PATENT DOCUMENT

Publication Number: US-10041847-B2
Application Number: US-201615373360-A
Country: US
Kind Code: B2

Title: Various stress free sensor packages using wafer level supporting die and air gap technique

Abstract:
Sensor packages and manners of formation are described. In an embodiment, a sensor package includes a supporting die characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die includes a sensor positioned directly above the air gap.

Claims:
What is claimed is: 
     
       1. A sensor package comprising:
 a first supporting die comprising a first pair of laterally opposite edges including a first supporting die edge and a second supporting die edge; and 
 a sensor die comprising a sensor and a second pair of laterally opposite edges including a first sensor die edge and a second sensor die edge, wherein a first contact area of the sensor die is bonded to the first supporting die in a cantilever configuration to divert stress away from the sensor such that a hanging area of the sensor die extends laterally from the first contact area and an air gap exists between the hanging area of the sensor die and the first supporting die, and the sensor is positioned directly above the air gap; 
 wherein the first supporting die edge is coplanar with the first sensor die edge along the first contact area, and the second supporting die edge is coplanar with the second sensor die edge along the hanging area to form a coplanar edge, wherein the air gap is open at the coplanar edge. 
 
     
     
       2. The sensor package of  claim 1 , wherein the first contact area of the sensor die is bonded to the first supporting die with a wafer bonding material. 
     
     
       3. The sensor package of  claim 2 , wherein the wafer bonding material is selected from the group consisting of AlGe and glass. 
     
     
       4. The sensor package of  claim 1 , further comprising a second supporting die;
 wherein a second contact area of the first supporting die is above and bonded to the second supporting die in a cantilever configuration. 
 
     
     
       5. The sensor package of  claim 1 , wherein the sensor die comprises a pressure sensor positioned directly above the air gap. 
     
     
       6. The sensor package of  claim 5 , further comprising an integrated circuit (IC) die, and the first supporting die is bonded to the IC die. 
     
     
       7. The sensor package of  claim 6 , further comprising a surface mount substrate selected from the group consisting of a land grid array (LGA), quad flat no-leads (QFN), and ceramic substrate, and the IC die is bonded to the surface mount substrate. 
     
     
       8. The sensor package of  claim 7 , further comprising a lid bonded to the surface mount substrate, wherein the lid surrounds the IC die, the first supporting die, and the sensor die, and the lid includes a pressure inlet. 
     
     
       9. The sensor package of  claim 7 , further comprising a wire bond electrically connecting the sensor die to the surface mount substrate. 
     
     
       10. The sensor package of  claim 7 , further comprising a first wire bond electrically connecting the sensor die to the IC die, and a second wire bond electrically connecting the IC die to the surface mount substrate. 
     
     
       11. The sensor package of  claim 1 , wherein the sensor die comprises a motion sensor positioned directly above the air gap; and further comprising an integrated circuit (IC) die bonded to the sensor die. 
     
     
       12. The sensor package of  claim 11 , further comprising a wire bond electrically connecting the IC die to the sensor die. 
     
     
       13. The sensor package of  claim 11 , further comprising a surface mount substrate selected from the group consisting of an LGA, QFN, and ceramic substrate, and the supporting die is bonded to the surface mount substrate. 
     
     
       14. The sensor package of  claim 13 , further comprising a wire bond electrically connecting the IC die to the surface mount substrate. 
     
     
       15. The sensor package of  claim 14 , further comprising a lid over the motion sensor die, wherein the lid is bonded to the surface mount substrate, and the lid surrounds the first supporting die, the sensor die, and the IC die. 
     
     
       16. The sensor package of  claim 1 , further comprising a through via extending through a base substrate of the first supporting die. 
     
     
       17. The sensor package of  claim 16 , wherein the first supporting die is selected from the group consisting of an interposer and integrated circuit (IC) die. 
     
     
       18. The sensor package of  claim 17 , wherein the first supporting die is an IC die, and the sensor die comprises a pressure sensor positioned directly above the air gap. 
     
     
       19. The sensor package of  claim 18 , wherein the pressure sensor comprise a diaphragm immediately adjacent the air gap. 
     
     
       20. The sensor package of  claim 17 , wherein the first supporting die is an interposer die, and the sensor die comprises a motion sensor positioned directly above the air gap. 
     
     
       21. The sensor package of  claim 20 , further comprising an integrated circuit (IC) die between the interposer die and the sensor die, and the interposer die is bonded to the IC die such that the air gap exists between the IC die and the interposer die. 
     
