FIG. 12B , except that the raised compliant material  172 C is an elongated compliant member  171 C supporting the flexible circuit member  184 C. Substrate  174 C includes a series of compliant spring members  171 C positioned under the flexible circuit member  184 C. The upper surface of the flexible circuit member  184 C is patterned with a series of rough contact pads  190 C. The lower surface of the flexible circuit member  184 C is prepared to receive solder paste or solder ball  194 C. The rigid substrate  174 C also includes a series of solder deposit alignment openings  175 C through which solder ball  194 C can couple the lower surface of the flexible circuit member  184 C with second circuit member  198 C. The compliant members  171 C provide reactive support to bias the flexible circuit member  184 C against contact pad  192 C on first circuit member  176 C. 
       FIG. 12D  illustrates another alternate compliant interconnect assembly  170 D generally as illustrated in  FIG. 12C , except that the raised compliant material  172 D operates without the polymeric sheeting of a flexible circuit member. The thickness of the compliant member  172 D can be engineered to provide the desired amount of resiliency. Substrate  174 D includes a series of conductive compliant members  171 D positioned to engage with the contact pad  192 D on the first circuit member  176 D. The lower surface of the conductive compliant member  171 D is prepared to receive solder paste or solder ball  194 D. The substrate  174 D also includes a series of solder deposit alignment openings  175 D through which solder ball  194 D can couple the lower surface of the conductive compliant members  171 D with second circuit member  198 D. 
       FIG. 13  illustrates an alternate compliant interconnect assembly  200  in accordance with the present invention. A pair of discrete compliant raised portions  202 ,  204  are attached to a carrier  206 . In the illustrated embodiment, the carrier  206  is a multi-layered structure. First and second flexible circuit members  210 ,  212  are positioned on opposite sides of the compliant interconnect assembly  200 , generally as illustrated in  FIG. 6 . Solder ball  214  connects solder ball pads  216 ,  218  on the respective flexible circuit members  210 ,  212 . The solder ball  214  can be replaced by a variety of connection methods such as wedge bonding, ultrasonic bonding, resistance bonding, wire bonding, or iso-tropic/anisotropic conductive adhesives. 
     Contact pads  220 ,  222  on the respective flexible circuit members  210 ,  212  are singulated. Adhesive  221  can optionally be used to bond contact pads  220 ,  222  to the raised compliant material  202 ,  204 . The flexible circuit members  210 ,  212  can optionally be bonded to the carrier  206 . The resulting compliant interconnect assembly  200  is interposed between first and second circuit members  226 ,  228  in a compressive relationship so that contact pads  220 ,  222  are compressively engaged with respective contact pads  230 ,  232 . 
       FIG. 14A  illustrates an alternate compliant interconnect assembly  300  in accordance with the present invention. The raised compliant material  302  is located on the first circuit member  304 . The raised compliant material  302  can be bonded to both the first circuit member  304  and the rear of contact pad  314 . In the illustrated embodiment, the first circuit member  304  is a packaged integrated circuit device. The first circuit member  304  can alternately be a printed circuit board, another flexible circuit, a bare-die device, an integrated circuit device, an organic or inorganic substrate, a rigid circuit and virtually any other type of electrical component. Solder ball pad  306  on the flexible circuit member  308  is electrically coupled to contact pad  310  on the first circuit device  304  by solder ball  312 . Contact pad  314  on the flexible circuit member  308  is supported by raised compliant material  302 . The contact pad  314  can be compressively engaged with pad  316  on the second circuit member  318 . 
     In an alternate embodiment,  FIG. 14A  illustrates a connector-on-package  320  in accordance with the present invention. The first circuit device  304  forms a substrate for package  322  containing bare die device  324 . In the illustrated embodiment, the bare die device  324  is a flip chip and/or wire bond integrated circuit structure, although any packaged integrated circuit device can be used in the present connector on package  320  embodiment. The compliant interconnect assembly  300  is formed on the substrate  304  as discussed above, yielding a packaged integrated circuit  324  with an integral connector  300 . 
