Plastic packaging mold for contact force sensors, and plastic packaging method

Abstract

Disclosed in the present invention are a plastic packaging mold for contact force sensors, and a plastic packaging method. The plastic packaging mold comprises: an upper mold comprising at least one first recess, wherein a plurality of second recesses arranged in an array are provided at the bottom face of the first recess; a release film covering the bottom face of the first recess and the bottom faces and side faces of the second recesses, wherein the release film is an elastically deformable flexible film, the first recess of the upper mold is configured to fit with a lower mold to form a sealed cavity, the sealed cavity is configured to contain a plurality of contact force sensors to be packaged, the second recesses are configured to accommodate pressure receiving portions of the contact force sensors to be packaged, and the cross sectional area of each of the second recesses is smaller than the area of a first surface of an upper silicon substrate of each of the contact force sensors to be packaged, so that the release film surrounding the second recesses covers an edge area of the first surface of the upper silicon substrate during plastic packaging; and the lower mold provided with at least one packaging material inlet, wherein the packaging material inlet is configured to inject a packaging material into the sealed cavity. The present invention can improve the plastic packaging efficiency of the contact force sensors and reduce manufacturing costs.

Description

Contact force sensor plastic packaging mold and plastic packaging method Technical Field

[0001] The present invention relates to the field of plastic packaging technology, and in particular to a contact force sensor plastic packaging mold and a plastic packaging method. Background Art

[0002] In recent years, force sensors for load sensing have been used in many fields, but the current market share of micro-force sensors is low and cannot meet the large-scale application requirements in industrial, medical, AI and other fields because the production cost of existing micro-force sensors is relatively high. Summary of the Invention

[0003] The present invention provides a contact force sensor plastic packaging mold and a plastic packaging method, so as to improve the plastic packaging efficiency of the contact force sensor and reduce the production cost.

[0004] According to the invention, the chip surface and its pressure contact points are exposed outside the plastic package, so that the chip sensitive structure will not be affected by the packaging material, thereby improving sensitivity and suppressing zero drift distortion, thereby improving performance.

[0005] According to one aspect of the present invention, a contact force sensor plastic packaging mold is provided, comprising:

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

[0007] The upper mold includes at least one first groove, and a 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 surface 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 accommodate a plurality of contact force sensors to be packaged; the second groove is used to accommodate the pressure receiving portion 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 plastic packaging;

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

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

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

[0013] Optionally, a plurality of packaging material inlets are provided in an area of ​​the lower mold opposite to each first groove.

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

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

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

[0017] According to another aspect of the present invention, a plastic encapsulation method is provided, wherein the plastic encapsulation mold of the contact force sensor according to any embodiment of the present invention is used for plastic encapsulation, and the plastic encapsulation method comprises:

[0018] Arranging a package substrate provided with a plurality of contact force sensors on the surface of the lower mold, wherein the contact force sensors are arranged on a side of the package substrate away from the lower mold;

[0019] The upper mold is disposed on a side of the packaging substrate away from the lower mold, the plurality of contact force sensors are located in the first groove, the pressure receiving portion of each contact force sensor is located in one of the second grooves, and the release film on the bottom surface of the first groove contacts the first surface of the upper silicon substrate of the contact force sensor where the pressure receiving portion is located;

[0020] Applying pressure to the upper mold to press the release film downward by a preset distance so that the release film covers a portion 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] The packaging material is injected through the packaging material inlet to plastic-encapsulate the plurality of contact force sensors.

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

[0023] Optionally, before applying pressure to the upper mold to press the release film downward by a preset distance so that 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 vacuum holes on the lower mold and the lower mold.

[0025] Optionally, after the packaging material is injected through the packaging material inlet to plastic-encapsulate the plurality of contact force sensors, the method further includes:

[0026] Curing the packaging material;

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

[0028] The packaging material and the packaging substrate are cut to separate a plurality of contact force sensors that have been plastic-sealed.

