Chip package assembly

Abstract

The present specification relates to the technical field of chip packaging, and particularly relates to a chip packaging assembly. A micro-electro-mechanical system (MEMS) die has a pad disposed thereon. The pad is below a top surface of the MEMS die. The top surface is distal from a packaging substrate when the MEMS die is disposed on the packaging substrate. Embodiments of the present specification can reduce packaging thickness.

Description

Technical Field

[0001] This specification relates to the field of chip packaging technology, and in particular to a bare chip for a microelectromechanical system (MEMS) and a chip packaging assembly. Background Technology

[0002] A micro-electro-mechanical system (MEMS) die is a chip that is not packaged. MEMS dies have a wide range of applications, such as being used as electro-acoustic transducers for microphones.

[0003] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solution of this application and facilitating the understanding of those skilled in the art. Utility Model Content

[0004] Microelectromechanical systems (MEMS) bare dies have pads. These pads are metallized areas used for electrical connections. To prevent breakage of the bonding wires, when the bonding wires are electrically connected to the pads, they must extend upwards from the pads to form a wire loop. When packaging the MEMS bare die, the package shell needs to cover both the MEMS bare die and the wire loop. In related technologies, the pads are flush with the surface of the MEMS bare die. This causes the wire loop to extend from the surface of the MEMS bare die, requiring a thicker package shell to cover both the MEMS bare die and the wire loop. Furthermore, the package shell is made of metal for grounding. Therefore, a certain safety distance must be maintained between the apex of the wire loop and the package shell to prevent contact between the bonding wires and the package shell. This further increases the package thickness of the MEMS bare die.

[0005] To address the aforementioned technical problems or other similar issues, embodiments of this specification provide a microelectromechanical system (MEMS) bare chip and a chip packaging assembly to reduce the packaging thickness of the MEMS bare chip.

[0006] This specification provides a bare microelectromechanical system (MEMS) chip with pads provided on it.

[0007] The pads are below the top surface of the bare microelectromechanical system chip;

[0008] When the bare chip of the microelectromechanical system is disposed on the packaging substrate, the top surface is away from the packaging substrate.

[0009] In some embodiments, a recessed region is provided on the top surface, and the pad is located in the recessed region.

[0010] In some embodiments, the pads are located on the transition slope of the bare die of the microelectromechanical system;

[0011] The transition slope connects the top surface and the side surface of the bare microelectromechanical system chip.

[0012] In some embodiments, the microelectromechanical system bare chip includes an electroacoustic transducer.

[0013] This specification also provides a chip packaging component, including:

[0014] Packaging substrate;

[0015] Microelectromechanical system bare chip disposed on the packaging substrate; pads are disposed on the microelectromechanical system bare chip, the pads being lower than the top surface of the microelectromechanical system bare chip, the top surface being far away from the packaging substrate;

[0016] Integrated circuit disposed on the packaging substrate;

[0017] Bonding wires are used to electrically connect the pads and the integrated circuit;

[0018] A cover is disposed on the packaging substrate to cover the bare microelectromechanical system chip and the integrated circuit.

[0019] In some embodiments, a recessed region is provided on the top surface, and the pad is located in the recessed region.

[0020] In some embodiments, the pads are located on the transition slope of the bare die of the microelectromechanical system;

[0021] The transition slope connects the top surface and the side surface of the bare microelectromechanical system chip.

[0022] In some embodiments, the microelectromechanical system bare chip and the integrated circuit are disposed on the same surface of the packaging substrate.

[0023] In some embodiments, the height of the microelectromechanical system bare chip relative to the packaging substrate is greater than the height of the integrated circuit relative to the packaging substrate.

[0024] In some embodiments, the microelectromechanical system bare chip includes an electroacoustic transducer, and the chip package assembly includes a microphone assembly.

[0025] In the technical solutions of this specification's embodiments, the pads of the microelectromechanical system (MEMS) bare chip are lower than the top surface of the MEMS bare chip. When the MEMS bare chip is mounted on a package substrate, the top surface is far from the package substrate. Therefore, by reducing the height of the pads, arc wires can be drawn from a position below the top surface, thereby reducing the package thickness of the MEMS bare chip.

[0026] The embodiments of this specification are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of these embodiments can be applied. It should be understood that the scope of the embodiments described herein is not limited thereto. Within the spirit and scope of the appended claims, the embodiments of this specification include many changes, modifications, and equivalents. Attached Figure Description

[0027] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the embodiments thereof and illustrate the implementation methods described herein, together with the textual description, to explain the technical principles of the embodiments thereof. Obviously, the drawings described below are merely some embodiments of this specification, and those skilled in the art can obtain other implementation methods based on these drawings without creative effort. In the drawings:

[0028] Figure 1 This is a schematic diagram of the packaging of a bare chip for a microelectromechanical system (MEMS) in related technologies.

