Abstract:
Methods and apparatus for a sensor having a die supporting a magnetic field sensor element, a leadframe having opposed first and second surfaces and leadfingers, a passive component coupled to the first and second ones of the leadfingers such that the component is an integrated part of an IC package, and a magnet adjacent to the second surface of leadframe to back bias the magnetic field sensor element.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/325,162 filed on Dec. 14, 2011, which is a continuation of U.S. patent application Ser. No. 11/457,626 filed on Jul. 14, 2006, which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Techniques for semiconductor packaging are well known in the art. In general, a die is cut from a wafer, processed, and attached to a leadframe. After assembly of the integrated circuit (IC) package, the IC package may then placed on a circuit board with other components, including passive components such as capacitors, resistors and inductors. Such passive components, which can be used in filtering the like, can result in the addition of a circuit board near the sensor, or additional real estate on a circuit board that may be present. 
         [0003]    As is known in the art, integrated circuits (ICs) are typically overmolded with a plastic or other material to form a package. Such ICs, for example sensors, often require external components, such as capacitors, to be coupled to the IC for proper operation. Magnetic sensors, for example, can require decoupling capacitors to reduce noise and enhance EMC (electromagnetic compatibility). However, external components require real estate on a printed circuit board (PCB) and additional processing steps. 
         [0004]    U.S. Pat. No. 5,973,388 to Chew et al. discloses a technique in which a leadframe includes a flag portion and a lead portion with a wire bonds connecting a die to the leadframe. Inner ends of the lead portions are etched to provide a locking structure for epoxy compound. The assembly is then encapsulated in an epoxy plastic compound. 
         [0005]    U.S. Pat. No. 6,563,199 to Yasunaga et al. discloses a lead frame with leads having a recess to receive a wire that can be contained in resin for electrical connection to a semiconductor chip. 
         [0006]    U.S. Pat. No. 6,642,609 to Minamio et al. discloses a leadframe having leads with land electrodes. A land lead has a half-cut portion and a land portion, which is inclined so that in a resin molding process the land electrode adheres to a seal sheet for preventing resin from reaching the land electrode. 
         [0007]    U.S. Pat. No. 6,713836 to Liu et al, discloses a packaging structure including a leadframe having leads and a die pad to which a chip can be bonded. A passive device is mounted between the contact pads. Bonding wires connect the chip, passive device, and leads, all of which are encapsulated. 
         [0008]    U.S. Patent Application Publication No. US 2005/0035448 of Hsu et al. discloses a chip package structure including a carrier, a die, a passive component, and conducting wires. Electrodes of the passive component are coupled to power and ground via respective conducting wires. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The exemplary embodiments contained herein will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0010]      FIG. 1  is a pictorial representation of a sensor having an integrated capacitor in accordance with exemplary embodiments of the invention; 
           [0011]      FIG. 2A  is a top view of a capacitor and leadframe; 
           [0012]      FIG. 2B  is a side view of the capacitor and leadframe of  FIG. 2A ; 
           [0013]      FIG. 3A  is a top view of a capacitor secured to a leadframe by conductive epoxy; 
           [0014]      FIG. 3B  is a side view of the assembly of  FIG. 3A ; 
           [0015]      FIG. 4A  is a top view of a sensor having integrated capacitors in accordance with an exemplary embodiment of the invention; 
           [0016]      FIG. 4B  is a side view of the sensor of  FIG. 4A ; 
           [0017]      FIG. 4C  is a top view of the capacitors of  FIG. 4A ; 
           [0018]      FIG. 4D  is a side view of the capacitors of  FIG. 4C ; 
           [0019]      FIG. 4E  is a top view of a sensor having integrated capacitors in accordance with an exemplary embodiment of the invention; 
           [0020]      FIG. 4F  is a side view of the sensor of  FIG. 4E ; 
           [0021]      FIG. 5  is a flow diagram showing an exemplary sequence of steps to fabricate the sensor of  FIG. 4A ; 
