Abstract:
An apparatus and method of supporting lead fingers during a wire bonding process and of preventing the bonding apparatus and clamping assembly from applying force against the die are available. The present invention includes the use of a movable arm with a portion that is positionable under a portion of the lead fingers of a lead frame during the wire bonding process to provide increased stability of the lead fingers and prevent the bonding apparatus and clamping assembly from applying force against the die. The present invention also provides for the transfer of heat from the heat block directly to the lead fingers during the wire bonding process. The present invention includes the use of a clamp for stabilizing lead fingers during the wire bonding process.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 08/709,639, filed Sept. 9, 1996, now U.S. Pat. No. 5,890,644, issued Apr. 6, 1999; which is a continuation-in-part of U.S. patent application Ser. No. 08/631,143, filed Apr. 15, 1996, now U.S. Pat. No. 5,673,845, issued Oct. 7, 1997; U.S. patent application Ser. No. 08/597,616, filed Feb. 6, 1996 now U.S. Pat. 5,647,528, issued Jul. 15, 1997; and U.S. patent application Ser. No. 08/592,058, filed Jan. 26, 1996, pending. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to forming wire bonds between the contact pads on semiconductor devices and individual lead frame fingers of a lead frame. 
     More specifically, the present invention is related to the apparatus and method of supporting the lead fingers of a lead frame during a wire bonding process using a support arm with a lead support portion that is positionable between the lead fingers and the die prior to the bonding process to help substantially stabilize the lead fingers during the bonding process. 
     2. State of the Art 
     Well known types of semiconductor devices are connected to lead frames and subsequently encapsulated in plastic for use in a wide variety of applications. Tropically, the lead frame is formed from a single continuous sheet of metal by metal stamping operations. In a conventional lead frame, the lead frame includes an outer supporting frame, a central semiconductor chip supporting pad and a plurality of lead fingers, each lead finger having, in turn, a bonding portion thereof near the central chip supporting pad. Ultimately, the outer supporting frame of the lead frame is removed after the wire bonds between the contact pads of the semiconductor chip device and the lead fingers are made and the semiconductor device and a portion of the lead frame have been encapsulated. 
     In the assembly of semiconductor devices utilizing such conventional lead frames, a semiconductor die is secured to the central supporting pad (such as by a solder or epoxy die-attach, although a double-sided adhesive tape-type attach has also been suggested in the art) and then the entire lead frame, with the semiconductor die thereon, is placed into a wire bonding apparatus including a clamp assembly for holding the lead frame and die assembly, and clamping the lead fingers for bonding. 
     In contrast to a conventional lead frame, U.S. Pat. 4,862,245 issued Aug. 29, 1989 to Pashby et al. illustrates a so-called “leads over chip” arrangement (“LOC”) on the semiconductor die. A plurality of lead fingers of the lead frame extends over the active surface of a semiconductor die toward a line of bond pads thereon wherein bond wires make the electrical connection between the lead fingers and the bond pads. An alpha barrier such as a polyamide tape (for example, Kapton™ tape) is adhered between the semiconductor die and the lead fingers. This configuration, which eliminates the use of the previously-referenced central die attach pad, may assist in limiting the ingress of corrosive environment contaminants after encapsulation of the semiconductor device, achieve a larger portion of the lead finger path length encapsulated in the packaging material, and reduce electrical resistance caused by the length of the bond wires (i.e. the longer the bond wire, the higher the resistance) and potential wire sweep problems in the encapsulation of the semiconductor device aggravated by long wire loops. 
     In a standard wire bonding process, the bond wires are attached, one at a time, from each bond pad on the semiconductor device to a corresponding lead finger. The bond wires are generally attached through one of three industry-standard wire bonding techniques: ultrasonic bonding-using a combination of pressure and ultrasonic vibration bursts to form a metallurgical cold weld; thermocompression bonding-using a combination of pressure and elevated temperature to form a weld; and thermosonic bonding-using a combination of pressure, elevated temperature, and ultrasonic vibration bursts. 
     To form a good bond during the wire bonding processing, it is preferable to perform the bonding at an elevated and somewhat stable temperature. Therefore, as noted above, the lead frame assembly including the attached semiconductor die is generally placed on a heater block. The semiconductor die is then clamped (via the lead frame) to the heater block by a clamping assembly. With a conventional lead frame, the lead fingers are clamped directly against the underlying heater block. Whereas, in an LOC lead frame, the lead fingers are biased between the clamp and the active surface of the semiconductor die heater block. Thus, in an LOC lead frame arrangement, the clamping assembly and bonding apparatus apply pressure against the die thereby causing possible damage. In addition, heating of the lead fingers in an LOC lead frame for wire bonding must be done through heating the die as opposed to directly heating the lead fingers by the heater block in a conventional lead frame. 
     Therefore, in an LOC lead frame configuration it would be advantageous to develop an apparatus to prevent the clamping assembly and bonding apparatus from applying force against the die. In addition, it would be advantageous to develop an apparatus for transferring heat directly from the heat block to the lead fingers. 
     In an LOC structure, the Kapton™ tape comprising the alpha barrier or dielectric between the semiconductor and the lead fingers becomes soft at the elevated temperature. The softening of the tapes allows the lead fingers and/or semiconductor die to move in response to ultrasonic energy or pressure (force) exerted by the wire bonding head (capillary). As a result, the mechanical integrity of the wire bond to the lead fingers is diminished. Furthermore, a “bouncing” motion is imparted to the lead fingers by the wire bonding head movement, which motion may be exacerbated by the heat softened tape. This bouncing motion can also result in poor wire bonds which subsequently fail. 
     Thus, die fabricators are somewhat compelled to select the die attach compound (or other means) and alpha barrier tape based on the thermal stability of the materials rather than on the basis of the most effective material for a given application. 
     Therefore, it would be advantageous to develop an apparatus that would replace the alpha barrier tape while stabilizing the semiconductor die and the lead fingers during the wire bonding process. 
     Typical apparatus and methods for clamping the lead frame during the wire bonding process or for clamping and advancing the lead frame are illustrated in U.S. Pat. No. 4,765,531, 5,082,165, 5,238,174, 5,264,002, 5,307,978, 5,322,207, and 5,372,972. However, such apparatus and methods do not address the problem of supporting the lead fingers during the wire bonding process or preventing the application of force on the die. 
     Such prior art apparatus and methods have been directed at advancing and orienting the lead frame, but have not attempted to solve the problems of forming reliable wire bonds between the contact pads of semiconductor devices and lead fingers of lead frames. 
     There have been other attempts to overcome the problem of the bouncing motion imparted to the lead fingers by the wire bonding head movement. For example, for bonding LOC structures, rigid clamping plates having bond site windows therein have been reconfigured so that the bond site window is reduced in size and the downwardly-extending lip or periphery contacts the lead fingers extending over the die and clamps the lead fingers directly thereto. However, the rigid clamp has been found to be too rigid and unyielding for use with an LOC configuration, and may possibly damage the die. Moreover, the use of a rigid clamp adds to the force exerted against the die and does nothing to prevent the application of force by the bonding apparatus. 
     The present invention is directed to an improved wire bonding apparatus and method for forming such wire bonds. 
