Semiconductor package structure and packaging method

Abstract

The application provides a semiconductor packaging structure and a packaging method. The semiconductor packaging structure comprises a base island, a pin, a sealing film and a cover. A silicon microphone chip is attached to a first surface of the base island. The pin is arranged around the periphery of the base island. The silicon microphone chip is electrically connected to the pin. The sealing film is arranged to seal the gap between the base island and the pin near the second surface. The cover is connected to the pin and covers the silicon microphone chip and the base island. The base island, the pin, the sealing film and the cover jointly form a second sound cavity. The cover is provided with a second sound inlet hole communicating with the second sound cavity. The second sound cavity comprises a first cavity located on the side of the first surface close to the cover and a second cavity located between the base island and the pin. The first cavity and the second cavity are in communication. The second cavity is located between the first surface and the sealing film.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a semiconductor packaging structure and packaging method. Background Technology

[0002] With the rapid development of the semiconductor industry, microphones have been widely used in various electronic products. Silicon microphones, due to their small size and high stability, are widely used in mobile terminals and other electronic products. A silicon microphone consists of a MEMS (Micro Electro Mechanical System) chip, which includes a silicon diaphragm and a silicon backplate. The working principle of the MEMS chip is to utilize the pressure gradient generated by sound changes to cause deformation of the silicon diaphragm due to sound pressure interference, thereby changing the capacitance between the silicon diaphragm and the silicon backplate, thus converting the sound pressure signal into a voltage signal. In current MEMS silicon microphone designs, sound mostly enters through a single aperture, meaning the sound signal enters the MEMS chip and metal cover from a single direction. When the sound signal is relatively weak, the sound pressure signal is also weaker, leading to a decrease in the sensitivity and signal-to-noise ratio of the MEMS silicon microphone product. Summary of the Invention

[0003] The purpose of this invention is to provide a semiconductor packaging structure and packaging method that can improve the pickup sensitivity and signal-to-noise ratio of silicon microphone products.

[0004] In a first aspect, the present invention provides a semiconductor packaging structure, comprising: A base island, the base island having a first surface and a second surface disposed opposite to each other, the first surface being on which a silicon microphone chip is mounted; Pins, the pins being disposed around the outer periphery of the base island, and the silicon microphone chip being electrically connected to the pins; A sealing film configured to close the gap between the base island and the pin, and disposed near the second surface; A cover is provided, which covers the silicon microphone chip and the base island, and the cover is connected to the pins; the base island, the pins, the sealing film, and the cover together form a second sound cavity; the cover is provided with a second sound inlet hole communicating with the second sound cavity; the second sound cavity includes a first cavity located on the first surface near the cover and a second cavity located between the base island and the pins, the first cavity and the second cavity communicating; the second cavity is located between the first surface and the sealing film.

[0005] In an optional embodiment, the second surface is provided with a first metal plate; the edge of the first metal plate forms a first bend, the first bend extends toward the first surface, and the first bend has a first gap with the sidewall of the base island; The edge of the first surface of the base island forms a second bend, which extends toward the second surface and has a first gap with the sidewall of the base island. The first bend and the second bend are disposed opposite to each other, and the sidewall of the base island, the first bend, and the second bend together form a first sound cavity. The gap between the first bend and the second bend forms a first sound inlet, which communicates with the first sound cavity. The second sound cavity communicates with the first sound cavity.

[0006] In an optional embodiment, a first adhesive layer is provided between the first metal plate and the base island.

[0007] In an optional embodiment, one end of the sealing film is connected to the pin, and the other end is connected to the first metal plate.

[0008] In an optional embodiment, the side of the sealing film away from the first surface is flush with the side of the first metal plate away from the first surface.

[0009] In an optional embodiment, the side of the sealing film near the first surface is lower than or flush with the side surface of the first bend near the second bend.

[0010] In an optional implementation, a first chip is further included, spaced apart from the silicon microphone chip, the first chip being mounted on the base island and connected to the pins.

[0011] In an optional implementation, the first chip is electrically connected to the silicon microphone chip.

[0012] In an optional embodiment, a second metal plate is attached to the side of the pin away from the cover, and the second metal plate is bent to form a third bend on the side of the pin near the base island. The third bend extends toward the first surface and has a second gap with the sidewall of the pin. The pin is bent on the side away from the second metal plate to form a fourth bend that is opposite to the third bend. The fourth bend extends toward the second surface and has a second gap with the sidewall of the pin. The sidewall of the pin near the base island, the third bend, and the fourth bend together form a third sound cavity; wherein, the gap between the third bend and the fourth bend forms a third sound inlet hole, and the third sound inlet hole communicates with the second sound cavity and the third sound cavity respectively.

