Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/708,188 filed on Oct. 1, 2012 and U.S. Provisional Application No. 61/826,307 filed on May 22, 2013 and are incorporated by reference in their entirety. 
    
    
     FIELD 
     The embodiments of the present invention relate to semiconductor device packaging and, more particularly, to WLCSP packaging having modifications that enhance the manufacturability and quality of products using these WLCSP. 
     BACKGROUND 
     The electronics industry continues to rely upon advances in semiconductor technology to realize higher-function devices in more compact areas. For many applications realizing higher-functioning devices requires integrating a large number of electronic devices into a single silicon wafer. As the number of electronic devices per given area of the silicon wafer increases, the manufacturing process becomes more difficult. 
     The packaging of an IC device is increasingly playing a role in its ultimate performance. For example, in mobile devices (i.e., mobile phones, tablet computers, laptop computers, remote controls, etc), WLCSP components are used in their assembly. WLCSP components save valuable space in the mobile device. After assembly, in some example processes, customers encapsulate these WLCSP devices by injection molding or casing. This manual post-processing of the WLCSP may result in the device being damage. Consequently, the customer may prefer to have the WLCSP product surrounded by non-brittle material, which prevents damage to the die itself, before receiving the product for assembly in to his mobile device. 
     There is a need for a WLCSP assembly process which can address the challenges raised by the needs of mobile applications. 
     SUMMARY 
     The present disclosure has been found useful in the packaging of semiconductor devices which find their way into portable electronic devices. In particular, WLCSP products which are furnished as unpackaged die to manufacturers of mobile devices, who in turn encapsulate these devices directly onto a printed circuit board (in an effort to conserve valuable space in the mobile device) may subject these unpackaged die to rough handling. The handling may result in cracking or other latent damage which may not show up until the mobile device reaches the end user. 
     The unpackaged die are encapsulated in a resilient material, such as an epoxy molding compound which absorbs the shocks of manual handling during assembly of the mobile device. The process can also be used for CSP with or without solder bumps. 
     In an example embodiment, there is a method for assembling a wafer level chip scale processed (WLCSP) device having solder balls defined thereon, the method comprises, defining a pedestal mounting strip per WLCSP device die thickness and surface area, the pedestal mounting strip have a topside and an underside. The pedestal mounting strip is fabricated out of a molding compound; the pedestal mounting strip has a grid of pedestals on the topside, each one of the grid pedestals has a surface area smaller than the surface area of the back-side of the WLCSP device. The WLCSP device is die attached onto the surface of each one of the grid pedestals, the WLCSP device forms an overhang on each one of the grid pedestals. Each one of the WLCSP devices on the pedestal mounting strip is encapsulated. The process assures that the encapsulant surrounds the WLCSP devices and flows under the overhang of each WLCSP device. 
     In another example embodiment, a semiconductor device is assembled to resist mechanical damage, the semiconductor device comprises an active circuit that has solder bumps defined on a top surface, these solder bumps provide electrical connection to the active circuit. There is a pedestal structure upon which the active circuit is mounted on an bottom surface, the pedestal structure has an area smaller than the area of the active device. An encapsulation, consisting of a molding compound, surrounds the sides and the underside of the active device and surrounding the solder balls. The encapsulation provides a resilient surface protecting the active device from mechanical damage. 
     In an example embodiment, a method for assembling a WLCSP semiconductor device having contact areas defined thereon comprises, defining a pedestal mounting strip per semiconductor device die thickness and surface area, the pedestal mounting strip have a topside and an underside. The pedestal mounting strip is fabricated out of a molding compound, the pedestal mounting strip having a grid of pedestals on the topside, each one of the grid pedestals having a surface area smaller than the surface area of the underside of the semiconductor device. The semiconductor device is die attached onto the surface of each one of the grid pedestals, the semiconductor device forming an overhang on each one of the grid pedestals. With a release foil, the contact areas are protected before encapsulating each one of the WLCSP devices. Each one of the semiconductor devices on the pedestal mounting strip is encapsulated, the user assures the encapsulant surrounds the semiconductor devices and flows under the overhang of each semiconductor device. After encapsulating each one of the WLCSP devices, the release foil is removed. In the corresponding position of the underside of the pedestal mounting strip, each one of the semiconductor devices is marked. 
