Patent Abstract:
A silicon MEMS device can have at least one solder contact formed thereupon. The silicon MEMS device can be configured to be mounted to a circuit board via the solder contact(s). The silicon MEMS device can be configured to be electrically connected to the circuit board via the solder contact(s).

Full Description:
TECHNICAL FIELD 
       [0001]    One or more embodiments relate generally to microelectromechanical systems (MEMS) and, more particularly, to the surface mounting of MEMS actuators. 
       BACKGROUND 
       [0002]    Microelectromechanical systems (MEMS) actuators are well known. Examples of MEMS actuators include comb drives, scratch drives, and thermal drives. MEMS actuators can be used in a variety of applications. 
         [0003]    MEMS actuators are generally mounted upon a substrate. For example, it can be desirable to mount a MEMS actuator to a printed circuit board (PCB) or the like. It is not always possible to package a MEMS actuator in a standard integrated circuit (IC) package. Standard integrated circuit packages can interfere with external moving parts of a MEMS actuator and thus prevent proper operation of the MEMS actuator. 
         [0004]    As a result, there is a need for improved methods and systems for mounting MEMS actuators, such as to printed circuit boards and the like, for example. 
       SUMMARY 
       [0005]    In accordance with an embodiment, a silicon MEMS device can have at least one solder contact formed thereupon. The silicon MEMS device can be configured to be mounted to a circuit board via the solder contact(s). The silicon MEMS device can be configured to be electrically connected to the circuit board via the solder contact(s). 
         [0006]    In accordance with an embodiment, a micro electromechanical systems (MEMS) actuator can have a plurality of electrical contacts, e.g. solder contacts, formed upon a corresponding plurality of flexures thereof for facilitating electrical communication with the MEMS actuator. The electrical contacts can be configured to facilitate surface mounting of the MEMS actuator, such as upon a printed circuit board, a flexible circuit, or the like. The flexures can mitigate stress applied to the MEMS actuator. 
         [0007]    In accordance with another embodiment, a system can have a circuit board, a MEMS actuator, and a miniature camera. The MEMS actuator can be surface mounted to the circuit board via flexures of the MEMS actuator. The MEMS actuator can be configured to move an optical element, such as a lens, of the miniature camera. 
         [0008]    In accordance with another embodiment, a method can include applying solder to pads of a circuit board, such as by using a solder mask. A MEMS actuator can be placed upon the circuit board in a desired orientation. The MEMS actuator can be placed upon the circuit board such that contacts of MEMS actuator that are formed on flexures are substantially aligned with the pads of the circuit board. The MEMS actuator can be reflow soldered to the circuit board. 
         [0009]    Thus, according to various embodiments, methods and systems are provided for mounting a MEMS actuator when the MEMS actuator is not packaged in a contemporary integrated circuit package. More particularly, such methods and system facilitate electrical connection to the MEMS actuator in a manner that mitigates stress applied to the MEMS actuator. 
         [0010]    The scope of the invention is defined by the claims, which are incorporated into this Summary by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of a surface mount actuator configured to attach to a circuit board with an arm of the actuator extending upwardly, in accordance with an embodiment. 
           [0012]      FIG. 2  is a top view of the surface mount actuator of  FIG. 1  mounted to the circuit board, in accordance with an embodiment. 
           [0013]      FIG. 3  is a side view of the surface mount actuator of  FIG. 1  mounted to the circuit board, in accordance with an embodiment. 
           [0014]      FIG. 4  is a perspective view of a surface mount actuator configured to attach to a circuit board with an arm of the actuator extending sideways, in accordance with an embodiment. 
           [0015]      FIG. 5  is a top view of the surface mount actuator of  FIG. 4  mounted to the circuit board, in accordance with an embodiment. 
           [0016]      FIG. 6  is a side view of the surface mount actuator of  FIG. 4  mounted to the circuit board, in accordance with an embodiment. 
           [0017]      FIG. 7  is a perspective view of a surface mount actuator configured to attach to a circuit board with an arm of the actuator extending downwardly, in accordance with an embodiment. 