     SUMMARY OF THE INVENTION 
     The present invention is related to the apparatus and method of supporting lead fingers during a wire bonding process. The present invention includes the use of a movable arm having a lead support portion for positioning under the lead fingers of a lead frame and/or between the die and the lead fingers during the bonding process to provide increased stability of the individual lead finger for improved bonding and to prevent the bonding apparatus and clamping assembly from applying force to the die. The present invention also provides for heat to be directly transferred from the heat block to the lead fingers during the wire bonding process. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The present invention will be better understood when the description of the invention is taken in conjunction with the drawings wherein: 
     FIG. 1 is a side view of the present invention used in the wire bonding of a semiconductor device arrangement having a conventional lead frame; 
     FIG. 2 is a cross-sectional view taken along A—A of the present inventions as depicted in FIG. 1, and further shows one method of dynamic attachment; 
     FIG. 3 is a cross-sectional view taken along A—A of the present invention as depicted in FIG. 1, and further shows another method of dynamic attachment; 
     FIG. 4 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a conventional lead frame; 
     FIG. 5 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a conventional lead frame; 
     FIG. 6 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a conventional lead frame; 
     FIG. 7 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a conventional lead frame; 
     FIG. 8 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a conventional lead frame; 
     FIG. 9 is a side view of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame without the leads adhered to the semiconductor device; 
     FIG. 10 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame without the leads adhered to the semiconductor device; 
     FIG. 11 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame without the leads adhered to the semiconductor device; 
     FIG. 12 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame without the leads adhered to the semiconductor device; 
     FIG. 13 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame without the leads adhered to the semiconductor device; 
     FIG. 14 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame without the leads adhered to the semiconductor device; 
     FIG. 15 is a side view of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame with the leads adhered to the semiconductor device; 
     FIG. 16 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame with the leads adhered to the semiconductor device; 
     FIG. 17 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame with the leads adhered to the semiconductor device; 
     FIG. 18 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame with the leads adhered to the semiconductor device; 
     FIG. 19 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame with the leads adhered to the semiconductor device; 
     FIG. 20 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having an LOC lead frame with the leads adhered to the semiconductor device; 
     FIG. 21 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a two piece lead frame with the leads adhered to the semiconductor device; 
     FIG. 22 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a two piece lead frame with the leads adhered to the semiconductor device; 
     FIG. 23 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a two piece lead frame with the leads adhered to the semiconductor device: 
     FIG. 24 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a two piece lead frame with the leads adhered to the semiconductor device; 
     FIG. 25 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a two piece lead frame with the leads adhered to the semiconductor device; 
     FIG. 26 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a two piece lead frame with the leads adhered to the semiconductor device; 
     FIG. 27 is a side view of an alternative embodiment of the present invention used in the wire bonding of a semiconductor device arrangement having a hybrid lead frame with leads on differing levels; 
     FIG. 28 is a view of the alternative embodiment of the present invention illustrated in drawing FIG. 27 with the alternative embodiment rotated ninety degrees ( 90 °) to illustrate the lead support for the lead fingers of the hybrid lead frame; 
     FIG. 29 comprises a flow chart of an exemplary process sequence for plastic package molding of a semiconductor device wire bonded to a lead frame using the lead support of the present invention; 
     FIG. 30 is a side schematic view of a typical transfer mold illustrating a pre-molding encapsulant position; 
     FIG. 31 is a side schematic view of a typical transfer mold illustrating a post-molding encapsulant position; 
     FIG. 32 illustrates a top schematic view of one side of a transfer mold of FIGS. 28 and 29 depicting encapsulant flow and venting of the primary mold runner and the mold cavities wherein the die assemblies are contained; 
     FIG. 33 depicts a first encapsulant flow scenario for a mold cavity during molding a lead frame and semiconductor manufactured using the present invention of a lead bonding support; 
     FIG. 34 depicts a second encapsulant flow scenario for a mold cavity during molding a lead frame and semiconductor manufactured using the present invention of a lead bonding support; and 
     FIG. 35 depicts a third encapsulant flow scenario for a mold cavity during molding a lead frame and semiconductor manufactured using the present invention of a lead bonding support. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to drawing FIG. 1, a semiconductor device (die)  10  is shown being supported by the paddle  12  of a conventional lead frame. A heat block  20  is used to heat the paddle  12  and die  10  during the wire bonding process. As shown, a suitable wire  16  has one end thereof  17  bonded to a bond pad of the die  10 . The wire  16  may be of any suitable type for connection and bonding purposes, such as gold, gold alloy, aluminum, aluminum alloy, etc. The other end  18  of the wire  16  is shown being bonded to the end  15  of a lead finger  14  of the lead frame by a suitable bonding apparatus  26 . The bonding apparatus  26  may be of any suitable type well known in the bonding area such as a tailless thermosonic or ultrasonic capillary type bonding apparatus which dispenses wire during the bonding process. If desired, in the wire bonding operation, further shown in contact with lead finger  14  is a portion of a conventional clamp  22  used to clamp portions of the lead frame during such bonding operations. The clamp  22  may be of any well known suitable type, such as those described hereinbefore, and is generic in shape. Further shown in drawing FIG. 1 is a movable and/or adjustable arm  24 , having a lead support portion  25 , attached to or an integral part of the movable and/or adjustable arm  24 . The movable and/or adjustable arm  24  is dynamically attached to the heat block  20  so that the lead support portion  25  can be positioned between the die  10  and the lead fingers  14 . The movable and/or adjustable arm  24  and lead support portion  25  thus allow for any desired size semiconductor device  10  to be wire bonded without a change to the heat block  20 . In addition, movable and/or adjustable arm  24  having lead support portion  25  conducts heat from the heat block  20  to the lead fingers  14 . 
     During the wire bonding process, it is desirable for the heat block to be heated to substantially 230 degrees Centigrade. Although the heat block may be any suitable temperature during the bonding operation, the heat block  20  temperature should not exceed 300 degrees Centigrade to prevent thermal damage to the die  10 . It is further preferred that the bond of the end  18  of the wire  16  made to the end  15  of the lead finger  14  of a conventional lead frame be made at a temperature of substantially 190 degrees Centigrade for bonding effectiveness. It is also preferred that the bonding apparatus exert a bonding force of substantially 50 to 100 grams when bonding the end  18  of the wire  16  to the end  15  of lead finger  14  for effective bond formation of the wire  16  to lead finger  14 . 
     The movement of the movable arm  24  may be effectuated by various means  28 . Such means are well known in the manufacturing area and may include an air cylinder, a solenoid, a magnet system, a motor, sprockets, a cable and pulley system, a lead screw, a cam arrangement, etc. 
     The movable arm  24  is dynamically attached to the heat block  20  so that as the heat block moves into position during the wire bonding process. The movable arm  24  having lead support portion  25  moves into position under the lead fingers  14 . Still referring to FIG. 1, movable and/or adjustable arm  24  is shown as traveling against the heat block  20  such that the direction of travel is substantially parallel with respect to the lower surface  19  of the lead fingers  14  of a conventional lead frame. 
     Referring to drawing FIG. 2, one method for dynamically attaching movable arm  24  to heat block  20  is by a tongue-and-groove type connection. A tongue  30 , shaped in the form of a dove tail, is formed in the heat block  20 . A mating groove  32  is formed in movable arm  24  so that the tongue  30  may slide within the groove. Thus, movable arm  24  is allowed to slide with respect to heat block  20  while maintaining contact with the heat block for efficient heat transfer. Alternatively, a tongue could be formed in the movable arm and the groove could be formed in the heat block. Other tongue-and-groove connections may be effectuated by forming different shaped tongue and grooves. For example, a square shaped tongue may be formed in heat block  20  and a mating groove formed in movable arm  24 . To reduce friction, linear bearings  42  may be used as well as low friction pads  44  or lubricants. 
     Referring to drawing FIG. 3, another method for dynamically attaching movable arm  24  to the heat block  20  is by having movable arm  24  travel in a track  48  that is formed in heat block  20 . Thus, movable arm  24  is allowed to slide, with respect to heat block  20 , while maintaining contact with the heat block for efficient beat transfer. Again, movement may be facilitated by the use of linear bearings  42  or low friction pads  44  or lubricants. Other methods for dynamically attaching the movable arm  24  to the heat block  20  are tracks, a track-and-carriage system, a hinge, a cam arrangement, etc. 
     Referring to drawing FIG. 4, movable and/or adjustable arm  24  may be attached to heat block  20  such that the direction of travel, with respect to lower surface  19  of lead fingers  14 , is angular or arcuate. A radius  54  may be formed in heat block  20  and movable and/or adjustable arm  24  such that the direction of travel of lead support portion  25  and movable arm  24  is arcuate, with respect to lower surface  19  of the lead fingers  14  of a conventional lead frame, as the lead support portion is positioned prior to wire bonding. 
     Referring to drawing FIG. 5, the surface of the heat block  20  and movable and/or adjustable arm  24  may also be angled  56 , with respect to lower surface  19  of the lead fingers  14 , such that the direction of travel of lead support portion  25  and movable arm  24  is angular, with respect to lower surface  19  of lead fingers  14 , as the lead support portion  25  of movable arm  24  is positioned prior to the wire bonding process. 