[0013] In an optional embodiment, the pin has a groove on the side away from the cover, and a second metal plate on the pin is disposed in the groove.

[0014] In an optional embodiment, a second adhesive layer is provided between the second metal plate and the pin.

[0015] In an optional embodiment, the sealing membrane is connected to the first metal plate and the second metal plate, respectively.

[0016] In an optional embodiment, the side of the sealing film closest to the first surface is simultaneously lower than both the first sound inlet and the third sound inlet.

[0017] In an optional embodiment, the pin has an edge step groove on the side away from the cover.

[0018] Secondly, the present invention provides a packaging method, comprising: A first groove is formed on the first surface of the substrate to separate the base island and the pin; A sealing film is formed on the first surface to close the opening of the first groove. A silicon microphone chip is mounted on the first surface of the base island; A cover is attached to the first surface of the pin to cover the base island and the silicon microphone chip; wherein the base island, the pin, the sealing film, and the cover together form a second sound cavity; the cover has a second sound inlet hole communicating with the second sound cavity; the second sound cavity includes a first cavity located on the side of the first surface near the cover and a second cavity located between the base island and the pin, the first cavity and the second cavity communicating; the second cavity is located between the first surface and the sealing film.

[0019] In an optional embodiment, after the step of forming a first groove on a first surface of the substrate to separate the base island and the pin, the method further includes: A first metal plate with a first bend is attached to the base island; the first bend has a first gap with the side wall of the base island; Remove the bottom of the first groove to separate the base island and the pin, and form a first flange at the edge of the base island; The first flange is bent toward the first surface to form a second bent portion opposite to the first bent portion; the second bent portion has a first gap with the sidewall of the base island; the sidewall of the base island, the first bent portion and the second bent portion together form a first sound cavity; wherein, the gap between the first bent portion and the second bent portion forms a first sound inlet hole, and the first sound inlet hole communicates with the first sound cavity; the second sound cavity communicates with the first sound cavity.

[0020] In an optional embodiment, in the step of forming a first groove on a first surface of the substrate to separate the base island and the pin: On one side of the first surface, the surface of the base island is lower than the surface of the pin; In the step of attaching the first metal plate having the first bend to the base island: The surface of the first metal plate is flush with the surface of the pin.

[0021] In an optional embodiment, the step of forming a first groove on a first surface of the substrate to separate the base island and the pin further includes: An edge step groove is formed on the pin.

[0022] In an optional embodiment, prior to the step of forming a sealing film on the first surface to close the opening of the first groove, the method further includes: A second metal plate having a third bend is mounted on the pin; the third bend has a second gap with the sidewall of the pin; The step of removing the bottom of the first groove to separate the base island and the pin, and forming a first flange at the edge of the base island, further includes: A second flange is formed on the side edge of the pin near the base island; The second flange bends toward the first surface to form a fourth bend that is opposite to the third bend; the fourth bend has a second gap with the sidewall of the pin; the sidewall of the pin, the third bend, and the fourth bend together form a third sound cavity; wherein the gap between the third bend and the fourth bend forms a third sound inlet hole, and the third sound inlet hole communicates with the third sound cavity and the second sound cavity respectively.

[0023] In an optional embodiment, the step of forming a sealing film on the first surface to close the opening of the first groove includes: A sealing film is formed on the first surface, wherein the thickness of the sealing film at the first groove is greater than the thickness of the sealing film on the first metal plate or the pin. After the step of bending the first flange toward the first surface to form a second bend that is opposite to the first bend, the sealing film is ground to expose the surface of the first metal plate and the surface of the pin; the sealing film is located between the first bend and the pin.