           [0022]      FIG. 5A  is a flow diagram showing an alternative sequence of steps to fabricate a sensor in accordance with exemplary embodiments of the invention; 
           [0023]      FIG. 5B  is a flow diagram showing a further sequence of steps to fabricate a sensor in accordance with exemplary embodiments of the invention; 
           [0024]      FIG. 6A  is a top view of a capacitor coupled to a leadframe in accordance with exemplary embodiments of the invention; 
           [0025]      FIG. 6B  is a cross-sectional view of the assembly of  FIG. 6A ; 
           [0026]      FIG. 6C  is a flow diagram showing an exemplary sequence of steps to fabricate the assembly of  FIG. 6A ; 
           [0027]      FIG. 7A  is a top view of a capacitor coupled to a leadframe; 
           [0028]      FIG. 7B  is a cross-sectional view of the assembly of  FIG. 7A ; 
           [0029]      FIG. 8A  is a top view of a capacitor coupled to a leadframe; 
           [0030]      FIG. 8B  is a cross-sectional view of the assembly of  FIG. 8  along lines A-A; 
           [0031]      FIG. 8C  is a cross-sectional view of the assembly of  FIG. 8  along lines B-B; 
           [0032]      FIG. 9A  is a top view of a capacitor coupled to a leadframe; 
           [0033]      FIG. 9B  is a cross-sectional view of the assembly of  FIG. 9A  along lines A-A; 
           [0034]      FIG. 9C  is a cross-sectional view of the assembly of  FIG. 9A  along lines B-B; 
           [0035]      FIG. 9D  is a top view of a capacitor coupled to a leadframe; 
           [0036]      FIG. 9E  is a cross-sectional view of the assembly of  FIG. 9D  along lines A-A; 
           [0037]      FIG. 9F  is a cross-sectional view of the assembly of  FIG. 9D  along lines B-B; 
           [0038]      FIG. 9G  is a pictorial representation of the assembly of  FIG. 9D ; 
           [0039]      FIG. 10A  is a top view of a capacitor coupled to a leadframe; 
           [0040]      FIG. 10B  is a cross sectional view of the assembly of  FIG. 10  along lines A-A; 
           [0041]      FIG. 10C  is a cross-sectional view of the assembly of  FIG. 10  along lines B-B; 
           [0042]      FIG. 10D  is a cross-sectional view of the assembly of  FIG. 10  along lines C-C; 
           [0043]      FIG. 11A  is a front view of a sensor having an integrated capacitor; 
           [0044]      FIG. 11B  is a side view of the sensor of  FIG. 11A ; 
           [0045]      FIG. 12A  is a front view of a prior art sensor; 
           [0046]      FIG. 12B  is a side view of the prior art sensor of  FIG. 12A ; and 
           [0047]      FIG. 12C  is a pictorial representation of the prior art sensor of  FIG. 12A . 
       
    
    
     DETAILED DESCRIPTION 
       [0048]      FIG. 1  shows an integrated circuit (IC) package  100  having integrated capacitors  102   a,b  in accordance with an exemplary embodiment of the invention. In the illustrated embodiment, the IC package  100  includes a die  104  having a magnetic sensor to detect a magnetic field, or change in magnetic field, which may change with the movement of an object of interest. The die  104  and capacitor(s)  102  can be positioned on a leadframe  106  having a series of lead fingers  108 . 
         [0049]    By integrating one or more capacitors  102  in accordance with exemplary embodiments described more fully below, the vertical direction of the package, or the magnetic field, is either minimally or not impacted, e.g., increased, as compared with known sensor packages. As will be appreciated by one of ordinary skill in the art, it is desirable for sensor ICs to minimize a distance between the sensor package and the object of interest. 
         [0050]      FIGS. 2A and 2B  show a capacitor  200  placed on tape  202 , such as KAPTON tape, in a region  204  defined by a leadframe  206 . More particularly, the leadframe is formed, cut, or otherwise manipulated to form the region  204  for the capacitor  200 . The capacitor  200  is below a surface  208  of the leadframe  206  so that a vertical dimension of the package is reduced when compared to the capacitor on the leadframe. 
         [0051]    The capacitor  200  is electrically coupled to the leadframe  206  using any suitable technique, such as wire-bonding, solder, conductive epoxy, etc. In certain embodiments, wire-bonding and/or conductive epoxy may be preferred as solder may potentially crack at the interface with the capacitor or leadframe due to thermal expansion caused by coefficient of thermal expansion (CTE) mismatches over temperature cycles. 