[0029] Figure 2 This is a schematic diagram of a bare chip for a microelectromechanical system (MEMS) in an embodiment of this specification.

[0030] Figure 3 This is a top view of the bare chip of the microelectromechanical system in the embodiments of this specification;

[0031] Figure 4 The bare chip edge of the microelectromechanical system in the embodiments of this specification Figure 3 Cross-sectional view along the AA direction;

[0032] Figure 5 The bare chip edge of the microelectromechanical system in the embodiments of this specification Figure 3 Cross-sectional view along the BB direction;

[0033] Figure 6 This is a schematic diagram of a bare chip for a microelectromechanical system (MEMS) in an embodiment of this specification.

[0034] Figure 7 This is a schematic diagram of the chip packaging assembly in the embodiments of this specification;

[0035] Figure 8 This is a schematic diagram of the chip packaging assembly in the embodiments of this specification. Detailed Implementation

[0036] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. The specific embodiments described herein are only used to explain this disclosure, and not to limit this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure are within the scope of protection of this disclosure. In addition, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0037] Please refer to the relevant technologies. Figure 1 The microelectromechanical system (MEMS) bare chip 1 has pads 11. Pads 11 are flush with the top surface 12 of the MEMS bare chip 1. To prevent breakage of the bonding wire 2, when the bonding wire 2 is electrically connected to the pad 11, it needs to extend upwards from the pad 11 to form a line arc 21. When packaging the MEMS bare chip 1, the package shell 3 needs to cover the MEMS bare chip 1 and the line arc 21. However, because the pads 11 are flush with the top surface 12, the line arc 21 extends from the top surface 12 of the MEMS bare chip 1, resulting in a relatively high height. This necessitates a thicker package shell 3 to cover the MEMS bare chip 1 and the line arc 21. Furthermore, the package shell 3 is made of metal for grounding. A certain safety distance needs to be maintained between the apex of the line arc 21 and the package shell 3 to prevent contact between the bonding wire 2 and the package shell 3, thus avoiding grounding of the bonding wire 2. This further increases the package thickness of the MEMS bare chip 1.

[0038] This specification provides an embodiment of a Micro-Electro-Mechanical System (MEMS) die. A MEMS die is an unpackaged chip. For example, a MEMS die can be an independent chip unit that has not been packaged after wafer dicing. MEMS dies have a wide range of applications. For example, a MEMS die can be used as an electroacoustic transducer for a microphone. Another example is its use as an accelerometer. Yet another example is its use as other electronic components. The shape of a MEMS die can be cuboid, cube, or other shapes.

[0039] Depending on its intended use, the internal structure of a microelectromechanical system (MEMS) bare chip can vary. For example, an MEMS bare chip can be used as an electroacoustic transducer for a microphone. The electroacoustic transducer converts sound signals into electrical signals. It includes a diaphragm and a backplate. A gap may exist between the diaphragm and the backplate, forming a variable capacitor. The diaphragm receives the sound signal, resulting in corresponding mechanical deformation. This mechanical deformation of the diaphragm is converted into a change in the capacitance of the variable capacitor, thus converting the sound signal into an electrical signal. Of course, the above internal structure of an electroacoustic transducer is just an example. Furthermore, when a MEMS bare chip is used as other electronic components, it can have other internal structures.

[0040] In some embodiments, a microelectromechanical system (MEMS) bare die has one or more bond pads. Bond pads are metallized areas used to achieve electrical connections. Bond pads can be electrically connected to the internal structure of the MEMS bare die via metal wires. Bond pads can also be electrically connected to bonding wires. Thus, using bonding wires, the internal structure of the MEMS bare die can be electrically connected to external devices (such as external electronic components). The materials of the bonding wires include, but are not limited to, conductive metals such as gold, silver, copper, and aluminum. Due to limitations in the material of the bonding wires, when the bonding wires are electrically connected to the bond pads, the bonding wires must extend upwards from the bond pads to form a wire loop to avoid breakage of the bonding wires.