           [0018]      FIG. 8  is a top view of the surface mount actuator of  FIG. 7  mounted to the circuit board, in accordance with an embodiment. 
           [0019]      FIG. 9  is a side view of the surface mount actuator of  FIG. 7  mounted to the circuit board, in accordance with an embodiment. 
           [0020]      FIG. 10  is a top view of the circuit board of  FIG. 8 , in accordance with an embodiment. 
           [0021]      FIG. 11  is a side view of a lens and lens mount configured for use with the surface mount actuator, in accordance with an embodiment. 
           [0022]      FIG. 12  is a side view of the surface mount actuator having contacts that extend across two surfaces thereof, in accordance with an embodiment. 
           [0023]      FIG. 13  is a side view of a surface mount actuator having electrical contacts on flexures, in accordance with an embodiment. 
           [0024]      FIG. 14  is an enlarged view of the flexure and contact of  FIG. 13 , in accordance with an embodiment. 
           [0025]      FIG. 15  is a front view of a cellular telephone having a miniature camera, wherein the miniature camera has an actuator, in accordance with an embodiment. 
           [0026]      FIG. 16  is a flow chart of a method for surface mounting an actuator, in accordance with an embodiment. 
       
    
    
       [0027]    Embodiments of the invention and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures. 
       DETAILED DESCRIPTION 
       [0028]    Systems and methods are disclosed herein to provide for the surface mounting of actuators. Embodiments of the actuators can be mounted in different orientations. Thus, the actuators can be more readily used in a variety of applications. 
         [0029]    Actuators typically have external moving parts. Contemporary packaging technologies, such as ball grid array (BGA) and quad flat no-lead (QFN), cannot readily be used with surface mount technology (SMT) to mount actuators because the packaging technology can interfere with desired operation of the actuator. That is, the packaging technology can interfere with movement of the external moving parts. 
         [0030]    It is desirable to isolate actuators, such as MEMS actuators, from stress. Stress can adversely affect the operation of such actuators. Mounting flexures can be provided to accommodate such stress. Electrical contacts can be formed upon such flexures. The electrical contacts can be solder contacts, for example. 
         [0031]      FIG. 1  is a perspective view of a surface mount actuator  100 , according to an embodiment. The surface mount actuator  100  is configured to attach to a circuit board  200  (see  FIG. 2 ) using surface mount technology, as discussed herein. 
         [0032]    A plunger, ram, or arm  101  of the actuator  100  extends upwardly, in accordance with an embodiment. Thus, the actuator  100  shown in  FIG. 1  can be oriented so as to provide up and down movement, i.e., movement in the directions indicated by arrow  103 . That is, the arm  101  can move back and forth in the directions indicated by arrow  103 . The arm  101  can thus move other items in these directions with minimal or no intermediate linkage. 
         [0033]    The actuator  100  can be used in a variety of applications, such as to move an optical element in a miniature camera  1100  ( FIGS. 11 and 12 ). For example, one or more of the actuators  100  can be used to move a lens  1101  ( FIGS. 11 and 12 ) to effect focusing of the miniature camera  1100 , to effect zooming of the miniature camera  1100 , and/or to effect optical image stabilization for the miniature camera  1100 . The arm  101  can define a platform, substrate, or lens mount to facilitate the attachment of the lens  1101  thereto. The arm  101  can attach directly to the lens  1101  or can attach to the lens  1101  via a lens mount  1102 . 
         [0034]    The actuator  100  can be a microelectromechanical systems (MEMS) actuator. For example, the actuator  100  can be an electrostatic actuator. The actuator  100  can have a plurality of plates, fingers, or electrodes  102 . The electrodes  102  shown in  FIG. 1  can represent various MEMS actuator structures. The electrodes  102  shown in  FIG. 1  can represent rows of fingers, for example. The electrodes  102  can be substantially surrounded by a housing or frame  105 . 