     In another example embodiment, there is a method for assembling wafer level chip scale processed (WLCSP) devices from a wafer substrate having a front-side surface upon which solder bumps are defined on active device die and an opposite back-side surface. The method comprises, applying a protection tape on the front-side surface; sawing with a “V-shaped” blade of a first kerf, on the back-side surface of the wafer substrate, in areas corresponding to saw lanes of the active device die, to a depth of about 50% of the wafer substrate thickness; continuing the sawing of the back-side surface with a blade of a second smaller kerf, so as to separate the active device die into singulated device die, wherein each of the singulated device die has an angled recessed profile with respect to the vertical faces of the device die; remounting the singulated device die on their front-side surfaces onto a sawing tape; die bonding the singulated device die onto a pedestal array, the pedestal array having a top-side surface with pre-defined landings for the back-side surface of each of the singulated device die, the pedestal array having a pitch larger than that of the device die; and encapsulating each one of the singulated device die on the pedestal array, and the encapsulant enveloping the WLCSP devices and flowing under the angled recess of each WLCSP device. 
     The above summaries of the present disclosure are not intended to represent each disclosed embodiment, or every aspect, of the present invention. Other aspects and example embodiments are provided in the figures and the detailed description that follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
         FIG. 1  is a flow diagram of an embodiment according to the disclosure; 
         FIGS. 2A-2E  illustrates the assembly of an example WLCSP device according an example embodiment; 
         FIGS. 3A-3C  illustrate embodiments of pedestal strips used to assemble WLCSP device according to the present disclosure; 
         FIGS. 4A-4C  illustrate device assembled using the pedestal strips of  FIGS. 3A-3C ; 
         FIG. 5  is a flow diagram of another embodiment according to the disclosure; 
         FIGS. 6A-6F  illustrate the defining of a pedestal in an example WLCSP device according to an embodiment of the present disclosure; 
         FIGS. 7A-7B  illustrate the application of the protective material for a plurality of WLCSP device die as depicted in  FIG. 6F ; and 
         FIGS. 8A-8C  depicts three example configurations of protective material applied onto the device die of  FIG. 6F . 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     The disclosed embodiments have been found useful in preventing damage to the Wafer Level Chip-Scale Product (WLCSP) devices during their assembly. The process provides mechanical protection to the silicon device by encapsulating the device in a resilient material. Such a process may be integrated into the customary back-end assembly. 
     In an example embodiment, the user takes a wafer substrate having devices. The wafer undergoes electrical tests (e.g., E-sort) to sort out non-functioning devices; other processes may forego E-sort and cull out non-functioning devices after packaging. The tested wafers are mounted on an adhesive tape. The wafers are then sawed and separated out into individual device die. Using an appropriate molding apparatus, epoxy mold compound (EMC) is formed into a strip having pedestals. The dimensions (i.e., size, height, etc.) of a formed pedestal are smaller than that of the WLCSP device and are governed by the particular WLCSP product. Thus, the WLCSP device will have an overhanging edge on its underside. The overhang facilitates the flow of encapsulant around the product device and provides an anchor with enhanced strength to the protective encapsulant which seals five or six sides of the device. The individual device die are mounted on the pedestals using suitable die bond techniques. After the device die are mounted, the pedestal strip is over-molded; the molding compound may be the same of different than that used to form the pedestal strip. In some WLCSP devices, solder bumps may have been applied thereon and are protected using a foil-assisted apparatus. Having been sealed in encapsulant, the WLCSP product devices may be laser marked on the side opposite the side having the solder bumps. Saw tape is applied the marked side of the sealed devices; the product devices are then sawed and singulated. 
     In another example embodiment, the pedestal may be formed within the device die itself A wafer having device die is mounted on a grinding tape. With a first blade, a wafer having active device die has V-shaped saw marks defined on the backside of the wafer in the X and Y directions of the saw lanes surrounding the active devices. With a second blade, the active device die are sawed apart; the cut is continued from where the V-shape cut left off. A given device die has a pedestal profile on its vertical faces. A strip made of metal, packaging EMC or other suitable material, is made in such a way that its pitch is slightly larger than the size of the device die; a grid of pedestal locations are formed. The pedestal shape enhances the flow of encapsulant around the product and the pedestal shape (i.e., size, height, etc.) which is WLCSP-specific, provides enhanced mechanical anchoring of the encapsulant for either 5 or 6-side encapsulation. Singulated devices are mounted on the grid of pedestal locations and encapsulated. After encapsulation, the devices are sawed apart into separate device now-having a resilient protective material surrounding five or six sides. 
