A bondable PDMS packaging method

Abstract

The present invention discloses a polydimethylsiloxane (PDMS) packaging solution that can be used for bonding, and relates to the technical field of packaging. The polydimethylsiloxane (PDMS) packaging places an assembly composed of one or more parts on a polished bottom substrate, and an outer frame is arranged around the assembly for forming and preventing polydimethylsiloxane (PDMS) from overflowing, and a glue injection cover is placed above the outer frame. The present invention can provide bonding surface flatness, bond with materials such as glass that can be bonded with polydimethylsiloxane (PDMS), and regularly package special-shaped parts.

Description

Technical Field

[0001] The invention relates to the technical field of packaging, and in particular to a method for packaging polydimethylsiloxane (PDMS) that can be used for bonding. Background Art

[0002] With the rise of implantable medical technology, more and more functional components need to be implanted in the human body. However, components implanted in the human body have clear requirements for biocompatibility, hardness, and volume. Polydimethylsiloxane (PDMS) is a biocompatible material that is easy to form and has low hardness. It is an ideal packaging material for implantation in the human body. At present, there is a lack of a solution to directly externally encapsulate the components to isolate them from the human body environment and perform modular assembly. Summary of the invention

[0003] The present invention aims at the deficiencies in the prior art and provides a bondable PDMS packaging method.

[0004] In order to achieve the above purpose, the technical solution of the present invention is:

[0005] A bondable PDMS packaging method adopts a casting jig, wherein the casting jig comprises a casting chamber, a bottom substrate and an upper cover, wherein the casting chamber has upper and lower openings, the bottom substrate is attached to the lower opening, and the upper cover is located at the upper opening and is provided with a casting inlet; the upper cover and the casting chamber are mutually positioned and attached by a first positioning structure, and the upper cover is also provided with a second positioning structure; the packaging method comprises the following steps:

[0006] 1) Assemble the part to be packaged with the bonding surface facing downward at a designated position in the casting chamber through the second positioning structure, and perform lead-out processing on the signal output end of the part to be packaged;

[0007] 2) Inject PDMS into the casting chamber through the casting inlet, keep it at 65°C-120°C for 15min-3h, wait until the PDMS is completely cured, and then take out the package;

[0008] 3) Clean the package and the glass substrate and bond them at a bonding temperature of 95°C-120°C for 15min-60min.

[0009] Optionally, the first positioning structure includes a plurality of casting chamber positioning holes provided on the outer peripheral wall of the casting chamber and a plurality of upper cover positioning holes provided on the outer periphery of the upper cover, and the upper cover and the casting chamber are mutually positioned and locked through the cooperation of the casting chamber positioning holes and the upper cover positioning holes.

[0010] Optionally, the part to be packaged has a side signal output terminal, the casting chamber has a side signal lead-out port on the side, the side signal output terminal is led out through the side signal lead-out port and is sealed by a sealing material.

[0011] Optionally, the part to be packaged has a lower signal output port, and in step 1), the auxiliary movable block is assembled on the lower signal output port; and in step 2), the auxiliary movable block is taken out after the package body is taken out.

[0012] Optionally, the side wall of the casting chamber is designed with a demoulding angle, the large angle of the demoulding opening is toward the bonding surface, and the demoulding angle is 85°-89°.

[0013] Optionally, the casting jig also includes an auxiliary positioning part, which has a third positioning structure that cooperates with the second positioning structure; in step 1), the part to be packaged is first fixed to the auxiliary positioning part, and then the part to be packaged is assembled by cooperating with the second positioning structure and the third positioning structure.

[0014] Optionally, in step 1), the step of fixing the part to be packaged and the auxiliary positioning part is: placing the part to be packaged on a positioning table of a positioning seat, installing the auxiliary positioning part above the part to be packaged, coating semi-cured PDMS between the auxiliary positioning part and the part to be packaged, placing the upper cover on the auxiliary positioning part for upper side engagement, and then completely curing the semi-cured PDMS to obtain an assembled part of the part to be packaged and the auxiliary positioning part.

[0015] Optionally, the auxiliary positioning part has a signal end, the auxiliary positioning part has a signal communication port and a signal output port communicating with the signal communication port, the signal communication port corresponds to the signal end, and semi-cured PDMS is coated on the mating surfaces of the signal communication port and the signal end.

