Capless semiconductor package with microelectromechanical system (MEMS)

Abstract

Embodiments of the present disclosure relate to a capless semiconductor package having a microelectromechanical system (MEMS). A semiconductor package includes an application-specific integrated circuit (ASIC) die and a microelectromechanical system (MEMS) die. The MEMS die and the ASIC die are coupled to a substrate including an opening extending through the substrate and in fluid communication with an air cavity, which is positioned between the MEMS die and the substrate and separates the MEMS die from the substrate. The opening exposes the air cavity to an external environment, and thereafter, the air cavity exposes a MEMS element of the MEMS die to the external environment. The air cavity separating the MEMS die from the substrate is formed using a manufacturing method that utilizes a thermally decomposable die attach material.

Description

Technical Field

[0001] The present disclosure relates to microelectromechanical systems (MEMS) sensors that are exposed to an external environment. Background Art

[0002] Many semiconductor packages with microelectromechanical systems (MEMS) dies include a cavity that exposes a sensor assembly of the MEMS die to an external environment. The sensor assembly monitors a physical quantity or mass of the external environment outside the package. Such semiconductor packages are typically formed using a rigid cap bonded to a substrate on which the MEMS die is positioned. The cap is shaped to form a cavity between the MEMS die and the cap and includes an opening or hole that exposes the cavity to the external environment. The opening and cavity expose the sensor assembly of the MEMS die to the external environment. For example, the sensor assembly can monitor: pressure, temperature, sound, light, or some other quantity, mass, or a combination of quantity and mass of the external environment to which the sensor assembly is exposed.

[0003] There is a large and growing market for semiconductor packages with MEMS sensors for monitoring a wide range of physical quantities and qualities in the external environment, the environment of an electronic device, input from a user, or any other physical quantity or quality that needs to be monitored. However, significant challenges exist in reducing the manufacturing cost, size, footprint, and thickness of semiconductor packages, as well as providing semiconductor packages that perform increasingly complex functions. Examples of electronic devices include laptops, monitors, televisions, smartphones, tablets, computers, flexible electronic devices, or any other electronic device that could benefit from monitoring a physical quantity or quality in the external environment.

[0004] A significant challenge is producing a semiconductor package having a MEMS die that is reduced in size, footprint, profile, and thickness while maintaining the ability of the MEMS die to monitor physical quantities and qualities of the external environment. As semiconductor packages having MEMS dies are reduced in size, footprint, profile, and thickness, it becomes more difficult to provide a cap with sufficient clearance to prevent malfunction of the MEMS die's sensor components while exposing them to the external environment for monitoring.

[0005] Another significant challenge is reducing the cost of producing semiconductor packages with MEMS dies. The cost of manufacturing semiconductor packages with MEMS dies increases as the number of components and materials used for the semiconductor package increases, and the number of manufacturing steps increases. For example, forming a semiconductor package with a cap for protecting the MEMS die includes manufacturing the cap, using a high-accuracy cap attachment machine to place the cap in the correct position, and using an adhesive to attach the cap to the substrate. Moreover, making such semiconductor packages smaller by manufacturing smaller caps would be expensive because, due to the smaller offsets and gaps and the low level of allowed tolerances in positioning the caps, making such semiconductor packages smaller would include manufacturing new high-accuracy cap attachment machines to handle the smaller caps and place the caps in the correct position. Summary of the Invention

[0006] In view of the above list of significant challenges (which is not a complete list), it is desirable to provide a semiconductor package having a microelectromechanical system (MEMS) die that: does not require a cap to protect the MEMS die or expose the MEMS die to the external environment, has a smaller thickness and a smaller size, does not require as many manufacturing steps, and allows for greater variation tolerances when manufacturing the semiconductor package, thereby increasing the yield of usable semiconductor packages formed.

[0007] The present disclosure relates to various embodiments of a semiconductor package that contains a MEMS die and does not require the use of a cap bonded to a substrate. In other words, the semiconductor package is a capless semiconductor package.

[0008] According to one embodiment of a semiconductor package containing a MEMS die, a molding compound covers the sidewalls and surfaces of the MEMS die and directly contacts the sidewalls and surfaces of the MEMS die, so that the MEMS die is held in place within the semiconductor package. The MEMS die is exposed to the external environment through an opening formed in the substrate and an air cavity positioned between the substrate and the sensor assembly of the MEMS die. This semiconductor package can be referred to as a capless semiconductor package. The MEMS die is electrically coupled to the substrate of the semiconductor package via bonding wires.

[0009] In this embodiment, if a cap is utilized to protect the sensor component of the MEMS die and expose it to the external environment, the mold compound functions in a similar manner to how the cap would normally function. However, by eliminating the need to include a cap, the manufacturing cost of producing a semiconductor package having a MEMS die is reduced, the yield of usable and functional semiconductor packages having a MEMS die is increased, and the overall thickness of the semiconductor package having a MEMS die is reduced. Costs are reduced and yields are increased because a high-precision cap attachment machine is not required to place the cap, the cap does not have to be manufactured, and the semiconductor package for protecting the MEMS die can be formed using standard strip molding processes and materials.

[0010] According to an alternative embodiment of a semiconductor package containing a MEMS die, a mold compound covers the sidewalls of the MEMS die, and a surface of the MEMS die is flush and coplanar with a surface of the mold compound. The surface of the MEMS die that is flush and coplanar with the surface of the mold compound is exposed to the external environment. The MEMS die is electrically coupled to the substrate via solder balls positioned within an air cavity separating the MEMS die from the substrate.

[0011] According to another alternative embodiment of the semiconductor package including the MEMS die, the molding compound covers the sidewalls and the surface of the MEMS die facing away from the substrate.The MEMS die is electrically coupled to the substrate via solder balls positioned within an air cavity separating the MEMS die from the substrate.

[0012] According to a method for manufacturing a semiconductor package including a MEMS die, the MEMS die is coupled to a substrate via a sacrificial material. The sacrificial material is a thermally decomposable die attach member that is removed by exposing the die attach member to heat. The method also includes forming an opening in the substrate that is aligned with both the sensor assembly of the MEMS die and the air cavity separating the MEMS die from the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the drawings, like reference numbers identify similar elements or actions unless context dictates otherwise. The sizes and relative portions of elements in the drawings are not necessarily drawn to scale. Figure 1A A cross-sectional view of an embodiment relating to a semiconductor package including a microelectromechanical system (MEMS) die and an application specific integrated circuit (ASIC) die;

[0014] Figure 1B is a cross-sectional view of an alternative embodiment of a semiconductor package including a MEMS die and an ASIC die;

[0015] Figure 1Cis a cross-sectional view of an alternative embodiment of a semiconductor package including a MEMS die and an ASIC die; Figure 2A A cross-sectional view of an alternative embodiment of a semiconductor package including a MEMS die and an ASIC die;

[0016] Figure 2B A cross-sectional view of an alternative embodiment of a semiconductor package including a MEMS die and an ASIC die;

[0017] Figure 3 A cross-sectional view of an alternative embodiment of a semiconductor package including a MEMS die and an ASIC die;

[0018] Figures 4A to 4E Embodiments directed to methods of manufacturing embodiments of semiconductor packages containing a MEMS die and an ASIC die;

[0019] Figure 5 A method relating to an alternative embodiment of manufacturing a semiconductor package containing a MEMS die and an ASIC die;

[0020] Figure 6 Embodiments are directed to electronic devices that include embodiments of a semiconductor package that includes a MEMS die and an ASIC die. DETAILED DESCRIPTION

[0021] In the following description, certain specific details are set forth to provide a thorough understanding of various embodiments of the present disclosure. However, those skilled in the art will appreciate that the present disclosure may be practiced without these specific details. In other instances, well-known structures associated with electronic components and semiconductor manufacturing techniques are not described in detail to avoid unnecessarily obscuring the description of the embodiments of the present disclosure.

