A molding die and molding method for a contact force sensor

Abstract

This invention discloses a molding die and molding method for a contact force sensor. The molding die includes: an upper mold with at least one first groove, the bottom surface of which has a plurality of second grooves arranged in an array; a release film covering the bottom surface of the first groove and the bottom and side surfaces of the second grooves; the release film is a flexible film that can be elastically deformed; the first groove of the upper mold is used to cooperate with the lower mold to form a sealed chamber, the sealed chamber being used to house a plurality of contact force sensors to be encapsulated; the second grooves are used to accommodate the pressure receiving part of the contact force sensor to be encapsulated, and the cross-sectional area of ​​the second groove is smaller than the area of ​​the first surface of the upper silicon substrate of the contact force sensor to be encapsulated, so that during molding, the release film surrounding the second groove covers the edge area of ​​the first surface of the upper silicon substrate; the lower mold is provided with at least one encapsulation material inlet, the encapsulation material inlet being used to inject encapsulation material into the sealed chamber. This invention can improve the molding efficiency of contact force sensors and reduce manufacturing costs.

Description

Technical Field

[0001] This invention relates to the field of encapsulation technology, and in particular to an encapsulation mold and encapsulation method for a contact force sensor. Background Technology

[0002] In recent years, force sensors for load sensing have been applied in many fields, but the current market share of micro-force sensors is low and cannot meet the large-scale application requirements of industries, medical fields, AI, etc., because the existing micro-force sensors are expensive to manufacture. Summary of the Invention

[0003] This invention provides a molding die and molding method for a contact force sensor, thereby improving the molding efficiency of the contact force sensor and reducing manufacturing costs.

[0004] According to the invention, by exposing the chip surface and its pressure contact points outside the encapsulation, the chip's sensitive structure is not affected by the encapsulation material, thereby improving sensitivity and suppressing zero-point drift distortion, thus improving performance.

[0005] According to one aspect of the present invention, a molding die for a contact force sensor is provided, comprising:

[0006] Upper mold, release film, and lower mold;

[0007] The upper mold includes at least one first groove, and the bottom surface of the first groove is provided with a plurality of second grooves arranged in an array.

[0008] The release film covers the bottom surface of the first groove and the bottom and side surfaces of the second groove; the release film is a flexible film that can be elastically deformed.

[0009] The first groove of the upper mold is used to cooperate with the lower mold to form a sealed chamber, and the sealed chamber is used to house a plurality of contact force sensors to be packaged; the second groove is used to accommodate the pressure receiving part of the contact force sensor to be packaged, and the cross-sectional area of ​​the second groove is smaller than the area of ​​the first surface of the upper silicon substrate of the contact force sensor to be packaged, so that the release film surrounding the second groove covers the edge area of ​​the first surface of the upper silicon substrate during molding.

[0010] The lower mold is provided with at least one encapsulation material inlet, which is used to inject encapsulation material into the sealed cavity.

[0011] Optionally, the contact force sensor encapsulation mold further includes:

[0012] A buffer layer is disposed on the surface of the lower mold away from the upper mold.

[0013] Optionally, the area of ​​the lower mold opposite each first groove is provided with multiple encapsulation material inlets.

[0014] Optionally, the junction of the sidewall of each of the second grooves and the bottom surface of the first groove has a chamfer.

[0015] Optionally, the thickness of the release film is greater than 30 micrometers.

[0016] Optionally, both the upper and lower molds include vacuum holes.

[0017] According to another aspect of the present invention, a molding method is provided, wherein a contact force sensor molding mold as described in any embodiment of the present invention is used for molding, the molding method comprising:

[0018] A packaging substrate equipped with multiple contact force sensors is disposed on the surface of the lower mold, wherein the contact force sensors are disposed on the side of the packaging substrate away from the lower mold;

[0019] The upper mold is placed on the side of the packaging substrate away from the lower mold. Multiple contact force sensors are located in the first groove. The pressure receiving part of each contact force sensor is located in a second groove. The release film on the bottom surface of the first groove is in contact with the first surface of the upper silicon substrate of the contact force sensor where the pressure receiving part is provided.

[0020] Pressure is applied to the upper mold to press the release film down a preset distance, so that the release film covers part of the side surface of the upper silicon substrate, wherein the side surface of the upper silicon substrate is the surface connected to the first surface of the upper silicon substrate;

[0021] Multiple contact force sensors are encapsulated by injecting encapsulation material through the encapsulation material inlet.