       FIG. 14B  illustrates an alternate compliant interconnect assembly  300 B generally as shown in  FIG. 14A . Contact pad  305 B on the flexible circuit member  308 B is electrically coupled directly to the contact pad  310 B on the first circuit member  304 B. The raised compliant material  302 B is attached to the circuit member  304 B and is reduced in height to compensate for the height loss due to removal of the solder ball. The first circuit member  304 B can be a printed circuit board, another flexible circuit, a bare-die device, an integrated circuit device, an organic or inorganic substrate, a rigid circuit and virtually any other type of electrical component. 
       FIG. 15A  illustrates an alternate compliant interconnect assembly  400  in accordance with the present invention. Raised compliant material  402  is mounted on a carrier  404  that is positioned adjacent to the first circuit member  406 . In the illustrated embodiment, the first circuit member  406  is a packaged integrated circuit device. The carrier  404  can be optionally bonded to the first circuit member  406 . Ball grid array (BGA) solder ball  408  (or solder paste) is used to electrically couple contact pad  410  on the first circuit member  406  with the solder ball pad  412  on the flexible circuit member  414 . The singulated contact pad  416  on the flexible circuit member  414  is supported by the raised compliant material  402  for compressive engagement with contact pad  418  on the second circuit member  420 . 
     In one application, the embodiment of  FIG. 1  SA can be used to “connectorize” a conventional BGA device  422  by adding the compliant interconnect assembly  400 . In essence, the compliant interconnect assembly  400  can be merged into an existing BGA device  422  to form an assembly  401  comprising the packaged integrated circuit  406  and the compliant interconnect assembly  400 . The contact pads  416  can simply be pushed against the PCB  420  to create a solderless connection without actually mounting a connector on the PCB  420 . Alternately, solder at the interface of the contact pads  416 ,  418  can be reflowed. The assembly  401  can be provided as a conversion kit for integrated circuit devices, thereby eliminating the need for a connector on the printed circuit board  420 . The connectorized embodiment of  FIG. 15A  can be used with any type of packaged integrated circuit, such as an LGA, PLCC, PGA, SOIC, DIP, QFP, LCC, CSP, or other packaged or unpackaged integrated circuits. 
       FIG. 15B  illustrates an alternate connectorized integrated circuit device  424  in accordance with the present invention. The compliant interconnect  434  includes raised compliant material  425  mounted on a carrier  426 . Singulated contact pad  427  on flexible circuit member  428  is supported by the raised compliant material  426  for compressive engagement with contact pad  429  on the first circuit member  430 . The connection between the contact pads  427 ,  429  can be created by compression or the reflow of solder. Integrated circuit device  431  is direct connected to the flexible circuit member  428 . The integrated circuit device  431  can be electrically coupled to the flexible circuit member  428  by flip chip bumps  432  and/or wire bonds  433 . Alternatively, terminals  436  on the integrated circuit device  431  can include locations of weakness (see  FIG. 10A ) that permit the bumps  432  to be snap-fit with the flexible circuit member  428  (see  FIG. 19 ). The integrated circuit device can be an unpackaged bare die device. In one embodiment, the integrated circuit device  431 , the compliant interconnect  434  and a portion of the flexible circuit member  428  can be retained in package  435 . 
       FIG. 16  is a perspective view of a replaceable chip module  440  coupled to a flexible circuit member  454  using a compliant interconnect assembly in accordance with the present invention. The housing  442  includes a plurality of device sites  444 ,  446 ,  448 ,  450  configured to receive various first circuit members. The housing  442  can be an insulator housing or an alignment frame, typically constructed from plastic or shielded metal. 