     The movement of the movable and/or adjustable arm  24  and the heat block  20  may be integrated so that as the heat block moves into position it causes the movable arm to move into position. In FIG. 5, a notch  50  is shown formed in movable arm  24  and extends into a slot  52  formed in a stationary member (not shown). Thus, as the heat block  20  moves upward to contact the die  10 , the heat block pushes against the movable and/or adjustable arm  24 , which is forced to travel upward and inward by the notch  50  traveling in the slot  52 . 
     Referring to drawing FIG. 6, a dual clamp assembly is shown in conjunction with the movable and/or adjustable arms  24  in order to farther stabilize the lead fingers during the wire bonding process. The conventional clamp  22  acts as a primary clamp and includes a bond site window  60 . The bond site window  60  is sized to allow access for a bonding apparatus  26  to a plurality of bond pads of semiconductor die  10  and to a plurality of lead fingers  14  of a conventional lead frame. 
     The bond site window  60  includes a secondary clamp  62 . The secondary clamp  62  is mounted to a resilient plate  64  with a first set screw or bolt  66 . The proximal end of each resilient plate  64  is attached to the conventional clamp  22  with a second set screw or bolt  68 . It is, of course, understood that secondary clamp  62  can be attached to the clamp  22  in any number of known configurations, including forming the secondary clamp  62  with an integral resilient portion which is secured to the clamp  22  or forming (for example, as by machining) the secondary clamp  62  as an integrated, resilient appendage of the clamp  22 . It is, of course, also understood that any number of secondary clamps  62  can be used, consistent with the need for adequate clearances for wire bonding. 
     When a semiconductor die  10  and a lead frame strip, including lead fingers  14  of a conventional lead frame, is aligned with the bond site window  60  in the clamp  22  and pressure is exerted on the lead frame, the contact end  63  of the secondary clamp  62  contacts the movable arm  24  through lead fingers  14  extending from the lead frame over the active die surface. The secondary clamp  62  does not damage the semiconductor die  10  under the secondary clamp contact end  63  because of the resilient nature of the secondary clamp  62  and because of movable arm  24  positioned between the semiconductor die  10  and the secondary clamp  62 . 
     The semiconductor die  10  has a conventional lead frame arrangement wherein the lead fingers  14  extend adjacent the upper (active) semiconductor die  10 . The bond site window contact lip  65  contacts the lead fingers  14  around tie periphery of the semiconductor die  10 . The secondary clamp  62  extends toward the center of the semiconductor die  10 . A plurality of bond wires  16  is then attached between the bond pads of the semiconductor die  10  and the lead fingers  14 . 
     The contact end  63  of the secondary clamp  62 , in its unbiased state, preferably extends slightly below the bond site window contact lip  65  of the bond site window  60  of the clamp  22 . The secondary clamp  62  may be formed from a substantially rigid, non-deformable material, such as metal, high-temperature plastic, fiber composites, or the like. A preferred material for the secondary clamp  62  is 440C stainless steel. 
     Referring to drawing FIG. 7, an independently actuated lead clamp is shown in conjunction with the movable and/or adjustable arms  24  in order to further stabilize the lead fingers during the wire bonding process. Independently actuated lead clamp  70  may, be used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  in position during the bonding process. The conventional clamp  22  helps insure that the lead finger is in contact with the movable arm  24  during the bonding process and helps minimize any deflection of the end  15  of the lead finger  14  so that the bonding apparatus  26  accurately and precisely contacts the end  15  to provide the desired wire bond. The action of independent actuated lead clamp  70  and, if desired, the additional use of conventional clamp  22 , provides improved clamping of a lead finger  14  during the wire bonding process, as well as insures that the lead finger  14  of a conventional lead frame is in intimate contact with the movable arm  24  for effectiveness. 
     Independent actuated lead clamp  70  may be of any suitable shape for use in independently clamping the lead finger  14 , in place of the use of conventional fixed clamp  22 , such as square, semicircular, rectangular, arcuate, etc. Also, the independent actuated lead clamp  70  may be resiliently mounted through the use of a shoulder  72  thereon, abutting a spring  74 , to control the amount of the force exerted on any lead finger  14  during the wire bonding operation. If desired, the independent actuated lead clamp  70  may include insulation or cushioning  76  on the end thereof. The independent actuated lead clamp  70  is actuated independently of bonding apparatus  26  and has the capability of independent movement along the x-axis, y-axis and z-axis with respect to the bonding apparatus  26 . The independent clamp  70  is also free to move about the bonding apparatus  26  and the central axis of the die  10  so that any lead finger  14  of a conventional lead frame that is to be connected to bond pads on the die  10 , regardless of location, may be accommodated. The independent actuated lead clamp  70  does not need to be, and preferably is not, concentrically centered about the bonding apparatus  26  so that it will not interfere with the operation thereof. Any desired number of independent actuated lead clamps  70  may be used about the bonding apparatus to minimize the amount of movement of the independent actuated lead clamp  70  between wire bonding operations. The independent actuated lead clamp  70  may be located in quadrants about the die  10  in any manner as desired. 
     During the bond operation, one or more of the independent actuated lead clamps  70  clamps the end  15  of lead finger  14  of a conventional lead frame prior to the bonding of a wire  16  thereto by one or more of the bonding apparatus  26 . The independent actuated lead clamp  70  applies sufficient pressure to the end  15  of lead finger  14  to press the lead finger  14  against movable and/or adjustable arm  24  to insure a satisfactory bond between the end  18  of any wire  16  and the end  15  of the lead finger  14 . 
     As shown, one or more of the independent actuated lead clamps  70  contacts the end  15  of lead finger  14  aft of the area of the wire end to the lead finger  14 . The bonds of the wire end  18  to the end  15  of the lead finger  14  are typically a wedge type wire bond, although a ball bond may be made, if desired. As shown, the heat block  20  is in contact with the paddle  12  and the movable and/or adjustable arm  24 , which, in turn, is in contact with the lead fingers  14 . 
     The independent actuated lead clamp  70  may have a modified end or foot thereon to provide a larger clamping area of the independent actuated lead clamp  70  on the end  15  of the lead finger  14  during bonding operations. The modified end or foot may be substantially the same width as the lead finger  14  of a conventional lead frame and may be mounted to have articulated movement about the end of the independent actuated lead clamp  70 , such as using a pin extending through suitable apertures in a pair of ears attached to the foot. 
     The independent actuated lead clamp  70  may be integrally attached to the conventional clamp  22  or may have an articulated mounting arrangement. The modified end or foot may be generally semicircular or arcuate in configuration, so as to engage a large portion of the end  15  of the lead finger  14  of a conventional lead frame surrounding the bonding apparatus  26  during the wire bonding operation to hold the end  15  in position. 
     The independent actuated lead clamp  70  may also be used in conjunction with a second independently actuated clamp. The second independently actuated clamp may be of any suitable type and structure, such as described and illustrated hereinbefore. The independent actuated lead clamp  70  and the second clamp may be actuated independently of each other and independently of the bonding apparatus  26 , as described and illustrated hereinbefore. 
     Referring to drawing FIG. 8, an independently actuated lead clamp  70  is shown having a lead finger penetrating portion  78  on the bottom thereof used in place of or in addition to the conventional clamp  22 , to maintain the lead finger  14  of a conventional lead frame during the bonding process. One or more of the independent actuated lead clamps  70 , having lead finger penetrating portions  78  located thereon, contacts and penetrates the end  15  of lead finger  14  aft of the area of the wire end  18  to the lead finger  14 . The independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, may be of any suitable shape for use in independently clamping the lead finger  14 , in place of the use of conventional clamp  22 , such as square, semicircular, rectangular, arcuate, etc. Also, as shown, the independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, may be resiliently mounted through the use of a shoulder  72  thereon, abutting a spring  74 , to control the amount of force exerted on any lead finger  14  during the wire bonding operation. As described hereinbefore, the independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, is actuated independently of bonding apparatus  26  and has the capability of independent movement alone the x-axis, y-axis and z-axis with respect to the bonding apparatus  26 . The independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, is also free to move about the bonding apparatus  26  and the central axis of the die  10 , so that any lead finger  14  of a conventional lead frame that is to be connected to a bond pad on The die  10 , regardless of location, may be accommodated. The independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, does not need to be, and preferably is not, concentrically centered about the bonding apparatus  26 , so that it will not interfere with the operation thereof Any desired number of independent actuated lead clamps  70 , having lead finger penetrating portion  78  thereon, may be used about the bonding apparatus to minimize the amount of movement of the independent actuated lead clamp  70  between wire bonding operations. Also, the independent actuated lead clamps  70  may be located in quadrants about the die  10 , or in any manner, as desired. 