[0016] Optionally, the signal output port serves as a positioning structure for positioning the auxiliary positioning part and the positioning seat or the upper cover.

[0017] Optionally, the parts to be packaged are components that need to be implanted in a living body, including microvalves, micropumps, passive electronic components or chips.

[0018] The beneficial effects of the present invention are:

[0019] The PDMS encapsulation of parts is achieved by using an encapsulation jig. The encapsulated parts can be isolated from the organism, and the appearance can be adjusted according to the mold size, so they can be customized. The regular PDMS encapsulation is conducive to modular assembly and optimizes the spatial layout of implantable devices. In addition, because the mold size is adjustable, the current encapsulation is not limited to the simultaneous encapsulation of a single part, but can be used for the PDMS encapsulation of multiple parts at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the overall structure of the first embodiment;

[0021] Figure 2 This is an exploded view of the overall structure of the first embodiment;

[0022] Figure 3 is a cross-sectional view of the overall structure of the first embodiment;

[0023] Figure 4 is a schematic diagram of side signal output in Embodiment 1;

[0024] Figure 5 is a cross-sectional view of the lower signal output in the first embodiment;

[0025] Figure 6 yes Figure 5 Schematic diagram of removing the active block after packaging is completed;

[0026] Figure 7 is a schematic diagram of the upper signal output in the first embodiment;

[0027] Figure 8 It is a schematic diagram of bonding of PDMS packaging parts in Example 1;

[0028] Fig. 9 is a cross-sectional view of the casting chamber in the first embodiment;

[0029] Fig.10 is a schematic diagram of a casting chamber for large-scale manufacturing in Example 1;

[0030] Fig.11 This is a schematic diagram of auxiliary positioning installation in Embodiment 2;

[0031] Fig.12 This is an exploded schematic diagram of auxiliary positioning installation in Example 2;

[0032] Fig.13 This is a schematic diagram of the side signal output of the auxiliary positioning installation in the second embodiment;

[0033] Fig.14 This is a schematic diagram of the side signal output of the auxiliary positioning installation in the second embodiment;

[0034] Fig.15 This is a schematic diagram of the auxiliary positioning installation of the side signal output in the second embodiment;

[0035] Fig.16 This is a schematic diagram of auxiliary positioning encapsulation casting in the second embodiment;

[0036] Explanation of the reference numerals: 1. silicon substrate; 2. casting chamber; 2A. single-piece casting chamber; 2B. large-scale casting chamber; 2-1. upper opening; 2-2. lower opening; 2-3. casting chamber positioning hole; 2-4. side signal lead-out port; 2-5. demolding aid; 3. upper cover; 3-1. PDMS casting inlet; 3-2. positioning column for the part to be packaged; 3-3. PDMS overflow port; 3-4. upper cover positioning hole; 4. part to be packaged; 4-1. side signal output port; 4-2. lower signal output port; 4-3. upper signal output port; 4A. part without positioning feature; 4A-1. part signal port; 5. PDMS; 5-1. PDMS bonding surface Lead-out port; 6- auxiliary movable block; 7, PDMS package; 7-1, PDMS package bonding surface; 8, glass; 8-1, glass bonding surface; 9, auxiliary positioning parts; 9-1, positioning hole; 9-2, signal channel port; 9-3, PDMS flow groove; 9-4, PDMS yield port; 9-5, lower signal output port; 9A, auxiliary positioning parts; 9A-1, upper signal output port; 9A-4, positioning hole; 10, positioning seat; 9B, auxiliary positioning parts; 9B-1, upper positioning hole; 9B-4, lower positioning hole; 9B-5, signal output port; 10-1, positioning platform; 10-2, positioning column; 10-3, screw hole; 11- assembly parts. DETAILED DESCRIPTION

[0037] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. The various drawings of the present invention are only for illustration to make it easier to understand the present invention, and the specific proportions can be adjusted according to design requirements. The upper and lower relationships of the relative elements and the definitions of the front / back in the figures described in the text should be understood by those skilled in the art to refer to the relative positions of the components, so they can all be flipped to present the same components, which should all fall within the scope disclosed in this specification.

[0038] Embodiment 1:

[0039] Reference Figure 1 , Figure 2 , Figure 3 A bondable polydimethylsiloxane (PDMS) packaging method involves a structure including a silicon substrate 1 as a bottom substrate, a casting chamber 2, an upper cover 3, a part to be packaged 4, and polydimethylsiloxane (PDMS) 5.