     In one embodiment, the replaceable chip module  440  illustrated in  FIG. 16  includes a second circuit member  451 , such as a PCB, having a  168  DIMM edge card connector  452  along one edge. Flex circuit member  454  is interposed between the second circuit member  451  and the housing  442  to form compliant interconnect assemblies  458  at one or more of the device sites  444 ,  446 ,  448 ,  450 . Various integrated circuit devices can be located at the device sites  444 ,  446 ,  448 ,  450 . The flexible circuit member  454  may extend across the entire second circuit member  451 , or just a portion thereof. Any of the compliant interconnect assemblies disclosed herein can be used for this purpose. The raised compliant material can correspondingly be formed on the first or second circuit members, or the substrate (see for example  FIG. 5 ). 
     In another embodiment, the second circuit member  451  is an extension of the flexible circuit member  454 . Stiffener  443  is optionally provided behind the flexible circuit member  451 . 
     The housing  442  includes a device site  444  for receiving a microprocessor device. Along one edge of the housing  442  are a series of device sites  446  configured to receive flash memory integrated circuit devices. Device sites  448 ,  450  are provided along the other edges of the housing  442  for receiving other circuit members supportive of the microprocessor. Each of the device sites  444 ,  446 ,  448 ,  450  optionally include appropriate covers  456   a - 456   c . The covers  456   a - 456   c  have beveled edges  449  for sliding engagement with a corresponding lips  453  on the housing  442 . 
     The flexible circuit member  454  extends beyond the housing  442 , permitting it to perform more functions than simple providing an interconnect between the first and second circuit members. For example, the flexible circuit member  454  can include integrated ground planes; buried passive functions such as capacitance; redistribution of terminal routing or pitch; and/or leads to bring in other signals or power from external sources to the device being connected without having to come in through the PCB  451 . Using the flexible circuit member to perform other functions reduces the number of terminals need to be connected to the main PCB  451  since all of the ground pins from the first circuit members can be coupled to the flex circuit and/or the substrate. Another advantage of this embodiment is that it is possible to alter the signals or power coming in through the flexible circuit member  454 , such as filtering, amplifying, decoupling etc. 
       FIG. 17  is a side sectional view of an assembly  468  comprising multiple compliant interconnect assemblies  470 ,  472  arranged in a stacked configuration with multiple circuit members  474 ,  476 ,  478  in accordance with the present invention. The interconnect assemblies  470 ,  472  correspond generally with those illustrated in  FIG. 6 , although any of the interconnect assemblies disclosed herein can be arranged in a stacked configuration. The circuit members  474 ,  476 ,  478  can be printed circuit boards, flexible circuits, bare-die devices, integrated circuit devices, organic or inorganic substrates, rigid circuits or combinations thereof. The assembly  468  is typically located in a housing (see  FIG. 16 ) to maintain alignment and a compressive relationship with the various components. The four flexible circuit members  480 ,  482 ,  484 ,  486  can be arrange parallel to each other or at various angles. Additionally, the flexible circuit members  480 ,  482 ,  484 ,  486  can be connected to each other, such as the connection  498  connecting flexible circuit member  482  to flexible circuit member  484 .  FIG. 18  illustrates one possible arrangement of the flexible circuit members  480 ,  482 ,  484 ,  486  layered together with the circuit member  474  on top of the assembly  468 . Distal ends  490 ,  492 , 494 ,  496  of the various flexible circuit members  480 ,  482 ,  484 ,  486  are free to connect to other circuits. 
       FIG. 19  illustrates an alternate compliant interconnect assembly  500  using a compliant interconnect generally as illustrated in  FIG. 12A . Raised compliant material  502  is attached to a carrier  504  that is interposed between first and second circuit members  506 ,  508 . The carrier  504  can be rigid or flexible. An additional support layer  510  can optionally be added to the carrier  504  to increase rigidity and/or compliance. Flexible circuit member  512  is electrically coupled to the contact pad  514  on second circuit member  508  by solder ball or solder paste  516 . When the first circuit member  506  is compressively engaged with the compliant interconnect assembly  500 , raised compliant material  502  biases contact pad  518  on the flexible circuit member  512  against contact pad  520  on the first circuit member  506 . 