[0022] Optionally, the preset distance is greater than or equal to 30 micrometers.

[0023] Optionally, before applying pressure to the upper mold to press the release film down a predetermined distance and before the release film covers a portion of the side surface of the upper silicon substrate, the method further includes:

[0024] Vacuuming is performed through the lower mold and the vacuum hole on the lower mold.

[0025] Optionally, after encapsulating multiple contact force sensors by injecting encapsulation material through the encapsulation material inlet, the process further includes:

[0026] Curing of the encapsulation material;

[0027] Remove the upper mold, release film, and lower mold;

[0028] The packaging material and packaging substrate are cut to separate multiple plastic-encapsulated contact force sensors.

[0029] In the plastic encapsulation mold of the contact force sensor in this embodiment of the invention, the upper mold includes at least one first groove, and the bottom surface of the first groove is provided with a plurality of second grooves arranged in an array. A release film covers the bottom surface of the first groove and the bottom and side surfaces of the second grooves. The release film is a flexible film. The first groove of the upper mold is used to cooperate with the lower mold to form a sealed chamber. The sealed chamber is used to house a plurality of contact force sensors to be encapsulated. Each second groove is used to accommodate the pressure receiving part of one contact force sensor to be encapsulated. The cross-sectional area of ​​the second groove is smaller than the area of ​​the first surface of the upper silicon substrate of the contact force sensor to be encapsulated, so that the pressure receiving part is located in the second groove during plastic encapsulation. The release film surrounding the second groove covers the upper silicon substrate. The edge region of the first surface allows the release film to deform during molding by pressing down the upper mold, covering part of the side surface of the upper silicon substrate connected to the first surface. Thus, after the encapsulation material is injected, since the pressure receiving part is located in the second groove and the release film covers the first surface of the upper silicon substrate and part of the side surface connected to the first surface, the encapsulation material will not cover the pressure receiving part and the first surface of the upper silicon substrate. Furthermore, the upper surface of the encapsulation material is lower than the first surface of the upper silicon substrate, ensuring that the contact force sensor has high sensitivity after molding. In addition, the solution of this embodiment can encapsulate multiple contact force sensors at one time, which can improve the molding efficiency of the contact force sensor and reduce the manufacturing cost.

[0030] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of a plastic encapsulation mold for a contact force sensor provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of another type of plastic encapsulation mold for a contact force sensor provided in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of a process for injecting encapsulation material.

[0035] Figure 4 This is a schematic diagram of a contact force sensor;

[0036] Figure 5This is a schematic diagram of the silicon substrate on the contact force sensor;

[0037] Figure 6 This is a schematic diagram of a packaging substrate provided in an embodiment of the present invention;

[0038] Figure 7 yes Figure 1 Enlarged view of the area enclosed by the dashed box (100);

[0039] Figure 8 This is a top view of a lower mold provided in an embodiment of the present invention;

[0040] Figure 9 This is a schematic diagram of an upper mold provided in an embodiment of the present invention;

[0041] Figure 10 This is a flowchart of a molding method provided in an embodiment of the present invention;

[0042] Figure 11 This is a schematic diagram of a single contact force sensor after cutting, provided in an embodiment of the present invention. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0045] This invention provides a plastic encapsulation mold for a contact force sensor. Figure 1 This is a schematic diagram of a plastic encapsulation mold for a contact force sensor provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another contact force sensor encapsulation mold provided in an embodiment of the present invention, for reference. Figure 1 and Figure 2 The molding die includes:

[0046] Upper mold 10, release film 20, and lower mold 30;

[0047] The upper mold 10 includes at least one first groove 11, and the bottom surface of the first groove 11 is provided with a plurality of second grooves 12 arranged in an array;

[0048] Release film 20 covers the bottom surface of the first groove 11 and the bottom and side surfaces of the second groove 12; release film 20 is a flexible film that can be elastically deformed;

[0049] The first groove 11 of the upper mold 10 is used to cooperate with the lower mold 30 to form a sealed chamber, and the sealed chamber is used to set a plurality of contact force sensors 40 to be packaged; the second groove 12 is used to accommodate the pressure receiving part 41 of a contact force sensor 40 to be packaged, and the cross-sectional area of ​​the second groove 12 is smaller than the area of ​​the first surface 42 of the upper silicon substrate of the contact force sensor 40 to be packaged, so that the release film 20 surrounding the second groove 12 covers the edge area of ​​the first surface 42 of the upper silicon substrate during molding.