[0029] In the contact force sensor plastic packaging mold of the embodiment of the present invention, the upper mold includes at least one first groove, 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 surface and side surfaces of the second groove, and 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, and the sealed chamber is used to set a plurality of contact force sensors to be packaged, and each second groove is used to accommodate a 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 pressure receiving part is located in the second groove during plastic packaging, and the release film surrounding the second groove covers the upper silicon substrate The edge area of ​​the first surface of the upper silicon substrate is formed by pressing the upper mold downward during molding, so that the release film can be deformed in the edge area of ​​the first surface to cover a portion of the side surface of the upper silicon substrate connected to the first surface. In this way, after the packaging material is injected, since the pressure receiving portion is located in the second groove and the release film covers the first surface of the upper silicon substrate and a portion of the side surface connected to the first surface, the packaging material will not cover the pressure receiving portion and the first surface of the upper silicon substrate, and the upper surface of the molding material is lower than the first surface of the upper silicon substrate, thereby ensuring that the contact force sensor has high sensitivity after molding. In addition, the solution of this embodiment can mold-seal multiple contact force sensors at a time, which can improve the molding efficiency of the contact force sensor and reduce the production cost.

[0030] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] FIG1 is a schematic diagram of a plastic packaging mold for a contact force sensor provided by an embodiment of the present invention;

[0033] FIG2 is a schematic diagram of another contact force sensor plastic packaging mold provided by an embodiment of the present invention;

[0034] FIG3 is a schematic diagram of a process of injecting packaging material;

[0035] FIG4 is a schematic diagram of a contact force sensor;

[0036] FIG5 is a schematic diagram of a silicon substrate on a contact force sensor;

[0037] FIG6 is a schematic diagram of a packaging substrate provided in an embodiment of the present invention;

[0038] FIG7 is an enlarged view of the area framed by the dotted box 100 in FIG1 ;

[0039] FIG8 is a top view of a lower mold provided by an embodiment of the present invention;

[0040] FIG9 is a schematic diagram of an upper mold provided by an embodiment of the present invention;

[0041] FIG10 is a flow chart of a plastic encapsulation method provided by an embodiment of the present invention;

[0042] FIG11 is a schematic diagram of a single contact force sensor after cutting provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] An embodiment of the present invention provides a contact force sensor plastic encapsulation mold. FIG1 is a schematic diagram of a contact force sensor plastic encapsulation mold provided by an embodiment of the present invention. FIG2 is a schematic diagram of another contact force sensor plastic encapsulation mold provided by an embodiment of the present invention. Referring to FIG1 and FIG2 , the plastic encapsulation mold 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 a plurality of second grooves 12 arranged in an array are provided on the bottom surface of the first groove 11;

[0048] The release film 20 covers the bottom surface of the first groove 11 and the bottom surface and side surfaces of the second groove 12; the 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 for arranging multiple contact force sensors 40 to be packaged. The second groove 12 is used to accommodate the pressure receiving portion 41 of one contact force sensor 40 to be packaged. 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 plastic packaging.

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

[0051] Specifically, both the upper mold 10 and the lower mold 30 can be made of metal materials, and exemplarily both can be made of stainless steel materials. The release film 20 is an elastically deformable flexible film that can produce a certain deformation when pressed. In addition, the release film 20 can be made of a material that is easier to separate from the packaging material, so that it can be better demolded after the plastic packaging is completed. The upper mold 10 may include one or two or more first grooves 11 arranged in an array. One first groove 11 is shown in Figure 1, and two first grooves 11 are shown in Figure 2. Figure 3 is a schematic diagram of the process of injecting packaging material. Referring to Figure 3, the packaging material inlet 21 can accommodate a packaging material injection device 60, and the packaging material injection device 60 injects packaging material 90 into the sealed chamber through the packaging material inlet 21.

[0052] Figure 4 is a schematic diagram of a contact force sensor, and Figure 5 is a schematic diagram of the silicon substrate on the contact force sensor. Referring to Figures 4 and 5, Figure 5 shows a schematic diagram of the surface of the upper silicon substrate 43 adjacent to the lower substrate 45. The contact force sensor can be a piezoresistive sensor, comprising an upper silicon substrate 43 and a lower substrate 45, a bridge circuit consisting of multiple piezoresistive elements 44 disposed between the upper silicon substrate 43 and the lower substrate 45, and a pressure receiving portion 41 formed of a protruding column or sphere disposed above the upper silicon substrate 43. When pressure is received by the pressure receiving portion 41, the upper silicon substrate 43 elastically deforms, causing the piezoresistive elements 44 therein to move toward the lower substrate 45. The output of the bridge circuit changes according to the displacement, and the pressure can be determined based on the output electrical signal. The contact force sensor is protected by a packaging material, but the pressure receiving portion 41 and the upper surface 42 of the upper silicon substrate 43 need to be exposed to improve sensitivity.