[0022] Unless the context requires otherwise, throughout this specification and the claims that follow, the word "comprise" and variations such as "including" and "comprising" should be interpreted in an open, inclusive sense, that is, as meaning "including but not limited to."

[0023] The use of ordinal numbers such as first, second, and third does not necessarily imply an ordering but may simply distinguish multiple instances of an action or structure.

[0024] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0025] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0026] As used in this specification and the appended claims, the terms "top" and "bottom" refer to the orientation of the surface of a semiconductor package when viewed in the figures. The terms "top" and "bottom" do not limit the surface of the semiconductor package in the figures to the specific orientation of the semiconductor package as disclosed in the figures.

[0027] As used in this specification and the appended claims, the terms "left" and "right" refer to the orientation of the surface of the semiconductor package when viewed in the figures. The terms "left" and "right" do not limit the surface of the semiconductor package in the figures to the specific orientation of the semiconductor package disclosed in the figures.

[0028] The present disclosure relates to various embodiments of a semiconductor package containing a MEMS die, the MEMS die including an air cavity (which may be referred to as a space, cavity, or opening) that separates the MEMS die from a substrate of the semiconductor package and exposes a sensor assembly or MEMS element of the MEMS die to an external environment. A mold compound or encapsulant of the semiconductor package surrounds the MEMS die and directly contacts the MEMS die to hold the MEMS die within the semiconductor package and protect the MEMS die.

[0029] Figure 1A A cross-sectional view of an embodiment of a semiconductor package 100a is provided. The semiconductor package 100a includes a substrate 102 on one side of the semiconductor package 100a. The substrate 102 includes an insulating polymer core and conductive connectors, conductive contacts, and conductive vias on or in the insulating polymer core. The conductive connectors, conductive contacts, and conductive vias are utilized to supply signals and power to the die 110, 116a in the semiconductor package 100a. For example, the die can be an application-specific integrated circuit (ASIC) die 110 or a microelectromechanical system (MEMS) die 116a that is electrically coupled to the conductive connectors, conductive contacts, and conductive vias of the substrate 102 of the semiconductor package 100a.

[0030] MEMS die 116a includes a sensor element 118, which may be a pressure sensor, a temperature sensor, an acoustic sensor, or any other type of MEMS sensor. Figure 1AThe sensor element 118 in FIG is a placeholder for any structure of the sensor element 118 of the MEMS die 116a. Figure 1B and Figure 1C The structure of the sensor element 118 of the MEMS die 116 a will be discussed in more detail with reference to possible structures of the sensor elements of the MEMS dies 116 b , 116 c in FIG.

[0031] In this embodiment, an ASIC die 110 and a MEMS die 116 a are coupled to a surface of a substrate 102. The surface of the substrate 102 includes a first contact pad 117 coupled to the ASIC die 110 via a bond wire 112 and a second contact pad 119 coupled to the MEMS die 116 a via a bond wire 124, respectively. A bottom surface 101 of the substrate 102 faces away from the MEMS die 116 a and the ASIC die 110. The bottom surface 101 of the substrate 102 includes a plurality of contact pads 121, which are coupled to the first contact pad 117 or the second contact pad 119 via conductive vias or other connections in the substrate 102 as discussed above. For simplicity, the conductive vias or other connections are not shown in the figure.

[0032] ASIC die 110 is coupled to the substrate via an adhesive or coupling material 108, which can be a conductive adhesive, a non-conductive adhesive, a die attach film, or any other material utilized to attach a die to a substrate. Adhesive or coupling material 108 is coupled to a bottom surface 151 of ASIC die 110 and to a top surface 103 of substrate 102. Top surface 153 of ASIC die 110 includes contact pads 114 coupled to active and passive components in substrate 102 via bond wires 112, and contact pads 111 coupled to contact pads 115 of MEMS die 116a via another bond wire 113. Bottom surface 151 of ASIC die 110 faces toward top surface 103 of substrate 102, while top surface 153 of ASIC die 110 faces away from top surface 103 of substrate 102.

[0033] Bond wires 112 that couple ASIC die 110 to substrate 102 include ends coupled to contact pads 114 and ends coupled to active or passive components within substrate 102 through contact pads 117. Bond wires 112 allow electrical signals and power to be supplied to ASIC die 110 from other electrical components, as discussed earlier. Bond wires 112 allow electrical signals to be sent through ASIC die 110 to other electrical components. These electrical signals may be command signals, control signals, data signals, or any other type of electrical signals used to communicate information between electrical components within an electronic device.

[0034] Similarly, bond wires 113 that couple contact pads 111 of ASIC die 110 to contact pads 115 of MEMS die 116 a include ends coupled to contact pads 111 of ASIC die 110 and ends coupled to contact pads 115 of MEMS die 116 a. Bond wires 113 allow electrical signals to be transmitted from ASIC die 110 to MEMS die 116 a, or vice versa. These electrical signals may be command signals, control signals, data signals, or any other type of electrical signals used to transmit information between electrical components. Contact pads 115 may be coupled to sensor elements 118 of MEMS die 116 a through conductive connections, such as conductive vias.

[0035] MEMS die 116a includes contact pads 122 coupled to conductive vias 120 and bond wires 124. Conductive vias 120 extend through MEMS die 116a from contact pads 122 toward sensor element 118, and conductive vias 120 couple contact pads 122 to sensor element 118.

[0036] Contact pad 122 of MEMS die 116 a is coupled to an end of a bonding wire 124, and the other end of bonding wire 124 is coupled to a second contact pad 119 in substrate 102. Bond wire 124 transmits electrical signals from the MEMS die to external electrical components and transmits electrical signals from external electrical components to MEMS die 116 a. These electrical signals may be command signals, control signals, data signals, or any other type of electrical signals used to transmit information between electrical components.

[0037] Semiconductor package 100a includes an air cavity 106, which may be referred to as a space, an opening, or a cavity. Air cavity 106 is positioned between a bottom surface 105 of a MEMS die 116a including a sensor element 118 and a top surface 103 of a substrate 102 facing the MEMS die 116a. Air cavity 106 separates bottom surface 105 of MEMS die 116a from top surface 103 of substrate 102.

[0038] The air cavity 106 is in fluid communication with and aligned with an opening 104 extending through the base 102. The opening 104 can be circular, rectangular, square, triangular, or any other desired shape. The opening 104 in the base allows the air cavity 106 to be exposed to the external environment and allows the sensor element 118 to be exposed to the external environment. The sensor element 118 monitors a physical quantity or quality of the external environment (such as pressure, temperature, sound, or any other desired quantity or quality of the external environment).

[0039] Air cavity 106 extends from a first sidewall 141 of MEMS die 116a to a second sidewall 143 of MEMS die 116a. In other words, in this embodiment, air cavity 106 has a width that is substantially equal to the width of MEMS die 116a. Air cavity 106 has a width that is substantially equal to the width of MEMS die 116a because the air cavity can be slightly larger or smaller when the semiconductor package is manufactured in a manner that produces an air cavity with a width equal to the width of the MEMS die. This understanding of the use of "substantially" will also apply to other similar uses of the word "substantially" in this disclosure.

