A sensor, sensor packaging method, wafer and small-size air pressure sensor

Abstract

The present invention discloses a sensor, a sensor packaging method, a wafer and a small-sized air pressure sensor, and relates to the field of sensor packaging technology. The sensor includes a housing, and a micro-electromechanical system chip and a signal processing chip are 3D stacked and packaged inside the housing by a packaging process. The packaging method of the sensor includes: mounting the signal processing chip to a substrate by FC, and performing bottom filling protection between the signal processing chip and the substrate; 3D stacking the micro-electromechanical system chip onto the signal processing chip; and packaging the housing and the substrate together by solder paste reflow or glue bonding. Good conductivity and low power consumption. High packaging efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor packaging, and in particular to a sensor, a sensor packaging method, a wafer and a small-sized air pressure sensor. Background Art

[0002] At present, the packaging process used by pressure sensors is basically the bonding and wafer mounting method. In response to the market demand for small size and high performance of pressure sensors, even the traditional packaging of the industry's top DB / WB equipment cannot meet the demand.

[0003] Through the above analysis, the problems and defects of the prior art are as follows:

[0004] (1) The existing sensors are large in size and weight, have poor conductivity, high power consumption, and low packaging efficiency.

[0005] (2) Reliability risks, such as the risk of gold wire detaching when subjected to harsh drops or vibrations

[0006] (3) Gold wire material cost is expensive.

[0007] The significance of solving the above problems and defects is that the present invention saves man-hours, improves efficiency and reduces size. Summary of the invention

[0008] In order to overcome the problems existing in the related art, the embodiments disclosed in the present invention provide a sensor, a sensor packaging method, a wafer and a small-sized air pressure sensor. The technical solution is as follows:

[0009] According to a first aspect of the disclosed embodiments of the present invention, a sensor is provided, including a housing, wherein a micro-electromechanical system chip and a signal processing chip are 3D stacked and packaged inside the housing by a packaging process.

[0010] Furthermore, a micro-electromechanical system chip and a signal processing chip are manufactured inside the shell by through silicon via processing or by using a DB / FC / Dispensing / Underfill comprehensive process; the DB / FC / Dispensing / Underfill comprehensive process is performed in sequence.

[0011] Furthermore, the MEMS chip is manufactured with a MEMS chip through hole by plasma etching, and the MEMS chip through hole is filled with MEMS chip copper.

[0012] Furthermore, the signal processing chip is manufactured with a signal processing chip through hole by plasma etching, and the signal processing chip through hole is filled with signal processing chip copper.

[0013] Furthermore, the micro-electromechanical system chip and the signal processing chip are both rewired, a seed layer is arranged at the lower part of the micro-electromechanical system chip, and seed layers are arranged at the upper part and the lower part of the signal processing chip.

[0014] Furthermore, the micro-electromechanical system chip has copper pillars deposited on the bottom by vapor deposition;

[0015] One end of the copper pillar is connected to the seed layer of the rewiring at the bottom of the micro-electromechanical system chip, and the other end is connected to the seed layer of the rewiring at the top of the signal processing chip;

[0016] The signal processing chip has solder balls deposited on the bottom by vapor deposition;

[0017] One end of the solder ball is connected to the seed layer of the rewiring at the bottom of the signal processing chip, and the other end is connected to the substrate.

[0018] Furthermore, the seed layer includes: an under bump metal layer and a redistribution layer. The under bump metal layer is located at the lower end of the redistribution layer, that is, the redistribution layer is first followed by the under bump metal layer.

[0019] According to a second aspect of the disclosed embodiment of the present invention, a sensor packaging method is provided, the sensor packaging method comprising:

[0020] The signal processing chip is mounted on the substrate by FC, and the bottom fill glue is provided between the signal processing chip and the substrate for protection;

[0021] 3D stacking the micro-electromechanical system chip onto the signal processing chip;

[0022] The shell and the substrate are packaged together by solder paste reflow or glue bonding.

[0023] According to a third aspect of the disclosed embodiments of the present invention, a wafer integrating the sensor is provided.