[0024] The semiconductor packaging structure and packaging method provided by this invention have the following advantages: By utilizing the gap between the base island and the pins to form a second cavity, the volume of the acoustic cavity is increased, and the effective space volume within the second acoustic cavity for sound wave propagation and reflection is increased, which further amplifies the sound pressure signal entering the second acoustic cavity, thereby improving the sound pickup sensitivity under weak signal conditions. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a first type of semiconductor packaging structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a second semiconductor packaging structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a third type of semiconductor packaging structure provided in an embodiment of the present invention; Figure 4 Another schematic diagram of the first metal plate of the semiconductor packaging structure provided in the embodiment of the present invention; Figure 5 This is one of the first process schematic diagrams of the packaging method provided in the embodiments of the present invention; Figure 6 This is a schematic diagram of the structure for mounting the first metal plate in the packaging method provided in this embodiment of the invention; Figure 7 This is a second schematic diagram of the first process of the packaging method provided in the embodiments of the present invention; Figure 8 This is the third schematic diagram of the first process of the packaging method provided in the embodiments of the present invention; Figure 9 This is a schematic diagram of the process of forming grooves on pins in the packaging method provided in an embodiment of the present invention. Figure 10 This is a schematic diagram of mounting a second metal plate on the pins and stamping to form a fourth bend in the packaging method provided in an embodiment of the present invention.

[0027] Icons: 110-Base island; 100-Substrate; 101-First surface; 102-Second surface; 111-First flange; 112-Second bend; 113-First sound cavity; 114-First sound inlet; 120-Pin; 121-Second flange; 122-Fourth bend; 123-Third sound inlet; 124-Third sound cavity; 130-Sealing membrane; 140-Cover; 141-Second sound inlet; 150-Silicone microphone core 151-Diaphragm; 153-Second sound cavity; 1531-First cavity; 1532-Second cavity; 160-First metal plate; 161-First bending portion; 163-First adhesive layer; 165-Fourth sound inlet hole; 166-Fourth sound cavity; 170-First chip; 180-Second metal plate; 181-Third bending portion; 103-First groove; 104-Groove; 105-Edge step groove; 106-Connecting rib. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] The semiconductor packaging structure proposed in this invention is mainly used in silicon microphone products, which helps to improve the pickup sensitivity and signal-to-noise ratio.

[0036] Please combine Figure 1 The semiconductor package structure includes a base island 110, leads 120, a sealing film 130, and a cover 140. The base island 110 has a first surface 101 and a second surface 102 disposed opposite to each other. A silicon microphone chip 150 is mounted on the first surface 101. The leads 120 surround the outer periphery of the base island 110 and are electrically connected to the silicon microphone chip 150 and the leads 120. The sealing film 130 is configured to close the gap between the base island 110 and the leads 120 and is disposed near the second surface 102. A cover 140 covers the silicon microphone chip 150 and the base island 110, and the cover 140 is connected to the pins 120. The base island 110, pins 120, sealing film 130, and cover 140 together form a second sound cavity 153. The cover 140 has a second sound inlet 141 that communicates with the second sound cavity 153. The second sound cavity 153 includes a first cavity 1531 located on the side of the first surface 101 near the cover 140 and a second cavity 1532 located between the base island 110 and the pins 120. The first cavity 1531 and the second cavity 1532 are connected. The second cavity 1532 is located between the first surface 101 and the sealing film 130. With this configuration, the second cavity 1532 between the base island 110 and the pins 120 increases the effective space volume for sound propagation and reflection, which further amplifies the sound pressure signal entering the second sound cavity 153, thereby improving the sound pickup sensitivity under weak signal conditions.

[0037] Optionally, the second surface 102 is provided with a first metal plate 160; the edge of the first metal plate 160 forms a first bent portion 161, which extends toward the first surface 101 and has a first gap with the sidewall of the base island 110. The edge of the first surface 101 of the base island 110 forms a second bent portion 112, which extends toward the second surface 102 and has a first gap with the sidewall of the base island 110. The first bent portion 161 and the second bent portion 112 are disposed opposite to each other, and the sidewall of the base island 110, the first bent portion 161 and the second bent portion 112 together form a first sound cavity 113. The gap between the first bent portion 161 and the second bent portion 112 forms a first sound inlet 114, which communicates with the first sound cavity 113; the second sound cavity 153 communicates with the first sound cavity 113. In this embodiment, the second cavity 1532 is connected to the first acoustic cavity 113.

[0038] Because a first acoustic cavity 113 is formed on the side wall of the base island 110, the effective volume of space available for sound wave propagation and reflection within the second acoustic cavity 153 is increased. This further amplifies the sound pressure signal entering the second acoustic cavity 153, thereby improving the pickup sensitivity under weak signal conditions and increasing the signal-to-noise ratio. It can be understood that due to the arrangement of the first acoustic cavity 113, sound waves are continuously reflected after entering the first acoustic cavity 113. The reflected sound waves and the newly entering sound waves are superimposed in phase, causing the air vibration amplitude to accumulate and increase, forming a stronger air pressure fluctuation at the first sound inlet 114, thus increasing the sound pressure.