     Refer to  FIG. 1 . In an example embodiment according to the present disclosure, a wafer having undergone electrical testing is mounted on a sawing tape  100 . Those WLCSP devices which passed electrical testing are separated out (i.e., “singulated”) and placed in temporary containers (e.g., “wafer packs”) for later use  110 . A strip of epoxy mold compound (EMC) or other suitable material is formed into grid of pedestals  120 . The size/height of the pedestals is defined by the dimensions of the WLCSP device  130 . For mobile applications, the size/height along with WLCSP device dimensions must take into account the limited space available in the given portable electronic device. Having formed the grid of pedestals  120 , the singulated WLCSP devices are mounted with a suitable material on the pedestal surfaces  140 . The mounting material may include, but is not limited to, wafer backside coating (WBC), die attach film (DAF), or an epoxy. With a suitable apparatus, the pedestal strip is over-molded with a suitable material; a foil-assisted (i.e., release film technology) molding machine may be used to protect those devices using solder balls  150 . As required for a given customer, the device code may be marked on the under-side of the strip using a LASER or other suitable technique  160 . The strip is placed onto sawing tape  170  on the marked underside. The product devices are separated  180 . The protective foil on the solder balls is removed just prior to the singulation. The separated product is removed from the sawing tape; product is placed into appropriate tray (i.e., JEDEC approved, etc.)  190 . The devices undergo final electrical testing, packing, and shipping to end user  195 . 
     Refer to  FIGS. 2A-2B . A strip  210  with pedestals  220  is molded from epoxy mold compound or other material. If backside shielding is required, the cavity strip  210  or the pedestals may be molded onto a metal frame or carrier  230 . This metal carrier  230  may serve as RF shielding for the device  240 . The size and height of the pedestal is determined by die size and required final package thickness. The shape of the pedestal  220  may be round or square or other suitable shape, as that of a regular polygon of N-sides. 
     Refer to  FIG. 2C . Upon each pedestal  220  is placed a device die  240  with its solder balls  250 ; the device die  240  is attached to pedestal  220  with a suitable die attach material  260 . As mentioned earlier, the die attach material  260  may be wafer backside coating (WBC), die attach film (DAF), or an epoxy. The type of die attach material  260  is governed by the particular process parameters, other suitable types of die attach material in the industry may be applicable to this disclosure, as well. 
     Refer to  FIG. 2D . Having attached the device die  240  to the pedestals  220 , the solder balls  250  are protected with a release foil  280 . An over-mold  270  surrounds the device die  240 . Since the die  240  are of larger dimensions than those of the pedestals and forms an overhang, the over-mold compound surrounds the device die  240  and envelopes the overhanging structure. The overhanging structure under the device die  240  serves as an anchor providing enhanced mechanical strength for the molding compound. This molding compound may be the same as that used in the formation of the cavity strip  210  or be a different material. 
     Refer to  FIG. 2E . The release foil  280  is removed. The cavity strip  210  with the over-molded devices  240  is placed on an adhesive coated sawing tape  290 . Wafer saw  55  cuts the devices  240  to a depth from the solder balls  250  to the adhesive side of the sawing tape  290 . The devices  240  are separated into individual devices. 
     In another example embodiment, pedestals of metal may be placed onto a metal strip. In another example embodiment, the pedestals may be manufactured integral to a metal strip. In another example embodiment, the pedestals may be punched into a metal strip. Refer to  FIG. 3A . In example embodiment, the pedestal strip  410  with pedestals  420  as used in  FIG. 2A  may be substituted with a metal strip  430  upon which pedestals  440  may be defined (refer to  FIG. 3B ). The metal strip  430  may have pedestals  440  integrally defined (i.e., formed, punched, extruded, etc.). 
     Refer to  FIG. 3C . In another example embodiment, a pedestal strip  450  may be molded from epoxy molding compound (EMC) or other suitable polymer material and have pedestals  460  defined thereon; or in another example, the pedestal strip  450  may be metal upon which polymer pedestals  460  are defined. In each of these examples, the spacing (W PS )  425 ,  445 ,  455  between the pedestals, the pedestal height T 2 , and pedestal base thickness (T 3 ), are defined by the product device die and end-user requirements. Example dimensions of these pedestal strips are shown in Table 1. In an example embodiment, T 2  can range from 0.05 mm to about 0.2 mm. T 3  depends on the final total thickness or shielding requirements; T 3  may range between about 0.05 mm and about 0.2 mm, as well. The use of metal in the pedestal strip would serve as electrical shielding for the assembled device. 
     