         [0035]      FIG. 2  is a top view of the actuator  100  of  FIG. 1  mounted to the circuit board  200 , in accordance with an embodiment. The actuator  100  can be surface mounted to the circuit board  200  using contacts  104  ( FIG. 1 ). The contacts  104  can be flat contacts, leads, pins, solder balls, or any other type of surface mount contacts. Thus, the actuator  100  can be mounted to the circuit board  200  using any of a variety of surface mounting techniques. 
         [0036]    The circuit board  200  can be a printed circuit board or a flexible circuit, for example. The circuit board  200  can be any type of substrate or material that is suitable for surface mounting of the actuator  100 . 
         [0037]    An actuator driver  201  can be in electrical communication with the actuator  100 . For example, traces  202  formed upon the circuit board  200 , can facilitate such electrical communication. Traces, pads or edge connectors  203  can facilitate communication of the driver  201  with other circuitry. For example, the edge connectors  203  can facilitate communication of the driver  201  with a controller, such as a microprocessor, that can be used to facilitate autofocus and/or optical image stabilization. The driver  201  can be located off of the circuit board  200 . 
         [0038]      FIG. 3  is a side view of the actuator  100  of  FIG. 1  mounted to the circuit board  200 , in accordance with an embodiment. Solder paste or solder balls  301  can electrically and mechanically attach the actuator  100  and the driver  201  to the circuit board  200  using surface mount technology. 
         [0039]      FIG. 4  is a perspective view of a surface mount actuator  400  configured to attach to a circuit board  500  (see  FIG. 5 ) using surface mount technology, as discussed herein. 
         [0040]    An aim  401  of the actuator  400  extends sideways, in accordance with an embodiment. Thus, the actuator  400  shown in  FIG. 4  can be oriented so as to provide side-to-side movement, i.e., movement in the directions indicated by arrow  403 . That is, the arm  401  can move back and forth in the directions indicated by arrow  403 . The arm  401  can thus move other items in these directions with minimal or no intermediate linkage. 
         [0041]    The actuator  400  can be used in a variety of applications, such as to move an optical element in the miniature camera  1100  ( FIG. 12 ). For example, one or more of the actuators  400  can be used to move the lens  1101  ( FIGS. 11 and 12 ) to effect focusing of the miniature camera  1100 , to effect zooming of the miniature camera  1100 , and/or to effect optical image stabilization for the miniature camera  1100 . The arm  401  can define a platform, substrate, or lens mount to facilitate the attachment of the lenses  1101  thereto. The arm  401  can attach directly to a lens  1101  or can attach to the lens  1101  via a lens mount  1102 . 
         [0042]    The actuator  400  can be a microelectromechanical systems (MEMS) actuator. For example, the actuator  400  can be an electrostatic actuator. The actuator  400  can have a plurality of plates, fingers, or electrodes  402 . The electrodes  402  shown in  FIG. 4  can represent various MEMS actuator structures. The electrodes  402  shown in  FIG. 4  can represent rows of fingers, for example. The electrodes  402  can be substantially surrounded by a housing or frame  405 . 
         [0043]      FIG. 5  is a top view of the actuator  400  of  FIG. 4  mounted to the circuit board  500 , in accordance with an embodiment. The actuator  400  can be surface mounted to the circuit board  500  using contacts  404  ( FIG. 4 ). The contacts  404  can be flat contacts, leads, pins, solder balls, or any other type of surface mount contacts. Thus, the actuator  400  can be mounted to the circuit board  500  using any of a variety of surface mounting techniques. 
         [0044]    The circuit board  500  can be a printed circuit board or a flexible circuit, for example. The circuit board  500  can be any type of substrate or material that is suitable for surface mounting of the actuator  400 . 
         [0045]    An actuator driver  501  can be in electrical communication with the actuator  100 . For example, traces  502  formed upon the circuit board  500 , can facilitate such electrical communication. Traces, pads or edge connectors  503  can facilitate communication of the driver  501  with other circuitry. The driver  501  can be located off of the circuit board  500 . 