     In one embodiment, the flexible circuit member  512  extends to a third circuit member  522 . The third circuit member  522  can be electrically coupled using any of the techniques disclosed herein, including the connectorized approach illustrated in  FIG. 15B . In the illustrated embodiment, terminals  524  on the flexible circuit  512  include an aperture  526  and a plurality of locations of weakness  528  (see  FIG. 10A ). The locations of weakness  528  permit solder ball  530  to snap-fit into aperture  526  to form a strong mechanical interconnect. The solder ball  530  can optionally be reflowed to further bind with the terminal  524 . If the solder ball  530  is reflowed, the segmented portions of the terminal  524  will flex into the molten solder. When the solder solidifies, the terminal  524  will be at least partially embedded in the solder ball  530 . The third circuit member  522  can be an integrated circuit device, such as an LGA device, BGA device, CSP device, flip chip, a PCB or a variety of other devices. 
       FIG. 20  is a schematic illustration of various conductive structures  556  formed on the contact pads  554  of flexible circuit member  550 . The conductive structures  556  facilitate electrical coupling with various types of contact pads on a circuit member. The structures  556  can be metal pieces soldered to the contact pads  554 , a build-up of solder or conductive adhesive or other conductive members bonded to the contact pads  554 . Structures  560  and  562  include generally flat upper surfaces  564  suitable to engage with an LGA device. Structure  566  includes a recess  568  generally complementary to the contact pads on a BGA device. Structure  570  includes a series of small protrusions  572  designed to frictionally engage with various contact pads. Structure  558  is a solder bump, such as may be found on a BGA device. The conductive structures  556  can be coupled with a circuit member using compression and/or reflowing the solder. 
       FIG. 21  illustrates an alternate compliant interconnect assembly  600  using an electrical trace  602  generally as illustrated in  FIGS. 10D-10I . The electrical trace  602  is attached to carrier  604 . The carrier  604  can be a rigid or a flexible dielectric material. After the electrical trace  602  is singulated, a second dielectric carrier  606  can optionally be located on the opposite surface. Distal ends  608  of the compliant members  610  are deformed to extend through openings  612  in the carrier  604 . 
     In the illustrated embodiment, the distal end  608  is deformed in a first direction and a solder ball  614  is electrically coupled to the proximal end of the compliant member  610 . When a first circuit member  616  is compressively engaged with the compliant interconnect assembly  600 , distal end  608  of the compliant member  610  electrically couples with contact pad  618  on the first circuit member  616 . Solder ball  614  is preferably melted to electrically couple with contact pad  620  on second circuit member  622 . The embodiment of  FIG. 21  is particularly suited to releasably attaching a bare die device  616  to a printed circuit board  622 . 
     The compliant interconnect assembly  600  is typically constructed by etching electrical trace  602 . A photoresist is printed onto tie bars that are to be removed. The distal ends  608  are then deformed and the electrical trace  602  is plated. The photoresist is then removed and the electrical trace  602  is laminated to the carrier  604 . An acid bath is used to etch away the tie bars that were previously covered with the photoresist. The carrier  604  holds the compliant members  610  in position. The second dielectric carrier  606  is then optionally laminated to the opposite side of the electrical trace  602 . 
       FIG. 22  illustrates an alternate compliant interconnect assembly  630  using an electrical trace  632  generally as illustrated in  FIGS. 10F-10I . The electrical trace  632  is attached to carrier  634 . After the electrical trace  632  is singulated, a second dielectric carrier  636  can optionally be located on the opposite surface. In the embodiment of  FIG. 22 , each compliant member  638  includes at least two distal ends  640 ,  642 . The distal end  640  is deformed to extend through openings  644  in the carrier  634  and the distal end  642  is deformed to extend through the opening  646  in the carrier  636 . 
     When a first circuit member  648  is compressively engaged with the compliant interconnect assembly  630 , distal end  640  electrically couples with contact pad  650  on the first circuit member  648 . Similarly, a second circuit member  652  can be compressively engaged with the distal end  642  to electrically couples with contact pad  654  on the second circuit member  652 . 