         [0052]      FIGS. 3A and 3B  show another embodiment of a sensor having a capacitor  300  located below a surface  302  of a leadframe  304 . In the illustrated embodiment, a bottom  306  of the capacitor is below a bottom surface  308  of the leadframe  304 . Conductive epoxy  310  is used to electrically connect and secure the capacitor  300  to the leadframe  304 . With this arrangement, more of a body of the package for the sensor can be used in the vertical direction for package thickness. This direction is a significant factor in the operation of magnetic sensors as will be readily appreciated by one of ordinary skill in the art. 
         [0053]    In an exemplary embodiment, a capacitor  300  is placed below a leadframe  302  and electrically connected to the leadframe and secured in position by the conductive epoxy  310 . In one embodiment, the capacitor  300  is generally centered on a longitudinal center  312  of the leadframe  302 . That is, an equal portion of the capacitor is above the top surface  314  and below the bottom surface  316  of the leadframe. However, in other embodiments, the capacitor  300  can be positioned differently with respect to the leadframe  302 . 
         [0054]    In an exemplary embodiment, an assembly fixture  350  ( FIG. 3B ) to position the capacitor  300  in relation to the leadframe  302  includes a tray  352  to provide a depression to secure the capacitor  300  in position during the assembly process. A die, for example silicon, would also be present on another portion of the leadframe, but is not shown for clarity. The tray  352  can be positioned to place the capacitor in a desired position with respect to the leadframe  302  while the conductive epoxy  310  is applied and cured. After the epoxy, or other connecting means, has cured, or set the tray may be removed and a mold compound, for example, can be over molded about the assembly to form an IC package. 
         [0055]    In another embodiment, solder is used to electrically connect and secure the capacitor to the leadframe. It is understood that other suitable materials can be used that can withstand mechanical forces present during the plastic package injection molding process. 
         [0056]      FIGS. 4A and 4B  show a further embodiment of an IC package  400  having first and second integrated capacitors  402   a,b  and illustrative dimensions in accordance with an exemplary embodiment of the invention. A die  404  is connected to a leadframe  406  having a cutout region  408  in which the capacitors  402  can be positioned below a surface  410  of the leadframe  406 . A plastic or other material can be used as molding  412  to encapsulate the assembly. 
         [0057]    As shown in  FIGS. 4C and 4D , in the illustrated embodiment, the capacitors  402  are mounted on tape  414 , such as polyimide tape (KAPTON is one trade name for polyimide tape) with conductive foil. A tape automated bonding process (TAB) with a continuous reel can be used for the capacitors  402 . With this arrangement, the assembly will remain intact during the molding process. With the capacitors  402  placed below the leadframe surface  410 , the required thickness of the package is reduced as compared with a package having a capacitor mounted on the leadframe. 
         [0058]    In the illustrative package of  FIGS. 4A and 4B , the IC package  400  having integrated capacitors  402   a,b  is a Hall effect sensor. As is well known in the art, the sensor  400  is useful to detect movement of an object of interest by monitoring changes in a magnetic field. 
         [0059]    The exemplary sensor package  400  has dimensions of about 0.24 inch long, about 0.184 inch wide, and about 0.76 inch deep, i.e., thickness. The leadframe  406  is about 0.01 inch in thickness with the cutout region about 0.04 inch to enable placement of the capacitors  402  below the leadframe surface. 
         [0060]    The capacitive impedance provided by the capacitors can vary. In general, the capacitance can range from about 500 pF to about 200 nF. 
         [0061]      FIGS. 4E-F  show another sensor package embodiment  450  including integrated capacitors  402   a,    402   b  having a leadframe  452  with a first slot  454  to reduce eddy currents in accordance with exemplary embodiments of the invention. In other embodiments, further slots  456 ,  458  can be provided in the leadframe. The sensor  450  has some commonality with the sensor  400  of  FIG. 4A , where like reference numbers indicate like elements. 
         [0062]    As is well known in the art, in the presence of an AC magnetic field (e.g., a magnetic field surrounding a current carrying conductor), AC eddy currents can be induced in the conductive leadframe  452 . Eddy currents form into closed loops that tend to result in a smaller magnetic field so that a Hall effect element experiences a smaller magnetic field than it would otherwise experience, resulting in a less sensitivity. Furthermore, if the magnetic field associated with the eddy current is not uniform or symmetrical about the Hall effect element, the Hall effect element might also generate an undesirable offset voltage. 