     
       22. The sensor package of  claim 21 , further comprising a second through via extending through the IC die.

Description:
RELATED APPLICATIONS 
     This application is a continuation of co-pending U.S. patent application Ser. No. 14/517,387, filed on Oct. 17, 2014, and claims the benefit of priority from U.S. Provisional Patent Application No. 62/044,857 filed on Sep. 2, 2014, both of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Field 
     Embodiments described herein relate to semiconductor packaging. More particularly embodiments relate to sensor packages and manners of fabrication. 
     Background Information 
     Sensor die can be formed from customized integrated circuits. Sensors are often used to sense environmental characteristics or act as a user input for electronic products. Sensors, unlike some general purpose integrated circuits, can have unique packaging and mounting requirements since sensors often require exposure to an ambient external environment, such as an ambient environment of a user using the electronic product having the sensor. As electronic products are becoming increasingly sophisticated and the size of the overall packages is reduced to meet market needs, these advances are associated with various packaging challenges to reduce cost and form factor of the packages. 
     SUMMARY 
     Sensor packages and methods of formation are described. In an embodiment, a sensor package includes a supporting die characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die may be bonded to the support anchor in a single-sided support cantilever configuration such that a hanging area of the sensor die extends laterally from a contact area of the sensor die directly over the support anchor, and the air gap exists between the hanging area of the sensor die and the recess area. The sensor die includes a sensor positioned directly above the air gap. The sensor package may additionally include one or more stopper structures protruding above the recess area. In this manner, the stopper structures can provide structural integrity to the sensor package and protect the bond between the sensor die and supporting die from breaking due to excessive bending into the air gap. For example, the stopper structures and support anchor may be integrally formed. In an embodiment, the sensor is positioned entirely directly above the air cavity. 
     Supporting die can be formed from various types of substrates depending upon application such as a bulk substrate, interposer, and integrated circuit (IC) die, such as an application specific integrated circuit (ASIC). Depending upon application, a through via interconnect may be formed through the supporting die, for example, for routing signal to output leads. Depending upon application, a separate IC die can be provided between the sensor die and supporting die, or provided on top of the sensor die. Additionally, the motion sensor die can be bonded to a stack of multiple supporting die. The support anchors for each of the multiple supporting die can assume a variety of arrangements, such as being orthogonally aligned or not being directly above one another. 
     In an embodiment, the sensor package is a wafer level pressure sensor package. In such an embodiment, the pressure sensor package includes a supporting IC characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die includes a pressure sensor positioned directly above the air gap. In an embodiment, the pressure sensor includes a diaphragm that is immediately adjacent the air cavity. In addition, a through via extends through a base substrate of the supporting IC die. Stopper structures may additionally protrude from the recess area. 
     In an embodiment, the sensor package is a wafer level motion sensor package. In such an embodiment, the motion sensor package includes a supporting interposer die with a top surface characterized by a recess area and a support anchor protruding above the recess area. An IC die is bonded to the support anchor such that an air gap exists between the IC die and the recess area, and a sensor die bonded to the IC die. The sensor die includes a motion sensor positioned directly above the air gap. A through via may extend though a base substrate of the supporting interposer die. A second through via may additionally extend through the IC die, such as an ASIC. 
     The sensor package may be a pressure sensor package compatible with land grid array (LGA), quad flat no-leads (QFN), and ceramic packaging substrates. In such an embodiment, the pressure sensor package includes a supporting die characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die includes a pressure sensor positioned directly above the air gap, and a lid is provided over the pressure sensor die. The lid may include a pressure inlet for operation of the pressure sensor. In an embodiment, the supporting die is bonded to an IC die. The IC die may be bonded to a surface mount substrate, such as an LGA, QFN, or ceramic substrate. In such a configuration, the lid is bonded to the surface mount substrate and surrounds the IC die, the supporting die, and the sensor die. In embodiment, the surface mount substrate is a ceramic substrate including sidewalls that surround the IC die, the supporting die, and the sensor die. Wire bonding may be used to electrically connect the sensor die to the surface mount substrate or the IC die. Wire bonding may also be used to electrically connect the IC die to the surface mount substrate. 
     The sensor package may be a motion sensor package compatible with LGA, QFN, or ceramic packaging substrates. In such an embodiment, the motion sensor package includes a supporting die with a top surface characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die includes a motion sensor positioned directly above the air gap, and an integrated circuit (IC) die bonded to the sensor die. In an embodiment, the sensor die includes a base substrate and a cap surrounding the motion sensor. In an embodiment, the supporting die is bonded to a surface mount substrate, such as an LGA, QFN, or ceramic substrate. Wire bonding may be used to electrically connect the IC die to the sensor die, and the IC die to the surface mount substrate. A lid can additionally be located over the motion sensor die. In an embodiment, the lid is bonded to the surface mount substrate, and the lid surrounds the supporting die, the sensor die, and the IC die. In an embodiment, the surface mount substrate is a ceramic substrate including sidewalls that surround the supporting die, the sensor die, and the IC die. 
     In an embodiment, a method of assembling a sensor package includes bonding a sensor wafer including an array of sensors to a supporting wafer comprising an array of cavities, where each sensor is directly above a corresponding cavity. An array of sensor packages is then singulated from the bonded sensor wafer and supporting wafer, wherein each sensor package includes a corresponding sensor directly above an air cavity. In an embodiment, the method includes etching the array of cavities in the supporting wafer. In an embodiment, the method includes forming an array of support anchors and an array of stopper structures on the supporting wafer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional side view illustration of a sensor wafer in accordance with an embodiment. 
         FIG. 2  is a cross-sectional side view illustration of a thinned down sensor wafer in accordance with an embodiment. 
         FIGS. 3-5  are cross-sectional side view illustrations of a manner for forming a supporting wafer in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view illustration a bonded sensor wafer and supporting wafer in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view illustration of thinning down a supporting wafer after bonding the sensor wafer and supporting wafer in accordance with an embodiment. 
         FIG. 8A  is a cross-sectional side view illustration of a stacked sensor die and supporting die in accordance with an embodiment. 
         FIG. 8B  is a top view illustration of a stacked sensor die and supporting die in accordance with an embodiment. 
         FIG. 8C  is a cross-sectional side view illustration of a stacked sensor die and supporting die in accordance with and embodiment. 
         FIG. 8D  is a schematic top view illustration of a supporting die in accordance with an embodiment. 
         FIG. 9A  is a cross-sectional side view illustration of a stacked sensor die and multiple supporting die in accordance with an embodiment. 
         FIG. 9B  is a top view illustration of a stacked sensor die and multiple supporting die in accordance with an embodiment. 
         FIG. 10A  is a top view illustration of a stacked sensor die and multiple supporting die in accordance with an embodiment. 