[0039] It is understandable that the thickness of the sealing membrane 130 is less than the thickness of the base island 110, thereby reducing the volume occupied by the sealing membrane 130 in the second acoustic cavity 153 and increasing the effective space volume available for sound wave propagation and reflection.

[0040] Optionally, a first adhesive layer 163 is provided between the first metal plate 160 and the base island 110. The first metal plate 160 is fixed to the base island 110 by the first adhesive layer 163. In this embodiment, the edge of the first adhesive layer 163 is flush with the sidewall of the base island 110.

[0041] Optionally, a sealing film 130 is connected between the pin 120 and the first metal plate 160, with one end of the sealing film 130 connected to the pin 120 and the other end connected to the first metal plate 160. In this embodiment, the side of the sealing film 130 away from the first surface 101 is flush with the side of the first metal plate 160 away from the first surface 101. The sealing film 130 does not cover the surface of the first metal plate 160 or the surface of the pin 120, which is beneficial for improving heat dissipation performance and for enhancing the mounting reliability of the base island 110 and the pin 120 to the substrate, etc. Of course, in other embodiments, the sealing film 130 may also cover part of the surface of the first metal plate 160 and part of the surface of the pin 120 to improve sealing performance.

[0042] Optionally, the side of the sealing membrane 130 near the first surface 101 is lower than or flush with the side surface of the first bend 161 near the second bend 112, to prevent the sealing membrane 130 from blocking the first sound inlet 114 and causing the first sound cavity 113 to fail.

[0043] Optionally, a first chip 170 is also included, spaced apart from the silicon microphone chip 150. The first chip 170 is mounted on the base island 110 and electrically connected to pins 120. Optionally, the first chip 170 is electrically connected to the silicon microphone chip 150. The first chip 170 can be various chips, and its type and quantity are not limited. The number of silicon microphone chips 150 is not limited; there can be one or more.

[0044] Optional, please refer to Figure 2 A second metal plate 180 is attached to the side of pin 120 away from the cover 140. The second metal plate 180 is bent to form a third bend 181 on the side of pin 120 near the base island 110. The third bend 181 extends toward the first surface 101 and has a second gap with the sidewall of pin 120. A fourth bend 122 is formed on the side of pin 120 away from the second metal plate 180, opposite to the third bend 181. The fourth bend 122 extends toward the second surface 102 and has a second gap with the sidewall of pin 120. The sidewall of pin 120 near the base island 110, the third bend 181, and the fourth bend 122 together form a third acoustic cavity 124. The gap between the third bend 181 and the fourth bend 122 forms a third sound inlet 123, which communicates with both the second acoustic cavity 153 and the third acoustic cavity 124. This arrangement, with a third acoustic cavity 124 also formed on the sidewall of pin 120, further increases the cavity volume and expands the effective space within the second acoustic cavity 153 for sound wave propagation and reflection, thereby improving the pickup sensitivity under weak signal conditions. Furthermore, the addition of the third acoustic cavity 124 further increases the cavity volume. Sound waves entering the third acoustic cavity 124 are continuously reflected, and the reflected sound waves and newly entering sound waves are superimposed in phase, resulting in a greater accumulation of air vibration amplitude and a stronger air pressure fluctuation at the third sound inlet 123, thus increasing the sound pressure level.

[0045] It should be noted that the first gap and the second gap may or may not be equal.

[0046] Optionally, a groove 104 is provided on the side of the pin 120 away from the cover 140, and a second metal plate 180 on the pin 120 is disposed within the groove 104. A second adhesive layer is provided between the second metal plate 180 and the pin 120. The second metal plate 180 is bonded and fixed to the pin 120 by the second adhesive layer. The groove 104 facilitates the positioning of the second adhesive layer and the second metal plate 180, and reduces the overall package height, resulting in a more compact structure. The first adhesive layer 163 and the second adhesive layer have the same material and function, and the first metal plate 160 and the second metal plate 180 have the same function and material.