         [0063]    The slot(s)  454  tends to reduce a size (e.g., a diameter or path length) of the closed loops in which the eddy currents travel in the leadframe  452 . It will be understood that the reduced size of the closed loops in which the eddy currents travel results in smaller eddy currents for a smaller local affect on the AC magnetic field that induced the eddy current. Therefore, the sensitivity of a current sensor having a Hall effect  460  element is less affected by eddy currents due to the slot(s)  454 . 
         [0064]    Instead of an eddy current rotating about the Hall effect element  460 , the slot  454  results in eddy currents to each side of the Hall element. While the magnetic fields resulting from the eddy currents are additive, the overall magnitude field strength, compared to a single eddy current with no slot, is lower due to the increased proximity of the eddy currents. 
         [0065]    It is understood that any number of slots can be formed in a wide variety of configurations to meet the needs of a particular application. In the illustrative embodiment of  FIG. 4E , first, second and third slots  454 ,  456 ,  458  are formed in the leadframe  452  in relation to a Hall effect element  460  centrally located in the die. The slots reduce the eddy current flows and enhance the overall performance of the sensor. 
         [0066]    It is understood that the term slot should be broadly construed to cover generally interruptions in the conductivity of the leadframe. For example, slots can includes a few relatively large holes as well as smaller holes in a relatively high density. In addition, the term slot is not intended to refer to any particular geometry. For example, slot includes a wide variety of regular and irregular shapes, such as tapers, ovals, etc. Further, it is understood that the direction of the slot(s) can vary. Also, it will be apparent that it may be desirable to position the slot(s) based upon the type of sensor. 
         [0067]    The slotted leadframe  452  can be formed from a metal layer of suitable conductive materials including, for example, aluminum, copper, gold, titanium, tungsten, chromium, and/or nickel. 
         [0068]      FIG. 5  shows a process  500  having an exemplary sequence of steps to provide a sensor having one or more integrated capacitors. In step  502 , conductive epoxy is applied to a desired location and in step  504  a die is attached to a leadframe. In step  506 , a capacitor is attached to the leadframe by the conductive epoxy. The assembly is cured in step  508  followed by wirebonding lead fingers to the die in step  510 . The assembly is then overmolded with a plastic material, for example, in step  512  followed by finishing steps  514 ,  516  of deflash/plating and trimming/singulation. 
         [0069]    Alternatively a flip-chip attachment could be used in which solder balls and/or bumps are applied to the die, which is then attached to the leadframe. A capacitor is attached to the leadframe followed by overmolding of the assembly after solder reflow. 
         [0070]      FIG. 5A  shows an alternative embodiment  550  of the process  500  of  FIG. 5  in which solder is used instead of conductive epoxy, wherein like reference numbers indicate like elements. In step  552 , solder is printed or otherwise dispensed in desired locations for attachment of capacitors in step  554 . In step  556 , the die is attached to the leadframe followed by curing etc in a manner similar to that of  FIG. 5 .  FIG. 5B  shows a further alternative embodiment  560  that may reduce cracking during wirebonding. In step  562 , epoxy is dispensed and in step  564  the die is attached. The epoxy is then cured in step  566  followed by wirebonding in step  568 . Then the capacitor is attached in step  572  and the assembly is cured in step  574  followed by molding, deflash/plating and trimming/singulation in respective steps  512 ,  514 ,  516 . 
         [0071]    It is understood that the illustrative process embodiments are exemplary. In addition, all steps may not be shown, for example, typically after molding the package the leads are plated, trimmed and then formed. It would also be possible to attach the capacitor with one type of solder and then the die can be flip chip attached to the leadframe with a second type of solder. Further, the process steps may be reversed depending on which solder has the higher reflow temperature. The higher temperature solder should be used first. The case of flip chip attach of the die and then the capacitors with an epoxy would also be possible. 
         [0072]    It is understood that a variety of attachment mechanisms can be used to secure and/or electrically connect the capacitor and leadframe. Exemplary mechanisms include tape and conductive epoxy, solder, tape and wire bonds, TAB (tape automated bonding), and non-conductive epoxy and wire bonding. 
         [0073]      FIGS. 6A and 6B  show a semiconductor package structure  600  including a leadframe  602  to which a die  604  and components  606   a, b, c  are attached. In general, components, such as capacitors and passive devices, can be coupled to the leadframe and fingers. This arrangement enhances the life cycle of components, such as passive components, improves noise reduction capability, and creates more space on printed circuit boards. 