         [0046]      FIG. 6  is a side view of the actuator  400  of  FIG. 1  mounted to the circuit board  500 , in accordance with an embodiment. Solder paste or solder balls  601  can electrically and mechanically attach the actuator  400  and the driver  501  to the circuit board  500  using surface mount technology. 
         [0047]      FIG. 7  is a perspective view of a surface mount actuator  700  configured to attach to a circuit board  800  (see  FIG. 8 ) using surface mount technology, as discussed herein. 
         [0048]    An arm  701  of the actuator  700  extends downwardly, in accordance with an embodiment. Thus, the actuator  700  shown in  FIG. 7  can be oriented so as to provide up and down movement, i.e., movement in the directions indicated by arrow  703 . That is, the arm  701  can move back and forth in the directions indicated by arrow  703 . The arm  701  can thus move other items in these directions with minimal or no intermediate linkage. 
         [0049]    The actuator  700  can be used in a variety of applications, such as to move an optical element in the miniature camera  1100  ( FIGS. 11 and 12 ). For example, one or more of the actuators  700  can be used to move a lens  1101  ( FIGS. 11 and 12 ) to effect focusing of the miniature camera  110   o , to effect zooming of the miniature camera  1100 , and/or to effect optical image stabilization for the miniature camera  1100 . The arm  701  can define a platform, substrate, or lens mount  1102  to facilitate the attachment of the lens  1101  thereto. The arm  701  can attach directly to a lens or can attach to the lens  1101  via a lens mount  1102 . 
         [0050]    The actuator  700  can be a microelectromechanical systems (MEMS) actuator. For example, the actuator  700  can be an electrostatic actuator. The actuator  700  can have a plurality of plates, fingers, or electrodes  702 . The electrodes  702  shown in  FIG. 7  can represent various MEMS actuator structures. The electrodes  702  shown in  FIG. 7  can represent rows of fingers, for example. The electrodes  702  can be substantially surrounded by a housing or frame  705 . 
         [0051]      FIG. 8  is a top view of the actuator  700  of  FIG. 7  mounted to the circuit board  800 , in accordance with an embodiment. The actuator  700  can be surface mounted to the circuit board  800  using contacts  704  ( FIG. 4 ). The contacts  704  can be flat contacts, leads, pins, solder balls, or any other type of surface mount contacts. Thus, the actuator  700  can be mounted to the circuit board  800  using any of a variety of surface mounting techniques. 
         [0052]    The circuit board  800  can be a printed circuit board or a flexible circuit, for example. The circuit board  800  can be any type of substrate or material that is suitable for surface mounting of the actuator  700 . 
         [0053]    An actuator driver  801  can be in electrical communication with the actuator  700 . For example, traces  802  formed upon the circuit board  800 , can facilitate such electrical communication. Traces, pads or edge connectors  803  can facilitate communication of the driver  801  with other circuitry. The driver  801  can be located off of the circuit board  800 . 
         [0054]      FIG. 9  is a side view of the actuator  700  of  FIG. 7  mounted to the circuit board  800 , in accordance with an embodiment. Solder paste or solder balls  901  can electrically and mechanically attach the actuator  700  and the driver  801  to the circuit board  800  using surface mount technology. 
         [0055]      FIG. 10  is a top view of the circuit board  800  of  FIG. 8 , in accordance with an embodiment. The circuit board  800  can have an opening  1001  formed therein. The opening  1001  can be generally circular (as shown), square, rectangular, oval, or any other shape. 
         [0056]    Pads  1002  can be formed upon the circuit board  800  to facilitate surface mounting of the actuator  700  the circuit board  800 . Pads  1003  can be formed upon the circuit board  800  to facilitate surface mounting of the driver  801  to the circuit board  800 . The traces  802  can provide electrical communication between the pads  1002  and at least some of the pads  1003 . 