[0041] In some embodiments, the pads may be lower than the top surface of the microelectromechanical system (MEMS) die. This means that when the MEMS die is mounted on the package substrate, the height of the pads relative to the package substrate is less than the height of the top surface relative to the package substrate. The top surface can be the functional surface of the MEMS die. The internal structure of the MEMS die (such as circuitry) can be exposed on the top surface. When the MEMS die is mounted on the package substrate, the top surface is the surface facing away from the package substrate, thus being away from it. Therefore, compared to having the pads flush with the surface of the MEMS die, having the pads lower than the top surface of the MEMS die reduces the height of the pads, allowing arcing lines to emerge from a position below the top surface. This reduces the height of the arcing line's apex relative to the package substrate, thereby reducing the package thickness of the MEMS die.

[0042] The packaging substrate is a substrate used for packaging microelectromechanical system (MEMS) bare chips. By placing the MEMS bare chip on the packaging substrate and placing a cover on the packaging substrate, the MEMS bare chip can be packaged. The packaging substrate and the cover disposed on the packaging substrate can form a package shell. The MEMS bare chip can be located within the cavity formed by the packaging substrate and the cover. As an example, the top surface of the MEMS bare chip can be parallel to the packaging substrate.

[0043] In some embodiments, please refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 The top surface 12 of the microelectromechanical system (MEMS) bare chip 1 has one or more recessed regions 13. One or more pads 11 can be disposed within one or more recessed regions 13. A pad 11 can be disposed at the bottom of a recessed region 13. Thus, by disposing the pads 11 within the recessed regions 13 of the top surface 12, the pads 11 are lower than the top surface 12 of the MEMS bare chip 1. This allows the arc 21 to extend from the bottom of the recessed region 13 of the top surface 12, reducing the height of the apex of the arc 21 relative to the package substrate and decreasing the package thickness of the MEMS bare chip 1.

[0044] The bottom of the recessed area 13 may be parallel to the top surface 12, or it may intersect with the top surface 13.

[0045] The recessed area 13 can be a square or circular groove. One or more sides of the recessed area 13 may be higher than the bottom. As an example, the recessed area 13 is located inside the top surface 12. All sides of the recessed area 13 are higher than the bottom, thus, the recessed area 13 can be a closed recessed area. As another example, the recessed area 13 is located at the edge of the top surface 12. Some sides of the recessed area 13 are higher than the bottom, thus, the recessed area 13 can be an open recessed area.

[0046] The top surface 12 of the microelectromechanical system (MEMS) bare chip 1 exposes the internal structure 14 of the MEMS bare chip 1. Pads 11 are electrically connected to the internal structure 14 via wires 15. Pads 11 are also electrically connected to bonding wires 2. Thus, using the bonding wires 2, the internal structure 14 of the MEMS bare chip 1 can be electrically connected to external devices (such as integrated circuits 3).

[0047] Optionally, the microelectromechanical system bare chip 1 may include a substrate 16 and an insulating layer 17 located on the substrate. Wires 15 for connecting the internal structure 14 and the pads 11 are located on the insulating layer 17. The substrate 16, the insulating layer 17, and the wires 15 may form a stacked structure.

[0048] In some embodiments, please refer to Figure 6One or more pads 11 may be located on one or more transition ramps 18 of the microelectromechanical system (MEMS) bare die 1. One pad 11 may be disposed on one transition ramp 18. The transition ramp 18 may connect the top surface 12 and the side surface 19 of the MEMS bare die. The high side of the transition ramp 18 may intersect the top surface 12, and the low side opposite the high side may intersect the side surface 19. Different transition ramps 18 may connect different sides 19 of the MEMS bare die 1.

[0049] Therefore, by placing the pad 11 on the transition slope 18, the pad 11 can be lower than the top surface 12 of the MEMS bare chip 1. This allows the arc 21 to extend from the transition slope 18, which is lower than the top surface 12, reducing the height of the arc 21's apex relative to the package substrate, thereby reducing the package thickness of the MEMS bare chip 1. Furthermore, the arc 21 extends from the pad 11 directly above it. Because the pad 11 is placed on the transition slope 18, the arc 21 extends directly above the transition slope 18. That is, the arc 21 extends in a direction inclined towards the top surface 12, rather than directly above it. Compared to extending directly above the top surface 12, extending the arc 21 in a direction inclined towards the top surface 12 further reduces the height of the arc 21's apex relative to the package substrate 4, thereby further reducing the package thickness of the MEMS bare chip 1.

[0050] The microelectromechanical system (MEMS) bare chip 1 has one or more sides 19. Sides 19 may be perpendicular to the package substrate 4. Sides 19 may be connected to the bottom surface of the MEMS bare chip 1. The bottom surface is the surface that contacts the package substrate 4.