         FIG. 10B  is a cross-sectional side view illustration of a stacked sensor die and multiple supporting die taken along cross-section X-X of  FIG. 10A  in accordance with an embodiment. 
         FIG. 10C  is a cross-sectional side view illustration of a stacked sensor die and multiple supporting die taken along cross-section Y-Y of  FIG. 10A  in accordance with an embodiment. 
         FIG. 10D  is a top view illustration of a supporting die with a spiral configuration in accordance with an embodiment. 
         FIG. 10E  is a top view illustration of a wafer bonding material applied to a supporting die with a spiral configuration and in accordance with an embodiment. 
         FIG. 10F  is a cross-sectional side view illustration of a stacked sensor die and multiple supporting die including a supporting die with a spiral configuration in accordance with an embodiment. 
         FIG. 10G  is a top view illustration of a supporting die with a pivot platform and spring arms in accordance with an embodiment. 
         FIG. 10H  is a cross-sectional side view illustration of a die stack including a supporting die with a pivot platform and spring arms in accordance with an embodiment. 
         FIG. 10I  is a top view illustration of a supporting die with a pivot platform and spring arms in accordance with an embodiment. 
         FIG. 10J  is a sectional side view illustration of a die stack including a supporting die with a pivot platform and spring arms in accordance with an embodiment 
         FIGS. 11A-11B  are cross-sectional side view illustrations of pressure sensor packages integrated onto a surface mount substrates with flip chip and wire bonding in accordance with embodiments. 
         FIGS. 11C-11D  are cross-sectional side view illustrations of pressure sensor packages integrated onto air cavity ceramic substrates with flip chip and wire bonding in accordance with embodiments. 
         FIGS. 11E-11F  are cross-sectional side view illustrations of pressure sensor packages integrated onto surface mount substrates with wire bonding in accordance with embodiments. 
         FIG. 12  is a cross-sectional side view illustration a bonded motion sensor wafer and supporting wafer in accordance with an embodiment. 
         FIG. 13A  is a cross-sectional side view illustration of a motion sensor package integrated onto a surface mount substrate in accordance with an embodiment. 
         FIG. 13B  is a cross-sectional side view illustration of a motion sensor package integrated onto an air cavity ceramic substrate in accordance with an embodiment. 
         FIG. 14  is a cross-sectional side view illustration a bonded pressure sensor wafer and supporting IC wafer in accordance with an embodiment. 
         FIGS. 15A-15B  are cross-sectional side view illustrations of wafer level pressure sensor packages in accordance with embodiments. 
         FIG. 16  is a cross-sectional side view illustration a bonded motion sensor wafer, IC wafer, and supporting interposer wafer in accordance with an embodiment. 
         FIG. 17  is a cross-sectional side view illustration of a wafer level motion sensor package in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments describe sensor packages and methods of fabrication. In various embodiments, description is made with reference to figures. However, certain embodiments may be practiced without one or more of these specific details, or in combination with other known methods and configurations. In the following description, numerous specific details are set forth, such as specific configurations, dimensions and processes, etc., in order to provide a thorough understanding of the embodiments. In other instances, well-known semiconductor processes and manufacturing techniques have not been described in particular detail in order to not unnecessarily obscure the embodiments. Reference throughout this specification to “one embodiment” means that a particular feature, structure, configuration, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more embodiments. 
     The terms “above”, “over”, “to”, “between” and “on” as used herein may refer to a relative position of one layer with respect to other layers. One layer “above”, “over” or “on” another layer or bonded “to” or in “contact” with another layer may be directly in contact with the other layer or may have one or more intervening layers. One layer “between” layers may be directly in contact with the layers or may have one or more intervening layers. 
     In one aspect, embodiments describe sensor packages and manners of fabrication which may address sensor package stress. It has been observed that sensor devices are sensitive to package stress, particularly pressure and motion sensors. For example, thermo-mechanical stress from the package or underlying substrate can cause sensor output shift, particularly as temperature changes. In addition, package stress impact to sensor output change may become more serious when package thickness and form factor are further reduced to meet market needs. In an embodiment, a wafer level supporting die and air gap technique is described in order to alleviate the impact of package stress on sensor devices. A supporting wafer having recessed areas is bonded with a sensor wafer using a wafer level bonding process. After singulation, the stacked die include a supporting die with a recess area and support anchor, and a sensor die bonded to the support anchor such that an air gap exists between the sensor die and the recess area. This stacked die arrangement can be integrated into a variety of sensor packages and may be compatible with both wafer level packaging (WLP) in which the top and bottom die (and solder bumps) are attached while still at the wafer scale, and for integration with surface mount substrates such as LGA, QFN, or ceramic substrates. Various surface mount interconnection methods may be used for electrically connecting the stacked die arrangement, such as flip chip bonding, wire bonding, and combinations of flip chip bonding and wire bonding. In an embodiment, the sensor die includes a sensor positioned directly above the air gap. In this manner, the support anchor and air gap between the sensor die and the supporting die may isolate stress away from the sensor while also supporting the sensor die. 
     In an embodiment of a wafer level supporting die and air gap technique, a portion of the sensor die including the sensor hangs above an air gap between the sensor die and a recess area in a supporting die. For example, this may be characterized as a cantilever-type configuration. In such a configuration, the sensor is contained within or on the sensor die. Thus, the sensor is not characterized by the cantilever-type structure, rather the cantilever-type structure diverts stress away from the sensor. Accordingly, the sensor may operate independently of the cantilever-type structure. In an embodiment of a wafer level supporting die and air gap technique, a sensor die is bonded to a pivot platform of a supporting die. In this manner the supporting die is able to divert stress away from the sensor die bonded to the pivot platform. 
     In the following description with regard to  FIGS. 1-10J , various methods and configurations are described for forming a stacked die including a sensor die bonded to one or more supporting die. It is to be appreciated, that while  FIGS. 1-10J  are described and illustrated with regard to a stacked die including a surface-micromachined pressure sensor, that the processing sequences and structural configurations may also be used for other sensors, such as bulk-micromachined pressure sensors and motion sensors. In addition, the processing sequences may be compatible with both wafer level packages (WLP), and integration with surface mount substrates such as LGA, QFN, and ceramic substrates. 
     Referring now to  FIGS. 1-2 , cross-sectional side view illustrations are provided of a sensor wafer  100  in accordance with an embodiment. In the particular embodiment illustrated in  FIG. 1  sensor wafer  100  includes an array of pressure sensors  110 . The pressure sensors  110  may be formed using a variety of fabrication techniques such as wafer bonding of silicon wafers, or any suitable semiconductor processing or MEMS fabrication technique. In the particular embodiment illustrated, the sensors  110  are formed using a surface-micromachined method and include diaphragms  104  formed over corresponding cavities  106  on a substrate  102 , such as a silicon substrate. In such a configuration, the diaphragms  104  may deflect outward away from the substrate  102  and inward toward the corresponding cavities  106 . After fabrication of the sensors  110  on the sensor wafer  100 , the full thickness of the substrate  102 , e.g. silicon substrate, can be thinned down as illustrated in  FIG. 2  for subsequent wafer bonding. In other embodiments, the sensors are formed using a bulk-micromachined method, and still may be characterized as including diaphragms  104  over corresponding cavities  106 . 