       FIGS. 23 and 24  illustrate a compliant interconnect assembly  660  with a first electrical trace  662  attached to carrier  664 . The first electrical trace  662  is singulated and the distal ends  666  of the compliant members  668  are deformed. Similarly, a second electrical trace  670  is attached to a carrier  672 , singulated and the distal ends  674  of the compliant members  676  deformed. The electrical traces  662 ,  670  are placed in a back to back configuration so that the respective compliant members  668 ,  676  are electrically coupled. 
     In the embodiment of  FIG. 23 , the compliant members  668 ,  674  include holes  686 ,  688  that can be electrically coupled using a mechanical connection such as a conductive plug or rivet, a heat stake, spot or ultrasonic welding, solder, compression, a coined feature that flattens against the opposing compliant member, electrical plating, or a variety of other methods. 
     In the embodiment of  FIG. 24 , the compliant members  668 ,  676  are electrically coupled by melting solder  690  between the joint, using the carriers  664 ,  672  as a solder mask to prevent solder from wicking up the distal ends  666 ,  674 . Alternatively, the compliant members  668 ,  676  can be electrically coupled using compression, solder paste, conductive adhesive, spot or ultrasonic welding, a coined feature that flattens against the opposing compliant member, or a variety of other techniques. In one embodiment, The distal ends  666 ,  674  are electrically coupled with contact pads  678 ,  680  on respective first and second circuit members  682 ,  684 , as discussed in connection with  FIGS. 21 and 22 . 
       FIG. 25  illustrates an alternate compliant interconnect assembly  700  generally as illustrated in  FIG. 21 , except that an additional circuitry plane  702  is added to the structure. For example, the circuitry plane  702  can be a power plane, a ground plane, or a connection to an external integrated circuit device  704 . The circuitry plane  702  is preferably electrically isolated between carriers  708 ,  710 , although some of the compliant members  713  can be electrically coupled to the circuitry plane  702 . Optional carrier  706  can be provided. In the illustrated embodiment, the circuitry plane  702  extends beyond the boundaries of the compliant interconnect assembly  700  to facilitate connection to a power source, a ground plane, or an external devices  704 . For example, the compliant interconnect assembly  700  can be inserted into the replaceable chip module  400  of  FIG. 16 , electrically coupling the circuitry plane  702  to the flexible circuit member  454  or the edge card connector  452 . 
     As discussed in connection with  FIG. 10E , a portion of the electrical trace  712  can serve as a ground plane or power plane in some embodiments. The present compliant interconnect assembly  700  provides for internal or embedded passive features such as decoupling capacitance as a result of the layered power plane  702  and the ground plane provided by a portion of the electrical trace  712 . In yet another embodiment, discrete electrical components  714 , such as capacitors, can be added to the present compliant interconnect assembly  700 . The circuitry plane  702  of the present embodiment improves the operating performance of the first and second circuit members  716 ,  718 . 
       FIG. 26  illustrates an alternate compliant interconnect assembly  750  generally as illustrated in  FIGS. 23 and 24 , except that an additional circuitry plane  752  is added to the structure. Again, the circuitry plane  752  can be a power plane, a ground plane, or a connection to an external integrated circuit device  754 . The circuitry plane  752  preferably extends beyond the boundaries of the compliant interconnect assembly  750  to facilitate connection to a power source or external devices  754 . The circuitry plane  752  is preferably electrically isolated between dielectric layers  762 ,  764 . The present compliant interconnect assembly  750  provides for internal or embedded passive features such as decoupling capacitance as a result of the layered power plane  752  and the ground plane provided by a portion of the electrical traces  756 ,  758 . Discrete electrical components  760 , such as capacitors, can optionally be added to the present compliant interconnect assembly  750 . 