[0040] In alternative embodiments, the air cavity positioned between and separating the MEMS die and the substrate may extend beyond the sidewalls of the MEMS die and have a width greater than the width of the MEMS die, or have a width less than the width of the MEMS die.

[0041] In this embodiment of the semiconductor package 100a, the sensor element 118 is aligned with the opening 104 in the substrate 102. However, in alternative embodiments of the semiconductor package, the MEMS element of the MEMS die may not be aligned with the opening extending through the substrate. Instead, in alternative embodiments of the semiconductor package, the MEMS element of the MEMS die may be offset from the opening extending through the substrate.

[0042] In this embodiment, the mold compound 126 covers the top surface 107 of the MEMS die 116a (which includes the contact pads 115 and 122), and the mold compound 126 covers the sidewalls 141 and 143 of the MEMS die 116a. The bottom surface 105 of the MEMS die 116a, where the sensor element 118 is located, remains exposed. The sensor element 118 is exposed to the external environment through the air cavity 106 and the opening 104 in the substrate 102 because the air cavity 106 and the opening 104 in the substrate 102 are in fluid communication.

[0043] The mold compound 126 can be an encapsulant material, an insulating material, or some other combination of materials. The direct contact of the mold compound 126 with the sidewalls 141, 143 of the MEMS die 116a holds the MEMS die 116a in place within the semiconductor package 100a so that the air cavity 106 separates the MEMS die 116a from the substrate 102. In other words, the MEMS die 116a is not in physical contact with the substrate 102.

[0044] In this embodiment, the air cavity 106 has a height H1 that is less than the height H2 of the substrate 102. However, in alternative embodiments, the cavity between the MEMS die and the substrate may have a height greater than the height of the substrate. In another alternative embodiment, the air cavity between the MEMS die and the substrate may have a height substantially equal to the height of the substrate.

[0045] In this embodiment, the mold compound 126 has a thickness T1 extending from the surface of the substrate 102 facing the MEMS die 116 a and the ASIC die 110 to the surface of the mold compound 126 facing away from the substrate 102. The air cavity 106 has a height H1 that is less than the height H2 of the opening 104 extending through the substrate 102. The MEMS die 116 a has a height H3. The sum of the height H1 of the air cavity 106 and the height H3 of the MEMS die 116 a is less than the thickness T1 of the mold compound 126.

[0046] exist Figure 1B and Figure 1C FIG shows a semiconductor package 100b, 100c according to an alternative embodiment. The semiconductor package 100b, 100c includes the same components as those described above. Figure 1A Similar features are discussed for the semiconductor package 100a in the foregoing, and for the sake of simplicity and brevity, reference numerals may be repeated. Additionally, for the sake of simplicity and brevity, only the details that differ in these alternative embodiments of the semiconductor packages 100b, 100c will be discussed. However, with respect to the sensor element 118, the alternative embodiment provides for a sensor element that may be incorporated into the foregoing. Figure 1A 1 , which are placeholders for more complex structures of sensor element 118.

[0047] Figure 1B The cross-sectional view of the semiconductor package 100b includes a MEMS die 116b and an ASIC die 110. The semiconductor package 100b includes Figure 1A 1. The semiconductor package 100a of FIG. 100b includes several features similar to those in the semiconductor package 100a of FIG. 100b. However, in the semiconductor package 100b, a sensor assembly 129 is shown on the surface of the MEMS die 116b. The sensor assembly 129, which is a cantilever pressure sensor, senses the pressure of the external environment. The sensor assembly 129 can be electrically coupled to the conductive via 120, the contact pad 122, and the bonding wire 124 coupled to the second contact pad 119 of the substrate 102. Although the sensor assembly 129 is shown as a cantilever beam pressure sensor for simplicity, the sensor assembly 129 can include several electrical contacts, a cavity in the MEMS die 116b that is aligned with the cantilever beam, and other active and passive components.

[0048] A cap 125 is coupled to the surface of the MEMS die 116 b that faces the substrate 102. The cap covers the sensor assembly 129 of the MEMS die 116 b and forms a cavity 127 that surrounds the sensor assembly 129 of the MEMS die 116 b. The cap 125 also includes an opening 123 extending through the cap 125 that exposes the sensor assembly 129 to the external environment. The opening 123 of the cap 125 is in fluid communication with the air cavity 106 positioned between the cap 125 and the substrate 102, and the air cavity 106 is in fluid communication with the opening 104 extending through the substrate 102.

[0049] In this alternative embodiment, the mold compound 126 covers the sidewalls 141, 143 of the MEMS die 116b, the top surface 107 of the MEMS die 116b facing away from the substrate 102, and the sidewalls 145, 147 of the cap 125. Similar to the mold compound 126 in the semiconductor package 100a, the mold compound 126 in the semiconductor package 100b directly contacts the sidewalls 141, 143 of the MEMS die 116b and the sidewalls 145, 147 of the cap 125, such that the air cavity 106 separates the MEMS die 116b and the cap 125 from the substrate 102. In other words, the cap 125 of the MEMS die 116b is not in physical contact with the substrate 102.

[0050] In semiconductor package 100b, cap 125 is on and coupled to bottom surface 105 of MEMS die 116b. Bottom surface 105 faces top surface 103 of substrate 102. Cap 125 has bottom surface 155 that faces top surface 103 of substrate 102. Bottom surface 155 of cap 125 is separated from top surface 103 of substrate 102 by air cavity 106.

[0051] In semiconductor package 100b, opening 123 in cap 125 is offset from opening 104 extending through substrate 102. However, in other alternative embodiments, opening 123 in cap 125 may be aligned with opening 104 in substrate 102.

[0052] Opening 123 in cap 125 has a width W1 that is less than width W2 of opening 104 in substrate 102. However, in other alternative embodiments, width W1 of opening 123 in cap 125 may be greater than or equal to width W2 of opening 104 in substrate 102.

[0053] In the semiconductor package 100b, the cap 125 and the sensor assembly 129 may be incorporated into Figure 1A In the semiconductor package 100a, wherein Figure 1AIn other words, the structure of the cap 125 and the sensor assembly 129 can be the sensor element 118 in the semiconductor package 100a. However, in other alternative embodiments of the semiconductor package, the sensor element 118 can have a different structure. For example, in Figure 1C The structure of the sensor assembly 133 of the MEMS die 116c in FIG. 1 is different.

[0054] Figure 1C FIG. 1 is a cross-sectional view of a semiconductor package 100c including a MEMS die 116c and an ASIC die 110. The semiconductor package 100c includes Figure 1A to Figure 1B However, in this alternative embodiment of semiconductor package 100c, sensor assembly 133 is a thin film that detects sound or vibration.

[0055] MEMS die 116c includes a first internal cavity 131 on a first side of a sensor assembly 133 and a second internal cavity 135 on a second side of the sensor assembly 133 opposite the first side of the sensor assembly 133. The sensor assembly 133 separates the first internal cavity 131 from the second internal cavity 135 of the MEMS die 116c. An opening 137 extends into the MEMS die 116c and is in fluid communication with the first internal cavity 131, the air cavity 106 separating the MEMS die 116c from the substrate 102, and the opening 104 extending through the substrate 102. Thus, the opening 104, the air cavity 106, and the first internal cavity 131 expose the sensor assembly 133 of the MEMS die 116c to the external environment.

[0056] In this alternative embodiment of semiconductor package 100 c, opening 137 in MEMS die 116 c has a width W3 that is less than width W4 of opening 104 in substrate 102. However, in other alternative embodiments, width W3 of opening 123 in cap 125 may be greater than or equal to width W4 of opening 104 in substrate 102.