[0024] According to a fourth aspect of the disclosed embodiments of the present invention, there is provided a small-sized air pressure sensor, comprising a housing, wherein the small-sized air pressure sensor is processed by a through silicon via process or a DB / FC / Dispensing / Underfill integrated process, and a micro-electromechanical system chip and a signal processing chip are manufactured inside the housing;

[0025] The MEMS chip is manufactured with a MEMS chip through hole by plasma etching, and the MEMS chip through hole is filled with MEMS chip copper;

[0026] The signal processing chip is provided with a signal processing chip through hole by plasma etching, and the signal processing chip through hole is filled with signal processing chip copper;

[0027] The micro-electromechanical system chip and the signal processing chip are both rewired, an under-bump metallization layer and a rewiring layer are arranged at the lower part of the micro-electromechanical system core, and an under-bump metallization layer and a rewiring layer are arranged at the upper and lower parts of the signal processing chip;

[0028] The micro-electromechanical system chip has copper pillars deposited on the bottom by vapor deposition;

[0029] One end of the copper pillar is connected to the under-bump metallization layer and the redistribution layer of the rewiring at the bottom of the micro-electromechanical system chip, and the other end is connected to the under-bump metallization layer and the redistribution layer of the rewiring at the top of the signal processing chip;

[0030] The signal processing chip has solder balls deposited on the bottom by vapor deposition;

[0031] One end of the solder ball is connected to the under-bump metal layer and the redistribution layer of the lower part of the signal processing chip, and the other end is connected to the substrate.

[0032] The effects and advantages obtained by combining experimental or test data with existing technologies include:

[0033] The size of the present invention can be significantly reduced by 30%.

[0034] The test data includes:

[0035] Test conditions:

[0036] Supply voltage: 1.8V.

[0037] Sampling frequency: 1Hz.

[0038] Working mode: Stand Mode (μA)

[0039] The test data comparison (reference table) is as follows, among which, the data of Bosch and ST are the traditional gold wire data.

[0040]

[0041]

[0042] The present invention abandons the traditional gold wire connection process and adopts an advanced packaging process to perform 3D stacking packaging of ASIC and MEMS, which has obvious advantages in terms of size and performance.

[0043] The invention has small size, light weight, good conductivity, low power consumption and high packaging efficiency.

[0044] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0046] Figure 1 Schematic diagram of a small-sized air pressure sensor provided by an embodiment of the present invention.

[0047] Figure 1 In: 1. Substrate; 2. Case; 3. Signal processing chip copper (ASIC Cu); 4. Copper pillar; 5. Micro-electromechanical system chip (MEMS); 6. Micro-electromechanical system chip copper (MEMS Cu); 7. Under bump metal layer (UBM) and redistribution layer (RDL); 8. Signal processing chip (ASIC); 9. Solder ball.

[0048] Figure 2 Schematic diagram of a traditional air pressure sensor provided by an embodiment of the present invention.

[0049] Figure 2 Chinese: 10. Traditional substrate (traditional Substrate); 11. Traditional case (traditional Case); 12. Traditional micro-electromechanical system chip (traditional MEMS); 13. Traditional gold wire (traditional Gold Wire); 14. Traditional signal processing chip (traditional ASIC). DETAILED DESCRIPTION

[0050] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0051] The present invention provides a sensor, comprising a housing (Case) 2, wherein a micro-electromechanical system chip (MEMS) 5 and a signal processing chip are 3D stacked and packaged inside the housing (Case) 2 by using a packaging process.

[0052] This technology can be applied to the field of advanced packaging, not limited to air pressure, such as combined sensors, MEMS sensors, and medical sensors, but the focus of the present invention is on products in the field of air pressure.

[0053] Preferably, the micro-electromechanical system chip (MEMS) 5 and the signal processing chip are manufactured inside the housing (Case) 2 by through silicon via processing or DB / FC / Dispensing / Underfill comprehensive process. The DB / FC / Dispensing / Underfill comprehensive process is performed in sequence.