[0053] FIG6 is a schematic diagram of a packaging substrate provided in an embodiment of the present invention. Referring to FIG4 and FIG6 , during plastic encapsulation, multiple contact force sensors 40 can be adhered to the packaging substrate 70 using a semiconductor die-bonding process with die-bonding adhesive, thereby being fixed to the packaging substrate 70. The surface of the packaging substrate 70 is provided with multiple SMD pads for electrically connecting the packaging substrate 70 to an external circuit. Through a wire bonding process, bonding wires, such as gold wires or aluminum wires, are used to connect the SMD pads to the electrical connection portion of the lower substrate 45 of the contact force sensor 40. The highest point of the bonding wires can be set based on the height of the surface of the molding material away from the packaging substrate 70 after plastic encapsulation. The highest point of the bonding wires should be set slightly lower than the surface of the molding material away from the packaging substrate 70.

[0054] Referring to Figures 2 and 6 , a package substrate 70, with multiple contact force sensors 40 affixed thereto, is positioned between a lower mold 30 and an upper mold 10. Each first recess 11 can accommodate multiple contact force sensors 40. Figure 6 illustrates two contact force sensor arrays: a first array 200 and a second array 300. The first array 200 can be positioned within one first recess 11, while the second array 300 can be positioned within another first recess 11. It should be noted that Figure 2 merely illustrates the number of contact force sensors 40 within a first recess 11 and does not limit the present invention.

[0055] 2 and 4 , the second groove 12 is used to accommodate the pressure receiving portion 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 portion 41, and the vertical projection of the second groove 12 on the contact force sensor 40 is located within the first surface 42 of the upper silicon substrate 43.

[0056] FIG7 is an enlarged view of the area outlined by the dashed box 100 in FIG1 . Referring to FIG1 and FIG7 , during molding, the release film 20 can be brought into contact with the first surface 42 of the upper silicon substrate 43, sealing the pressure receiving portion 41 within the second recess 12. Because the release film 20 is a flexible film, the upper mold 10 can be pressed downward to cause the release film 20 to cover the edge of the first surface 42 and deform therein, covering the portion of the side surface 46 of the upper silicon substrate 43 connected to the first surface 42. Consequently, after the packaging material is injected, because the pressure receiving portion 41 is located in the second recess 12 and the release film covers the first surface 42 of the upper silicon substrate 43 and the portion of the side surface connected to the first surface 42, the packaging material does not cover the pressure receiving portion 41, the first surface 42 of the upper silicon substrate 43, and the portion of the side surface 46 of the upper silicon substrate 43. This ensures that the contact force sensor 40 has a high sensitivity after molding. Furthermore, the solution of this embodiment allows for molding multiple contact force sensors 40 at a time, thereby improving molding efficiency and reducing manufacturing costs. For example, the downward pressing distance of the release film 20 can be adjusted so that the molding material 90 is about 30 μm away from the upper surface of the packaging substrate 70 and lower than the first surface 42 of the upper silicon substrate 43 .

[0057] In the contact force sensor mold of the embodiment of the present invention, the upper mold 10 includes at least one first groove 11. The bottom surface of the first groove 11 is provided with a plurality of second grooves 12 arranged in an array. The 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.

[0058] 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 a pressure receiving portion 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 pressure receiving portion 41 is located in the second groove 12 during plastic sealing, and 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 when plastic sealing, the release film 20 can be deformed in the edge area of ​​the first surface 42 by pressing the upper mold 10 downward, covering the portion of the upper silicon substrate 43 connected to the first surface 42. Side surface 46, so that after the packaging material is injected, since the pressure receiving portion 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 connected to the first surface 42, the packaging material will not cover the pressure receiving portion 41 and the first surface 42 entering the upper silicon substrate 43, so that the upper surface of the molding material 90 away from the packaging substrate 70 is lower than the first surface 42 of the silicon substrate 43 on the chip, and can be exemplarily about 30um lower than the first surface 42, ensuring that the contact force sensor 40 has higher sensitivity and improved performance after molding, and the solution of this embodiment can mold multiple contact force sensors 40 at a time, which can improve the molding efficiency of the contact force sensor and reduce the production cost.