[0057] In semiconductor package 100c, opening 137 is aligned with opening 104 in substrate 102. However, in other alternative embodiments, opening 137 may be offset from opening 104.

[0058] In semiconductor package 100 c, mold compound 126 covers the top surface 103 and sidewalls 141, 143 of MEMS die 116 c. The direct contact of mold compound 126 with sidewalls 141, 143 of MEMS die 116 c holds MEMS die 116 c in place within semiconductor package 100 a, such that air cavity 106 separates MEMS die 116 c from substrate 102. In other words, MEMS die 116 c is not in physical contact with substrate 102.

[0059] In the semiconductor package 100c, the first internal cavity 131, the sensor assembly 133, and the second internal cavity 135 correspond to the sensor element 118 in the semiconductor package 100a. However, in other alternative embodiments of the semiconductor package, the sensor element 118 may have a different structure. Figure 1A The sensor element 118 in the embodiment may have any desired structure for monitoring the quality or physical quantity of the external environment (such as pressure, temperature, sound, light or any other desired quality or quantity of the external environment), and is not limited to the Figures 1B to 1C Those structures described in .

[0060] exist Figures 1A to 1C In the semiconductor packages 100a, 100b, and 100c of FIG. 1 , the walls 139 of the mold compound 126 are flush with the sidewalls 141 and 143 of the MEMS dies 116a, 116b, and 116c. The walls 139 of the mold compound 126 surround the air cavity 106. However, in alternative embodiments of the semiconductor package, the walls 139 may not be flush or coplanar with the sidewalls 141 and 143 of the MEMS dies 116a, 116b, and 116c of the semiconductor package. Instead, or in addition, a portion of the mold compound 126 may be on the bottom surface 105 of the MEMS dies 116a, 116b, and 116c that faces the substrate 102, or the walls 139 may be positioned inward from the sidewalls 141 and 143 of the MEMS dies 116a, 116b, and 116c. Alternatively, the wall 139 may be spaced apart from the plurality of sidewalls 141 , 143 of the MEMS dies 116 a , 116 b , 116 c to provide the air cavity 106 with a width greater than the MEMS dies 116 a , 116 b , 116 c .

[0061] Figure 2AFIG2 is a cross-sectional view of a semiconductor package 200a including a MEMS die 216 and an ASIC die 210 according to an alternative embodiment. The ASIC die 210 and the MEMS die 216 are coupled to the top surface 203 of the substrate 202. The ASIC die 210 is coupled to the top surface 203 of the substrate 202 via an adhesive or coupling material 208 on the bottom surface 251 of the ASIC die 210. The adhesive or coupling material 208 can be a conductive adhesive, a non-conductive adhesive, a die attach film, or any other adhesive material desired. The MEMS die 216 includes a sensor element 218.

[0062] The top surface 203 of the substrate 202 includes a first contact pad 217 coupled to a contact 214 on the top surface 253 of the ASIC die 210 via a bond wire 212. Figures 1A to 1C Unlike the semiconductor packages 100a, 100b, and 100c in the drawings, the ASIC die 210 electrically communicates with the MEMS die 216 via conductive elements in the substrate 202, which are not shown for simplicity. For example, the conductive elements in the substrate 202 may be conductive vias, conductive connectors, or some other conductive connectors that are coupled. Alternatively, corresponding contact pads among a plurality of contact pads 221 on the bottom surface 201 of the substrate 202 facing away from the ASIC die 210 and the MEMS die 216 are coupled to contact pads 217 and 225 on the top surface of the substrate 202 facing the ASIC die 210 and the MEMS die 216. Alternatively, corresponding contact pads 217 of the substrate 202 coupled to the ASIC and corresponding contact pads 225 of the substrate 202 coupled to the MEMS die 216 may be electrically coupled to each other via conductive elements within the substrate 202, which are again not shown for simplicity.

[0063] A plurality of contact pads 225 on the substrate 202 are coupled to a plurality of contact pads 222 on the bottom surface 205 of the MEMS die 216. The bottom surface 205 of the MEMS die 216 faces the top surface 203 of the substrate 202. Each of the plurality of contact pads 222 of the MEMS die 216 is aligned with and coupled to a corresponding contact pad 225 of the substrate 202. The contact pads 222 of the MEMS die 216 are coupled to the contact pads 225 of the substrate 202 through solder balls 220, which are present within the air cavity 206 that separates the substrate 202 from the MEMS die 216.

[0064] In this embodiment, the solder balls 220 are spaced apart from the sidewalls 227 of the mold compound 224, which are flush with the sidewalls 241, 243 of the MEMS die 216. The sidewalls 227 of the mold compound 224 surround the air cavity 206. However, in alternative embodiments of the semiconductor package 200a, the solder balls 220 may contact or cover these walls of the mold compound 224. Furthermore, the solder balls 220 may be replaced by other known conductive connectors, such as pins and conductive adhesives.

[0065] In this embodiment, the molding compound has sidewalls 227 that are flush and coplanar with the sidewalls 241 of the MEMS die 216. Figures 1A to 1C However, in alternative embodiments, the mold compound 224 may extend onto the bottom surface 205 of the MEMS die 216 that faces the substrate 202, a portion of the mold compound 224 may be on the bottom surface 205 of the MEMS die 216, or the wall 139 may be positioned inward from the plurality of sidewalls 241 of the MEMS die 216. In another alternative embodiment, the sidewalls 227 may be positioned outward from the plurality of sidewalls 241, 243 of the MEMS die 216.

[0066] Air cavity 206 may be referred to as a space, an opening, or a cavity. Air cavity 206 is positioned between bottom surface 205 of MEMS die 216 where sensor element 218 is located and top surface 203 of substrate 202 facing MEMS die 216. Air cavity 206 separates bottom surface 205 of MEMS die 216 from top surface 203 of substrate 202.

[0067] An opening 204 extending through the base 202 is in fluid communication with and aligned with the air cavity 206. The opening 204 may be circular, rectangular, square, triangular, or any other desired shape. The opening 204 in the base 202 allows the air cavity 206 and the sensor element 218 to be exposed to the external environment.

[0068] The sensor element 218 monitors a quantity or quality of the external environment (such as pressure, temperature, sound, or any other desired quantity or quality of the external environment). The air cavity 206 extends from a first respective sidewall 241 of the MEMS die 216 to a second respective sidewall 241 of the MEMS die 216. In this embodiment, the air cavity 206 has a width substantially equal to the width of the MEMS die 216. However, in alternative embodiments, the air cavity 206 can extend beyond the sidewalls of the MEMS die and have a width greater than the width of the MEMS die, or have a width less than the width of the MEMS die.

[0069] and Figures 1A to 1C The semiconductor packages 100a, 100b, and 100c are different. Figure 2A In this embodiment of the semiconductor package 200a in FIG. 1 , the MEMS die 216 has a top surface 207 facing away from the substrate 202. The top surface 207 is flush or coplanar with the top surface 223 of the mold compound 224 facing away from the substrate 202. This allows the semiconductor package 200a to be manufactured to be smaller than in FIG. Figures 1A to 1C The semiconductor packages 100 a , 100 b , and 100 c are thinner.