[0047] Optionally, the sealing membrane 130 is connected to the first metal plate 160 and the second metal plate 180 respectively. The side of the sealing membrane 130 closest to the first surface 101 is lower than both the first sound inlet 114 and the third sound inlet 123, to prevent the sealing membrane 130 from blocking the first sound inlet 114 and the third sound inlet 123, and to avoid failure of the first sound cavity 113 and the third sound cavity 124.

[0048] In this embodiment, the side of the sealing film 130 away from the first surface 101 is flush with the surface of the first metal plate 160 and the surface of the second metal plate 180, respectively.

[0049] Optionally, an edge step groove 105 is provided on the side of pin 120 away from cover 140. It is understood that the edge step groove 105 is located on the outer side of pin 120, while the groove 104 for mounting the second metal plate 180 is located on the inner side of pin 120. The edge step groove 105 improves the soldering reliability of pin 120 and enhances the side-climbing performance of solder paste during pin 120 soldering.

[0050] In this embodiment, a diaphragm 151 is provided on the side of the silicon microphone chip 150 away from the base island 110. Sound enters the second sound cavity 153 through the second sound inlet 141, and is continuously reflected within the second sound cavity 153 before reaching the diaphragm 151. The vibration signal of the diaphragm 151 is converted into an electrical signal. It can be understood that after entering the second sound cavity 153, the sound can enter the first sound cavity 113 and the third sound cavity 124 respectively, undergoing continuous reflection within these cavities. This increases the effective space volume available for sound wave propagation and reflection within the first and third sound cavities 113 and 124, further amplifying the sound pressure signal entering the second sound cavity 153 and increasing the signal strength. This, in turn, helps improve the pickup sensitivity and signal-to-noise ratio under weak signal conditions.

[0051] Please combine Figure 3 and Figure 4Optionally, the first metal plate 160 extends towards the second cavity 1532 to form a fourth sound cavity 166 with a fourth sound inlet 165. One end of the sealing membrane 130 is connected to the side wall of the pin 120, and the other end is connected to the outer side wall of the fourth sound cavity 166. The fourth sound cavity 166 further increases the spatial volume of the sound cavity. After the sound waves enter the fourth sound cavity 166, they are continuously reflected. The reflected sound waves and the newly entered sound waves are superimposed in phase, and the amplitude of air vibration increases. This creates a stronger air pressure fluctuation at the fourth sound inlet 165, thereby increasing the sound pressure.

[0052] This invention also provides a packaging method, which mainly includes the following steps: Please combine Figure 5 and Figure 6 Step S1: A first groove 103 is formed on the first surface 101 of the substrate 100 to separate the base island 110 and the pin 120.

[0053] Optionally, a copper plate is provided as the substrate 100. The substrate is cut using a cutting process to divide the substrate into base islands 110, leads 120, and connecting ribs 106 located between adjacent products.

[0054] Optionally, the depth of the first groove 103 is less than the thickness of the substrate 100, and the pin 120 and the base island 110 are not completely separated. The bottom of the first groove 103 is still connected to the base island 110 and the pin 120.

[0055] Step S2: A first metal plate 160 having a first bent portion 161 is attached to the base island 110; the first bent portion 161 has a first gap with the side wall of the base island 110.

[0056] Optionally, a first adhesive layer 163 is applied to a first metal plate 160 having a first bent portion 161 using a lamination process. The first metal plate 160 is then laminated onto the base island 110 using the first adhesive layer 163, wherein the first bent portion 161 on the first metal plate 160 is located outside the sidewall of the base island 110, and a first gap exists between the first bent portion 161 and the sidewall of the base island 110. The first adhesive layer 163 can be a conductive or non-conductive adhesive film. Baking and curing are then performed to improve the bonding reliability of the first metal plate 160.

[0057] Step S3: A sealing film 130 is formed on the first surface 101 to close the opening of the first groove 103.

[0058] Optionally, a sealing film 130 is laminated onto the first surface 101 of the substrate 100 using a vacuum lamination process. The sealing film 130 is cured on the first surface 101 by vacuum adsorption. The sealing film 130 covers the first metal plate 160 and extends to the pin 120 to seal the gap opening between the pin 120 and the base island 110. In this embodiment, the thickness of the sealing film 130 at the gap opening between the pin 120 and the base island 110 is greater than its thickness on the first metal plate 160. Furthermore, the sealing film 130 does not reach the first sound inlet 114 in the thickness direction, thus preventing the sealing film 130 from blocking the first sound inlet 114.