[0059] Optionally, referring to FIG1 , the contact force sensor plastic packaging mold further includes:

[0060] The buffer layer 80 is disposed on a surface of the lower mold 30 away from the upper mold 10 .

[0061] Specifically, the buffer layer 80 is used to buffer the force applied to the upper mold 10 to prevent the upper silicon substrate of the contact force sensor 40 from being damaged when the pressure is applied.

[0062] FIG8 is a top view of a lower mold provided by an embodiment of the present invention. Referring to FIG8 , optionally, a plurality of packaging material inlets 31 are provided in the area of ​​the lower mold 30 opposite to each first groove 11 .

[0063] For example, referring to Figure 8, the dotted box in Figure 8 shows the vertical projection of the first groove 11 on the lower mold 30. A plurality of packaging material inlets 31 are set in the area of ​​the lower mold 30 opposite to each first groove 11. The plurality of packaging material inlets 31 can be arranged in sequence along the edge of the lower mold 30. The plurality of packaging material inlets 31 can increase the inflow speed of the packaging material and further increase the plastic sealing speed.

[0064] FIG9 is a schematic diagram of an upper mold provided by an embodiment of the present invention. Referring to FIG9 , optionally, a chamfer 121 is provided at the intersection of the side wall of each second groove 12 and the bottom surface of the first groove 11 .

[0065] Specifically, the chamfer 121 can be an R chamfer, and the radius of the chamfer 121 can be about 0.5 mm, but is not limited to this value. The intersection of the side wall of the second groove 12 and the bottom surface of the first groove 11 is provided with a chamfer 121, which can prevent the isolation membrane from being damaged at the intersection of the side wall of the second groove 12 and the bottom surface of the first groove 11.

[0066] Optionally, referring to FIG. 1 and FIG. 4 , the thickness of the release film 20 is greater than 30 microns.

[0067] Specifically, in order to ensure that the molding material does not cover the first surface 42 of the upper silicon substrate 43 of the contact force sensor 30 after the molding is completed, the release film 30 needs to cover at least the width of the side surface 46 greater than or equal to 30 microns during the molding. The thickness of the release film 20 is set to be greater than 30 microns to ensure that the release film 20 can cover a larger area of ​​the side surface 46 by pressing the upper mold 10 downward. It is ensured that the molding material does not cover the first surface 42 of the upper silicon substrate 43 of the contact force sensor 30 after the molding is completed, and the upper surface of the molding material is lower than the first surface 42, thereby ensuring that the contact force sensor 40 has a higher sensitivity.

[0068] Optionally, referring to FIG. 1 , both the upper mold 10 and the lower mold 30 include vacuum holes 50 .

[0069] Specifically, 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, and the cavity formed by the first groove 11, the packaging substrate 70 and the lower mold 30 can be vacuumed through the vacuum hole 50 on the upper mold 10, 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.

[0070] An embodiment of the present invention further provides a plastic encapsulation method, which uses the contact force sensor plastic encapsulation mold according to any embodiment of the present invention for plastic encapsulation. FIG10 is a flow chart of a plastic encapsulation method provided by an embodiment of the present invention. Referring to FIG10 , the plastic encapsulation method includes:

[0071] S110 , disposing a packaging substrate provided with a plurality of contact force sensors on a surface of a lower mold, wherein the contact force sensors are disposed on a side of the packaging substrate away from the lower mold.

[0072] S120, placing the upper mold on a side of the packaging substrate away from the lower mold, with the plurality of contact force sensors located in the first grooves, the pressure receiving portion of each contact force sensor located in one of the second grooves, and the release film on the bottom surface of the first groove in contact with the first surface of the upper silicon substrate of the contact force sensor where the pressure receiving portion is located;

[0073] S130, applying pressure to the upper mold to press the release film downward by a preset distance so that the release film covers a portion 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;

[0074] S140 , injecting packaging material through a packaging material inlet to plastic-encapsulate the plurality of contact force sensors.

[0075] In the molding method of the embodiment of the present invention, during molding, the cavity formed by each first groove, the packaging 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, and the release film surrounding the second groove covers the edge area of ​​the first surface of the upper silicon substrate. During molding, the release film can be deformed in the edge area of ​​the first surface by pressing the upper mold downward, covering part of the side surface of the upper silicon substrate connected to the first surface. In this way, after injecting the packaging material, 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 packaging material will not cover the pressure receiving part and the first surface of the upper silicon substrate, and the upper surface of the molding 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 mold multiple contact force sensors at a time, which can improve the molding efficiency of the contact force sensor and reduce the production cost.