[0040] Reference Figure 1 , Figure 2 , Figure 3The polished side of the silicon substrate 1 faces the casting chamber 2. The casting chamber 2 is closely attached to the silicon substrate 1 to prevent polydimethylsiloxane (PDMS) from leaking from the bottom. The casting chamber 2 is provided with an upper opening 2-1 and a lower opening 2-2. The upper opening 2-1 is the entry direction of polydimethylsiloxane (PDMS), and the lower opening 2-2 is used for bonding. There are four through holes on the four sides of the casting chamber as casting chamber positioning holes 2-3. The positioning holes 2-3 help the casting chamber The chamber 2 and the upper cover 3 are mutually locked and positioned. The upper cover 3 is directly above the polydimethylsiloxane (PDMS) pouring inlet 3-1. In order to control the polydimethylsiloxane (PDMS) in the pouring chamber 2, the upper cover 3 is provided with a polydimethylsiloxane (PDMS) overflow port 3-3. The four sides of the upper cover are the pouring inlet upper cover positioning holes 3-4 that are mutually positioned and locked with the pouring chamber. The pouring chamber positioning holes 2-3 and the upper cover positioning holes 3-4 constitute the first positioning structure. In order to ensure that the position of the part 4 to be packaged is controlled at the specified position of the pouring chamber 2, there is a specially positioned positioning column 3-2 for the part to be packaged below the upper cover 3 as the second positioning structure.

[0041] There are different signal output designs for the signal output in different directions of the packaged parts 4. Figure 4 When the part 4 to be packaged has a side signal output terminal 4-1, the casting chamber 2 is designed with an opening on the side as a side signal lead-out port 2-4 for leading out the side signal output terminal 4-1. The part 4 to be packaged is positioned and installed by the upper cover 3. Before the polydimethylsiloxane (PDMS) is cast, the side signal lead-out port 2-4 is sealed with semi-cured polydimethylsiloxane (PDMS) or high-temperature tape, and then the polydimethylsiloxane (PDMS) is cast from the casting inlet 3-1. Reference Figure 5 and Figure 6 When the part 4 to be packaged has a lower signal output port 4-2, the auxiliary movable block 6 assists the pouring of polydimethylsiloxane (PDMS). Before the pouring of polydimethylsiloxane (PDMS), the auxiliary movable block 6 is installed at the lower signal output port 4-2 below the part to be packaged. After the pouring of polydimethylsiloxane (PDMS) is completed, the solidified part 4 to be packaged and the polydimethylsiloxane (PDMS) 5 package are taken out from the pouring chamber 2, and then the movable block 6 is taken out with tweezers or other devices. At this time, due to the help of the movable block 6, there is a port 5-1 for signal lead-out under the polydimethylsiloxane (PDMS) 5. At this time, the lower side of the polydimethylsiloxane (PDMS) will be used for bonding and signal lead-out at the same time. Reference Figure 7When the packaged part 4 has an upper signal output terminal 4-3, the signal output port is in the same direction as the pouring port. The signal output direction of the packaged part 4 can be one or more directions, so the above signal lead-out design can appear alone or in the form of a combined design, and the signal flow form is not only an electrical signal, but also a fluid motion form.

[0042] The PDMS packaging process is to first assemble the part to be packaged 4 with the positioning column 3-2 of the part to be packaged of the upper cover 3, and then match the upper cover 3 equipped with the part to be packaged 4 with the casting chamber 2 through the positioning holes on the four sides and perform the above-mentioned signal lead-out preprocessing according to the position of the signal output port of the part to be packaged 4, and then seal the bottom surface of the casting chamber 2 with the silicon substrate 1. After the casting assembly is completed, PDMS is injected from the casting inlet 3-1, and then the temperature of the hot plate or oven is adjusted between 65℃-120℃, and the duration is 15min-3h. After the PDMS is completely cured, the package body is taken out, and the part to be packaged 4 is wrapped in PDMS and strictly isolated from the outside world, and the signal lead-out can be realized.

[0043] Reference Figure 8 , put the packaged package 7 and glass 8 into the plasma cleaning machine together, set the parameters between 100W-300W, inject oxygen or air, last between 1min-2min, and the vacuum degree is below 0.02mbar. After the PDMS package 7 and glass 8 are taken out together, align and bond them. If the position accuracy requirement is not high, you can use the auxiliary fixture for manual bonding. If the position accuracy requirement is high, you can use the placement machine for auxiliary bonding. The bonding setting temperature is between 95℃-120℃ and the time is between 15min-60min.