       FIGS. 3-5  include cross-sectional side view illustrations of a manner for forming a supporting wafer  200  in accordance with an embodiment. Referring to  FIG. 3 , the process may begin with a base substrate  202 , such as a silicon wafer. Recess areas  207  are etched into the base substrate  202  using dry reactive ion etching (DRIE) or any suitable anisotropic etching technique. In an embodiment, the formation of recess areas  207  results in the formation of support anchors  204  that protrude above the recess areas  207 . Stopper structures  208  may also optionally be formed. In an embodiment, stopper structures  208  are formed at the same time as the formation of recess areas  207 . In an embodiment, stopper structures  208  and support anchors  204  are integrally formed with the base substrate  202 . In an embodiment, stopper structures  208  and support anchors  204  have the same height. Stopper structures  208  may also be formed such that support anchors  204  are taller than the stopper structures. In an embodiment, stopper structures  208  may be deposited after the formation of recess areas  207 . As described in further detail below, stopper structures  208  may be formed to prevent breaking of the bonded contact area between the supporting die and sensor die of in the resultant die stack. In an exemplary application, recess areas  207  have a depth of approximately 10 μm, with support anchors  204 , and optionally, stopper structures  208  protruding approximately 10 μm above the recess areas. 
     Referring now to  FIG. 5 , a wafer bonding material  210  is applied to the supporting wafer  200 . In the particular embodiment illustrated, the wafer bonding material  210  is selectively applied to the support anchors  204 . A variety of suitable wafer bonding materials may be used, such as deposited AlGe, or printed, e.g. screen printed, glass paste. In an embodiment, the wafer bonding material  210  is applied to the sensor wafer  100  rather than the supporting wafer  200  such that it will align with the support anchors  204  on the supporting wafer  200 . The sensor wafer  100  and supporting wafer  200  are then bonded together with the wafer bonding material  210  as illustrated in  FIG. 6 . In the embodiment illustrated, air gaps  206  are formed between the sensor wafer  100  and supporting wafer  200 . For example, air gaps  206  may have a height defined by a height of the support anchors  204  and wafer bonding material  210  thickness. In an embodiment, the air gaps  206  also span over one or more stopper structures  208 . In an embodiment, following bonding of the sensor wafer  100  and supporting wafer  200 , the supporting wafer  200  can then be thinned down as illustrated in  FIG. 7 . The bonded, thinned structure may then be diced into die stacks  250 . In the particular embodiment illustrated, dicing may be performed along the dotted lines shown in  FIG. 7 , with adjacent mirror image die stack  250  each being diced from a shared air cavity  206 . 
     Referring now to  FIGS. 8A-8B , cross-sectional side view and top view illustrations are provided of a singulated die stack in accordance with an embodiment. In the particular embodiment illustrated, the die stack  250  includes a pressure sensor  110 . For example, the pressure sensor includes a diaphragm  104  and cavity  106  underneath the diaphragm. The die stack  250  includes a supporting die  203  including a top surface  201  characterized by a recess area  207  and a support anchor  204  protruding above the recess area  207 . A sensor die  103  is bonded to the support anchor  204  such that an air gap  206  exists between the sensor die  103  and the recess area  207 , and the sensor die  103  includes pressure sensor  110  positioned directly above the air gap  206 . One or more stopper structures  208  may protrude from the recess area  207 . The support anchor  204  may have the same height, or be taller than the one or more stopper structures  208 . In an embodiment, the support anchor  204  and one or more stopper structures  208  are integrally formed with the base substrate  202 , such as a silicon substrate. In such a configuration, the top surface  201  is additionally characterized by the stopper structures  208 . 
     In accordance with embodiments, a die stack includes a supported contact area  112  of the sensor die  103 , and hanging area  114  of the sensor die that is not bonded to a structure directly underneath. The hanging area  114  may correspond to an area of the air gap  206  directly underneath. The supported contact area  112  may correspond to the bond area between the support anchor  204  and sensor die  103 . The amount of supported contact area  112  can be used to isolate stress transfer to the sensor  110 , while achieving sufficient mechanical strength. For example, an open air gap  206  may exist at peripheral regions underneath the sensor die  103  along sides not supported by a support anchor  204 . For the exemplary rectangular package structure illustrated in  FIG. 8B , an open air gap  206  may exist along three edges of substrate  102  of sensor die  103 , with a fourth edge being supported by support anchor  204 . Such a configuration may be characterized as a single-sided support cantilever shape. However, alternative configurations are possible. For example, multiple edges may be supported by support anchor  204 , or one or more edges may be only partially supported by support anchor  204 . Accordingly, a variety of configurations are envisioned. 
     While the embodiments described and illustrated with regard to  FIGS. 8A-8B  resemble that illustrated in the process described an illustrated in  FIGS. 1-7 , the process sequence described in  FIGS. 1-7  is intended to be exemplary and is not so limited. For example, the process sequence described and illustrated in  FIGS. 1-7  may be compatible with alternative sensor types, and die stack configurations for stress isolation, such as those illustrated and described in  FIGS. 8C-10J . 
       FIGS. 8C-8D  include cross-sectional side view and top view illustrations for a singulated die stack in accordance with an embodiment. The arrangement in  FIGS. 8C-8D  is similar to the cantilever configuration of  FIGS. 8A-8B , with one edge being only partially supported by a support anchor.  FIG. 8D  is a schematic top view illustration of a supporting die  203  in which the support anchor  204  is only partially formed near one of the supporting die  203  edges. Thus, the supported contact area is reduced, and the hanging area  114  extends away from the supported contact area in both X-Y directions. For the exemplary rectangular package structure illustrated in  FIG. 8D , an open air gap  206  may exist along three edges of substrate  102  of sensor die  103 , and partially along a fourth edge being supported by support anchor  204 . Such a configuration may also be characterized as a single-sided support cantilever shape. An outline of a diaphragm  104  cavity  106  is provided to illustrate the position of the sensor  110  over the air gap  206 . 
     Referring now to  FIGS. 9A-9B , cross-sectional side view and top view illustrations are provided for a die stack  250  including multiple supporting die in accordance with an embodiment. The die stack  250  may be formed using a wafer level supporting die and air gap technique similar to that illustrated and described with regard to  FIGS. 1-7 . In such a configuration, the multiple supporting die may be used for additional stress isolation. In the particular embodiment illustrated, the sensor die  103  is bonded to a first supporting die  203 A such than an air gap  206  exists between the sensor die  203 A and the recess area  207  of the first supporting die  203 A. A second supporting die  203 B may be formed similarly as first supporting die  203 A, including a top surface characterized by a recess area  207  and a support anchor  204  protruding above the recess area  207 . In the embodiment illustrated in  FIGS. 9A-9B , the first supporting die  203 A is above and bonded to the support anchor  204  of the second supporting die  203 B with a wafer bonding material  210 , where the support anchor  204  of the first supporting die  203 A is not directly above the support anchor  204  of the second supporting die  203 B. In an embodiment, support anchors  204  of the first and second supporting die  203 A,  203 B are located on opposite sides of the die stack  250 . For example, referring to  FIG. 9B , the supported contact area  112  between the sensor die  103  and first supporting die  203 A, and the supported contact area  116  between the first supporting die  203 A and the second supporting die  203 B can be located on opposite sides of the die stack  250 . In an embodiment, the sensor  110  may be partially located directed above the supported contact area  116  (corresponding to the bond area between first supporting die  203 A and support anchor  204  of second supporting die  203 B), while the sensor  110  is not directly above the supported contact area  112  (corresponding to the bond area between sensor die  103  and support anchor  204  of first supporting die  203 A). 