[0059] Please combine Figure 7 Step S4: Remove the bottom of the first groove 103 to separate the base island 110 and the pin 120, and form a first flange 111 at the edge of the base island 110.

[0060] Optionally, a cutting process can be used to remove the bottom of the first groove 103, so that the base island 110 and the pin 120 are completely separated. During cutting, a portion of the bottom of the first groove 103 needs to be left at the edge of the base island 110 to form the first flange 111.

[0061] Step S5: The first flange 111 is bent toward the first surface 101 to form a second bent portion 112 that is disposed opposite to the first bent portion 161.

[0062] Optionally, the base island 110 is stamped using a stamping process, forming a second bent portion 112 by stamping the first flange 111 from the second surface 102 toward the first surface 101. The second bent portion 112 has a first gap with the sidewall of the base island 110; the sidewall of the base island 110, the first bent portion 161, and the second bent portion 112 together form a first sound cavity 113; wherein, the gap between the first bent portion 161 and the second bent portion 112 forms a first sound inlet 114, and the first sound inlet 114 communicates with the first sound cavity 113.

[0063] Step S6: Optionally, using a grinding process, such as grinding with a grinding wheel or diamond grinding, the sealing film 130 on the surface of the first metal plate 160 and the pin 120 is ground away to expose the surfaces of the first metal plate 160 and the pin 120, that is, the sealing film 130 only exists in the gap between the base island 110 and the pin 120.

[0064] Please combine Figure 8 Step S7: Attach the silicon microphone chip 150 to the first surface 101 of the base island 110. Connect the silicon microphone chip 150 and the pins 120 by wire bonding.

[0065] Optionally, the substrate 100 is flipped, and a silicon microphone chip 150 is mounted on the side of the base island 110 away from the first metal plate 160. When mounting the silicon microphone chip 150, a first chip 170 can also be mounted onto the base island 110 as needed. The first chip 170 and its pins 120 are connected by wire bonding, and the silicon microphone chip 150 and the first chip 170 are also connected by wire bonding. The first chip 170 includes, but is not limited to, GPU chips, RF chips, memory chips, or other chips, and its type and quantity are unlimited.

[0066] Step S8: A cover 140 is attached to the first surface 101 of the pin 120 to cover the base island 110 and the silicon microphone chip 150; wherein, the base island 110, the pin 120, the sealing film 130 and the cover 140 together form a second sound cavity 153; the cover 140 is provided with a second sound inlet hole 141 communicating with the second sound cavity 153; the second sound cavity 153 is communicating with the first sound cavity 113.

[0067] It should be noted that the second acoustic cavity 153 includes a first cavity 1531 located on the side of the first surface 101 near the cover 140 and a second cavity 1532 located between the base island 110 and the pin 120. The first cavity 1531 and the second cavity 1532 are connected; the second cavity 1532 is located between the first surface 101 and the sealing membrane 130. This configuration increases the effective space volume for sound propagation and reflection in the second cavity 153 between the base island 110 and the pin 120, further amplifying the sound pressure signal entering the second acoustic cavity 153, thereby improving the pickup sensitivity under weak signal conditions.

[0068] Finally, the connecting rib 106 is cut and separated into individual products.

[0069] Optionally, in step S1, after forming the first groove 103, the base island 110 is thinned so that on the side of the first surface 101 of the substrate 100, the surface of the base island 110 is lower than the surface of the pin 120. Optionally, the thickness of the base island 110 thinned is the sum of the thicknesses of the first adhesive layer 163 and the first metal plate 160. In this way, after mounting the first metal plate 160, the surface of the first metal plate 160 is flush with the surface of the pin 120.

[0070] In some embodiments, in step S1, the outer edge of the pin 120 may also be cut to form an edge step groove 105, which helps to improve the reliability of the pin 120 soldering.

[0071] Please combine Figure 9 and Figure 10It is understood that, in order to form a dual-cavity structure, in step S1, a groove 104 for mounting the second metal plate 180 can also be formed on the pin 120. In step S2, when mounting the first metal plate 160, the second metal plate 180 with a third bend 181 is also mounted on the pin 120, and the third bend 181 has a second gap with the side wall of the pin 120.