[0054] Preferably, the micro-electromechanical system chip (MEMS) 5 is manufactured with a micro-electromechanical system chip (MEMS) 5 through hole by plasma etching, and the micro-electromechanical system chip (MEMS) 5 through hole is filled with micro-electromechanical system chip copper (MEMSCu) 6.

[0055] Preferably, the signal processing chip is provided with a signal processing chip through hole by plasma etching, and the signal processing chip through hole is filled with signal processing chip copper (ASIC Cu) 3.

[0056] Preferably, the micro-electromechanical system chip (MEMS) 5 and the signal processing chip are both rewired, a seed layer is arranged at the lower part of the micro-electromechanical system chip, and seed layers are arranged at the upper part and the lower part of the signal processing chip.

[0057] The micro-electromechanical system chip (MEMS) 5 has copper pillars deposited on the bottom by vapor deposition;

[0058] One end of the copper pillar is connected to the seed layer of the rewiring at the bottom of the micro-electromechanical system chip (MEMS) 5, and the other end is connected to the seed layer of the rewiring at the top of the signal processing chip;

[0059] The signal processing chip is deposited with solder balls 9 at the bottom by vapor deposition:

[0060] One end of the solder ball 9 is connected to the seed layer of the rewiring at the bottom of the signal processing chip, and the other end is connected to the substrate 1 .

[0061] The seed layer includes: an under bump metallization layer (UBM) and a redistribution layer (RDL) 7. The under bump metallization layer is located at the lower end of the redistribution layer, that is, the redistribution layer is first followed by the under bump metallization layer.

[0062] The present invention will be further described below in conjunction with specific embodiments.

[0063] The small-sized air pressure sensor provided by the embodiment of the present invention is as follows: Figure 1As shown, it includes: a substrate (Substrate) 1, a case (Case) 2, a signal processing chip copper (ASIC Cu) 3, a copper pillar (Collar Pillar) 4, a micro-electromechanical system chip (MEMS) 5, a micro-electromechanical system chip copper (MEMS Cu) 6, an under-bump metallization layer (UBM) and a redistribution layer (RDL) 7, a signal processing chip (ASIC) 8, and a solder ball (Solder ball) 9.

[0064] In the present invention, the packaging principle of the small-size air pressure sensor includes:

[0065] Wafer processing principle: ASIC and MEMS are processed by through silicon via process Figure 1 In the form of a micro-electromechanical system chip (MEMS) 5 and a signal processing chip (ASIC) 8.

[0066] Depending on the equipment capabilities, through holes are made by plasma etching and then filled with copper by electroplating to achieve conductive connections, such as Figure 1 The copper of signal processing chip (ASIC Cu) 3 and micro-electromechanical system chip (MEMS Cu) 6 in the silicon hole copper is better than the traditional gold wire (traditional gold wire) 13 (such as Figure 2 )Better conductivity and higher efficiency.

[0067] Re-routing of seed layer UBM and RDL for ASIC and MEMS according to the connection requirements of the chip, such as Figure 1 The under bump metal layer (UBM) and redistribution layer (RDL) 7 are formed in the form of the wafer, and then copper pillar and solder ball are grown on the wafer by vapor deposition, such as Figure 1 The height of the copper pillar (Collar Pillar) 4 and the solder ball (Solder ball) 9 in the wafer can be as high as 20μm and the height of the solder ball can be as high as 60μm. After the basic wafer chip is processed and manufactured, it is finally thinned. According to the characteristics of the wafer, Figure 1 The signal processing chip (ASIC) 8 in the system is thinned to 75μm or less.

[0068] The advanced packaging steps provided by the present invention include:

[0069] ASIC 8 is mounted to Substrate 1 by FC. To improve reliability and prevent small-sized Solder Ball from cracking, underfill protection is performed between ASIC 8 and Substrate 1.

[0070] Secondly, MEMS 5 is stacked onto ASIC 8;

[0071] Finally, package Case 2 and Substrate 1 together by solder paste reflow or glue bonding.

[0072] The present invention saves 30-40% of volume, has better conductivity and lower power consumption, can improve the volume size and performance of the air pressure sensor, does not need to punch gold wire during the packaging process, and can also improve the packaging efficiency.