         [0074]    A series of unattached lead fingers  608   a, b, c  are positioned in a spaced relationship to the leadframe  602  to enable finger-leadframe connection via respective components  606   a, b, c  in the illustrated embodiment. The die  604  is positioned on a top surface  602   a  of the leadframe  602  and one or more of the components  606  are attached to a bottom surface  602   b  of the leadframe. The components  606  can also be coupled to a lead finger to electrically connect the lead finger  608  to the leadframe  602 . Wire bonds  610 , for example, can be used to make electrical connections between the die  604  and the leadframe. 
         [0075]    With this arrangement, passive component integration can be achieved on a leadframe pad using one or more matured surface mount technology (SMT) process, such as screen printing, dispensing, surface mount device attachment, etc. 
         [0076]    The leadframe  602  and/or lead fingers  608  can be fabricated by etching, stamping, grinding and/or the like. The passive component  606  attachment can be performed before singulation and package body molding so that the singulation process will not adversely affect the quality of the internal components. As is known in the art, and disclosed for example in U.S. Pat. No. 6,886,247 to Drussel, et al., singulation refers to the separation of printed circuit boards from the interconnected PCB&#39;s in the panel of substrate material. 
         [0077]      FIG. 6C  shows an exemplary sequence of steps  650  for fabricating the assembly of  FIGS. 6A and 6B . In step  652 , the die is attached to the leadframe followed by curing in step  654 . After curing, wirebonds are attached in step  656  and the assembly is then molded in step  658  and deflashed/plated in step  660 . In step  662 , solder is printed or otherwise dispensed followed by attachment of the capacitor(s), solder reflow, and washing in step  664 . In step  666 , trimming and singulation is performed. In the illustrated embodiment, the copper of leadframe is exposed for attachment of the capacitor to the package after the molding is completed. 
         [0078]      FIGS. 7A and 7B  show an assembly  700  having an embedded capacitor  702  provided using an integration approach. A die  704  is positioned on a top surface  706   a  of a leadframe  706  with lead fingers  708   a, b, c  positioned with respect to the leadframe. The capacitor  702 , or other component, has a first end  702   a  placed on a first bonding pad  710  on the leadframe and a second end  702   b  placed on a second bonding pad  712  on the first lead finger  708   a.  The leadframe has a downset area  714  having a surface that is below a top surface  706   a  of the leadframe to receive the capacitor  702 . Similarly, the first lead finger  708   a  has a downset area  716  below a top surface  718  of the lead finger to receive the capacitor second end  702   b.    
         [0079]    With this arrangement, the top surface  720  of the capacitor is lowered with respect to the top surface  706   a  of the leadframe due to the downset areas  714 ,  716  of the leadframe and the first lead finger. 
         [0080]    An exemplary impedance range for the capacitors is from about 500 pF to about 100 nF. It is understood that a variety of capacitor types and attachment technology techniques can be used to provide sensors having integrated capacitors. In one particular embodiment, surface mount capacitors are used having exemplary dimensions of 1.6 mm long by 0.85 mm wide by 0.86 mm thick. 
         [0081]      FIGS. 8A-C  show another embodiment  700 ′ having some commonality with the assembly of  FIGS. 2A and 2B . The downset areas  714 ′,  716 ′ are formed as squared grooves in the respective leadframe  706 ′ and first lead finger  708   a.    
         [0082]    An integrated circuit having an integrated capacitor is useful for applications requiring noise filtering at its input or output, such as with a bypass capacitor. For example, positions sensors, such as Hall effect devices, often use bypass capacitors in automotive applications. 
         [0083]      FIGS. 9A-C  show a further embodiment  800  of an assembly having first and second integrated components  802 ,  804 . A die  805  is positioned on a leadframe  806  having first and second  808   a, b  lead fingers extending from the lead frame. Further lead fingers  810   a - e , which are separate from the leadframe  806 , are in spaced relation to the leadframe. The first intact lead finger  808   a  has first and second downset areas  812   a, b  on outer areas of the lead finger to receive ends of the first and second components  802 ,  804 . First and second detached lead fingers  810   a,  b have respective downset areas  814 ,  816  to receive the other ends of the first and second components  802 ,  804 . The components  802 ,  804  provide the desired electrical connection as shown. Wire bonds  818  can provide electrical connections between the lead fingers and the die  805 . 