[0072] In step S4, when forming the first flange 111, a second flange 121 is also formed on the edge of the pin 120 near the base island 110. In step S5, during the process of stamping the first flange 111 to form the second bent portion 112, the second flange 121 is also stamped. Thus, the second flange 121 is bent toward the first surface 101 to form a fourth bent portion 122 opposite to the third bent portion 181; the fourth bent portion 122 has a second gap with the sidewall of the pin 120; the sidewall of the pin 120, the third bent portion 181, and the fourth bent portion 122 together form a third sound cavity 124; wherein, the gap between the third bent portion 181 and the fourth bent portion 122 forms a third sound inlet hole 123, and the third sound inlet hole 123 communicates with the third sound cavity 124 and the second sound cavity 153 respectively.

[0073] Optionally, in the process of forming the sealing film 130 on the first surface 101, the thickness of the sealing film 130 at the first groove 103 is greater than the thickness of the sealing film 130 on the first metal plate 160 or the pin 120. After the step of bending the first flange 111 toward the first surface 101 to form a second bend 112 opposite to the first bend 161, the sealing film 130 is ground to expose the surface of the first metal plate 160 and the surface of the pin 120; the sealing film 130 is located between the first bend 161 and the pin 120. Specifically, the sealing film 130 is located between the first bend 161 and the third bend 181.

[0074] In summary, the semiconductor packaging structure and packaging method provided by this invention have the following beneficial effects, including: A second cavity 1532 is formed using the gap between the base island 110 and the pin 120, increasing the acoustic cavity volume. A first bending portion 161 and a second bending portion 112 are used to form a first acoustic cavity 113 with a first sound inlet hole 114 on the sidewall of the base island 110, further increasing the acoustic cavity volume. This increases the effective space volume within the second acoustic cavity 153 for sound wave propagation and reflection, allowing the sound pressure signal entering the second acoustic cavity 153 to be further amplified, thereby improving the pickup sensitivity under weak signal conditions. A third acoustic cavity 124 is formed on the sidewall of the pin 120, further increasing the effective space volume for sound wave propagation and reflection, which can improve pickup sensitivity and signal-to-noise ratio.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A semiconductor packaging structure, characterized in that, include: A base island, the base island having a first surface and a second surface disposed opposite to each other, the first surface being on which a silicon microphone chip is mounted; Pins, the pins surrounding the outer periphery of the base island, and the silicon microphone chip being electrically connected to the pins; A cover, which is connected to the pins, and which covers the silicon microphone chip and the base island; A sealing film configured to close the gap between the base island and the pin, and disposed near the second surface; The base island, the pin, the sealing membrane, and the cover together form a second sound cavity; the cover is provided with a second sound inlet hole communicating with the second sound cavity; the second sound cavity includes a first cavity located on the first surface near the cover and a second cavity located between the base island and the pin, the first cavity and the second cavity communicating; the second cavity is located between the first surface and the sealing membrane.

2. The semiconductor packaging structure according to claim 1, characterized in that, The second surface is provided with a first metal plate; the edge of the first metal plate forms a first bend, the first bend extends toward the first surface, and the first bend has a first gap with the sidewall of the base island; The edge of the first surface of the base island forms a second bend, which extends toward the second surface and has a first gap with the sidewall of the base island. The first bend and the second bend are disposed opposite to each other, and the sidewall of the base island, the first bend, and the second bend together form a first sound cavity. The gap between the first bend and the second bend forms a first sound inlet, which communicates with the first sound cavity. The second sound cavity communicates with the first sound cavity.

3. The semiconductor packaging structure according to claim 2, characterized in that, A first adhesive layer is provided between the first metal plate and the base island.

4. The semiconductor packaging structure according to claim 2, characterized in that, One end of the sealing membrane is connected to the pin, and the other end is connected to the first metal plate.

5. The semiconductor packaging structure according to claim 4, characterized in that, The side of the sealing film away from the first surface is flush with the side of the first metal plate away from the first surface.

6. The semiconductor packaging structure according to claim 4, characterized in that, The side of the sealing film near the first surface is lower than or flush with the side surface of the first bend near the second bend.

7. The semiconductor packaging structure according to claim 1, characterized in that, It also includes a first chip spaced apart from the silicon microphone chip, the first chip being mounted on the base island and connected to the pins.

8. The semiconductor packaging structure according to claim 7, characterized in that, The first chip is electrically connected to the silicon microphone chip.