       FIGS. 10A-10C  provide cross-sectional side view and top view illustrations for a die stack  250  including multiple supporting die in accordance with an embodiment. The die stack  250  may be formed using a wafer level supporting die and air gap technique similar to that illustrated and described with regard to  FIGS. 1-7 . In the particular embodiment illustrated,  FIG. 10B  is taken along cross-section X-X of  FIG. 10A , while  FIG. 10C  is taken along cross-section Y-Y of  FIG. 10A . As illustrated, the sensor die  103  is bonded to a first supporting die  203 A as previously described with supported contact area  112 . A second supporting die  203 B may be formed similarly as first supporting die  203 A, including a top surface characterized by a recess area  207  and a support anchor  204  protruding above the recess area  207 . In the embodiment illustrated in  FIGS. 10A-10C , the first supporting die  203 A is above and bonded to the support anchor  204  of the second supporting die  203 B with a wafer bonding material  210  corresponding to supported contact area  118 , where the support anchor  204  of the first supporting die  203 A is aligned orthogonally with the support anchor  204  of the second supporting die  203 B. In this manner, the first supporting die  203 A may isolate bending in the Y-direction (orthogonal to X-X), while the second supporting die  203 B may isolate bending in the X-direction (orthogonal to Y-Y). In this manner, contact area between the sensor die  103  and supporting dies  203 A,  203 B can be reduced while modulating bending from the bottom side of the package. Referring to  FIG. 10A , support anchor  204  and corresponding supported contact area  112  between the sensor die  103  and first supporting die  203 A, and support anchor  204  and corresponding supported contact area  118  between the first supporting die  203 A and the second supporting die  203 B may be orthogonal to each other. Support anchors  204  and corresponding supported contact areas  112 ,  118  may additionally overlap. 
     Thus far, each die stack  250  configuration has included a sensor die bonded to a support anchor in a single-sided support cantilever configuration such that a hanging area of the sensor die extends laterally from a contact area of the sensor die directly over the support anchor, and an air gap exists between the hanging area of the sensor die and the recess area, with the sensor of the sensor die positioned directly above the air gap.  FIGS. 10D-10J  provide additional configurations including a supporting die with a spring arms and a pivot platform in accordance with embodiments. In such configurations, the sensor die  103  may be bonded to a support anchor  204  on the pivot platform, and may hang over an air gap between the sensor die and supporting die  203  in a cantilever configuration. Additional stress isolation may be provided by the spring arms. In an embodiment, the sensor die  103  is larger than the contact area between the sensor die and the support anchor  204 . 
       FIG. 10D  is a top view illustration of a supporting die  203  with a spiral configuration in accordance with an embodiment. As illustrated, a supporting die  203  includes channels  205  formed through a base substrate  202  to form spring arms  211  and pivot platform  209 . In the embodiment illustrated, the spring arms  211  are formed in a spiral configuration. The channels  205  may be formed through an entire thickness of the base substrate  202 . A support anchor  204  protrudes from the pivot platform  209  to provide a contact surface.  FIG. 10E  is a top view illustration of a supporting die  203  after formation of a wafer bonding material  210  on the support anchor  204 . 
       FIG. 10F  is a cross-sectional side view illustration of die stack  250  including a supporting die with a spiral configuration in accordance with an embodiment. The die stack  250  may be formed using a wafer level supporting die and air gap technique similar to that illustrated and described with regard to  FIGS. 1-7 . As shown in  FIG. 10F , a sensor die  103  is bonded to a first supporting die  203 A with spiral configuration as described with regard to  FIGS. 10D-10E . The first supporting die  203 A may additionally be bonded to a support anchor  204  of a second supporting die  203 B. The support anchors  204  of the first and second supporting die  203 A,  204 B may be located at a variety of locations. In the particular embodiment illustrated, the support anchor  204  of the second supporting die  203 B is located at a side edge of the die stack  250 , and support anchor  204  of the first supporting die  203 A is located at a more laterally central area of the die stack  250  consistent with a spiral configuration. 
       FIG. 10G  is a top view illustration of a supporting die with a pivot platform and spring arms in accordance with an embodiment. As illustrated, a supporting die  203  includes channels  205  formed through a base substrate  202  to form spring arms  211  and pivot platform  209 . In the embodiment illustrated, the two spring arms  211  are provided, with each spring arm including one or more turns (e.g. 90 degrees, or 180 degrees). This may increase the length and flexibility of the cantilever configuration of the spring arms. The channels  205  may be formed through an entire thickness of the base substrate  202 . A support anchor  204  protrudes from the platform  209  to provide a contact surface for a sensor die. In an embodiment, the support anchor  204  is formed as a portion of the pivot platform  209  and rises above the spring arms  211 . In an embodiment, the entire pivot platform  209  forms the support anchor  204  and rises above the spring arms  211 . As shown in  FIG. 10G , a wafer bonding material  210  can be located on a top surface of the support anchor  204  for bonding with a sensor die  103 , and on a back surface (illustrated by dotted lines) for bonding with another supporting die. 
       FIG. 10H  is a cross-sectional side view illustration of a die stack  250  including a supporting die with a pivot platform and spring arms in accordance with an embodiment. The die stack  250  may be formed using a wafer level supporting die and air gap technique similar to that illustrated and described with regard to  FIGS. 1-7 . As shown in  FIG. 10H , a sensor die  103  is bonded to a first supporting die  203 A with a pivot platform and spring arms as described with regard to  FIG. 10G . The first supporting die  203 A may additionally be bonded to a support anchor  204  of a second supporting die  203 B. The support anchors  204  of the first and second supporting die  203 A,  204 B may be located at a variety of locations. In the particular embodiment illustrated, the support anchor  204  of the second supporting die  203 B is located at a side edge of the die stack  250 , and support anchor  204  of the first supporting die  203 A is located at a more laterally central area of the die stack  250  consistent with a pivot platform surrounded by outer edges of the base substrate  202 . 
       FIG. 10I  is a top view illustration of a supporting die with a pivot platform and spring arms in accordance with an embodiment.  FIG. 10I  is similar to  FIG. 10G , with one difference showing a die attach material  310  underneath the supporting die  203  and around the outer edges of the base substrate  202 . In an embodiment, die attach material  310  is formed of an elastomeric material, such as silicone, which may be characterized as a high flexibility and low stress adhesive material employed in packaging. In an embodiment, the wafer bond material  210  forms a more rigid bond than the die attach material  310 . Die attach material  310  may be a non-electrically conductive material. In accordance with some embodiments, conductive joints are not formed through die attach material  310 , and wire bonding is used to make electrical connection to a surface mount substrate. 