[0044] Reference Fig. 9 , the PDMS package is made in a single piece. The casting chamber 2A can be made by 3D printing or machining. The materials used must be able to withstand a temperature of at least 65°C. High-temperature resistant resins, aluminum alloys, titanium alloys, UPE, PEEK and other materials can be used. In order to help demolding, the side wall needs to be sprayed or soaked with demolding aids 2-5, which can be PDMS demolding agents, or low-roughness high-temperature tapes, tin foil, PVDF films, etc. are pasted on the side wall in the form of adhesive. In addition, the demolding angle should be designed, with the large angle of the demolding opening facing the bonding surface, and the demolding angle α ranges from 85° to 89°.

[0045] Reference Fig.10 For large-scale manufacturing of PDMS packages, a forming model can be made to manufacture a large number of casting chambers 2B at one time. When the casting chamber 2B is manufactured on a large scale to package the parts 4 to be packaged, manual layout can be used, or a robot can be used to fix the position for positioning and packaging casting.

[0046] Embodiment 2:

[0047] Reference Fig.11 , Fig.12 , Fig.13 , the parts to be packaged do not have position features for positioning, but the parts to be packaged need to have an exact position during packaging or bonding. Before packaging, an auxiliary positioning part 9 is added to help with positioning. The part to be packaged 4A is placed on the positioning table 10-1 of the positioning seat 10 for preliminary positioning, and then the manufactured auxiliary positioning part 9 is installed above the part to be packaged. The lower signal output port 9-5 of the auxiliary positioning part 9 is completely flush with the plane of the positioning seat 10, and the lower signal output port 9-5 is in a matching relationship with the positioning column 10-2. According to the bonding accuracy of the signal output port, the matching relationship can be interference, transition, or clearance fit. At the matching surface of the signal communication port 9-2 of the auxiliary positioning part 9 and the part signal port 4A-1, after the two are assembled, the matching surface is coated with semi-cured PDMS to complete the assembly of the auxiliary positioning part 9 and the part 4A without positioning features. Before the semi-cured PDMS is completely cured, the positioning column 3-2 of the part to be packaged of the upper cover 3 cooperates with the positioning hole 9-1 of the auxiliary positioning part 9 on the upper side to prevent the part 4A without positioning features from being deflected by only the lower signal output port 9-5. The PDMS flow groove 9-3 of the auxiliary positioning part helps to accelerate the flow of PDMS in the casting chamber 2, and the PDMS yield port 9-4 increases the bonding area after the PDMS is cured and increases the bonding strength. After the positioning components are installed, four bolts pass through the screw holes of the positioning seat 10 and wait for the semi-cured PDMS to be completely cured. In order to accelerate the curing, the components can be transferred to a hot plate or a hot box at a temperature between 65°C and 120°C. After curing, the assembled parts consisting of the auxiliary positioning parts and the part to be packaged 4A are separated from the positioning seat 10.

[0048] Reference Fig.14 and Fig.15 In addition to the signal lead-out of the lower side consistent with the bonding surface, the signal lead-out of the parts without positioning features can also be led out from the upper side and the side. When the signal is output from the upper signal output port 9A-1 of the auxiliary positioning part 9A, the upper signal output port 9A-1 serves as both part positioning and signal lead-out functions, and the lower positioning hole 9A-4 is used to position the packaged parts. When the signal is output from the side, the upper and lower positioning holes 9B-1 and 9B-4 of the auxiliary positioning part 9B only play a role in positioning, and the signal output port 9B-5 outputs the signal from the side.

[0049] Reference Fig.16The PDMS packaging sequence of the assembly part 11 is to first assemble the positioning hole 9-1 of the assembly part 11 with the positioning column 3-2 of the part to be packaged of the upper cover 3, and then mate the upper cover 3 equipped with the assembly part 11 with the casting chamber 2 through the positioning holes on the four sides, and then seal the bottom surface of the casting chamber 2 with the silicon substrate 1. After the casting assembly is completed, PDMS is injected from the PDMS casting inlet 3-1 of the upper cover 3, and then the temperature of the hot plate or oven is adjusted between 65℃-120℃, and the duration is 15min-3h. After the PDMS is completely cured, the package body is taken out and bonded to the glass substrate.