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Dimensions of Example Pedestal Strips/Die Sizes 
               
               
                 (Dimensions in mm) 
               
             
          
           
               
                 Type of Strip 
                 Die Size Used 
                 No. of Die 
                 Pedestal Height 
                 Pedestal Width 
                 Pedestal Spacing 
               
               
                 (FIG.) 
                 (W D ) 
                 Positions 
                 (T 2 ) 
                 (W P ) 
                 (W PS ) 
               
               
                   
               
             
          
           
               
                 3A 
                 2.5 
                 25 × 80 
                 0.1 
                 2.0 
                 1.0 
               
               
                 3A 
                 4.0 
                 15 × 50 
                 0.15 
                 3.0 
                 1.5 
               
               
                 3A 
                 1 
                  50 × 150 
                 0.08 
                 0.7 
                 0.8 
               
               
                 3B 
                 2.5 
                 23 × 76 
                 0.1 
                 2.0 
                 1.25 
               
               
                 3B 
                 4.0 
                 14 × 48 
                 0.15 
                 3.0 
                 1.75 
               
               
                 3B 
                 1 
                  47 × 140 
                 0.08 
                 0.7 
                 1.05 
               
               
                 3C 
                 2.5 
                 23 × 76 
                 0.1 
                 2.0 
                 1.25 
               
               
                 3C 
                 4.0 
                 14 × 48 
                 0.15 
                 3.0 
                 1.75 
               
               
                 3C 
                 1 
                  47 × 140 
                 0.08 
                 0.7 
                 1.05 
               
               
                   
               
             
          
         
       
     
       FIGS. 4A-4C  depict assembled device die according to the previous discussion.  FIG. 4A  illustrates a device die  470  mounted and encapsulated on the pedestal strip of  FIG. 3A . Device die  470  in mounted on the pedestal  475  of epoxy molding compound (EMC) or equivalent material; device die  470  is encapsulated in additional molding compound  480 .  FIG. 4B  illustrates a device die  470 ′ mounted and encapsulated on the pedestal strip of  FIG. 3B . Device die  470 ′ is mounted on the metal pedestal  475 ′; device die  470 ′ is encapsulated in additional molding compound  480 ′.  FIG. 4C  illustrates device die  470 ″ mounted on a pedestal strip of  FIG. 3C . The pedestal  475 ″ has a molded pedestal mounted onto a metal substrate; the device die  470 ″ is encapsulated in additional molding compound  480 .″ 
       FIGS. 4A-4C  have dimension lines depicting the measurements of the example device die assembled onto the three example pedestal strips. Refer to Table 2 for some example dimensions for several device die sizes. 
     
       
         
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Dimensions of Example Device Die Assembled (Dimensions in mm) 
               
             
          
           
               
                 Type of 
                 Die Size 
                 Vertical Width 
                 Overall 
                 Pedestal Base 
                 Pedestal 
                 Total Pedestal 
                 Pedestal 
                 Device Die 
               
               
                 Device 
                 Used 
                 Protection 
                 Thickness 
                 Thickness 
                 Height 
                 Height 
                 Width 
                 Thickness 
               
               
                 Die 
                 (W D ) 
                 (W L ) 
                 (T 1 ) 
                 (T 3 ) 
                 (T 2 ) 
                 (T 4 ) 
                 (W P ) 
                 (T D ) 
               
               
                   
               
             
          
           
               
                 4A 
                 2.5 
                 0.125 
                 0.45 
                 0.15 
                 0.1 
                 0.25 
                 2 
                 0.2 
               
               
                 4A 
                 4.0 
                 0.125 
                 0.5 
                 0.20 
                 0.15 
                 0.35 
                 3 
                 0.15 
               
               
                 4A 
                 1 
                 0.125 
                 0.35 
                 0.15 
                 0.08 
                 0.23 
                 0.7 
                 0.12 
               
               
                 4B 
                 2.5 
                 0.25 
                 0.45 
                 0.1 
                 0.1 
                 0.2 
                 2 
                 0.25 
               
               
                 4B 
                 4.0 
                 0.25 
                 0.45 
                 0.1 
                 0.15 
                 0.25 
                 3 
                 0.2 
               
               
                 4B 
                 1 
                 0.25 
                 0.3 
                 0.08 
                 0.08 
                 0.16 
                 0.7 
                 0.14 
               
               
                 4C 
                 2.5 
                 0.25 
                 0.45 
                 0.1 
                 0.1 
                 0.2 
                 2 
                 0.25 
               
               
                 4C 
                 4.0 
                 0.25 
                 0.45 
                 0.1 
                 0.15 
                 0.25 
                 3 
                 0.2 
               