         [0057]      FIG. 11  is a side view of a lens  1101  and a lens mount  1102  configured for use with the actuator  100 ,  400 ,  700 , in accordance with an embodiment. The lens  1101  and the lens mount  1102  can be used in a miniature camera  1100 , for example. The lens  1101  can be attached to the lens mount  1102  with epoxy  1103 , for example. The lens  1101  can be attached to the lens mount  1102  in any desired fashion. The lens mount  1102  can have a plurality of faces, such as faces  1104 ,  1105  and  1106 , for example. 
         [0058]    The lens mount  1102  can be configured such that a desired one of the faces,  1104 ,  1105 , or  1106  can be attached to the surface  110 ,  410 ,  710  of the arm  101 ,  401 ,  701 . In this manner the lens  1101  can be attached to the actuator  100 ,  400 ,  700  with an orientation that facilitates desire movement of the lens. 
         [0059]    For example, the lens mount  1102  can be attached to the arm  101  ( FIG. 1 ) such that face  1105  is in contact with surface  110  of arm  101 . Such attachment can facilitate movement of lens  101  along its optical axis  1112  in the direction of arrow  103  ( FIG. 1 ) so as to effect focusing and/or zooming of a miniature camera. 
         [0060]    As a further example, the lens mount  1102  can be attached to the arm  401  ( FIG. 6 ) such that face  1104  is in contact with surface  410  of arm  401 . Such attachment can facilitate movement of lens  101  perpendicular to its optical axis  1112  so as to effect optical image stabilization for a miniature camera. 
         [0061]    The lens mount  1102  can be attached to the arm  401  with epoxy, for example. The lens mount  1102  can be attached to the arm  101 ,  401 ,  701  at any desired angle and need not necessarily be attached such that the optical axis  1112  of the lens  1101  is either parallel to or perpendicular to the direction of motion of the actuator  100 ,  400 ,  700 . 
         [0062]      FIG. 12  is a side view of the surface mount actuator  1240  that has been surface mounted to a substrate  1241 , such as a printed circuit board. The actuator  1240  can have contacts  1251  that extend across two surfaces of the actuator  1240 , in accordance with an embodiment. Each contact  1251  can extend across both a side  1261 ,  1262  and a bottom  1263  of the actuator  1240 . In this manner more reliable electrical and mechanical connection with corresponding pads  1253  of the substrate  1241  can be facilitated. Thus, solder  1252  can have more surface area with which to bond and provide electrical and mechanical connection. 
         [0063]    Various embodiments can have such contacts  1251  that extend across two or more surfaces thereof. For example, any of the actuators  100 ,  400 , and  700  can have contacts  1251  that extend across two or more surfaces thereof. 
         [0064]    An arm  1242  can extend from the top of the actuator  1240 . Alternatively, the arm  1242  can extend from a side of the actuator or can extend from the bottom thereof, as discussed herein. 
         [0065]      FIG. 13  is a side view of a surface mount actuator  1300  having an electrical contact  1303  formed on a flexure  1304 , in accordance with an embodiment. The flexure  1304  can tend to isolate the MEMS actuator  1300  from stress caused by the surface mounting process. The flexure  1304  can tend to isolate the MEMS actuator  1300  from stress caused by a difference of the coefficient of thermal expansion (CTE) between the actuator  1300  and the substrate upon which the actuator  1300  is mounted. 
         [0066]    An arm  1310  can extend from the top of the actuator  1300 , as shown in  FIG. 13 . Alternatively, the arm  1310  can extend from a side of the actuator  1300  (e.g., the actuator  1300  can be configured to be mounted sideways), or can extend from the bottom of the actuator  1300  (e.g., the actuator  1300  can be configured to be mounted upside down), as discussed herein. Electrodes  1302  of the actuator  1300  can effect actuation thereof. Any type of electrodes  1302  can be used to define any type of actuator. 
         [0067]    One or more of the contacts  1305  can be fixed, i.e., can lack a flexure  1304 . Any desired combination of contacts  1303  having flexures  1304  and contacts  1305  lacking flexures can be used. Thus, mechanical isolation from stress can be provided in any desired direction and for any desire contacts  1303 . 