[0070] In semiconductor package 200a, mold compound 224 has a thickness T2 extending from top surface 203 of substrate 202 to a top surface 223 of mold compound 224 facing away from substrate 202. Air cavity 206 and solder ball 220 have a height H4 that is less than a height H5 of opening 204 extending through substrate 202. MEMS die 216 has a height H6. The height H4 of air cavity 206 and solder ball 220, the height H5 of opening 204, and the height H6 of MEMS die 216 are all less than the thickness T2 of mold compound 224. The sum of the height H4 of air cavity 206 and solder ball 220, and the height H6 of MEMS die 216 is substantially equal to the thickness T2 of mold compound 224.

[0071] Figure 2B The present invention relates to a semiconductor package 200b similar to the semiconductor package 200a. The features of the semiconductor package are the same, however, the molding compound 224 covers the plurality of sidewalls 241, 243 of the MEMS die 216 and covers the top surface 207 of the MEMS die 216. The molding compound 224 has a thickness T3 that is greater than the sum of the height H4 of the air cavity 206 and the height H6 of the MEMS die 216.

[0072] Figure 3 is a cross-sectional view of a semiconductor package 400. The features of the semiconductor package 400 are similar to those of the Figure 1A 100a and are provided with similar reference numerals. However, in semiconductor package 400, ASIC die 110 is coupled to the top surface 107 of MEMS die 116a, which faces away from substrate 102, via adhesive 418. Adhesive 418 can be a conductive adhesive, a non-conductive adhesive, or some other adhesive. For example, if adhesive 418 is a conductive adhesive, ASIC die 110 can be electrically coupled to MEMS die 216 via the conductive adhesive.

[0073] In this embodiment, air cavity 106 has a height H7, and base 102 and opening 104 have a height H8 greater than height H7 of air cavity 106. In alternative embodiments, height H7 of air cavity 106 may be greater than or equal to height H8 of base 102.

[0074] MEMS die 116a has a height H9, and ASIC die 110 has a height H 10 In this embodiment, the height H9 of the MEMS die 116a is greater than the height H9 of the ASIC die 110. 10 In an alternative embodiment, the height H9 of the MEMS die 116a may be less than or equal to the height H9 of the ASIC die 110. 10 .

[0075] The mold compound 126 has a thickness T4 extending from the top surface 103 of the substrate 102 facing the MEMS die 116a and the ASIC die 110. The thickness T4 of the mold compound 126 is greater than the height H7 of the air cavity 106, the height H9 of the MEMS die 116a, and the height H 10 The mold compound 126 covers the sidewalls 141, 143 (these sidewalls 141, 143 may be referred to as the right sidewall 141 and the left sidewall 143 of the MEMS die 116a) and covers the sidewalls 141, 143 of the ASIC die 110. The mold compound 126 holds the MEMS die 116a in place, spaced apart from the substrate 102 by the air cavity 106. In other words, the MEMS die 116a is not in physical contact with the substrate 102.

[0076] ASIC die 110 includes contact pads 114 coupled to contact pads 117 on a top surface 103 of substrate 102 facing MEMS die 116 a and ASIC die 110. Similar to contact pads 119 of substrate 102 coupled to MEMS die 116 a using bond wires 124, contact pads 117 of substrate 102 are coupled to contact pads 114 of ASIC die 110 via bond wires 424. Contact pads 117 are coupled to at least one contact pad 121 of a plurality of contact pads 121.

[0077] exist Figure 3In this embodiment of the semiconductor package 400 in FIG. 4 , the walls 139 of the mold compound 126 are flush with the sidewalls 141 , 143 of the MEMS die 116 a. The walls 139 of the mold compound 126 surround the air cavity 106. However, in alternative embodiments of the semiconductor package, the walls 139 may not be flush or coplanar with the plurality of sidewalls 141 , 143 of the MEMS die 116 a of the semiconductor package 400. Instead, the walls 139 may be on the bottom surface 105 of the MEMS die 116 a that faces the substrate 102, a portion of the mold compound 126 may be on the bottom surface 105 of the MEMS die 116 a, or the walls 139 may be positioned inward from the sidewalls 141 , 143 of the MEMS die 116 a. Alternatively, the sidewalls 141 , 143 of the MEMS die 116 a may be positioned closer to the opening 104 in the substrate 102 than the walls 139. In other words, the air cavity 106 may have a width that is greater than the width of the MEMS die 116 a , or the walls 139 may be positioned outward from the sidewalls 141 , 143 of the MEMS die 116 a .

[0078] These above-described embodiments of semiconductor packages 100a, 100b, 100c, 200a, 200b, 400 are thinner than semiconductor packages that utilize caps rather than mold compound to protect the ASIC die and MEMS die. The reason these semiconductor packages are thinner than semiconductor packages that utilize caps rather than mold compound to protect the ASIC die and MEMS die is because space must be provided between the cap and the die to form the bond wires that couple the die to the substrate. In contrast, when utilizing mold compound, the mold compound can be more precisely formed such that the mold compound has an overall height that is less than the cap, but still provides protection to the bond wires because the mold compound reinforces the bond wires. Similarly, if the mold compound is used as in Figures 2A to 2B The semiconductor package disclosed in

[15] similarly uses solder balls to couple the MEMS die to the substrate, and can be thinner than a package using a cap because the surface of the MEMS die can be made flush with the surface of the molding compound, which is very difficult to do with a cap to protect the MEMS die. The molding compound surrounds the die and also provides different reinforcement than the cap. Figures 4A to 4E A flow chart of a method for manufacturing the semiconductor package discussed above is provided. Specifically, Figures 4A to 4E Describes the use Figure 1A A method for manufacturing a semiconductor package 100a is provided.

[0079] exist Figure 4A10. The first step 501 illustrated in FIG. 10 includes coupling the MEMS die 116a and the ASIC die 110 to the substrate 102. The MEMS die 116a is coupled to the top surface of the substrate 102 via an adhesive or coupling material 504. In this embodiment, the adhesive or coupling material 504 is a thermally decomposable die attach, a thermally decomposable adhesive, a thermally decomposable die attach material, or a thermally decomposable coupling material. Alternatively, the adhesive or coupling material 504 can be other known sacrificial materials. The thermally decomposable die attach 504 covers the surface of the MEMS die 116a including the sensor element 118. The sensor element 118 is covered by the thermally decomposable die attach 504. The sensor element 118 faces the substrate 102.

[0080] The thermally decomposable die attach 504 includes sidewalls 543. In this embodiment, the sidewalls 543 of the thermally decomposable die attach 504 are coplanar or flush with the sidewalls 141, 143 of the MEMS die 116a. However, in alternative embodiments, the sidewalls 543 of the thermally decomposable die attach 504 may extend outward from the sidewalls 141, 143 of the MEMS die 116a, may extend inward from the sidewalls 141, 143 of the MEMS die 116a, or may extend outward or inward in any desired combination.

[0081] The thermally decomposable die attach material 504 may be a tetracyclododecene-based sacrificial polymer (TD) material; a polycarbonate material, such as polyethylene carbonate (PEC), polypropylene carbonate (PPC), polycyclohexene carbonate (PCC), a copolymer of polypropylene carbonate (PPC) and polycyclohexene carbonate (PCC); a polyoxymethylene (POM) or acetal material; a polynorbornene (PNB) material; a parylene material; or any other thermally decomposable die attach material as desired. However, these thermally decomposable materials are preferred thermally decomposable materials for coupling the MEMS die 116a to the top surface 103 of the substrate 102 facing the MEMS die 116a because these materials can be removed by the heat or temperature typically generated by a reflow oven, which will be relatively Figure 4E This is discussed in more detail.The temperature range for decomposing the thermally decomposable die attach 504 is 240 to 300 degrees Celsius.