         [0084]    In the illustrated embodiment, the lead fingers  808   a,    810   a,b  are coined to provide the downset areas  812 ,  814 ,  816 . By placing the components, e.g., capacitors, inductors, resistors, etc., in the coined downset areas, the thickness of the overall package is reduced. 
         [0085]    Such an arrangement provides advantages for a magnetic field sensor since the package thickness may be reduced. That is, an inventive sensor having an integrated component can have the same thickness as a comparable conventional sensor without an integrated component. It is readily understood by one of ordinary skill in the art that the magnetic gap is a parameter of interest for magnetic sensors and the ability to reduce a package thickness may provide enhanced magnetic sensor designs. 
         [0086]      FIGS. 9D-G  show another embodiment  800 ′ of an assembly having first and second components  802 ,  804 , integrated in package, such as a magnetic sensor. The embodiment  800 ′ has some similarity with the embodiment  800  of  FIGS. 9A-C , where like reference numbers indicate like elements. The components  802 ,  804  are secured to the leadframe  806 ′ without downset areas. The components  802 ,  804  are located on an opposite side of the die  805  as wirebonds  818  used to connect various die locations to the leadfingers. The components  802 ,  804  are on the opposite side of the die as the leads  820  that extend from the package. In the illustrated embodiment, the tie bars proximate the components  802 ,  804  are cut or trimmed from the final package. By placing the components  802 ,  804  on an opposite side of the die  805  as external leads  820 , a more compact package is provided. 
         [0087]      FIGS. 10A-D  show another embodiment  900  having some similarity with the assembly of  FIGS. 9D-F . The components are placed on an opposite side of the leadframe  806 ′ as the die  805 ′. This arrangement optimizes the device for use with a magnetic sensor where a magnet is placed of the back side of the device and the leads are angled at ninety degrees (see  FIG. 6 ) to optimize the size of the sensor. 
         [0088]      FIGS. 11A-B  show an exemplary sensor package  950  having an integrated capacitor with a body diameter that is reduced as compared with a conventional sensor without an integrated capacitor shown in  FIGS. 12A-C . The leads  952  are angled ninety degrees from the leadframe within the package body  954 . In one embodiment, the external leads  952  are on the opposite side of the die as the integrated capacitor, as shown in  FIG. 9D . With the inventive integrated capacitor, the sensor provides a robust, noise-filtered solution in a reduced size. For example, the sensor package  950  of  FIGS. 11A , B can have a diameter of about  7 . 6  mm, while a comparable prior art sensor shown in  FIGS. 12A-C  has a diameter of about 9.8 mm. 
         [0089]    To fabricate the package  950  of  FIGS. 11A-B , the leads are formed/bent by ninety degrees. The part is inserted in a premolded housing to align the package body and the leads. For a Hall sensor, for example, a magnet and concentrator (not shown) may be added. The assembly is then overmolded. 
         [0090]    The exemplary invention embodiments are useful for System-in-Package (SiP) technology in a variety of applications, such as automotive applications. The inventive packaging contributes to optimizing the life cycle of passive components, improving noise reduction capability, and creating more space on circuit boards. In addition, the invention optimizes the positioning of components to reduce space requirements and enhance device sensing ability. 
         [0091]    In another embodiment, a sensor includes on a leadframe a first die having a sensor element and a second die having circuitry and at least one integrated capacitor. While exemplary embodiments contained herein discuss the use of a Hall effect sensor, it would be apparent to one of ordinary skill in the art that other types of magnetic field sensors may also be used in place of or in combination with a Hall element. For example the device could use an anisotropic magnetoresistance (AMR) sensor and/or a Giant Magnetoresistance (GMR) sensor. In the case of GMR sensors, the GMR element is intended to cover the range of sensors comprised of multiple material stacks, for example: linear spin valves, a tunneling magnetoresistance (TMR), or a colossal magnetoresistance (CMR) sensor. In other embodiments, the sensor includes a back bias magnet. The dies can be formed independently from Silicon, GaAs, InGaAs, InGaAsP, SiGe or other suitable material. 
         [0092]    Other embodiments of the present invention include pressure sensors, and other contactless sensor packages in general in which it is desirable to have integrated components, such as capacitors. 
         [0093]    One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.