         [0068]      FIG. 14  is an enlarged view of the flexure  1304  and contact  1303  of  FIG. 13 , in accordance with an embodiment. The flexure  1304  can be comparatively stiff along its longitudinal direction, as indicated by arrow  1331 . The flexure  1304  can be comparatively soft along one or more of its transverse directions, as indicated by arrow  1332 . The flexures  1304  can be configured to be soft in any desired direction and can be configured to be stiff in any desired direction. 
         [0069]    Generally, it is desirable that the stiff direction of the flexures  1304  be along the direction of motion of the actuator  100 ,  400 ,  700 , so as to facilitate operation of the actuator  100 ,  400 ,  700  without loss of motion due to flexing of the flexures  1304 . The flexures  1304  can be soft in any or all other directions. 
         [0070]      FIG. 15  is a front view of a cellular telephone  1200  having a miniature camera  1100 , wherein the miniature camera  1100  has an actuator  100 ,  400 ,  700 , in accordance with an embodiment. The actuator  100 ,  400 ,  700  can move an optical element, such as the lens  1101 , so as to effect focus (either manual focus or autofocus), zoom, and/or optical image stabilization. 
         [0071]    The miniature camera  1100  can have any desire number of actuators  100 ,  400 ,  700  in any desired combination. For example, the miniature camera  1100  can have one actuator  100 ,  400 ,  700  dedicated to focusing, one actuator  100 ,  400 ,  700  dedicated zooming, and two actuators  100 ,  400 ,  700  dedicated to optical image stabilization. The actuators  100 ,  400 ,  700  dedicated to focusing and zooming can move one or more lenses, such as lens  1101 , along their optical axes. The actuators  100 ,  400 ,  700  dedicated optical image stabilization can move one or more lenses, such as lens  1101 , approximately perpendicular to their optical axes. 
         [0072]      FIG. 16  is a flow chart of a method for surface mounting an actuator  100 ,  400 ,  700 , in accordance with an embodiment. Solder can be applied to the pads (such as  1002  of  FIG. 10 ) of the circuit board  200 ,  500 ,  800  using a solder mask, as indicated in block  1201 . Alternatively, the solder can be applied to the contacts  104 ,  404 ,  704  of the actuator  100 ,  400 ,  700 . 
         [0073]    The actuator  100 ,  400 ,  700  can be placed on the circuit board  200 ,  500 ,  800 , as indicated in block  1202 . The actuator  100 ,  400 ,  700  can be unpackaged, e.g., not contained within a contemporary integrated circuit package such as a ball grid array package or a quad flat no-lead package. The actuator  100 ,  400 ,  700  can be placed on the circuit board  200 ,  500 ,  800  with the contacts  104 ,  404 ,  704  of the actuator  100 ,  400 ,  700  aligned with the pads (such as  1002  of  FIG. 10 ) of the circuit board  200 ,  500 ,  800 . The contacts can be formed upon flexures  1304  of the actuator  100 ,  400 ,  700 . 
         [0074]    The actuator  100 ,  400 ,  700  can be placed on the circuit board  200 ,  500 ,  800  in various orientations, as indicated in block  1203 . For example, the actuator  100  can be placed on the circuit board  200 ,  400 ,  700  with the arm  101  extending upwardly, away from the circuit board  200 , as shown in  FIGS. 2 and 3 . The actuator  100 ,  400 ,  700  can be placed on the circuit board  200 ,  500 ,  800  in any desired orientation, including non-perpendicular orientations such as at 30°, 45°, and 60° (as measured between any desired feature of the actuator  100 ,  400 ,  700  and any desired feature of the circuit board  200 ,  400 ,  500 —such as a side thereof). The pads, such as pads  1003  of  FIG. 10 , can be configured so as to accommodate a desired orientation. 
         [0075]    Alternatively, the actuator  400  can be placed on the circuit board  500  with the arm  401  extending sideways, generally parallel to the circuit board  500 , as shown in  FIGS. 5 and 6 . Alternatively, the actuator  700  can be placed on the circuit board  800  with the arm  701  extending downwardly, away from the circuit board  800 , as shown in  FIGS. 8 and 9 . 