9. The semiconductor packaging structure according to claim 2, characterized in that, A second metal plate is attached to the side of the pin away from the cover. The second metal plate is bent to form a third bend on the side of the pin near the base island. The third bend extends toward the first surface and has a second gap with the sidewall of the pin. The pin is bent on the side away from the second metal plate to form a fourth bend that is opposite to the third bend. The fourth bend extends toward the second surface and has a second gap with the sidewall of the pin. The sidewall of the pin near the base island, the third bend, and the fourth bend together form a third sound cavity; wherein, the gap between the third bend and the fourth bend forms a third sound inlet hole, and the third sound inlet hole communicates with the second sound cavity and the third sound cavity respectively.

10. The semiconductor packaging structure according to claim 9, characterized in that, The pin has a groove on the side away from the cover, and a second metal plate on the pin is disposed in the groove.

11. The semiconductor packaging structure according to claim 9, characterized in that, A second adhesive layer is provided between the second metal plate and the pin.

12. The semiconductor packaging structure according to claim 9, characterized in that, The sealing membrane is connected to the first metal plate and the second metal plate respectively.

13. The semiconductor packaging structure according to claim 9, characterized in that, The side of the sealing film closest to the first surface is simultaneously lower than both the first sound inlet and the third sound inlet.

14. The semiconductor packaging structure according to any one of claims 1 to 13, characterized in that, The pin has an edge step groove on the side away from the cover.

15. A packaging method, characterized in that, include: A first groove is formed on the first surface of the substrate to separate the base island and the pin; A sealing film is formed on the first surface to close the opening of the first groove. A silicon microphone chip is mounted on the first surface of the base island; A cover is attached to the first surface of the pin to cover the base island and the silicon microphone chip; wherein the base island, the pin, the sealing film, and the cover together form a second sound cavity; the cover has a second sound inlet hole communicating with the second sound cavity; the second sound cavity includes a first cavity located on the side of the first surface near the cover and a second cavity located between the base island and the pin, the first cavity and the second cavity communicating; the second cavity is located between the first surface and the sealing film.

16. The packaging method according to claim 15, characterized in that, After the step of forming a first groove on the first surface of the substrate to separate the base island and the pin, the method further includes: A first metal plate with a first bend is attached to the base island; the first bend has a first gap with the side wall of the base island; Remove the bottom of the first groove to separate the base island and the pin, and form a first flange at the edge of the base island; The first flange is bent toward the first surface to form a second bent portion opposite to the first bent portion; the second bent portion has a first gap with the sidewall of the base island; the sidewall of the base island, the first bent portion and the second bent portion together form a first sound cavity; wherein, the gap between the first bent portion and the second bent portion forms a first sound inlet hole, and the first sound inlet hole communicates with the first sound cavity; the second sound cavity communicates with the first sound cavity.

17. The packaging method according to claim 16, characterized in that, In the step of forming a first groove on the first surface of the substrate to separate the base island and the pin: On one side of the first surface, the surface of the base island is lower than the surface of the pin; In the step of attaching the first metal plate having the first bend to the base island: The surface of the first metal plate is flush with the surface of the pin.

18. The packaging method according to claim 16, characterized in that, The step of forming a first groove on the first surface of the substrate to separate the base island and the pin also includes: An edge step groove is formed on the pin.

19. The packaging method according to claim 16, characterized in that, Before the step of forming a sealing film on the first surface to close the opening of the first groove, the method further includes: A second metal plate having a third bend is mounted on the pin; the third bend has a second gap with the sidewall of the pin; The step of removing the bottom of the first groove to separate the base island and the pin, and forming a first flange at the edge of the base island, further includes: A second flange is formed on the side edge of the pin near the base island; The second flange bends toward the first surface to form a fourth bend that is opposite to the third bend; the fourth bend has a second gap with the sidewall of the pin; the sidewall of the pin, the third bend, and the fourth bend together form a third sound cavity; wherein the gap between the third bend and the fourth bend forms a third sound inlet hole, and the third sound inlet hole communicates with the third sound cavity and the second sound cavity respectively.

20. The packaging method according to claim 16, characterized in that, The step of forming a sealing film on the first surface to close the opening of the first groove includes: A sealing film is formed on the first surface, wherein the thickness of the sealing film at the first groove is greater than the thickness of the sealing film on the first metal plate or the pin. After the step of bending the first flange toward the first surface to form a second bend that is opposite to the first bend, the sealing film is ground to expose the surface of the first metal plate and the surface of the pin; the sealing film is located between the first bend and the pin.

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