[0050] The lower mold 30 is provided with at least one encapsulation material inlet 21, which is used to inject encapsulation material into the sealed cavity.

[0051] Specifically, both the upper mold 10 and the lower mold 30 can be made of metal, such as stainless steel. The release film 20 is a flexible film that can deform elastically, and can undergo a certain deformation when pressed. Furthermore, the release film 20 can be made of a material that is easily separated from the encapsulation material, allowing for better demolding after molding. The upper mold 10 may include one or more arrayed first grooves 11. Figure 1 A first groove 11 is shown in the figure. Figure 2 Two first grooves 11 are shown in the figure. Figure 3 This is a schematic diagram of the process of injecting encapsulation material, for reference. Figure 3 The encapsulation material inlet 21 can accommodate the encapsulation material injection device 60, which injects the encapsulation material 90 into the sealed cavity through the encapsulation material inlet 21.

[0052] Figure 4 This is a schematic diagram of a contact force sensor. Figure 5 This is a schematic diagram of the silicon substrate on the contact force sensor, for reference. Figure 4 and Figure 5 , Figure 5A schematic diagram of the surface of the upper silicon substrate 43 adjacent to the lower substrate 45 is shown. The contact force sensor can be a piezoresistive sensor, including the upper silicon substrate 43 and the lower substrate 45, a bridge circuit composed of multiple piezoresistive elements 44 disposed between the upper silicon substrate 43 and the lower substrate 45, and a pressure receiving part 41 made of a protruding pillar or sphere disposed above the upper silicon substrate 43. After receiving pressure, the upper silicon substrate 43 undergoes elastic deformation, causing the piezoresistive elements 44 therein to move towards the lower substrate 45. The output of the bridge circuit changes according to the displacement, and the pressure magnitude can be determined from the output electrical signal. The contact force sensor is covered and protected by encapsulation material, and the pressure receiving part 41 and the upper surface 42 of the upper silicon substrate 43 need to be exposed to improve sensitivity.

[0053] Figure 6 This is a schematic diagram of a packaging substrate provided in an embodiment of the present invention, for reference. Figure 4 and Figure 6 During molding, multiple contact force sensors 40 can be adhered to the packaging substrate 70 using a semiconductor die bonding process with die bond adhesive, thus fixing them onto the packaging substrate 70. The surface of the packaging substrate 70 is provided with multiple SMD PADs for electrical connection between the packaging substrate 70 and external circuitry. Through wire bonding, using bonding wires such as gold or aluminum wires, the SMD PADs are connected to the electrical connection portion of the lower substrate 45 of the contact force sensor 40. The highest point of the bonding wire can be set according to the height of the molding material away from the surface of the packaging substrate 70 after molding; the highest point of the bonding wire should be set at a position slightly lower than the surface of the molding material away from the packaging substrate 70.

[0054] refer to Figure 2 and Figure 6 An encapsulation substrate 70 with multiple contact force sensors 40 fixed thereon is disposed between the lower mold 30 and the upper mold 10, and each first groove 11 can accommodate multiple contact force sensors 40. Figure 6 The diagram shows two contact force sensor arrays, a first array 200 and a second array 300. The first array 200 can be located within one first groove 11, and the second array 300 can be located within another first groove 11. It should be noted that... Figure 2 The number of contact force sensors 40 within the first groove 11 is shown only as an example and is not intended to limit the invention.

[0055] refer to Figure 2 and Figure 4The second groove 12 is used to accommodate the pressure receiving part 41 of the contact force sensor 40 to be packaged, and the cross-sectional area of ​​the second groove 12 is smaller than the area of ​​the first surface 42 of the upper silicon substrate 43 of the contact force sensor 40 to be packaged. That is, after the contact force sensor 40 is fixedly disposed between the upper mold 10 and the lower mold 30, the vertical projection of the second groove 12 on the contact force sensor 40 covers the pressure receiving part 41, and the vertical projection of the second groove 12 on the contact force sensor 40 is located in the first surface 42 of the upper silicon substrate 43.