         [0076]    A single actuator can have contacts formed up a plurality of surfaces thereof. For example, the actuator can have one set of contacts formed upon the bottom thereof (as shown in  FIG. 1 ), another set of contacts formed upon the side thereof (as shown in  FIG. 4 ), and yet another set of contacts formed upon the top thereof (as shown in  FIG. 7 , if the surface of the actuator  700  having the arm  701  extending therefrom is considered to be the top thereof, so as to be consistent with  FIG. 1 ). The contacts can be redundant, such that any desired set can be used for surface mounting of the actuator. In this manner, a single actuator can be provided for use in a plurality of different orientations. 
         [0077]    Thus, the single actuator can be configured to be mounted to a circuit board in any one of a variety of different orientations. For example, the actuator can be configured to be mounted to the circuit board with an arm thereof extending upwardly, extending sideways, or extending downwardly. That is, the actuator can have contacts formed upon any surface thereof. 
         [0078]    The arm  101 ,  401 ,  701  can be considered to be an external part with respect to the actuator  100 ,  400 ,  700 . The arm  101 ,  401 ,  701  moves with respect to the actuator  100 ,  400 ,  700 . Since the actuator  100 ,  400 ,  700  has an external moving part, contemporary packaging technologies, such as ball grid array (BGA) and quad flat no-lead (QFN) cannot be used with surface mount technology (SMT) to mount the actuator  100 ,  400 ,  700  because the packaging technology would interfere with desired movement of the arm  101 ,  401 ,  701 . 
         [0079]    The actuator can have a footprint of approximately 0.5 mm×1.5 mm. This footprint is only slight larger than a standard 0402 surface mount component. 
         [0080]    According to an embodiment, the actuator itself can define a package. Thus, features of the actuator can function as features of a package so as to facilitate mounting of the actuator. For example, contacts formed upon flexures of the actuator can facilitate surface mounting of the actuator to a substrate. 
         [0081]    The actuator can be any type of MEMS actuator or non-MEMS actuator. Examples of MEMS actuators include comb drives, scratch drives, and thermal drives. Example of non-MEMS actuators are voice coil actuators and piezoelectric actuators. The discussion of a MEMS actuator herein is by way of example only. 
         [0082]    The term “surface mounting”, as used herein, can be defined to include various techniques of surface mounting technology (SMT). Examples of surface mounting techniques can include the use of flat contacts, leads, pins, and/or solder balls. 
         [0083]    The contacts can be formed of any conductor or semiconductor material. The contacts can be formed of metal to facilitate the use of solder to surface mount the actuator to a substrate. For example, the contacts can be formed of aluminum nickel (Al/Ni) or titanium platinum nickel (Ti/Pt/Ni). 
         [0084]    The metallization of the substrate can be patterned such that the actuator rotates when the solder melts. In this way, the actuator can be placed in one direction (e.g. flat) upon the substrate and can end upon at 90° with respect to this direction (such that the actuator is standing upright when mounted). 
         [0085]    The use of surface mounting more readily facilitates the mounting of actuators, such as MEMS actuators, in different orientations. Since the actuators can be more readily mounted in different orientations, the actuators can be used in a variety of applications. 
         [0086]    The flexures can accommodate substantial mismatches in the coefficient of expansion between the actuator and the substrate upon which the actuator is mounted. Such flexures can also mitigate stress applied to the actuator due to shock, vibration, handling (such as by a person handling a mounted part and/or automated placement equipment, e.g., pick and place equipment). 
         [0087]    Each flexure can have one electrical contact formed thereon. Each flexure can have a plurality of electrical contacts formed thereon. One or more flexures can have dummy contacts formed thereon. Each dummy contact can facilitate mechanical mounting of the actuator without providing any electrical connection thereto. Some contacts can be on flexures and some contacts can be without flexures. Any combination of contacts and flexures can be used. 
         [0088]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Technology Classification (CPC): 1