       FIG. 27  illustrates an alternate compliant interconnect assembly  770  generally as illustrated in  FIG. 22 , except that an additional circuitry plane  772  is added to the structure. Again, the circuitry plane  772  can be a power plane or a connection to an external integrated circuit device  774 . The circuitry plane  772  preferably extends beyond the boundaries of the compliant interconnect assembly  770  to facilitate connection to a power source or external devices  774 . The present compliant interconnect assembly  770  provides for internal or embedded passive features such as decoupling capacitance as a result of the layered power plane  772  and the ground plane provided by a portion of the electrical traces  776  attached to carrier  782 . The circuitry plane  772  is preferably sandwiched between layers of dielectric material  778 ,  780 . Discrete electrical components  784 , such as capacitors, can optionally be added to the present compliant interconnect assembly  770 . 
       FIGS. 28A-28D  illustrate various aspects of an alternate compliant interconnect assembly  800  in accordance with the present invention. As discussed in connection with  FIGS. 21-27 , the flexible circuit member is preferably attached to a carrier before singulation so to retain the spatial relationship of the compliant members (see  FIGS. 10D-10I ). In the embodiment of  FIGS. 28A-28D , the flexible circuit member, which is typically a sheet of conductive material, is singulated prior to attachment to carrier  806  to form a plurality of discrete compliant members  804 . The discrete compliant members  804  are attached to a carrier  806  using a variety of techniques, such as thermal or ultrasonic bonding, adhesives, mechanical attachment, and the like. 
     In the illustrated embodiment, the carrier  806  includes pairs of adjacent slots  808 ,  810 . Center portion  812  of the carrier  806  between the slots  808 ,  810  acts as a torsion bar. A discrete compliant member  804  is inserted though the slot  808  and attached to the center portion  812 , preferably by crimping. Alternatively, the compliant members  804  can be attached to the carrier  806  through single slot  814 . Upper and lower dielectric layers  816 ,  818  are preferably added to the top and bottom of the compliant interconnect assembly to prevent shorting or contact rollover during compression. An additional circuitry plane  820  and dielectric covering layer  822 , as discussed above, can also be added to the present compliant interconnect assembly  800 . 
     As best illustrated in  FIGS. 28C and 28D , the center portion  812  twists and/or deforms to permit the compliant members  804  to compensate for non-planarity in the first and second circuit members  824 ,  826  (see  FIG. 28   a ). Distal ends  828 ,  830  of the compliant members  804  also flex when compressed by the first and second circuit members  824 ,  826 . The amount of displacement and the resistance to displacement can be adjusted by changing the size and shape of the center portion  812  on the carrier  806 , and/or by constructing the carrier  806  from a more rigid or less rigid material that resists displacement of the compliant members  804 . In one embodiment, a flexible circuit member, such as shown in  FIGS. 10D-10I  is attached to the carrier  806 . The combination of the flexible circuit member and the discrete compliant members provides maximum flexibility in constructing the present compliant interconnect assembly  800 . 
       FIG. 29  illustrates a variation of the compliant interconnect assembly  800  of  FIGS. 28A-28D . The compliant interconnect assembly  840  includes a plurality of discrete compliant members  842  attached to a carrier  844  as discussed above. Distal end  846  is positioned to electrically couple with contact pad  848  on first circuit member  850 . Solder ball  852  replaces the distal end  830  in  FIG. 28A . The solder ball  852  is positioned to electrically couple with contact pad  854  on second circuit member  856 . 
       FIG. 30  is a top view of a compliant interconnect assembly  900  as shown in  FIGS. 21-29 . Carrier  902  includes an array of holes  904  through which distal ends of the compliant members extend to engage with circuit members (see  FIGS. 21-29 ). Any additional circuit planes (see  FIGS. 25-26 ) are preferably ported from the side of the compliant interconnect assembly  900 , preferably by flexible circuit members  906 ,  908 . 
     The embodiments disclosed herein are basic guidelines, and are not to be considered exhaustive or indicative of the only methods of practicing the present invention. There are many styles and combinations of properties possible, with only a few illustrated. Each connector application must be defined with respect to deflection, use, cost, force, assembly, &amp; tooling considered. 
     Patents and patent applications disclosed herein, including those cited in the background of the invention, are hereby incorporated by reference. Other embodiments of the invention are possible. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.