[0056] Figure 7 yes Figure 1 A magnified view of the area enclosed by the dashed box (100), for reference. Figure 1 and Figure 7 During encapsulation, the release film 20 can be made to contact the first surface 42 of the upper silicon substrate 43, so that the pressure receiving part 41 is sealed in the second groove 12. Since the release film 20 is a flexible film, the upper mold 10 can be pressed down to make the release film 20 cover the edge area of ​​the first surface 42 and deform the edge area of ​​the first surface 42, covering part of the side surface 46 of the upper silicon substrate 43 connected to the first surface 42. In this way, after the encapsulation material is injected, since the pressure receiving part 41 is located in the second groove 12 and the release film covers the first surface 42 of the upper silicon substrate 43 and part of the side surface connected to the first surface 42, the encapsulation material will not cover the pressure receiving part 41, the first surface 42 of the upper silicon substrate 43 and part of the side surface 46 of the upper silicon substrate 43, ensuring that the contact force sensor 40 has high sensitivity after encapsulation. Furthermore, the solution of this embodiment can encapsulate multiple contact force sensors 40 at one time, which can improve the encapsulation efficiency of the contact force sensor and reduce the manufacturing cost. For example, the distance at which the release film 20 is pressed down can be adjusted so that the molding compound 90 is about 30 μm away from the upper surface of the encapsulation substrate 70 and is lower than the first surface 42 of the upper silicon substrate 43.

[0057] In the plastic encapsulation mold of the contact force sensor of this embodiment, the upper mold 10 includes at least one first groove 11, and a plurality of second grooves 12 arranged in an array are provided on the bottom surface of the first groove 11. A release film 20 covers the bottom surface of the first groove 11 and the bottom and side surfaces of the second grooves 12. The release film 20 is a flexible film. The first groove 11 of the upper mold 10 is used to cooperate with the lower mold 30 to form a sealed chamber. The sealed chamber is used to house a plurality of contact force sensors 40 to be encapsulated. The second groove 12 is used to accommodate the pressure receiving part 41 of one contact force sensor 40 to be encapsulated. The cross-sectional area of ​​the second groove 12 is smaller than the area of ​​the first surface 42 of the upper silicon substrate of the contact force sensor 40 to be encapsulated, so that the pressure receiving part 41 is located in the second groove 12 during plastic encapsulation. The release film 20 surrounding the second groove 12 covers the edge area of ​​the first surface 42 of the upper silicon substrate, so that during plastic encapsulation, the pressure receiving part 41 is located in the second groove 12. The pressing upper mold 10 can deform the release film 20 at the edge of the first surface 42, covering part of the side surface 46 of the upper silicon substrate 43 connected to the first surface 42. Thus, after the encapsulation material is injected, since the pressure receiving part 41 is located in the second groove 12 and the release film covers the first surface 42 of the upper silicon substrate 43 and the part of the side surface connected to the first surface 42, the encapsulation material will not cover the pressure receiving part 41 and enter the first surface 42 of the upper silicon substrate 43. This makes the upper surface of the molding material 90 away from the encapsulation substrate 70 lower than the first surface 42 of the chip upper silicon substrate 43. For example, it can be about 30 μm lower than the first surface 42, ensuring that the contact force sensor 40 has high sensitivity and improved performance after molding. Furthermore, the solution of this embodiment can mold multiple contact force sensors 40 at one time, which can improve the molding efficiency of the contact force sensor and reduce the manufacturing cost.

[0058] Optional, continue to refer to Figure 1 The contact force sensor encapsulation mold also includes:

[0059] A buffer layer 80 is disposed on the surface of the lower mold 30 away from the upper mold 10.

[0060] Specifically, the buffer layer 80 is used to buffer the force when pressure is applied to the upper mold 10, so as to avoid damage to the upper silicon substrate of the contact force sensor 40 when pressure is applied.

[0061] Figure 8 This is a top view of a lower mold provided in an embodiment of the present invention, for reference. Figure 8 Optionally, the lower mold 30 is provided with a plurality of encapsulation material inlets 31 in the area opposite to each first groove 11.

[0062] For example, refer to Figure 8 , Figure 8The dashed box shows the vertical projection of the first groove 11 onto the lower mold 30. Multiple encapsulation material inlets 31 are provided in the area of ​​the lower mold 30 opposite to each first groove 11. The multiple encapsulation material inlets 31 can be arranged sequentially along the edge of the lower mold 30. The multiple encapsulation material inlets 31 can increase the inflow rate of the encapsulation material and further improve the molding speed.

[0063] Figure 9 This is a schematic diagram of an upper mold provided in an embodiment of the present invention, for reference. Figure 9 Optionally, the junction of the sidewall of each second groove 12 and the bottom surface of the first groove 11 has a chamfer 121.