       FIG. 10J  is a cross-sectional side view illustration of a die stack  250  including a supporting die with a pivot platform and spring arms in accordance with an embodiment. The die stack  250  may be formed using a wafer level supporting die and air gap technique similar to that illustrated and described with regard to  FIGS. 1-7 . As shown in  FIG. 10J , a sensor die  103  is bonded to a supporting die  203  with a pivot platform and spring arms as described with regard to  FIG. 10I . In the particular embodiment illustrated, the support anchor  204  of the supporting die  203  is located at a more laterally central area of the die stack  250  consistent with a pivot platform surrounded by outer edges of the base substrate  202 . A die attach material  310  may be located on a back surface of the supporting die  203  along a periphery of the supporting die  203 . Still referring to  FIG. 10J , the back side of the supporting die may include a cavity  220  in which support anchors  224  extend from a recess area  222 . In this manner, supporting die can be directly bonded to a substrate, such as a surface mount substrate, with a reduced contact area for stress isolation. 
       FIG. 11A  is a cross-sectional side view illustration of a pressure sensor package integrated onto a surface mount substrate, such as an LGA, QFN, or ceramic substrate with flip chip and wire bonding in accordance with an embodiment. In an embodiment, the pressure sensor package includes a die stack including a pressure sensor die  103 , supporting die  203 , and air gap  206  formed with a wafer batch process for stress isolation from a bottom surface of the package adjacent the surface mount substrate  400 . While  FIG. 11A  illustrates the integration of the die stack  250  illustrated and described with regard to  FIGS. 8A-8B , it is understood that a number of configurations may be integrated onto the surface mount substrate in  FIG. 11A , including the variations described and illustrated with regard to  FIGS. 9A-10J . Referring again to  FIG. 11A , the bonded sensor die  103  and supporting die  203  of  FIGS. 8A-8B  is bonded to an integrated circuit (IC) die  300  using a die attach material  310 . In an embodiment, die attach material  310  is formed of an elastomeric material, such as silicone, which may be characterized as high flexibility and low stress adhesive material employed in packaging. In an embodiment, the wafer bond material  210  forms a more rigid bond than die attach material  310 . Die attach material  310  may be a non-electrically conductive material. In accordance with some embodiments, conductive joints are not formed through die attach material  310 , and wire bonding is used to make electrical connection to the sensor die. In an embodiment, IC die  300  is an application specific integrated circuit (ASIC) die. In an embodiment, IC die  300  is a field programmable gate array (FPGA) die. 
     As illustrated in  FIG. 11A , the IC die  300  is flip chip bonded to the surface mount substrate  400  with bumps  320 , and underfill material  330  such as an epoxy underfill material. IC die  300  may be bonded to the surface mount substrate  400  prior to or after bonding the supporting die  203  to the IC die  300 . The sensor die  103  may then be electrically connected to the surface mount substrate  400  by wire bonding wire  410 . In an embodiment, a lid  500  is then bonded to the surface mount substrate  400  using a suitable bonding material to provide mechanical protection to the die stack, wire  410 , and pressure sensor  110 . A pressure inlet  510  is provided in the lid  500  to allow an ambient external environment atmosphere inside the package for interaction with the pressure sensor  110 . In an embodiment, the lid  500  surrounds the IC die  300 , supporting die  203 , and the sensor die  103 . 
     In the particular embodiment illustrated in  FIG. 11A , sensor die  103  is illustrated as including a surface-micromachined pressure sensor  110 . Embodiments are not so limited. For example,  FIG. 11B  is a cross-sectional side view illustration of a pressure sensor package similar to that illustrated in  FIG. 11A  with a bulk-micromachined pressure sensor  110  in accordance with an embodiment. 
       FIGS. 11C-11D  are cross-sectional side view illustrations of pressure sensor packages integrated onto air cavity ceramic substrates with flip chip and wire bonding in accordance with embodiments.  FIGS. 11C-11D  are similar to those embodiments illustrated and described with regard to  FIGS. 11A-11B , with one difference being that surface mount substrate  400  is an air cavity ceramic substrate including sidewalls  402 . In such embodiments, the sidewalls  402  surround the IC die  300 , supporting die  203  and sensor die  103 . A lid  500  including a pressure inlet  510  is bonded to the sidewalls  402 . Similar to  FIGS. 11A-11B , the IC die  300  may be flip chip bonded to the air cavity ceramic surface mount substrate  400  and sensor die  103  wire bonded to the air cavity ceramic surface mount substrate  400 . 
       FIGS. 11E-11F  are cross-sectional side view illustrations of pressure sensor packages integrated onto surface mount substrates with wire bonding in accordance with embodiments. While the previous embodiments described and illustrated with regard to  FIGS. 11A-11D  have disclosed flip chip bonding to the surface mount substrate  400 , this is not required. In the embodiments illustrated in  FIGS. 11E-11F , IC die  300  is bonded to the surface mount substrate  4000  with a die attach material  310  and electrically connected to the surface mount substrate  400  with wire bonds  410 . 
       FIGS. 12-13B  are cross-sectional side view illustrations for manners of integrating a motion sensor package onto a surface mount substrate in accordance with embodiments. In an embodiment, the motion sensor package includes a motion sensor die  125 , supporting die  203 , and air gap  206  formed with a wafer batch process for stress isolation from a bottom surface of the package adjacent the surface mount substrate  400 . Referring to  FIG. 12  a cross-sectional side view illustration is provided of a motion sensor wafer  121  bonded to a supporting wafer  200  with wafer bonding material  210 , prior to singulation of individual die stacks  260  along dotted singulation lines. The motion sensor wafer  121  may include a base substrate  122  and caps  124  surrounding motion sensors  120 . As shown, each cap  124  may form a cavity  126  around a corresponding motion sensor  120 , which is not required to be exposed to the atmosphere outside of cap  124  for operation of the motion sensor. For example, a suitable motion sensor may be a comb driver. 
     Referring now to  FIG. 13A , a die stack  260  including a motion sensor die  125 , supporting die  203 , and air gap  206  is integrated with surface mount substrate  400 , such as an LGA, QFN, or ceramic substrate. Each motion sensor die  125  may include a singulated portion of the base substrate  122 , and cap  124  surrounding a corresponding motion sensor  120 . It is understood that a number of die stack configurations may be integrated onto the surface mount substrate in  FIG. 13A , including the variations similar to those described and illustrated with regard to  FIGS. 9A-10J . Referring again to  FIG. 13A , the bonded motion sensor die  125  and supporting die  203  is bonded to a surface mount substrate, such as an LGA, QFN, or ceramic substrate  400  using a die attach material  310 . In an embodiment, die attach material  310  is formed of an elastomeric material, such as silicone, which may be characterized as a high flexibility and low stress adhesive material employed in packaging. In an embodiment, the wafer bond material  210  forms a more rigid bond than die attach material  310 . Die attach material  310  may be a non-electrically conductive material. In accordance with some embodiments, conductive joints are not formed through die attach material  310 , and wire bonding is used to make electrical connection to the sensor die. In an embodiment, an IC die  300  is bonded the motion sensor die  125 , such as bonded to the cap  124 . In an embodiment, IC die  300  is an application specific integrated circuit (ASIC) die. In an embodiment, IC die  300  is a field programmable gate array (FPGA) die. 
     The IC die  300  may then be electrically connected to the surface mount substrate  400  and motion sensor die  125  by wire bonding wires  410 . In an embodiment, a lid  500  is then bonded to the surface mount substrate  400  using a suitable bonding material to provide mechanical protection to the die stack and wires  410 . A pressure inlet is not required in the lid  500  to allow an ambient external environment atmosphere inside the package for interaction with the motion sensor  120 . In an embodiment, the lid  500  surrounds the IC die  300 , supporting die  203 , and the sensor die  125 . 