               
                 4C 
                 1 
                 0.25 
                 0.3 
                 0.08 
                 0.08 
                 0.16 
                 0.7 
                 0.14 
               
               
                   
               
             
          
         
       
     
     Note that W L  is flexible, based on different singulation saw blades used, thus a wide range is possible (as in Table 1), excluding manufacturing tolerances, the range is about 125 μm to about 250 μm. 
     In another example embodiment according to the present disclosure, the device die may be fabricated to have a pedestal defined integrally in its structure. Refer to  FIG. 5 . A wafer having undergone back-grinding has solder bumps applied to the electrical connection areas of active device die on the wafer&#39;s front-side surface. The wafer having solder bumps is mounted on the front-side  505  onto a protective tape (which shields the solder bumps from potential damage during subsequent processing). With a “V-shaped” saw blade (or a saw blade with a sloped cutting edge profile) of a first kerf, the back-side of the wafer is sawed on locations corresponding to saw lanes between the active device die  510 ; the depth of the sawing is about 50% of the wafer thickness. In other processes, other shapes of blades may be used. In an example process, the locations are targeted with an infrared camera (IR) or other suitable imaging system. With a saw blade having a straight profile and a second kerf which is narrower than the first kerf, the device die are sawed apart  515 . The sawed-apart die are separated  520 . A pedestal strip is prepared that is customized for a given device die&#39;s dimensions (i.e., thickness, area, etc.)  525 . The separated device die back-side surfaces are die-bonded onto pedestal top-side surfaces with a suitable material  535 . Suitable material may include, but not necessary be limited to glue, eutectic die attach, solder, etc. The appropriate material for die bonding would be governed by the pedestal strip material used. Through an over-molding process with a foil-assisted molding apparatus, the bonded device die on the pedestal strip are encapsulated in a resilient molding compound  540 . The foil-assisted molding apparatus protects the solder bumps from damage. On the underside of the pedestal strip, the device code may be laser-inscribed  545 . The completed pedestal strip having device die is placed onto a sawing tape  550 . The product devices are sawed apart and separated  555 . Product is removed from the sawing tape and placed into trays  560 . Product may be final tested, packed and shipped to the end user  565 . 
     In another example embodiment, the “V” shaped profile may be accomplished with a photo-lithographic process. The front-side surface of the wafer substrate (containing the active devices) may be masked with a protective film. The back-side surface of the wafer substrate may be masked so as to leave exposed those areas corresponding to saw lanes of active devices. With a preferential etch, angled profiles, similar to those obtained with the sawing process discussed supra, may be achieved. The etching process may be a wet-etch, dry etch, or combination thereof. 
     Refer to  FIGS. 6A-6F . A series of cross-sectional views illustrates the preparation of pedestal device die (i.e., a “mushroom” WLCSP). A silicon wafer  610  having undergone back-grinding, has active device die to which solder bumps  620  have been applied. A front-side tape  630  provides protection for the solder bumps  620 , from the rigors of handling. With a saw blade  65  of a first kerf, and a sloped profile  640  (i.e. a pedestal slot), the back-side of the wafer is sawed in the locations corresponding to the active device saw lanes. With a saw blade  75  of a second kerf (narrower than the first kerf), the silicon wafer  610  is sawed into separate device die  615  each having a pre-determined number of solder bumps  625 . The separated device die  615  now have angled edge profiles with recesses  645 . 
     Having prepared the pedestal device die  615 , having an angled profile with a recess  655 , the user may select from a number of options in providing protection to the back-side surface of the die. 
     Refer to  FIG. 7A . A plurality of pedestal die  715  may be mounted onto a material  730  that will ultimately provide the back-side protection. The material may be a plastic material such as epoxy molding compound (EMC) or be metal, such as copper, brass, nickel, tin, etc. or alloys, of one another. In another example process, the protective material  730  may have an optional second layer  740 , so as to make a composite protective layer of metal  730  and molding compound  740 . Refer to  FIG. 7B . A molding compound  735  envelopes the plurality of device die  715 . A protective film (not illustrated) covers the solder bumps from damage during encapsulation with molding compound  735 . The pedestal profiles  755  of the plurality of device die  715  provides additional mechanical anchoring of the molding compound  735 . The molded plurality of device die  715  is mounted onto a sawing/dicing film  750 . A saw blade  85  of an appropriate kerf slices through the depths of the molding compound  735  and the protective layer  730 . The plurality of device  715 , now protected on five-sides, the back-side surface and the four vertical faces. In some example processes, it is possible to get molding compound on the front surface, as well by using a Foil Assisted Molding machine, FAM, and partially pushing the solder bumps into this film. In another process, compression molding technology may successfully apply molding compound onto the front surface and surround the solder bumps. 
     Having provided protection on the five surfaces of the device die substantially minimizes the likelihood of assembly damage by the end-user building his subsystems. 
     Refer to  FIGS. 8A-8C . Three side views of device die having been encapsulated in a protective material are shown.  FIG. 8A , device die  810  has protective material  835  of a molding compound enveloping the vertical faces and solder bump side  812  and back-side surface. An additional metal protective layer  825  is laminated to the molding compound  835  on the back-side surface.  FIG. 8B , device  815  has molding compound  845  enveloping the vertical faces and the solder-bump side  822 . On the back-side surface of device die  815  is a metal protective layer  855 .  FIG. 8C , device  820  only has molding compound  865  enveloping the vertical faces, back-side, and solder bump side  832 . The backside surface of device die  820  had only the molding compound  740 , of  FIG. 7A , applied in lieu of the metal layer  730 ; the additional molding compound  865  being applied in a further step. Depending upon the specific process, in an alternate embodiment, the solder-bumps may be shielded from the molding process and therefore, not be surrounded with molding compound in the finished product. The specific device die size may govern the feature sizes of the example techniques shown in  FIGS. 8A-8C . Table 3 outlines some example device dimensions and their corresponding device die protection. 
     