[0064] Specifically, the chamfer 121 can be an R chamfer, and the radius of the chamfer 121 can be about 0.5mm, but is not limited to this value. Setting the chamfer 121 at the junction of the side wall of the second groove 12 and the bottom surface of the first groove 11 can prevent damage to the isolation membrane at the junction of the side wall of the second groove 12 and the bottom surface of the first groove 11.

[0065] Optional, see reference Figure 1 and Figure 4 The thickness of the release film 20 is greater than 30 micrometers.

[0066] Specifically, in order to ensure that the molding material does not cover the first surface 42 of the silicon substrate 43 of the contact force sensor 30 after molding, the release film 30 needs to cover at least 30 micrometers of the width of the side 46 during molding. The thickness of the release film 20 is set to be greater than 30 micrometers. This ensures that by pressing down the upper mold 10, the release film 20 can cover a larger area of ​​the side 46, ensuring that the molding material does not cover the first surface 42 of the silicon substrate 43 of the contact force sensor 30 after molding. Furthermore, the upper surface of the molding material is lower than the first surface 42, ensuring that the contact force sensor 40 has high sensitivity.

[0067] Optional, see reference Figure 1 Both the upper mold 10 and the lower mold 30 include a vacuum hole 50.

[0068] Specifically, a vacuum can be drawn between the lower mold 30 and the packaging substrate 70 through the vacuum hole 50, so that the lower mold 30 can adsorb and fix the packaging substrate. A vacuum can be drawn through the vacuum hole 50 on the upper mold 10 to form a cavity with the first groove 11, the packaging substrate 70 and the lower mold 30, so that the packaging substrate 70 and the contact force sensor 40 are better fixed between the lower mold 30 and the upper mold 10.

[0069] This invention also provides a molding method, which uses the contact force sensor molding mold described in any embodiment of this invention for molding. Figure 10 This is a flowchart of a molding method provided in an embodiment of the present invention, see reference. Figure 10 The sealing methods include:

[0070] S110. A packaging substrate with multiple contact force sensors is disposed on the surface of the lower mold, wherein the contact force sensors are disposed on the side of the packaging substrate away from the lower mold.

[0071] S120. The upper mold is placed on the side of the packaging substrate away from the lower mold. Multiple contact force sensors are located in the first groove. The pressure receiving part of each contact force sensor is located in a second groove. The release film on the bottom surface of the first groove is in contact with the first surface of the upper silicon substrate of the contact force sensor where the pressure receiving part is provided.

[0072] S130. Apply pressure to the upper mold to press the release film down a preset distance so that the release film covers part of the side surface of the upper silicon substrate, wherein the side surface of the upper silicon substrate is the surface connected to the first surface of the upper silicon substrate.

[0073] S140. Inject encapsulation material through the encapsulation material inlet to encapsulate multiple contact force sensors.

[0074] In the encapsulation method of this invention, each first groove, the cavity formed by the encapsulation substrate and the lower mold can accommodate multiple contact force sensors. The pressure receiving part of the contact force sensor is located in the second groove. The release film surrounding the second groove covers the edge area of ​​the first surface of the silicon substrate. During encapsulation, pressing down the upper mold can deform the edge area of ​​the release film on the first surface, covering part of the side surface of the silicon substrate connected to the first surface. Thus, after the encapsulation material is injected, since the pressure receiving part is located in the second groove and the release film covers the first surface of the silicon substrate and part of the side surface connected to the first surface, the encapsulation material will not cover the pressure receiving part or the first surface of the silicon substrate, and the upper surface of the encapsulation material is lower than the first surface of the silicon substrate. This ensures that the contact force sensor has high sensitivity after encapsulation. Furthermore, the solution of this embodiment can encapsulate multiple contact force sensors at once, which can improve the encapsulation efficiency of the contact force sensor and reduce the manufacturing cost.

[0075] Optional, the preset distance is greater than or equal to 30 micrometers.

[0076] This design allows the release film to cover a large area of ​​the side surface of the silicon substrate after being squeezed, ensuring that the encapsulation material does not cover the first surface of the silicon substrate of the contact force sensor after encapsulation, thus ensuring that the contact force sensor has high sensitivity.

[0077] Optionally, before applying pressure to the upper mold to press the release film down a predetermined distance and before the release film covers a portion of the side surface of the upper silicon substrate, the method further includes:

[0078] Vacuuming is performed through the lower mold and the vacuum hole on the lower mold.

[0079] Optionally, after encapsulating multiple contact force sensors by injecting encapsulation material through the encapsulation material inlet, the process further includes:

[0080] Curing of the encapsulation material;

[0081] Remove the upper mold, release film, and lower mold;

[0082] The packaging material and packaging substrate are cut to separate multiple plastic-encapsulated contact force sensors.