       FIG. 13B  is a cross-sectional side view illustration of a motion sensor package integrated onto air cavity ceramic substrate with wire bonding in accordance with an embodiment.  FIG. 13B  is similar to the embodiment illustrated and described with regard to  FIG. 13A , with one difference being that surface mount substrate  400  is an air cavity ceramic substrate including sidewalls  402 . In such an embodiment, the sidewalls  402  surround the IC die  300 , supporting die  203 , and the sensor die  125 . A lid  500  including a pressure inlet  510  is bonded to the sidewalls  402 . Similar to  FIG. 13A , the IC die  300  and sensor die  125  may be wire bonded to the air cavity ceramic surface mount substrate  400 . 
       FIGS. 14-15B  are cross-sectional side view illustrations for manners of integrating a pressure sensor in a wafer level package in accordance with embodiments. In an embodiment, the pressure sensor package includes a pressure sensor die  103 , supporting IC die  303 , and air gap  206  formed with a wafer batch process for stress isolation from a bottom surface of the package. Referring to  FIG. 14  a cross-sectional side view illustration is provided of a pressure sensor wafer  100  bonded to a supporting IC wafer  301  with wafer bonding material  210 , prior to singulation of individual die stacks  270  along dotted singulation lines. The pressure sensor wafer  100  may include a base substrate  102  pressure sensors  110 , such as diaphragms  104  formed over cavities  106 . The supporting IC wafer  301  may be formed similar to a supporting wafer  200  described above, including recess areas  207  etched into a base substrate  302 , support anchors  204  that protrude above the recess areas  207 , and stopper structures  208 . In an embodiment, the supporting IC wafer  301  additionally includes through vias  314  for routing signal to output leads, a backside redistribution layer  316  and topside contact  312 . 
     Referring now to  FIG. 15A , in an embodiment a wafer level pressure sensor package includes a die stack  270  including a pressure sensor die  103 , supporting IC die  303 , and air gap  206 . The supporting IC die  303  includes a top surface  201  characterized by a recess area  207  and a supporting anchor  204  protruding above the recess area. A through via  314  extends through base substrate  302  of the supporting IC die  303  from a bottom surface of the base substrate  302  adjacent the redistribution layer  316  to the top surface of the base substrate  302  along the support anchor  204 . The sensor die  103  is bonded to the support anchor  204  such at an air gap  206  exists between the sensor die  103  and the recess area  207 , and the sensor die  103  includes a pressure sensor  110  positioned directly above the air gap  206 . A plurality of ball bumps  320  can be placed on the redistribution layer  316  for integrating the package, for example with a printed circuit board. In an embodiment, the supporting IC die  303  is an application specific integrated circuit (ASIC) die. In an embodiment, the supporting IC die  303  is a field programmable gate array (FPGA) die. In this aspect, the supporting IC die  303  is used for both operating the pressure sensor, and isolating stress from the pressure sensor. In the particular embodiment illustrated, the diaphragm  104  of the pressure sensor  110  is immediately adjacent the air cavity  106 . In such a configuration the diaphragm is mechanically protected within the package and a separate lid is not required. In addition, such a configuration may be compatible for mounting the package with a pick and place tool, e.g. picking up the top side of the pressure sensor die with the pick and place tool. Furthermore, the air cavity  106  also functions as a pressure inlet for operation of the pressure sensor  110  in such a configuration. In the particular embodiment illustrated in  FIG. 15A , sensor die  103  is illustrated as including a surface-micromachined pressure sensor  110 . Embodiments are not so limited. For example,  FIG. 15B  is a cross-sectional side view illustration of a pressure sensor package similar to that illustrated in  FIG. 15A  with a bulk-micromachined pressure sensor  110  in accordance with an embodiment. It is understood that the die stacks  270  illustrated in  FIGS. 15A-15B  may assume a number of modified configurations, including the variations similar to those described and illustrated with regard to  FIGS. 9A-10J . 
       FIGS. 16-17  are cross-sectional side view illustrations for a manner of integrating a motion sensor in a wafer level package in accordance with an embodiment. In an embodiment, the motion sensor package includes a motion sensor die  125 , IC die  300 , supporting interposer die  503 , and air gap  206  formed with a wafer batch process for stress isolation from a bottom surface of the package. 
     Referring to  FIG. 16  a cross-sectional side view illustration is provided of a motion sensor wafer  121  and IC wafer  311  bonded to a supporting interposer wafer  501  with wafer bonding material  210 , prior to singulation of individual die stacks  280  along dotted singulation lines. The motion sensor wafer  121  may include a base substrate  122 , pressure sensors  120 , sidewalls  123  surrounding the pressure sensors  120 . For example, the motion sensor wafer  121  may be fabricated with a wafer bonding process of multiple wafers to form the pressure sensors  120  surrounded by sidewalls  123 . Sidewalls  123  may form a cavity  126  around a corresponding motion sensor  120 , which is not required to be exposed to an ambient external environment atmosphere outside of cavity  126  for operation of the motion sensor. For example, a suitable motion sensor may be a comb driver. The IC wafer  311  may include a plurality of through vias  314  extending through a thickness of the IC wafer substrate  300 , such as a silicon substrate. The supporting interposer wafer  501  may be formed similar to a supporting wafer  200  described above, including recess areas  207  etched into a base substrate  502 , support anchors  204  that protrude above the recess areas  207 , and stopper structures  208 . In an embodiment, the supporting interposer wafer  501  additionally includes through vias  514  for routing signal to output leads, a backside redistribution layer  516  and topside contact  512 . 
     Referring now to  FIG. 17 , in an embodiment a wafer level motion sensor package includes a die stack  280  including a motion sensor die  125 , IC die  300 , supporting interposer die  503 , and air gap  206 . The supporting interposer die  503  includes a top surface  201  characterized by a recess area  207  and a supporting anchor  204  protruding above the recess area. A through via  514  extends through base substrate  502  of the supporting interposer die  503  from a bottom surface of the base substrate  502  adjacent the redistribution layer  516  to the top surface of the base substrate  502  along the support anchor  204 . The IC die  300  is bonded to the support anchor  204  such at an air gap  206  exists between the IC die  300  and the recess area  207 . The sensor die  125  is bonded to the IC die  300 , and includes a motion sensor  120  positioned directly above the air gap  206 . A plurality of ball bumps  320  can be placed on the redistribution layer  516  for integrating the package, for example with a printed circuit board. In an embodiment, IC die  300  is an application specific integrated circuit (ASIC) die. In an embodiment, IC die  300  is a field programmable gate array (FPGA) die. In the particular embodiment illustrated, the motion sensor  120  is contained internally within the package and a lid is not required for mechanical protection. In addition, such a configuration may be compatible for mounting the package with a pick and place tool, e.g. picking up the top side of the motion sensor die with the pick and place tool. It is understood that the die stack  280  illustrated in  FIG. 17  may assume a number of modified configurations, including the variations similar to those described and illustrated with regard to  FIGS. 9A-10J . 
     In utilizing the various aspects of the embodiments, it would become apparent to one skilled in the art that combinations or variations of the above embodiments are possible for forming a sensor package. Although the embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the appended claims are not necessarily limited to the specific features or acts described. The specific features and acts disclosed are instead to be understood as embodiments of the claims useful for illustration.