[0051] In some embodiments, a plurality of pads, such as two pads, may be provided on the bare die of the microelectromechanical system (MEMS). The plurality of pads may all be located within a recessed area of ​​the top surface. Alternatively, the plurality of pads may all be located on a transition ramp. Alternatively, one or more of the plurality of pads may be located within a recessed area of ​​the top surface, with the remaining pads located on a transition ramp.

[0052] Based on the above-described bare microelectromechanical system (MEMS) chip, this specification also provides a chip packaging component.

[0053] Chip-packaged components can be microelectromechanical systems (MEMS) microphone assemblies. MEMS microphone assemblies are characterized by low cost, small size, and high sensitivity, and are widely used in devices such as hearing aids, mobile phones, smart speakers, and personal computers. Alternatively, chip-packaged components can also be other electronic devices.

[0054] In some embodiments, please refer to Figure 7 and Figure 8The chip packaging assembly may include a microelectromechanical system bare chip 1, bonding wires 2, integrated circuit 3, packaging substrate 4, and cover 5.

[0055] The microelectromechanical system (MEMS) bare chip 1 and integrated circuit 3 can be mounted on the packaging substrate 4. The packaging substrate 4 is used to support electronic components such as the MEMS bare chip 1 and integrated circuit 3. The packaging substrate 4 can be a printed circuit board or other base.

[0056] The microelectromechanical system (MEMS) bare die 1 and integrated circuit 3 can be disposed on the same surface of the packaging substrate 4 to facilitate electrical connection via wire bonding. The thickness of the MEMS bare die 1 is greater than the thickness of the integrated circuit 3. Therefore, when disposed on the packaging substrate 4, the top surface 12 of the MEMS bare die 1 can be higher than the top surface of the integrated circuit 3. When the MEMS bare die 1 is disposed on the packaging substrate 4, its top surface 12 is the surface facing away from the packaging substrate 4, thus being away from the packaging substrate 4. When the integrated circuit 3 is disposed on the packaging substrate 4, its top surface is the surface facing away from the packaging substrate 4, thus being away from the packaging substrate 4.

[0057] Microelectromechanical system (MEMS) bare chip 1 is used to generate electrical signals. Integrated circuit 3 can be an application-specific integrated circuit (ASIC). Integrated circuit 3 can be an unpackaged bare chip. Integrated circuit 3 is used to process the electrical signals output by MEMS bare chip 1, such as amplification or filtering. MEMS bare chip 1 and integrated circuit 3 are electrically connected via bonding wire 2. As an example, MEMS bare chip 1 is connected to integrated circuit 3 via bonding wire 2, and integrated circuit 3 is connected to package substrate 4 via wires. External electronic devices can be connected to package substrate 4 via wires. Thus, the electrical signals generated by MEMS bare chip 1 can be transmitted to external electronic devices via integrated circuit 3.

[0058] The bonding wire 2 is used for electrical connection between the microelectromechanical system (MEMS) bare chip 1 and the integrated circuit 3. A cover 5 can be disposed on the packaging substrate 4 to cover the MEMS bare chip 1, the integrated circuit 3, and the bonding wire 2. Thus, the MEMS bare chip 1, the bonding wire 2, and the integrated circuit 3 can be located within the cavity formed by the packaging substrate 4 and the cover 5, thereby forming a MEMS package assembly.

[0059] The cover 5 can be made of metal for grounding. There can be a certain gap between the vertex of the arc 21 and the cover 5.

[0060] In some embodiments, pads 11 are provided on the microelectromechanical system (MEMS) bare chip 1. Bonding wires 2 can electrically connect the pads 11 and the integrated circuit 3. The pads 11 can be lower than the top surface 12 of the MEMS bare chip 1. The top surface 12 is away from the package substrate 14. Thus, by reducing the height of the pads 11, the arc wires 21 can be led out from a position below the top surface 12, thereby reducing the height of the apex of the arc wires 21 relative to the package substrate 4, reducing the thickness of the cover 5, and thus reducing the thickness of the chip package assembly.

[0061] Optionally, a recessed region 13 is provided on the top surface 12, and the pad 11 may be located in the recessed region 13.

[0062] Alternatively, the pad 11 may also be located on the transition ramp 18 of the microelectromechanical system (MEMS) bare chip 1. The transition ramp 18 may connect the top surface 12 and the side surface 19 of the MEMS bare chip 1.