[0082] After the MEMS die 116 a is coupled to the top surface 103 of the substrate 102 via the thermally decomposable die attach 504, the contact pads 122 of the MEMS die 116 a are coupled to the contact pads 119 on the top surface 103 of the substrate 102 via bonding wires 124. The contact pads 122 are on the top surface 107 of the MEMS die 116 a facing away from the substrate 102. The bonding wires 124 can be formed using a wire bonding technique, such as a wire bonding loop formation technique, a ball bonding technique, a wedge bonding technique, or any other desired wire bonding technique. The bonding wires 124 are formed to have an end coupled to the contact pads 122 on the MEMS die 116 a and an end coupled to the contact pads 119 on the top surface 103 of the substrate 102 facing the MEMS die 116 a.

[0083] ASIC die 110 is coupled to the top surface 103 of substrate 102 via an adhesive or coupling material 108. Adhesive or coupling material 108 is on the bottom surface 151 of ASIC die 110. Adhesive or coupling material 108 can be a conductive adhesive, a non-conductive adhesive, or any other desired adhesive or coupling material 108. However, adhesive or coupling material 108 is typically not a thermally decomposable die attach, unlike thermally decomposable die attach 504 that is utilized to couple MEMS die 116 a to substrate 102.

[0084] Similar to the MEMS die 116a, after the ASIC die 110 is coupled to the top surface 103 of the substrate 102 via the adhesive or coupling material 108, the contact pads 114 of the ASIC die 110 are coupled to the contact pads 117 on the top surface 103 of the substrate 102 via the bonding wires 112. The contact pads 114 are on the top surface 153 of the ASIC die 110 facing away from the substrate 102. The bonding wires 112 can be formed using a wire bonding technique, such as a wire bonding loop formation technique, a ball bonding technique, a wedge bonding technique, or any other desired wire bonding technique. The bonding wires 112 are formed to have ends coupled to the contact pads 114 on the top surface 153 of the ASIC die 110 and ends coupled to the contact pads 117 on the top surface 103 of the substrate 102. Contact pads 117, which are coupled to contact pads 114 on the top surface 103 of substrate 102 via bonding wires 112, are coupled to at least one external contact pad 121 of a plurality of external contact pads 121 on the bottom surface 101 of substrate 102. External contact pads 121 are coupled to and electrically communicate with external electrical components. Thus, contact pads 114 of ASIC die 110, bonding wires 112, contact pads 117 on the top surface 103 of substrate 102, and at least one contact pad 121 of the plurality of contact pads 121 on the bottom surface 101 of substrate 102 allow ASIC die 110 to electrically communicate with external electronic components outside semiconductor package 100a.

[0085] Bond wires 113 extend from contact pads 111 on the top surface 153 of ASIC die 110 to contact pads 115 on the top surface 107 of MEMS die 116 a. Bond wires 112 may be formed using a wire bonding technique, such as a wire bond loop formation technique, a ball bonding technique, a wedge bonding technique, or any other desired wire bonding technique. However, in alternative embodiments of the semiconductor package, contact pads 111 of ASIC die 110 and contact pads 115 on MEMS die 116 a may not be present, and thus, bond wires 113 may not be present.

[0086] exist Figure 4BThe second step 503 illustrated in FIG includes forming a mold compound 126 to surround the MEMS die 116 a, the ASIC die 110, the bond wires 112, 113, 124, the adhesive or coupling material 108, and the thermally decomposable die attach 504. The mold compound 126 is on the top surface 103 of the substrate 102. The mold compound 126 covers and directly contacts the top surface 153 of the ASIC die 110 and the top surface 107 of the MEMS die 116 a. The mold compound 126 covers and directly contacts the plurality of sidewalls 141, 143 of the MEMS die 116 a, and the mold compound 126 covers and directly contacts the plurality of sidewalls of the ASIC die 110. The mold compound 126 can be formed using injection molding, pressure and compression molding, strip molding, or any other mold compound forming technique. Mold compound 126 is formed such that it holds MEMS die 116a in a fixed position within the semiconductor package that allows air cavity 106 to separate bottom surface 105 of MEMS die 116a from top surface 103 of substrate 102. However, this will be discussed in more detail later.

[0087] exist Figure 4C , includes forming an opening 104 in substrate 102. Opening 104 in substrate 102 extends from bottom surface 101 of substrate 102 to top surface 103 of substrate 102. Opening 104 exposes a thermally decomposable die attach 504 that couples MEMS die 116a to substrate 102. Opening 104 is formed in substrate 102 by removing a portion of substrate 102 aligned with sensor element 118 of MEMS die 116a. Removing a portion of substrate 102 to form opening 104 can be accomplished using laser drilling, cutting, etching, or some other type of removal technique as desired. However, in a preferred embodiment of third step 505, opening 104 is formed using laser drilling. When laser drilling is used to form the opening 104, a portion of the thermally decomposable die attach 504 may also be removed due to the heat of the laser when the opening 104 is formed in the substrate 102 to expose the thermally decomposable die attach 504. The opening 104 is formed in the substrate 102 to ultimately be utilized to expose the air cavity 106 aligned with the sensor element 118 and the sensor element 118 to the external environment of the semiconductor package 100a. However, this will be discussed in more detail later.

[0088] In an alternative embodiment, this may be done before coupling the MEMS die 116a to the substrate 102. Figure 4D5. However, in that case, the MEMS die 116a should be thick enough so that when the mold compound 126 is later formed to cover the MEMS die 116a, the MEMS die 116a is thick enough to withstand the pressure applied to the MEMS die 116a when the mold compound 126 is formed. Otherwise, if the MEMS die 116a is not thick enough in this alternative method, the MEMS die 116a may be cracked when the mold compound 126 is formed on the MEMS die 116a. Therefore, a preferred embodiment is to form the opening 104 in the substrate 102 aligned with the MEMS die 116a after forming the MEMS die 116a and the mold compound 126 on the substrate 102.

[0089] exist Figure 4E The fourth step 507 illustrated in FIG includes exposing the thermally decomposable die attach 504 to heat. The opening 104 formed in the third step is used to expose the thermally decomposable die attach 504 to heat generated by a heat source 526. The heat source 526 can be a photothermal source, a reflow oven, or any other desired heat source. However, in this case, a preferred option is to utilize a reflow oven as the heat source 526. The reflow oven generally heats the semiconductor package within the reflow oven appropriately without damaging or destroying other active and passive components within the semiconductor package. The reflow oven is also beneficial because it can be used to cause reflow of solder material to form solder connections within the semiconductor package.

[0090] As earlier in Figure 4A As discussed in the description of , the thermally decomposable die attach 504 can be any of a number of materials that can be decomposed using the temperature or heat generated by the heat source 526. For example, a reflow oven is typically used to generate a temperature between 240° C. and 260° C. to decompose the thermally decomposable die attach 504. However, in alternative embodiments of the method, the heat source 526 can generate a temperature greater than or less than the temperature range between 240° C. and 260° C. The length of time that the semiconductor package and thermally conductive adhesive 504 are exposed to the temperatures provided by the reflow oven or heat source 526 will depend on the size of the entire semiconductor package, the number of thermally decomposable die attach 504, the type of die present within the semiconductor package, and several other factors.

[0091] Figure 4EThe completed semiconductor package 100a is shown after the thermally decomposable die attach 504 is decomposed by exposure to heat. By removing the thermally decomposable die attach 504 in a fourth step 507, an air cavity 106 is formed, which is positioned between the MEMS die 116a and the substrate 102. The air cavity 106 separates the substrate 102 from the MEMS die 116a, so that the MEMS die 116a is physically separated from the substrate 102.