       
         
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Example Dimensions of Devices Assembled According to Disclosure (Dimensions in mm) 
               
             
          
           
               
                   
                   
                 Width of 
                   
                 Width of 
                   
                   
                   
                 Thickness of 
                 Thickness of 
                 Overall 
               
               
                   
                   
                 Protective layer 
                 Width of 
                 Die on 
                 Depth of 
                   
                   
                 First Layer 
                 2 nd  Layer of 
                 Thickness of 
               
               
                   
                 Die 
                 on Vertical 
                 Pedestal 
                 Backside 
                 Pedestal 
                 Die 
                 Overall 
                 of Protective 
                 Protective 
                 Protective 
               
               
                   
                 Size 
                 Faces 
                 Slot 
                 Surface 
                 Slot 
                 Thickness 
                 Thickness 
                 Material 
                 Material 
                 Layer 
               
               
                 FIG. 
                 W D   
                 W L   
                 Ws 
                 W P   
                 T P   
                 T D   
                 T 1   
                 T 2   
                 T 3   
                 T 4   
               
               
                   
               
             
          
           
               
                 8A 
                 2.5 
                 0.125 
                 0.1 
                 2.3 
                 0.08 
                 0.2 
                 0.4 
                 0.05 
                 0.1 
                 0.15 
               
               
                 8A 
                 4.0 
                 0.125 
                 0.1 
                 3.8 
                 0.08 
                 0.2 
                 0.4 
                 0.05 
                 0.1 
                 0.15 
               
               
                 8A 
                 1 
                 0.125 
                 0.06 
                 .88 
                 0.05 
                 0.15 
                 0.35 
                 0.05 
                 0.08 
                 0.13 
               
               
                 8B 
                 2.5 
                 0.125 
                 0.1 
                 2.3 
                 0.08 
                 0.2 
                 0.4 
                 0.05 
                 0 
                 N/A 
               
               
                 8B 
                 4.0 
                 0.125 
                 0.1 
                 3.8 
                 0.08 
                 0.2 
                 0.4 
                 0.05 
                 0 
                 N/A 
               
               
                 8B 
                 1 
                 0.125 
                 0.06 
                 .88 
                 0.05 
                 0.15 
                 0.35 
                 0.05 
                 0 
                 N/A 
               
               
                 8C 
                 2.5 
                 0.125 
                 0.1 
                 2.3 
                 0.08 
                 0.2 
                 0.4 
                 0.05 
                 0 
                 N/A 
               
               
                 8C 
                 4.0 
                 0.125 
                 0.1 
                 3.8 
                 0.08 
                 0.2 
                 0.4 
                 0.05 
                 0 
                 N/A 
               
               
                 8C 
                 1 
                 0.125 
                 0.06 
                 .88 
                 0.05 
                 0.15 
                 0.35 
                 0.05 
                 0 
                 N/A 
               
               
                   
               
             
          
         
       
     
     Numerous other embodiments of the invention will be apparent to persons skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Technology Category: 5