     The independently actuated lead clamp  70  has a lead finger penetrating portion  78  on the bottom thereof used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  in position during the bonding process. Such independent actuated lead clamp  70  helps insure that the lead finger  14  is in contact with the movable and/or adjustable arm  24  during the bonding process, immobilizes the lead finger  14  during the wire bonding process, and helps minimize any deflection of the end  15  of the lead finger  14  so that the bonding apparatus  26  accurately, precisely contacts the end  15  to provide the desired wire bond. The action of such independent actuated lead clamp  70  and, if desired, the additional use of conventional clamp  22 , provides improved clamping and immobilization of a lead finger  14  during the wire bonding process, as well as insures that the lead finger  14  is in intimate contact with the movable and/or adjustable arm  24  for effectiveness. 
     During the wire bonding process, it is desirable for the heat block  20  to be heated, as previously described hereinbefore. Similarly, the bonding apparatus should exert substantially the same amount of force, as described hereinbefore. 
     During the bond operation, one or more of the independent actuated lead clamps  70 , having a lead finger penetrating portion  78  located on the end thereof, clamps the end  15  of lead finger  14  prior to the bonding of a wire  16  thereto by one or more of the bonding apparatus  26 . The independent actuated lead clamp  70  applies sufficient pressure to the end  15  of the lead finger  14  to insure a satisfactory bond between the end of any wire  16  and the end  15  of the lead finger  14 . 
     As shown, one or more of the independent actuated lead clamps  70  contacts the end  15  of lead finger  14  aft of the area of the bond of wire end  18  to the lead finger  14 . The bonds of the wire end  18  to the end  15  of the lead finger  14  are typically a wedge type wire bond, although a ball bond may be made, if desired. As shown, the heat block  20  is in contact with the paddle  12  of the lead frame. The lead fingers  14  of a conventional lead frame are in contact with the movable arm  24  which, in turn, is in contact with the heat block  20 . 
     As also shown, the conventional clamps  22  are formed to have a penetrating portion  80  thereon which penetrates the end  15  of lead finger  14  of a conventional lead frame. In this manner, the conventional clamp  22  provides improved clamping and immobilization of a lead finger  14  during the wire bonding process, as well as insures that the lead finger  14  is in intimate contact with the movable and/or adjustable arm  24  for effectiveness. As shown, the clamps  22  and  70  having lead finger penetrating portions thereon cause the lead finger  14  to engage the movable arm  24  with the movable arm being in contact with the heat block  20 . However, care should be taken to prevent the lead finger penetrating portion  78  of the independent actuated lead clamp  70  from either damaging the lead finger  14 , affecting its electrical characteristics, or severing the lead finger  14 . 
     The independent actuated lead clamp  70  may be formed having a modified end or foot thereon to provide a larger clamping area of the independent actuated lead clamp  70  on the end  15  of the lead finger  14  during bonding operations. The modified end or foot is substantially the same width as the lead finger  14  and may be mounted to have articulated movement about the end of the independent actuated lead clamp  70 , such as using a pin extending through suitable apertures in a pair of ears attached to the foot and the end of the modified independent actuated lead clamp  70 . Located on the bottom of the modified end or foot of the independent actuated lead clamp  70  are suitable lead finger penetrating members which penetrate the lead finger  14  to immobilized it during wire bonding operations, as described hereinbefore. The lead finger penetrating portion  78  may comprise a plurality of round shaped members located to either extend along the axis of a lead finger  14  or extend transversely thereof or may comprise a knife edge shape extending transversely across the axis of a lead finger  14 . The shapes are to be merely illustrative of a variety of shapes for the lead finger penetrating portion  78 , which may be used. The modified end or foot may be semicircular or arcuate in configuration so as to engage a large portion of the end  15  of the lead finger  14  surrounding the bonding apparatus  26  during the wire bonding operation to hold the end  15  in position. Also, a soft metal coating located on the lead finger  14  may be penetrated by either the independent actuated lead clamp  70  or the conventional clamp  22 . The soft metal coating applied to the lead finger  14  may be of any suitable type, such as gold, silver, aluminum, etc., which will allow for the easy penetration of the coating by a portion of either the independent actuated lead clamp  70  or the clamp  22 . The independent actuated lead clamp  70  may act on the opposite side of the lead from the bonding apparatus  26 . It should be understood that any of the penetrating clamps, hereinbefore described, may act on the opposite side of the conventional clamp  22  during the wire bonding operations regarding a lead finger  14 . It is not necessary that the penetrating clamp be positioned on the same side of the lead finger  14  as the bonding apparatus  26 . 
     Referring to drawing FIG. 9, a semiconductor device (die)  10  is shown in relation to a leads-over-chip (LOC) lead frame without being supported directly by adhesive connection to the lead fingers  14  of the lead frame. (Note, that as shown in FIGS. 9 through 14, the die  10  is supported only by the wire  16  between the bond pads on the die  10  and the lead fingers  14 .) A heat block  20  is used to heat the die  10  during the wire bonding process. As shown, a suitable wire  16 , as described hereinbefore, has one end thereof  17  bonded to a bond pad of the die  10 . The wire  16  may be of any suitable type for connection and bonding purposes, such as gold, gold alloy, aluminum, aluminum alloy, etc. The other end  18  of the wire  16  is shown being bonded to the end  15  of a lead finger  14  of the lead frame by a suitable bonding apparatus  26 . The bonding apparatus  26  may be of any suitable type well known in the bonding area, such as described hereinbefore. If desired, in the wire bonding operation, further shown in contact with lead finger  14  is a portion of a conventional clamp  22  used to clamp portions of the lead frame during such bonding operations. The conventional clamp  22  may be of any well known suitable type, such as those described hereinbefore, and is generic in shape. Further shown in drawing FIG. 9 is movable arm  24 , having a lead support portion  25 , attached to or an integral part of the movable arm  24 . The movable arm  24  is dynamically attached to the heat block  20  so that the lead support portion  25  can be positioned between the die  10  and the lead fingers  14  of the LOC lead frame. The movable arm  24  and lead support portion  25  thus substantially prevent the application of any force against the die  10  from the bonding apparatus  26  and the conventional clamp  22 . In addition, movable arm  24  and lead support portion  25  conduct heat from the heat block  20  to the lead fingers  14 . The action of movable arm  24  and lead support portion  25  provide improved support of a lead finger  14  during the wire bonding process, as well as insure that the force applied by bonding apparatus  26  and conventional clamp  22  is substantially against lead support portion  25  and movable arm  24  rather than against the die  10 . After the bonding of the wire  16  to the lead fingers  14  of the LOC lead frame, the wires  16  support the die  10  during subsequent molding operations to encapsulate the die  10  and a portion of the LOC lead frame. 
     The movement of the movable arm  24  may be effectuated by various means  28 , such as described hereinbefore. 
     The movable arm  24  is dynamically attached to the heat block  20  so that as the heat block moves into position during the wire bonding process. The movable arm and lead support portion  25  move into position between the lead fingers  14  and the die  10 . As shown, movable arm  24  is shown as traveling against the heat block  20  such that the direction of travel is substantially parallel with respect to the lower surface  19  of the lead fingers  14  of a LOC lead frame. 
     Referring to drawing FIG. 10, movable arm  24  may be attached to heat block  20  such that the direction of travel, with respect to lower surface  19  of lead fingers  14  of a LOC lead frame, is angular or arcuate. A radius  54  may be formed in heat block  20  and movable arm  24  such that the direction of travel of lead support portion  25  and movable arm  24  is arcuate, with respect to lower surface  19  of the lead fingers  14  of a conventional lead frame, as the lead support portion is positioned prior to wire bonding. 
     Referring to drawing FIG. 11, the surface of the heat block  20  and movable arm  24  may also be angled  56 , with respect to lower surface  19  of the lead fingers  14  of a LOC lead frame, such that the direction of travel of lead support portion  25  and movable arm  24  is angular, with respect to lower surface  19  of lead fingers  14  of a LOC lead frame, as the lead support portion and movable arm are positioned prior to the wire bonding process. 