[0092] Although for the sake of simplicity and brevity, the following discussion involves Figure 1A The semiconductor package 100a in FIG. 1 is shown in FIG. 1 , but the following discussion also applies to Figures 1B to 1C 、 Figures 2A to 2B as well as Figure 3 100b, 100c, 200a, 200b, 400 in an alternative embodiment of the semiconductor package.

[0093] As discussed earlier, the air cavity 106 is formed using a thermally decomposable die attach 504. The thermally decomposable die attach 504 allows the air cavity 106 to be formed between the MEMS die 116a and the substrate 102 after the mold compound 126 has been formed on the MEMS die 116a, the ASIC die 110, and the substrate 102. By removing the thermally decomposable die attach 504 after the mold compound 126 is formed, there is no need to couple a cap to the substrate 102 to protect the MEMS die 116a and the ASIC die 110 on the substrate 102. Instead, the mold compound 116a protects the ASIC die 110 and the MEMS die 116a from external stresses and forces that could cause the ASIC die 110 and the MEMS die 116a to fail. By eliminating the need for caps to protect the ASIC die 110 and the MEMS die 116a, the cost of manufacturing materials is reduced because no caps are required to form the semiconductor package, and high-precision machines and tools do not need to be utilized to couple the caps to the substrate 102. The yield of usable packages formed by this method is also increased because coupling the caps to the substrate 102 to protect the ASIC die 110 and the MEMS die 116a requires high-precision tools and a high degree of precision. Therefore, by eliminating the need for such a high-precision process for placing the caps, the tolerances used to form the semiconductor package are wider and more forgiving than the high-precision tolerances required when positioning the caps on the semiconductor package. In other words, when using caps to protect the semiconductor die and forming the semiconductor package, alignment issues often occur when coupling the caps to the substrate to protect the die of the semiconductor package.

[0094] By forming the semiconductor package 100a using the mold compound 126 and the thermally decomposable die attach 504, the semiconductor package 100a can be made thinner. The semiconductor package 100a can be made thinner because the gap between the bonding wires 113 and 124 and the surface of the mold compound 126 facing away from the substrate 102 is smaller than when a cap is used to protect the components of the semiconductor package. Therefore, a thinner semiconductor package can be manufactured than when a cap is used to protect the MEMS die and the ASIC die.

[0095] In an alternative embodiment, the mold compound 224 can be made flush with the surface of the MEMS die in the semiconductor package 200a. Figure 2A As shown in FIG. 2 , the mold compound 224 in the semiconductor package 200 a is flush with the top surface 207 of the MEMS die 216 facing away from the substrate 202 .

[0096] By utilizing the mold compound 126 and the thermally decomposable die attach 504 to form the mold compound 126 to protect the MEMS die 116a and the ASIC die 110, fewer steps are required to form the complete package, and the lead time is reduced to manufacture the complete semiconductor package 100a. The lead time is reduced because coupling the cap to the substrate 102 in the correct position to protect the MEMS die 116a and the ASIC die 110 is a high-precision process, and since it is a high-precision process, it is also a relatively time-insensitive process. By eliminating the need for the cap, several steps can be eliminated from the manufacturing method when a cap is not required to form the semiconductor package 100a. For example, there is no need to place or form an adhesive to couple the cap to the substrate 102, no need to place the cap, and no need to utilize a high-precision placement tool to form the semiconductor package 100a. In contrast, covering the MEMS die 116 a and the ASIC die 110 with the mold compound 126 (which protects the MEMS die 116 a and the ASIC die 110 ) can significantly reduce the lead time for producing the semiconductor package 100 a because no caps need to be placed on each individual ASIC die 110 and MEMS die 116 a.

[0097] Figure 5 Involving formation Figures 2A to 2B Step 509 of the method of forming the semiconductor package 200a, 200b. In the method of forming the semiconductor package 200a, 200b, the method is Figures 4A to 4E The method of forming the semiconductor package 100a is similar to that of Figures 4A to 4EUnlike the method of forming semiconductor package 100a in FIG. 1 , bonding wires are not coupled to MEMS die 216 in semiconductor packages 200a, 200b. Although the following discussion applies to Figures 2A to 2B However, for the sake of simplicity and brevity, the following discussion will only refer to the semiconductor packages 200a, 200b. Figure 2A The semiconductor package 200a in FIG. 1 and FIG. 2 are formed as discussed earlier. Figure 1A When describing the method of the semiconductor package 100a in FIG. 1 , only the different points will be discussed.

[0098] exist Figure 5 , a first step 509 of the method of forming a semiconductor package 200a is illustrated in . In the method, a plurality of solder balls 220 are coupled to a plurality of contact pads 222 on a bottom surface 205 of a MEMS die 216 having a sensor element 218 and facing a substrate 202. Each respective solder ball 220 of the plurality of solder balls 220 is aligned with a respective contact pad 225 of a plurality of contact pads 225 on a top surface 203 of the substrate 202 facing the MEMS die 216. The plurality of solder balls 220 are surrounded by a thermally decomposable die attach or material 504 that couples the MEMS die 216 to the substrate 202. The plurality of solder balls 220 contact the plurality of contact pads 225. However, in an alternative embodiment of the method, a portion of the thermally decomposable die attach 504 may separate each respective solder ball 220 of the plurality of solder balls 220 from the plurality of contact pads 225 on the substrate 202. In . Figure 4B The first step 501 shown in FIG can be utilized to form a Figures 2A to 2B 1 and 2. The semiconductor packages 200a and 200b are shown in FIG.

[0099] When formed Figures 2A to 2B When the air cavity 206 is formed in the MEMS die 216, the thermally decomposable die attach 504 on the bottom surface 205 of the MEMS die 216 has sidewalls 543 that are flush with the sidewalls 241, 243 of the MEMS die 216. In an alternative embodiment, the sidewalls 543 of the thermally decomposable die attach 504 may extend outward from the sidewalls 241, 243 of the MEMS die 216, which means that the width of the thermally decomposable die attach 504 is greater than the width of the MEMS die 216. Alternatively, in another alternative embodiment, the sidewalls 543 of the thermally decomposable die attach 504 may extend inward from the sidewalls 241, 243 of the MEMS die 216, which means that the width of the thermally decomposable die attach 504 is less than the width of the MEMS die 216.

[0100] Alternatively, when utilizing in the process Figure 5In an alternative first step 509 of the embodiment, the thermally decomposable die attach 504 is exposed to heat from a heat source 526, which may be a reflow oven, to remove the thermally decomposable die attach 504 to form the air cavity 206. The heat from the heat source 526 causes the plurality of solder balls 220 to reflow while the thermally decomposable material 504 is decomposed and removed. When the plurality of solder balls 220 are reflowed by the heat from the heat source 526, the plurality of solder balls 220 couple the plurality of contact pads 225 on the top surface 203 of the substrate 202 to the plurality of contact pads 222 on the bottom surface 205 of the MEMS die 216. This forms an electrical connection between the MEMS die 216 and the substrate 202. This may be done as discussed earlier. Figures 2A to 2B The completion of this reflow of the plurality of solder balls 220 is seen in . Furthermore, the solder balls 220 may be replaced by other known conductive connectors, such as pins and conductive adhesives that may be initially present in the thermally decomposable die attach 504 .