[0073] like Figure 2 As shown, the conventional air pressure sensor provided includes: a conventional substrate (conventional Substrate) 10, a conventional case (conventional Case) 11, a conventional micro-electromechanical system chip (conventional MEMS) 12, a conventional gold wire (conventional Gold Wire) 13, and a conventional signal processing chip (conventional ASIC) 14. In the conventional package, a certain amount of space is occupied in the length, width, and height directions in order for the Gold wire 13 to realize electrical connection.

[0074] The present invention is further described below in conjunction with experimental comparative data.

[0075] The size of the present invention can be significantly reduced by 30%.

[0076] The test data includes:

[0077] Test conditions:

[0078] Supply voltage: 1.8V.

[0079] Sampling frequency: 1Hz.

[0080] Working mode: Stand Mode (μA)

[0081] The test data comparison (reference table) is as follows, among which the data of Bosch and ST are traditional goldwire data.

[0082]

[0083] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0084] It should be understood that the present disclosure is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure should be limited by the appended claims.

Claims

1. A sensor, comprising a housing, characterized in that: The micro-electromechanical system chip and the signal processing chip are 3D stacked and packaged inside the housing by using a packaging process; The micro-electromechanical system chip and the signal processing chip are both rewired, a seed layer is arranged at the lower part of the micro-electromechanical system chip, and a seed layer is arranged at the upper part and the lower part of the signal processing chip; The micro-electromechanical system chip has copper pillars deposited on the bottom by vapor deposition; One end of the copper pillar is connected to the seed layer of the rewiring at the bottom of the micro-electromechanical system chip, and the other end is connected to the seed layer of the rewiring at the top of the signal processing chip; The signal processing chip has solder balls deposited on the bottom by vapor deposition; One end of the solder ball is connected to the seed layer of the rewiring at the bottom of the signal processing chip, and the other end is connected to the substrate; A micro-electromechanical system chip and a signal processing chip are manufactured inside the housing by through silicon via processing or DB / FC / Dispensing / Underfill comprehensive process; The signal processing chip is manufactured with a signal processing chip through hole by plasma etching, and the signal processing chip through hole is filled with signal processing chip copper.

2. The sensor according to claim 1, characterized in that The MEMS chip is manufactured with a MEMS chip through hole by plasma etching, and the MEMS chip through hole is filled with MEMS chip copper.

3. The sensor according to claim 1, characterized in that The seed layer comprises: an under-bump metallization layer and a redistribution layer; the under-bump metallization layer is located at the lower end of the redistribution layer.

4. A wafer, characterized in that: The wafer is integrated with the sensor according to any one of claims 1 to 3.

5. A small-sized air pressure sensor, comprising a housing, characterized in that: The small-sized air pressure sensor is processed by through silicon via process or DB / FC / Dispensing / Underfill comprehensive process, and a micro-electromechanical system chip and a signal processing chip are manufactured inside the housing; The MEMS chip is manufactured with a MEMS chip through hole by plasma etching, and the MEMS chip through hole is filled with MEMS chip copper; The signal processing chip is provided with a signal processing chip through hole by plasma etching, and the signal processing chip through hole is filled with signal processing chip copper; The micro-electromechanical system chip and the signal processing chip are both rewired, an under-bump metallization layer and a rewiring layer are arranged at the lower part of the micro-electromechanical system core, and an under-bump metallization layer and a rewiring layer are arranged at the upper and lower parts of the signal processing chip; The micro-electromechanical system chip has copper pillars deposited on the bottom by vapor deposition; One end of the copper pillar is connected to the under-bump metallization layer and the redistribution layer of the rewiring at the bottom of the micro-electromechanical system chip, and the other end is connected to the under-bump metallization layer and the redistribution layer of the rewiring at the top of the signal processing chip; The signal processing chip has solder balls deposited on the bottom by vapor deposition; One end of the solder ball is connected to the under-bump metal layer and the redistribution layer of the lower part of the signal processing chip, and the other end is connected to the substrate.

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