[0076] Optionally, the preset distance is greater than or equal to 30 microns.

[0077] This arrangement allows the release film to cover a larger area of ​​the side surface of the upper silicon substrate after being squeezed, ensuring that the molding material does not cover the first surface of the upper silicon substrate of the contact force sensor after the molding is completed, thereby ensuring that the contact force sensor has higher sensitivity.

[0078] Optionally, before applying pressure to the upper mold to press the release film downward by a preset distance so that the release film covers a portion of the side surface of the upper silicon substrate, the method further includes:

[0079] Vacuuming is performed through the vacuum holes on the lower mold and the lower mold.

[0080] Optionally, after the packaging material is injected through the packaging material inlet to plastic-encapsulate the plurality of contact force sensors, the method further includes:

[0081] Curing the packaging material;

[0082] Remove the upper mold, release film and lower mold;

[0083] The packaging material and the packaging substrate are cut to separate a plurality of contact force sensors that have been plastic-sealed.

[0084] Specifically, the plastic packaging material may include epoxy resin glue or UV glue, etc. The plastic packaging material can be cured by heat curing or ultraviolet irradiation.

[0085] FIG11 is a schematic diagram of a single contact force sensor after cutting provided by an embodiment of the present invention. Referring to FIG11 , a molding compound 90 covers the packaging substrate 70 and the contact force sensor except for the first surface 42 of the upper silicon substrate 43, the pressure receiving portion 41, and a portion of the side surface 46. The upper surface 91 of the molding compound 90 is lower than the first surface 42 and may be approximately 30 microns lower than the first surface 42.

[0086] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0087] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A contact force sensor plastic packaging mold, characterized in that: include: Upper mold, release film and lower mold; The upper mold comprises at least one first groove, and a plurality of second grooves arranged in an array are arranged on the bottom surface of the first groove; The release film covers the bottom surface of the first groove and the bottom surface 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 chamber, and the sealed chamber is used to set 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 plastic sealing; The lower mold is provided with at least one packaging material inlet, and the packaging material inlet is used to inject packaging material into the sealed chamber.

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

3. The contact force sensor plastic packaging mold according to claim 1, characterized in that: A plurality of packaging material inlets are arranged in the area of ​​the lower mold opposite to each first groove.

4. The contact force sensor plastic packaging mold according to claim 1, characterized in that: A junction between the side wall of each second groove and the bottom surface of the first groove has a chamfer.

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

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

7. A plastic packaging method, characterized in that: The contact force sensor plastic encapsulation mold according to any one of claims 1 to 6 is used for plastic encapsulation, and the plastic encapsulation method comprises: Arranging a packaging substrate provided with a plurality of contact force sensors on the surface of the lower mold, wherein the contact force sensors are arranged on a side of the packaging substrate away from the lower mold; The upper mold is arranged on a side of the packaging substrate away from the lower mold, a plurality of contact force sensors are arranged in the first groove, a pressure receiving portion of each contact force sensor is arranged in a second groove, and a release film on the bottom surface of the first groove is in contact with a first surface of the upper silicon substrate of the contact force sensor on which the pressure receiving portion is arranged; Applying pressure to the upper mold to press the release film downward by a preset distance so that the release film covers a portion of the side surface of the upper silicon substrate, wherein the side surface of the upper silicon substrate is a surface connected to the first surface of the upper silicon substrate; The packaging material is injected through the packaging material inlet to plastic-encapsulate the plurality of contact force sensors.

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

9. The plastic encapsulation method according to claim 7, characterized in that: Before applying pressure to the upper mold to press the release film down by a preset distance so that the release film covers a portion of the side surface of the upper silicon substrate, the method further includes: The vacuum is drawn through the vacuum holes on the lower die and the lower die.

10. The plastic encapsulation method according to claim 7, characterized in that: After the plurality of contact force sensors are encapsulated by injecting the encapsulation material through the encapsulation material inlet, the method further includes: Curing the packaging material; Remove the upper mold, release film and lower mold; The packaging material and the packaging substrate are cut to separate a plurality of contact force sensors that have been plastic-sealed.

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