[0101] Figure 6 The electronic device 602 includes a semiconductor package 604. The semiconductor package 604 is based on the above Figures 1A to 3 The embodiments discussed in Figures 1A to 3 The semiconductor package 604 is within the range of Figures 4A to 4E as well as Figure 5 The manufacturing method disclosed in Figures 4A to 4E as well as Figure 5 Methods to manufacture within the range.

[0102] In the electronic device 602, the semiconductor package 604 is electrically coupled to a microprocessor 606 within the electronic device 602. The microprocessor 606 sends electrical signals to the semiconductor package 604, and the microprocessor 606 receives electrical signals from the semiconductor package 604. For example, the microprocessor 606 can transmit a power signal, a command signal, or any other signal that controls or provides power to the semiconductor package 604. Conversely, the semiconductor package 604 can send a data signal, an information signal, or any other signal that provides feedback, data, or information to the microprocessor 606 that is utilized to control the electronic device 602. The semiconductor package 604 and the microprocessor 606 can be coupled by electrical connections, such as wiring, conductive vias, a PCB, or any other electrical connections as desired. For example, with respect to Figure 1AIn the semiconductor package in the embodiment of the present invention, the ASIC die 110 receives power signals and electrical signals from and sends power signals and electrical signals to the power supply 608, the microprocessor 606, and the memory 610 that are in electrical communication with the substrate 102. Since the ASIC die 110 is coupled to the substrate 102, the ASIC die 110 is in electrical communication with the power supply 608, the microprocessor 606, and the memory 610.

[0103] The microprocessor 606 is coupled to a power supply 608. The microprocessor 606 directs and controls where the power from the power supply is supplied. For example, the microprocessor 606 controls and transmits a certain percentage of the power from the power supply to the semiconductor package, controls and transmits another percentage of the power to the touch display of the electronic device, and controls and transmits the amount of power supplied to each electrical component within the electronic device 602.

[0104] Microprocessor 606 is coupled to memory 610. Microprocessor 606 sends data or information to memory 610 for storage. For example, microprocessor 606 may transmit a data signal or information signal received from semiconductor package 604 to memory 610 for storage. Alternatively, microprocessor 606 may transmit any other data signal or information signal from any other electronic component within the electronic device to which microprocessor 606 is coupled.

[0105] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the description described in detail above. Generally, in the following claims, the terms used should not be interpreted as limiting the claims to the specific embodiments disclosed in this specification and claims, but should be interpreted to include all possible embodiments and the full range of equivalents authorized by such claims. Therefore, the claims are not limited by this disclosure.

Claims

1. A device comprising: a substrate comprising a first surface, a second surface, and an opening, wherein the second surface faces away from the first surface, and the opening extends from the first surface through the substrate to the second surface; a micro-electromechanical system (MEMS) die aligned with the opening, the MEMS die being separated from the second surface of the substrate by a cavity, the MEMS die comprising: a third surface facing the second surface of the substrate, the cavity extending from the third surface of the MEMS die to the second surface of the substrate; a plurality of sidewalls transverse to the third surface; and a MEMS element aligned with the cavity in the substrate; A molding compound covers the plurality of sidewalls of the MEMS die and defines sides of the cavity.

2. The apparatus according to claim 1, further comprising: an adhesive coupling the ASIC die to the second surface of the substrate; as well as Bond wires couple the ASIC die to the MEMS die.

3. The apparatus according to claim 1, wherein: The MEMS die further includes a fourth surface, the fourth surface facing away from the second surface of the substrate; as well as The molding compound further includes a fifth surface facing away from the second surface of the substrate, the fifth surface being coplanar with the fourth surface.

4. The apparatus of claim 1 , further comprising an adhesive layer and an ASIC die, wherein: The MEMS die further includes a fourth surface, the fourth surface facing away from the second surface of the substrate; as well as The ASIC die is coupled to the fourth surface of the MEMS die through the adhesive layer.

5. The apparatus of claim 1 , wherein the MEMS die further comprises: a plurality of first contact pads on the third surface of the MEMS die; a plurality of second contact pads on the second surface of the substrate; as well as A plurality of solder balls are coupled between the plurality of first contact pads on the MEMS die and the plurality of second contact pads on the substrate, the plurality of solder balls are positioned within the cavity, and the plurality of solder balls are a distance away from the side surface of the cavity.

6. A device comprising: a substrate having an opening extending through the substrate from a first surface of the substrate to a second surface of the substrate; a micro-electromechanical system (MEMS) die aligned with the opening, the MEMS die comprising a sensor assembly and a plurality of sidewalls, the sensor assembly aligned with the opening in the substrate, the plurality of sidewalls being transverse to the first surface of the substrate and the second surface of the substrate; a cavity in fluid communication with and aligned with the opening and the sensor assembly, the cavity separating the MEMS die from the substrate and extending from the substrate to the MEMS die; and an encapsulation surrounding the MEMS die, the encapsulation including sidewalls defining sides of the cavity. 7 . The apparatus of claim 6 , wherein the sidewalls of the encapsulant are aligned with the sidewalls of the MEMS die, respectively. 8 . The apparatus of claim 6 , wherein the sidewalls of the encapsulant each include a first portion and a second portion, the first portions respectively contacting the sidewalls of the MEMS die, and the second portions defining the sides of the cavity.

9. The apparatus according to claim 8, further comprising: adhesive layer; an application-specific integrated circuit (ASIC) die coupled to the surface of the MEMS die via the adhesive layer; as well as Bond wires electrically couple the ASIC die to the substrate.

10. The apparatus according to claim 6, further comprising: adhesive layer; an application-specific integrated circuit (ASIC) coupled to the substrate via the adhesive layer; as well as Bond wires electrically couple the ASIC to the substrate.

11. The apparatus according to claim 10, further comprising: Bond wires couple the MEMS die to the ASIC.

12. The apparatus of claim 6, wherein the cavity has a width greater than a width of the opening, and the cavity has a height less than a height of the opening.

13. The apparatus of claim 6, wherein the MEMS die further comprises: a plurality of contact pads adjacent to the sensor component of the MEMS die; as well as A plurality of solder balls are coupled between the plurality of contact pads of the MEMS die and the substrate, the plurality of solder balls are positioned within the cavity, and the plurality of solder balls are spaced a distance from the side surfaces of the cavity.

14. The apparatus of claim 13, wherein: The encapsulation member includes a first surface facing away from the substrate; and The MEMS die includes a second surface facing away from the substrate, the second surface being coplanar with the first surface of the encapsulant.

15. A method comprising: coupling the MEMS die to the substrate using a sacrificial layer on a first surface of the MEMS die facing the substrate; forming a molding compound covering the first sidewalls of the MEMS die and the second sidewalls of the sacrificial adhesive layer; forming an opening extending through the substrate and exposing the sacrificial layer; as well as The sacrificial layer is removed, the removal forming a space separating the first surface of the MEMS die from the substrate.

16. The method of claim 15, wherein forming the opening further comprises: The opening is aligned with the sensor component of the MEMS die. The method of claim 15 , wherein the sacrificial layer is a thermally decomposable die attach.

18. The method of claim 17, wherein removing the thermally decomposable die attach further comprises: A reflow oven is utilized to expose the thermally decomposable die attach to heat.

19. The method of claim 15, wherein forming the opening in the substrate further comprises: The substrate is laser drilled.

20. The method of claim 15, further comprising: securing a second die to the second surface of the MEMS die; and forming bond wires coupling the second die to the substrate.

21. The method of claim 15, further comprising: securing a second die to the substrate, the second die being laterally spaced relative to the MEMS die; as well as Bond wires are formed coupling the second die to the substrate.

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