     The movement of the movable arm  24  and the heat block  20  may, be integrated so that as the heat block moves into position it causes the movable arm to move into position. As shown, notch  50  is formed in movable arm  24  and extends into a slot  52  formed in a stationary member (not shown). Thus, as the heat block  20  moves upward to contact the die  10 , the heat block pushes against the movable arm  24 , which is forced to travel upward and inward by the notch  50 , traveling in the slot  52 . 
     Referring to drawing FIG. 12, a dual clamp assembly is shown in conjunction with the movable arms  24  in order to further stabilize the lead fingers  14  of an LOC lead frame during the wire bonding process. The conventional clamp  22  acts as a primary clamp and includes a bond site window  60 . The bond site window  60  is sized to allow access for a bonding apparatus  26  to a plurality of bond pads of semiconductor die  10  and to a plurality of lead fingers  14  of a conventional lead frame. 
     The bond site window  60  includes a secondary clamp  62 . The secondary clamp  62  has the same construction and operation as has been described hereinbefore. 
     The semiconductor die  10  has a LOC lead frame arrangement wherein the lead fingers  14  extend over the upper (active) semiconductor die  10 . The bond site window contact lip  65  contacts the lead fingers  14  of the LOC lead frame around the periphery of the semiconductor die  10 . The secondary clamp  62  extends toward the center of the semiconductor die  10 . A plurality of bond wires  16  is then attached between the bond pads of the semiconductor die  10  and the lead fingers  14 . 
     The contact end  63  of the secondary clamp  62 , in its unbiased state, preferably extends slightly below a bond site window contact lip  65  of the bond site window  60  of the clamp  22 . 
     Referring to drawing FIG. 13, an independently actuated lead clamp is shown in conjunction with the movable arms in order to further stabilize the lead finger  14  of a LOC lead frame during the wire bonding process. Independently actuated lead clamp  70  may be used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  in position during the bonding process. The independent clamp  22  is the same as hereinbefore described in construction and operation to help insure that the lead finger is in contact with the movable arm  24  during the bonding process and helps minimize any deflection of the end  15  of the lead finger  14  so that the bonding apparatus  26  accurately and precisely contacts the end  15  to provide the desired wire bond. The action of independent actuated lead clamp  70  and, if desired, the additional use of conventional clamp  22 , provides improved clamping of a lead finger  14  during the wire bonding process as well as insures that the lead finger  14  of a conventional lead frame is in intimate contact with the movable arm  24  for effectiveness. 
     Referring to drawing FIG. 14, as described hereinbefore, an independently actuated lead clamp  70  is shown, having a lead finger penetrating portion  78  on the bottom thereof, used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  of a LOC lead frame during the bonding process. One or more of the independent actuated lead clamp  70 , having lead finger penetrating portions  78  located thereon contacts and penetrates the end  15  of lead finger  14  aft of the area of the wire end  18  to the lead finger  14 . 
     Referring to drawing FIG. 15, a semiconductor device (die)  10  is shown in relation to a leads-over-chip (LOC) lead frame being supported directly by adhesive attachment through adhesive coatings  1  on the tape  2  to the lead fingers  14  on the lead frame. (Also, note that as shown in FIGS. 15 through 20, a die  10  is shown in relation to a LOC lead frame being supported directly by adhesive attachment through adhesive coatings  1  on the tape  2  to the lead fingers  14  on the lead frame.) A heat block  20  is used to heat the die  10  during the wire bonding process. As shown, a suitable wire  16 , as described hereinbefore has one end thereof  17  bonded to a bond pad of the die  10 . The other end  18  of the wire  16  is shown being bonded to the end  15  of a lead finger  14  of the lead frame by a suitable bonding apparatus  26 . The bonding apparatus  26  may be of any suitable type well known in the bonding area, as described hereinbefore. If desired, in the wire bonding operation, further shown in contact with lead finger  14 , is a portion of a conventional clamp  22  used to clamp portions of the lead frame during such bonding operations. The conventional clamp  22  may be of any well known suitable type, such as those described hereinbefore, and is generic in shape. Further shown in drawing FIG. 15 is movable arm  24 , having a lead support portion  25 , attached to or an integral part of the movable arm  24 . The movable arm  24  is dynamically attached to the heat block  20  so that the lead support portion  25  can be positioned between the die  10  and the lead fingers  14  of the LOC lead frame. The movable arm  24  and lead support portion  25  thus substantially prevent the application of any force against the die  10  from the bonding apparatus  26  and the conventional clamp  22 . In addition, movable arm  24  and lead support portion  25  conduct heat from the heat block  20  to the lead fingers  14 . The action of movable arm  24  and lead support portion  25  provides improved support of a lead finger  14  during the wire bonding process as, well as insures that the force applied by bonding apparatus  26  and conventional clamp  22  is substantially against lead support portion  25  and movable arm  24 , rather than against the die  10 . During subsequent molding operations to encapsulate the die  10 , a portion of the LOC lead frame of the die  10  is supported by the lead fingers  14  of the LOC lead frame through the adhesive coatings  1  and tape  2 . 
     The movement of the movable arm  24  may be effectuated by various means  28 , as described hereinbefore. 
     The movable arm  24  is dynamically attached to the heat block  20  so that as the heat block moves into position during the wire bonding process. The movable arm and lead support portion  25  move into position between the lead fingers  14  and the die  10 . The movable arm  24  is shown as traveling against the heat block  20  such that the direction of travel is substantially parallel with respect to the lower surface  19  of the lead fingers  14  of a LOC lead frame. 
     Referring to drawing FIG. 17, movable arm  24  may be attached to heat block  20 , such that the direction of travel, with respect to lower surface  19  of lead fingers  14  of a LOC lead frame is angular or arcuate. A radius  54  may be formed in heat block  20  and movable arm  24 , such that the direction of travel of lead support portion  25  and movable arm  24  is arcuate, with respect to lower surface  19  of the lead fingers  14  of a conventional lead frame, as the lead support portion is positioned prior to wire bonding. 
     Referring to drawing FIG. 16, the surface of the heat block  20  and movable arm  24  may also be angled  56 , with respect to lower surface  19  of the lead fingers  14  of a LOC lead frame, such that the direction of travel of lead support portion  25  and movable arm  24  is angular, with respect to lower surface  19  of lead fingers  14  of a LOC lead frame, as the lead support portion and movable arm are positioned prior to the wire bonding process. 
     The movement of the movable arm  24  and the heat block  20  may be integrated so that as the heat block moves into position it causes the movable arm to move into position. In FIG. 16, a notch  50  is shown formed in movable arm  24  and extending into a slot  52  formed in a stationary member (not shown). Thus, as the heat block  20  moves upward to contact the die  10 , the heat block pushes against the movable arm  24 , which is forced to travel upward and inward by the notch  50  traveling in the slot  52 . 
     Referring to drawing FIG. 18, a dual clamp assembly is shown in conjunction with the movable arms  24  in order to further stabilize the lead fingers  14  of an LOC lead frame during the wire bonding process. The conventional clamp  22  acts as a primary clamp and includes a bond site window  60 . The bond site window  60  is sized to allow access for a wire bonding apparatus  26  to a plurality of bond pads of semiconductor die  10  and to a plurality of lead fingers  14  of a conventional lead frame. 
     The bond site window  60  includes a secondary, clamp  62 . The secondary clamp  62  is mounted to a resilient plate  64  with a first set screw or bolt  66 . The proximal end of each resilient plate  64  is attached to the conventional clamp  22  with a second set screw or bolt  68 . It is, of course, understood that secondary clamp  62  can be attached to the conventional clamp  22  in any number of known configurations, including forming the secondary clamp  62  with an integral resilient portion which is secured to the conventional clamp  22  or forming (for example, as by machining) the secondary, clamp  62  as an integrated, resilient appendage of the conventional clamp  22 . It is, of course, also understood that any number of secondary clamps  62  can be used, consistent with the need for adequate clearances for wire bonding. 
     As described hereinbefore, when a semiconductor die  10  and a lead frame strip, including lead fingers  14  of a LOC lead frame, are aligned with the bond site window  60  in the conventional clamp  22  and pressure is exerted on the lead frame, the contact end  63  of the secondary clamp  62  contacts the movable arm  24  through lead fingers  14  extending from the lead frame over the active die surface. The secondary clamp  62  does not damage the semiconductor die  10  under the secondary clamp contact end  63  because of the resilient nature of the secondary clamp  62  and because of movable arm  24  positioned between the semiconductor die  10  and the secondary clamp  62 . 