Metadata:
Filing Date: 20161208
Publication Date: 20180807
Grant Date: 20180807
Priority Date: 20140902
Inventors: HAN, CALEB C.
JIANG, TONGBI
ZHAI, JUN
Assignee: APPLE INC
CPC Classifications: [{"code": "H01L2224/73265", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/32145", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/32145", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L19/0618", "inventive": true, "first": false, "tree": "[]"}, {"code": "B81B2207/07", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L19/146", "inventive": true, "first": false, "tree": "[]"}, {"code": "B81B2201/025", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16225", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/73204", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/73265", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/1461", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16225", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B2203/0315", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L9/0045", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2924/16195", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/48095", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81C1/0023", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L9/0048", "inventive": true, "first": false, "tree": "[]"}, {"code": "B81B2201/0264", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/94", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B2203/0127", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/16151", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L19/148", "inventive": true, "first": false, "tree": "[]"}, {"code": "B81B2207/012", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B7/0048", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2924/16151", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/94", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L7/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "B81B2207/094", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/48095", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/16195", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81C2203/0792", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/73204", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/48095", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B2203/0127", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01L7/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "B81B7/0048", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L2224/73265", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/16225", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B2207/07", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/1461", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/73204", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81C1/0023", "inventive": true, "first": false, "tree": "[]"}, {"code": "B81B2207/094", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L41/1136", "inventive": true, "first": false, "tree": "[]"}, {"code": "B81B2201/0264", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/32145", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/16151", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2224/94", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L41/094", "inventive": true, "first": false, "tree": "[]"}, {"code": "B81C2203/0792", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L2924/16195", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B2207/012", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B2201/025", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B2203/0315", "inventive": false, "first": false, "tree": "[]"}, {"code": "B81B7/0048", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10N30/306", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L19/0618", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L9/0045", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L9/0048", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10N30/2042", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L19/146", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L19/148", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 55402134