[0050] The parts to be packaged are any feasible components that need to be implanted in the human body, and can be microvalves, micropumps, passive electronic components, chips, and other parts that need to be isolated from the human body.

[0051] In this way, the encapsulated parts are isolated from the organism, and the appearance can be adjusted according to the mold size, so they can be customized. The regular PDMS encapsulation is conducive to modular assembly and optimizes the spatial layout of the implanted device. Moreover, because the mold size is adjustable, the current encapsulation is not limited to the simultaneous encapsulation of a single part, but can be used for the PDMS encapsulation of multiple parts at the same time.

[0052] The above embodiments are only used to further illustrate a bondable PDMS packaging method of the present invention, but the present invention is not limited to the embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the technical solution of the present invention.

Claims

1. A bondable PDMS packaging method, characterized in that: A casting jig is used, the casting jig includes a casting chamber, a bottom substrate and an upper cover, the casting chamber has upper and lower openings, the bottom substrate is attached to the lower opening, the upper cover is located at the upper opening and is provided with a casting inlet; the upper cover and the casting chamber are mutually positioned and attached through a first positioning structure, the first positioning structure includes a plurality of casting chamber positioning holes provided on the outer peripheral wall of the casting chamber and a plurality of upper cover positioning holes provided on the outer periphery of the upper cover, the upper cover and the casting chamber are mutually positioned and locked through the casting chamber positioning holes and the upper cover positioning holes; the upper cover is also provided with a second positioning structure, the second positioning structure is a positioning column for the part to be packaged located below the upper cover; the packaging method includes the following steps: 1) Assemble the part to be packaged with the bonding surface facing downward at a designated position in the casting chamber through the second positioning structure, and lead out the signal output end of the part to be packaged; 2) Inject PDMS into the casting chamber through the casting inlet, keep it at 65℃-120℃ for 15min-3h, wait for PDMS to be completely cured, and then take out the package; 3) Clean the package and the glass substrate and bond them at a temperature of 95°C-120°C for 15min-60min.

2. The bondable PDMS packaging method according to claim 1, characterized in that: The part to be packaged has a side signal output end, and the casting chamber has a side signal lead-out port on the side, and the side signal output end is led out through the side signal lead-out port and is sealed by a sealing material.

3. The bondable PDMS packaging method according to claim 1, characterized in that: The part to be packaged has a lower signal output port. In step 1), the auxiliary movable block is assembled on the lower signal output port. In step 2), the auxiliary movable block is taken out after the package is taken out.

4. The bondable PDMS packaging method according to claim 1, characterized in that: The side wall of the casting chamber is designed with a demoulding angle, the large angle of the demoulding opening is toward the bonding surface, and the demoulding angle is 85°-89°.

5. The bondable PDMS packaging method according to claim 1, characterized in that: The casting jig also includes an auxiliary positioning part, which has a third positioning structure that cooperates with the second positioning structure; in step 1), the part to be packaged is first fixed to the auxiliary positioning part, and then the part to be packaged is assembled by cooperating with the second positioning structure and the third positioning structure.

6. The bondable PDMS packaging method according to claim 5, characterized in that: In step 1), the steps of fixing the part to be packaged and the auxiliary positioning part are: placing the part to be packaged on a positioning table of a positioning seat, installing the auxiliary positioning part above the part to be packaged, coating semi-cured PDMS between the auxiliary positioning part and the part to be packaged, placing the upper cover on the auxiliary positioning part for upper side engagement, and then completely curing the semi-cured PDMS to obtain an assembled part of the part to be packaged and the auxiliary positioning part.

7. The bondable PDMS packaging method according to claim 6, characterized in that: The auxiliary positioning part has a signal end, a signal communication port and a signal output port communicating with the signal communication port, the signal communication port corresponds to the signal end, and semi-cured PDMS is coated on the matching surfaces of the signal communication port and the signal end.

8. The bondable PDMS packaging method according to claim 7, characterized in that: The signal output port serves as a positioning structure between the auxiliary positioning part and the positioning seat, or serves as a positioning structure between the auxiliary positioning part and the upper cover.

9. The bondable PDMS packaging method according to claim 1, characterized in that: The parts to be packaged are components that need to be implanted into a living body, including microvalves, micropumps, passive electronic components or chips.

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