     The semiconductor die  10  has a LOC lead frame arrangement wherein the lead fingers  14  extend over the upper (active) semiconductor die  10 . The bond site window contact lip  65  contacts the lead fingers  14  of the LOC lead frame around the periphery of the semiconductor die  10 . The secondary clamp  62  extends toward the center of the semiconductor die  10 . A plurality of bond wires  16  is then attached between the bond pads of the semiconductor die  10  and the lead fingers  14 . 
     The contact end  63  of the secondary clamp  62 , in its unbiased state, preferably extends slightly below bond site window contact lip  65  of the bond site window  60  of the conventional clamp  22 . The secondary clamp  62  may be formed from a substantially rigid, non-deformable material such as metal, high-temperature plastic, fiber composites, or the like. A preferred material for the secondary clamp  62  is 440C stainless steel. 
     Referring to drawing FIG. 19, an independently actuated lead clamp is shown in conjunction with the movable arms in order to further stabilize the lead fingers  14  of a LOC lead frame during the wire bonding process. Independently actuated lead clamp  70  may be used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  in position during the bonding process. The independent clamp  22  is the same as hereinbefore described in structure and operation to help insure that the lead finger is in contact faith the movable arm  24  during the bonding process and helps minimize any deflection of the end  15  of the lead finger  14  so that the bonding apparatus  26  accurately and precisely contacts the end  15  to provide the desired wire bond. The action of independent actuated lead clamp  70  and, if desired, the additional use of conventional clamp  22 , provides improved clamping of a lead finger  14  during the wire bonding process, as well as insures that the lead finger  14  of a conventional lead frame is in intimate contact with the movable arm.  24  for effectiveness. 
     Referring to drawing FIG. 20, as described hereinbefore, an independently actuated lead clamp  70  is shown, having a lead finger penetrating portion  78  on the bottom thereof, used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  of a LOC lead frame during the bonding process. One or more of the independent actuated lead clamps  70 , having lead finger penetrating portions  78  located thereon, contacts and penetrates the end  15  of lead finger  14  aft of the area of the wire end  18  to the lead finger  14 . The independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, may be of any suitable shape for use in independently clamping the lead finger  14 , in place of the use of conventional clamp  22 . Also, as shown, the independent actuated lead clamp  70 , hating lead finger penetrating portion  78  thereon, may be resiliently mounted through the use of a shoulder  72  thereon, abutting a spring  74 , to control the amount of force exerted on any lead finger  14  during the wire bonding operation. 
     Referring to drawing FIG. 21, a semiconductor chip (die)  10  is shown being supported by the paddle  12  of a two piece lead frame. such as described in United States Patent 4,984,059. A heat block  20  is used to heat the paddle  12  and die  10  during the wire bonding process. As shown, a suitable wire  16 , such as described hereinbefore, has one end thereof  17  bonded to a bond pad of the die  10 . The other end  18  of the wire  16  is shown being bonded to the end  15  of a lead finger  14  of the lead frame by a suitable bonding apparatus  26 . The bonding apparatus  26  may be of any suitable type well known in the bonding area, such as described hereinbefore. If desired, in the wire bonding operation, further shown in contact with lead finger  14 , is a portion of a conventional clamp  22  used to clamp portions of the lead frame during such bonding operations. The conventional clamp  22  may be of any well known suitable type, such as those described hereinbefore, and is generic in shape. Further shown in drawing FIG. 21 is movable arm  24 , having a lead support portion  25 , attached to or an integral part of the movable arm  24 . The movable arm  24  is dynamically attached to the heat block  20  so that the lead support portion  25  can be positioned between the die  10  and the lead fingers  14 . The movable arm  24  and lead support portion  25  thus substantially prevent the application of any force against the die  10  from the bonding apparatus  26  and the conventional clamp  22 . In addition, movable arm  24  and lead support portion  25  conduct heat from the heat block  20  to the lead fingers  14 . The action of movable arm  24  and lead support portion  25  provides improved support of a lead finger  14  during the wire bonding process, as well as insures that the force applied by bonding apparatus  26  and conventional clamp  22  is substantially against lead support portion  25  and movable arm  24 , rather than against the die  10 . 
     The movement of the movable arm  24  may be effectuated by various means  28 , such as described hereinbefore. 
     The movable arm  24  is dynamically attached to the heat block  20  so that as the heat block moves into position during the wire bonding process. The movable arm  24  and lead support portion  25  move into position between the lead fingers  14  and the die  10 . The movable arm  24  is shown as traveling against the heat block  20 , such that the direction of travel is substantially parallel with respect to the lower surface  19  of the lead fingers  14  of a conventional lead frame. 
     Referring to drawing FIG. 22, movable arm  24  may be attached to heat block  20 , such that the direction of travel, with respect to lower surface  19  of lead fingers  14  is angular or arcuate. A radius  54  may be formed in heat block  20  and movable arm  24 , such that the direction of travel of lead support portion  25  and movable arm  24  is arcuate, with respect to lower surface  19  of the lead fingers  14  of a conventional lead frame, as the lead support portion is positioned prior to wire bonding. 
     Referring to drawing FIG. 23, the surface of the heat block  20  and movable arm  24  may also be angled  56 , with respect to lower surface  19  of the lead fingers  14 ,. such that the direction of travel of lead support portion  25  and movable arm  24  is angular, with respect to lower surface  19  of lead fingers  14 , as the lead support portion and movable arm are positioned prior to the wire bonding process. 
     The movement of the movable arm  24  and the heat block  20  may be integrated so that as the heat block moves into position it causes the movable arm to move into position. In FIG. 23, a notch  50  is shown formed in movable arm  24  and extends into a slot  52  formed in a stationary member (not shown). Thus, as the heat block  20  moves upward to contact the die  10 , the heat block pushes against the movable arm  24 , which is forced to travel upward and inward by the notch  50  traveling in the slot  52 . 
     Referring to drawing FIG. 24, a dual clamp assembly is shown in conjunction with the movable arms  24  in order to further stabilize the lead fingers during the wire bonding process. The conventional clamp  22  acts as a primary clamp and includes a bond site window  60 . The bond site window  60  is sized to allow access for a wire bonding apparatus  26  to a plurality of bond pads of semiconductor die  10  and to a plurality of lead fingers  14  of a conventional lead frame. 
     The bond site window  60  includes a secondary clamp  62 , the same in construction and operation as described hereinbefore. The secondary clamp  62  is mounted to a resilient plate  64  with a first set screw or bolt  66 . The proximal end of each resilient plate  64  is attached to the conventional clamp  22  with a second set screw or bolt  68 . It is, of course, understood that secondary clamp  62  can be attached to the conventional clamp  22  in any number of known configurations, including forming the secondary clamp  62  with an integral resilient portion which is secured to the conventional clamp  22  or forming (for example, as by machining) the secondary clamp  62  as an integrated, resilient appendage of the conventional clamp  22 . It is, of course, also understood that any number of secondary clamps  62  can be used, consistent with the need for adequate clearances for wire bonding. 
     When a semiconductor die  10  and a lead frame strip, including lead fingers  14  of a two piece lead frame, is aligned with the bond site window  60  in the conventional clamp  22  and pressure is exerted on the lead frame, the contact end  63  of the secondary clamp  62  contacts the movable arm  24  through lead fingers  14  extending from the lead frame over the active die surface. The secondary clamp  62  does not damage the semiconductor die  10  under the secondary clamp contact end  63  because of the resilient nature of the secondary clamp  62  and because of movable arm  24  positioned between the semiconductor die  10  and the secondary clamp  62 . 
     The semiconductor die  10  has a two piece lead frame arrangement wherein the lead fingers  14  extend over the upper (active) semiconductor die  10 . The bond site window contact lip  65  contacts the lead fingers  14  around the periphery of the semiconductor die  10 . The secondary clamp  62  extends toward the center of the semiconductor die  10 . A plurality of bond wires  16  is then attached between the bond pads of the semiconductor die  10  and the lead fingers  14 . 