[0063] Optionally, a plurality of pads 11 are provided on the microelectromechanical system (MEMS) bare die 1. One pad 11 is located on a transition slope 18, and the remaining pads 11 are located within a recessed region 13 of the top surface 12. For example, one pad 11 is located on the transition slope 18 connected to a specific side. The specific side is the side of the MEMS bare die 1 facing the integrated circuit 3. Specifically, for example, two pads 11 are provided on the MEMS bare die 1. One pad 11 is located on the transition slope 18 connected to a specific side, which is the side of the MEMS bare die 1 facing the integrated circuit 3; the other pad 11 is located within the recessed region 13.

[0064] In some embodiments, one or more pads may also be provided on the integrated circuit 3. The bonding wire 2 can electrically connect the pads 11 of the microelectromechanical system (MEMS) bare die 1 and the pads of the integrated circuit 3. The pads of the integrated circuit 3 may be flush with the top surface of the integrated circuit 3. For example, the pads of the integrated circuit 3 may be directly provided on the top surface of the integrated circuit 3. Alternatively, the pads of the integrated circuit 3 may be lower than the top surface of the integrated circuit 3. For example, one or more recessed regions are provided on the top surface of the integrated circuit 3. One or more pads of the integrated circuit 3 may be provided within one or more recessed regions. A pad may be provided at the bottom of a recessed region. The recessed regions on the top surface of the integrated circuit 3 are similar to the recessed regions on the top surface of the MEMS bare die 1, and the two can be explained in comparison. Furthermore, one or more pads of the integrated circuit 3 may be located on one or more transition ramps of the integrated circuit 3. A pad may be provided on a transition ramp. The transition ramp connects the top surface and the side surface of the integrated circuit 3. The transition ramps of the integrated circuit 3 are similar to the transition ramps of the MEMS bare die 1, and the two can be explained in comparison.

[0065] In some embodiments, the packaging substrate 4 may also be provided with pads. The pads on the packaging substrate 4 can be electrically connected to the integrated circuit 3 via wires. This facilitates the internal electrical connection of external electronic devices to the chip packaging assembly through the packaging substrate 4.

[0066] In some embodiments, the packaging substrate 4 may have through-holes. The through-holes are located in the area contacting the microelectromechanical system (MEMS) bare chip 1. When the MEMS bare chip 1 is disposed on the packaging substrate 4, the MEMS bare chip 1 can cover the through-holes. The through-holes can serve as sound holes. Sound signals and other signals can be transmitted to the MEMS bare chip 1 through the through-holes. The MEMS bare chip 1 collects sound signals and other signals. For example, if the chip package assembly is a microphone assembly, the through-holes can improve the sensitivity of the microphone assembly.

[0067] Those skilled in the art will understand that the descriptions of the various embodiments in this specification have different focuses, and parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. Furthermore, it is understood that those skilled in the art, after reading this specification, can conceive of any combination of some or all of the embodiments listed in this specification without creative effort, and such combinations are also within the scope of disclosure and protection of this specification.

[0068] Although this specification has been described through embodiments, those skilled in the art will understand that the above embodiments are merely illustrative of the core ideas of this specification. Those skilled in the art will appreciate that many variations and modifications are possible with this specification. It is intended that the appended claims encompass these variations and modifications without departing from the spirit of this specification.

Claims

1. A chip packaging component, characterized in that, include: Packaging substrate; Microelectromechanical system bare chip disposed on the packaging substrate; A pad is provided on the bare microelectromechanical system chip, the pad being lower than the top surface of the bare microelectromechanical system chip, and the top surface being far away from the packaging substrate; Integrated circuit disposed on the packaging substrate; Bonding wires are used to electrically connect the pads and the integrated circuit; A cover is disposed on the packaging substrate to cover the bare microelectromechanical system chip and the integrated circuit.

2. The chip packaging assembly according to claim 1, characterized in that, A recessed area is provided on the top surface, and the pad is located in the recessed area.

3. The chip packaging assembly according to claim 1, characterized in that, The pads are located on the transition slope of the bare die of the microelectromechanical system; The transition slope connects the top surface and the side surface of the bare microelectromechanical system chip.

4. The chip packaging assembly according to claim 1, characterized in that, The microelectromechanical system bare chip and the integrated circuit are disposed on the same surface of the packaging substrate.

5. The chip packaging assembly according to claim 4, characterized in that, The thickness of the bare chip of the microelectromechanical system is greater than the thickness of the integrated circuit.

6. The chip packaging assembly according to claim 1, characterized in that, The bare chip of the microelectromechanical system includes an electro-acoustic transducer, and the chip package includes a microphone assembly.

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