[0083] Specifically, molding materials can include epoxy resin adhesives or UV adhesives, and can be cured by heat curing or ultraviolet radiation.

[0084] Figure 11 This is a schematic diagram of a single contact force sensor after cutting, provided in an embodiment of the present invention. (Refer to...) Figure 11 The molding compound 90 covers the encapsulation substrate 70 and the area of ​​the contact force sensor except for the first surface 42 of the upper silicon substrate 43, the pressure receiving part 41 and part of the side 46. The upper surface 91 of the molding compound 90 is lower than the first surface 42, and can be about 30 micrometers lower than the first surface 42.

[0085] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0086] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A plastic encapsulation mold for a contact force sensor, characterized in that, include: Upper mold, release film, and lower mold; The upper mold includes at least one first groove, and the bottom surface of the first groove is provided with a plurality of second grooves arranged in an array. The release film covers the bottom surface of the first groove and the bottom and side surfaces of the second groove; the release film is a flexible film that can be elastically deformed. The first groove of the upper mold is used to cooperate with the lower mold to form a sealed cavity, and the sealed cavity is used to house a plurality of contact force sensors to be packaged; the second groove is used to accommodate the pressure receiving part of the contact force sensor to be packaged, and the cross-sectional area of ​​the second groove is smaller than the area of ​​the first surface of the upper silicon substrate of the contact force sensor to be packaged, so that the release film surrounding the second groove covers the edge area of ​​the first surface of the upper silicon substrate during molding; wherein, by pressing down the upper mold, the release film covers the edge area of ​​the first surface, and the edge area of ​​the first surface is deformed, covering part of the side surface of the upper silicon substrate connected to the first surface, so that the upper surface of the packaging material is lower than the first surface of the upper silicon substrate; The lower mold is provided with at least one encapsulation material inlet, which is used to inject encapsulation material into the sealed cavity.

2. The plastic encapsulation mold for the contact force sensor according to claim 1, characterized in that, Also includes: A buffer layer is disposed on the surface of the lower mold away from the upper mold.

3. The plastic encapsulation mold for the contact force sensor according to claim 1, characterized in that: The area of ​​the lower mold opposite each first groove is provided with multiple encapsulation material inlets.

4. The plastic encapsulation mold for the contact force sensor according to claim 1, characterized in that: The junction of the sidewall of each second groove and the bottom surface of the first groove has a chamfer.

5. The plastic encapsulation mold for the contact force sensor according to claim 1, characterized in that: The thickness of the release film is greater than 30 micrometers.

6. The plastic encapsulation mold for the contact force sensor according to claim 1, characterized in that: Both the upper and lower molds include vacuum holes.

7. A molding and sealing method, characterized in that, The contact force sensor is encapsulated using the encapsulation mold according to any one of claims 1-6, the encapsulation method comprising: A packaging substrate equipped with multiple contact force sensors is disposed on the surface of the lower mold, wherein the contact force sensors are disposed on the side of the packaging substrate away from the lower mold; The upper mold is placed on the side of the packaging substrate away from the lower mold. Multiple contact force sensors are located in the first groove. The pressure receiving part of each contact force sensor is located in a second groove. The release film on the bottom surface of the first groove is in contact with the first surface of the upper silicon substrate of the contact force sensor where the pressure receiving part is provided. Pressure is applied to the upper mold to press the release film down a preset distance, so that the release film covers part of the side surface of the upper silicon substrate, wherein the side surface of the upper silicon substrate is the surface connected to the first surface of the upper silicon substrate; Multiple contact force sensors are encapsulated by injecting encapsulation material through the encapsulation material inlet.

8. The molding method according to claim 7, characterized in that: The preset distance is greater than or equal to 30 micrometers.

9. The molding method according to claim 7, characterized in that, Before applying pressure to the upper mold to press the release film down a predetermined distance and before the release film covers part of the side of the upper silicon substrate, the process also includes: Vacuuming is performed through the lower mold and the vacuum hole on the lower mold.

10. The molding method according to claim 7, characterized in that, After encapsulating multiple contact force sensors by injecting encapsulation material through the encapsulation material inlet, the process also includes: Curing of the encapsulation material; Remove the upper mold, release film, and lower mold; The packaging material and packaging substrate are cut to separate multiple plastic-encapsulated contact force sensors.

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