     The contact end  63  of the secondary clamp  62 , in its unbiased state, preferably extends slightly below bond site window contact lip  65  of the bond site window  60  of the conventional clamp  22 . 
     Referring to drawing FIG. 25, an independently actuated lead clamp  70 , such as described hereinbefore, is shown in conjunction with the movable arms  24  in order to further stabilize the lead fingers  14  of a two piece lead frame during the wire bonding process. Independently actuated lead clamp  70  may be used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  in position during the bonding process. The independent conventional clamp  22  helps insure that the lead finger is in contact with the movable arm  24  during the bonding process and helps minimize any deflection of the end  15  of the lead finger  14 , so that the bonding apparatus  26  accurately and precisely contacts the end  15  to provide the desired wire bond. The action of independent actuated lead clamp  70  and, if desired, the additional use of conventional clamp  22 , provides improved clamping of a lead finger  14  during the wire bonding process, as well as insures that the lead finger  14  of a two piece lead frame is in intimate contact with the movable arm  24  for effectiveness. 
     Independent actuated lead clamp  70  may be of any suitable shape for use in independently clamping the lead finger  14 , in place of the use of conventional clamp  22 . Also, the independent actuated lead clamp  70  may be resiliently mounted through the use of a shoulder  72  thereon, abutting a spring  74 , to control the amount of force exerted on any lead finger  14  during the wire bonding operation. If desired, the independent actuated lead clamp  70  may include insulation or cushioning  76  on the end thereof. 
     During the bond operation, one or more of the independent actuated lead clamps  70  clamps the end  15  of lead finger  14  of a two piece lead frame prior to the bonding of a wire  16  thereto by one or more of the bonding apparatus  26 . The independent actuated lead clamp  70  applies sufficient pressure to the end  15  of lead finger  14  to press the lead finger  14  against movable arm  24  to insure a satisfactory bond between the end  18  of any wire  16  and the end  15  of the lead finger  14 . 
     As shown, one or more of the independent actuated lead clamps  70  contacts the end  15  of lead finger  14  aft of the area of the wire end  18  to the lead finger  14 . The bonds of the wire end  18  to the end  15  of the lead finger  14  are typically a wedge type wire bond, although a ball bond may be made if desired. As shown the heat block  20  is in contact with the paddle  12  and the movable arm  24 , which, in turn, is in contact with the lead fingers  14 . 
     The independent actuated lead clamp  70  may have a modified end or foot thereon to provide a larger clamping area of the independent actuated lead clamp  70  on the end  15  of the lead finger  14  during bonding operations. The modified end or foot may be substantially the same width as the lead finger  14  of a conventional lead frame and may, be mounted to have articulated movement about the end of the independent actuated lead clamp  70 , such as using a pin extending through suitable apertures in a pair of ears attached to the foot. 
     The independent actuated lead clamp  70  may be integrally attached to the conventional clamp  22  or may have an articulated mounting arrangement. The modified end or foot may be generally semicircular, or arcuate, in configuration so as to engage a large portion of the end  15  of the lead finger  14  of a conventional lead frame surrounding the bonding apparatus  26  during the wire bonding operation to hold the end  15  in position. 
     The independent actuated lead clamp  70  may also be used in conjunction with a second independently actuated clamp. The second independently actuated clamp may be of any suitable type and structure, such as described and illustrated hereinbefore. The independent actuated lead clamp  70  and the second clamp may be actuated independently of each other and independently of the bonding apparatus  26 , as described and illustrated hereinbefore. 
     Referring to drawing FIG. 26, an independently actuated lead clamp  70 , such as described hereinbefore, is shown, having a lead finger penetrating portion  78  on the bottom thereof, used in place of or in addition to the convention clamp  22  to maintain the lead finger  14  of a two-piece lead frame during the bonding process. One or more of the independent actuated lead clamps  70 , having lead finger penetrating area of the wire end  18  bonded to the lead finger  14 . The independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, may be of any suitable shape for use in independently clamping the lead finger  14 , in place of the use of conventional clamp  22 . Also, as shown, the independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, may be resiliently mounted through the use of a shoulder  72  thereon, abutting a spring  74 , to control the amount of force exerted on any lead finger  14  during the wire bonding operation. As described hereinbefore, the independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, is actuated independently of bonding apparatus  26  and has the capability of independent movement along the x-axis, y-axis and z-axis with respect to the bonding apparatus  26 . The independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, is also free to move about the bonding apparatus  26  and the central axis of the die  10 , so that an) lead finger  14  of a conventional lead frame that is to be connected to a bond pad on the die  10 , regardless of location, may be accommodated. The independent actuated lead clamp  70 , having lead finger penetrating portion  78  thereon, does not need to be, and preferably is not, concentrically centered about the bonding apparatus  26 , so that it will not interfere with the operation thereof. Any desired number of independent actuated lead clamps  70 , having lead finger penetrating portion  78  thereon, may be used about the bonding apparatus  26  to minimize the amount of movement of the independent actuated lead clamp  70  between wire bonding operations. Also, the independent actuated lead clamps  70  may be located in quadrants about the die  10 , or in any manner as desired. 
     The independently actuated lead clamp  70  has a lead finger penetrating portion  78  on the bottom thereof used in place of or in addition to the conventional clamp  22  to maintain the lead finger  14  in position during the bonding process. Such independent actuated lead clamp  70  helps insure that the lead finger  14  is in contact with the movable arm  24  during the bonding process, immobilizes the lead finger  14  during the wire bonding process, and helps minimize any deflection of the end  15  of the lead finger  14  so that the bonding apparatus  26  accurately, precisely contacts the end  15  to provide the desired wire bond. The action of such independent actuated lead clamp  70  and, if desired, the additional use of conventional clamp  22 , provides improved clamping and immobilization of a lead finger  14  during the wire bonding process, as well as insures that the lead finger  14  is in intimate contact with the movable arm  24  for effectiveness. 
     During the wire bonding process, it is desirable for the heat block to be heated, as previously described hereinbefore. Similarly, the bonding apparatus should exert substantially the same amount of force, as described hereinbefore. 
     During the bond operation, one or more of the independent actuated lead clamps  70 , having a lead finger penetrating portion  78  located on the end thereof, clamps the end  15  of lead finger  14  prior to the bonding of a wire  16  thereto by one or more of the bonding apparatus  26 . The independent actuated lead clamp  70  applies sufficient pressure to the end  15  of the lead finger  14  to insure a satisfactory bond between the end of any wire  16  and the end  15  of the lead finger  14 . 
     As shown, one or more of the independent actuated lead clamps  70  contacts the end  15  of lead finger  14  aft of the area of the wire end  18  bonded to the lead finger  14  The bonds of the wire end  18  to the end  15  of the lead finger  14  are typically a wedge type wire bond, although a ball bond may be made if desired. As shown, the heat block  20  is in contact with the paddle  12  of the lead frame. The lead fingers  14  of a two piece lead frame are in contact with the movable arm  24  which, in turn, is in contact with the heat block  20 . 
     As also shown, the conventional clamps  22  are formed to have a penetrating portion  80  thereon, which penetrates the end  15  of lead finger  14  of a conventional lead frame. In this manner, the conventional clamp  22  provides improved clamping and immobilization of a lead finger  14  during the wire bonding process, as well as insures that the lead finger  14  is in intimate contact with the movable arm  24  for effectiveness. As shown, the clamps  22  and  70 , having lead finger penetrating portions  78  thereon, cause the lead finger  14  to engage the movable arm  24  with the movable arm  24  being in contact with the heat block  20 . However, care should be taken to prevent the lead finger penetrating portion  78  of the independent actuated lead clamp  70  from either damaging the lead finger  14 . affecting its electrical characteristics, or severing the lead finger  14 . 
     The independent actuated lead clamp  70  may be formed having a modified end or foot thereon, to provide a larger clamping area of the independent actuated lead clamp  70  on the end  15  of the lead finger  14  during bonding operations, as described hereinbefore. It should be understood that any of the penetrating clamps, hereinbefore described, may act on the opposite side of the conventional clamp  22  during the wire bonding operations regarding a lead finger  14 . It is not necessary that the penetrating clamp be positioned on the same side of the lead finger  14  as the bonding apparatus  26 . 
     Referring to drawing FIG. 27, a semiconductor device (die)  10  is shown being supported by the paddle  12  of a hybrid lead frame having lead fingers  14  located on differing levels with respect to the semiconductor device  10 . That is, a portion of the lead fingers is located on a first level with respect to the lead frame and another portion of the lead fingers is located on a second level with respect to the lead frame. The portion of the lead fingers  14  of the lead frame are supported by heat block  20  during the bonding operation while the other portion of lead fingers  14  is supported by the lead support portion  25  of movable arm  24  (not shown) during the wire bonding operations. A heat block  20  is used to heat the paddle  12  and die  10  during the wire bonding process. As shown, a suitable wire  16 , such as described hereinbefore. has one end thereof  17  bonded to a bond pad of the die  10 . The wire  16  may be of any suitable type for connection and bonding purposes, as described hereinbefore. The other end  18  of the wire  16  is shown being bonded to the end  15  of a lead finger  14  of the lead frame by a suitable bonding apparatus  26 . The bonding apparatus  26  may be of any suitable type well known in the bonding area, as described hereinbefore. If desired, in the wire bonding operation, firer shown in contact with lead finger  14  is a portion of a conventional clamp  22  used to clamp portions of the lead frame during such bonding operations. The conventional clamp  22  may be of any well known suitable type such as those described hereinbefore, and is generic in shape. As shown in drawing FIG. 28, movable arm  24 , having a lead support portion  25 , is attached to or an integral part thereof The movable arm  24  is dynamically attached to the heat block  20  so that the lead support portion  25  can be positioned under a portion of the lead fingers  14 . The movable arm  24  and lead support portion  25  thus allow for improved wire bonding to the elevated lead fingers  14  of the hybrid lead frame. In addition, movable arm  24 , having lead support portion  25 , conducts heat from the heat block  20  to the lead fingers  14 . 
     The movement of the movable arm  24  may be effectuated by various means  28 , such as described hereinbefore. The movable arm  24  is dynamically attached to the heat block  20  so that as the heat block moves into position during the wire bonding process, the movable arm  24 , having lead support portion  25 , moves into position under a portion of the lead fingers  14 . 
     Referring to drawing FIG. 28, the movable arm  24  is shown in relation to the semiconductor device  10  and lead fingers  14  of the hybrid lead frame. As illustrated. The heat block  20  supports the lower level or first portion of lead fingers  14  during wire bonding operations while the lead support portion  25  of the movable arm  24  supports the upper level or other portion of the lead fingers  14  during wire bonding operations by wire bonding apparatus  26 . 
     METHOD OF BONDING 
     Referring to drawing FIGS. 1,  4  and  5 , in the method of the present invention, a die  10  is positioned within the bonding area of the bonding apparatus  26 . A movable arm  24 , having a lead support portion  25 , is positioned such that the lead support portion  25  is between the die  10  and the lead fingers  14 . A conventional clamp  22  serves to help straighten the lead frame and position the lead fingers  14  during subsequent bonding operations. Next, the die  10  and the lead fingers  14  are heated to the desired temperature before bonding operations by the heat block  20  acting through movable and/or adjustable arm  24 . The wire bonding apparatus  26  is then actuated to form a wire bond on end  17  of wire  16  to an appropriate bond pad on die  10 . After the formation of the bond of end  17  of wire  16  to the bond pad of die  10 , the bonding apparatus is moved to appropriate end  15  of lead finger  14  for the formation of a suitable wire bond thereto by end  18  of wire  16 . During this process, lead support portion  25  of movable and/or adjustable arm  24  acts to substantially oppose the application of force from the bonding apparatus  26  and conventional clamp  22  and to stabilize the lead fingers  14 . After the wire  16  has been bonded to the desired bond pad of die  10  and end  15  of lead finger  14 , the process is repeated until all desired wire bonds between lead fingers  14  and bond pads of die  10  are completed. 
     Referring to drawing FIG. 6, if desired to have additional clamping of the lead finger  14 , a secondary clamp  62  and a conventional clamp  22  may be used with the bonding apparatus  26 . The secondary clamp  62  may be actuated and moved from the lead finger  14  with, before, or after the removal of the bonding apparatus  26  from the lead finger. 
     Referring to drawing FIG. 7, if desired to have additional clamping of the lead finger  14 , either a conventional clamp  22  and/or a second independent actuated lead clamp  70  may be used with the bonding apparatus  26 . The second independent actuated lead clamp  70  may be actuated and moved from the lead finger  14  with, before, or after the removal of the bonding apparatus  26  from the lead finger. 
     Referring to drawing FIG. 8, if desired to have additional clamping of the lead finger  14 , either a conventional clamp  22  and/or a second independent actuated lead clamp  70 , having a lead finger penetrating portion  78  thereon, may be used with the bonding apparatus  26 . The second independent actuated lead clamp  70  may be actuated and moved from the lead finger  14  with, before or after the removal of the bonding apparatus  26  from the lead finger. It will be understood that the alternative embodiments of the present invention, shown in the other drawing figures corresponding to those described hereinabove, are wire bonded in a similar fashion. 
     FIG. 29 is a flow chart of a typical process sequence for plastic package molding of a semiconductor device wire bond to a lead frame by the use of a lead support portion  25  of movable arm  24  according to the present invention. It should be noted that the solder dip/plate operation has been shown as one step for brevity; normally plating would occur prior to trim and form. 
     FIGS  30  and  31  show pre-molding and post-molding positions of encapsulant during a transfer molding operation using a typical mold apparatus comprising upper and lower mold halves  500  and  502 , each mold half including a platen  514  or  516  with its associated chase  518  or  520 . Heating elements  522  are employed in the platens to maintain an elevated and relatively uniform temperature in the runners and mold cavities during the molding operation. FIG. 32 shows a top view of one side of the transfer mold apparatus of FIGS. 30 and 31. In the transfer mold apparatus shown, the encapsulant flows into each mold cavity  544  through the short end thereof. 
     In operation, a heated pellet of resin mold compound  530  is disposed beneath ram or plunger  532  in pot  534 . Tie plunger descends, melting the pellet and forcing the melted encapsulant down through sprue  536  and into primary runner  538 , from which it travels to transversely-oriented secondary runners  540  and across gates  542  into and through the mold cavities  544  through the short side thereof flowing across the die assemblies  100 , wherein die assemblies  100  comprising dies  102  with attached lead frames  104  are disposed (usually in strips so that a strip of six lead frames, for example, would be cut and placed in and across the six cavities  544  shown in FIG.  32 ). Air in the runners  538  and  540  and mold cavities  544  is vented to the atmosphere through vents  546  and  548 . At the end of the molding operation, the encapsulant is “packed” by application of a higher pressure to eliminate voids and reduce non-uniformities of the encapsulant in the mold cavities  544 . After molding, the encapsulated die assemblies are ejected from the cavities  544  by ejector pins  550 , after which they are post-cured at an elevated temperature to complete cross-linking of the resin, followed by other operations, as known in the art, and set forth in FIG. 29 by way of example. It will be appreciated that other transfer molding apparatus configurations, as well as variations in the details of the described method, are known in the art. However, none of such are pertinent to the invention, and so will not be discussed herein. 
     Encapsulant flow in the mold cavities  544  is demonstrably non-uniform. The presence of the die assembly  100  comprising a die  102  with lead frame  104  disposed across the mid-section of a cavity  544  splits the viscous encapsulant flow front  106  into upper  108  and lower  110  components. Further, the presence of the (relatively) large die  102 , with its relatively lower temperature in the middle of a cavity  544 , permits the flow front  106  on each side of the die  102  to advance ahead of the front which passes over and under the die  102 . FIGS. 33 and 34 show two mold cavity encapsulant flow scenarios where, respectively, the lower flow front  110  and the upper flow front  108  lead the overall encapsulant flow front  106  in the cavity  544  containing the die assembly  100 . FIG. 35 depicts the advance of a flow, front  106  from above, before and after a die  102  is encountered, the flow being depicted as time-separated instantaneous flow fronts  106   a ,  106   b ,  106   c ,  106   d ,  106   e  and  106   f.    
     It will be understood that the present invention may have changes, additions, deletions, modifications, and a different sequence of operation which fall within the scope of the invention. For instance, the lead support portion may be actuated in various directions with respect to the semiconductor device during the wire bonding process. The lead support portion may be segmented or in multiple pieces, etc.