Preparation method of low-cost slapper assembly based on three-dimensional integration of glass substrate

Abstract

The invention discloses a low-cost impact sheet assembly preparation method based on glass substrate three-dimensional integration, and the method comprises the following steps: providing a first substrate, forming a through hole array on the first substrate through a glass through hole technology, and carrying out the metallization of through holes, and forming conductive through holes; carrying out metal deposition on the top surface of the first substrate to form a metal lamination layer, and carrying out graphical processing on the metal lamination layer to form an explosion bridge foil array; generating a flyer layer on the top surface of the first substrate through a spin-coating process (or a dry film profile pressing mode); processing an acceleration bore hole in a second substrate, and carrying out wafer bonding on the second substrate and the flyer layer to obtain a wafer stack; and cleaning and cutting the wafer stack to obtain an independent slapper exploder component. According to the invention, by adopting a low-cost polymer material, a large-scale and low-cost mass production fuze microsystem high-voltage transducer is developed. The method has the advantages of high product consistency and low manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of microelectromechanical systems (MEMS) technology, and in particular to a low-cost method for fabricating impactor components based on three-dimensional integration of glass substrates. Background Technology

[0002] Manufacturing and integration based on microelectronic processes are key characteristics of fourth-generation intelligent pyrotechnics. Traditional pyrotechnic fuses are large, have complex assembly processes, are costly, and have relatively limited functionality. This severely restricts their application in commercial and military fields. Existing technological solutions suffer from several bottlenecks that limit their cost and performance, such as cost, production efficiency, and consistency control issues.

[0003] In terms of core structural precision control, the accelerator chamber is a key component that determines the tip velocity and attitude of the flyer blades. Existing technologies mostly use high molecular polymers such as polyimide to form a thick film through multiple spin coatings. This process makes it difficult to precisely control the thickness and perpendicularity of the chamber wall, resulting in poor performance consistency of batch products, and also has limitations in the mechanical strength and environmental resistance of the polymer.

[0004] In terms of production costs, the manufacturing process of existing inline impact plate assemblies relies on expensive polymer materials and specialized equipment. For example, the multiple spin coating process requires a high-precision coating system, increasing the costs of raw materials and equipment maintenance. In addition, the assembly process is complex, involving multiple manual operation steps, such as precise alignment and bonding, resulting in high labor costs. At the same time, poor process consistency leads to low product yield and increased scrap rate, further driving up the overall production cost and limiting large-scale commercial applications.

[0005] In terms of production efficiency, the existing multi-step spin coating process is time-consuming, requiring curing or heat treatment after each spin coating, thus extending the overall production cycle and making it difficult to achieve high-speed continuous production. The complexity of the assembly process also reduces the degree of automation, relying on manual intervention, resulting in slow production speed and limited capacity; in addition, unstable precision control often requires rework or adjustments, further dragging down production efficiency and failing to meet the market's demand for large-volume, rapid delivery. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention utilizes through-glass via (TGV) technology and low-cost polymer materials to develop a high-voltage transducer for large-scale, low-cost mass production of fuze microsystems. Its advantages lie in high product consistency and low manufacturing cost, providing core technological support for next-generation intelligent pyrotechnics, micro-thrusters, and other applications, thus possessing significant economic and strategic value.

[0007] The technical solution adopted in this invention is: to provide a low-cost method for fabricating impact sheet components based on three-dimensional integration of glass substrates, the method comprising the following steps: S1: A first substrate is provided, and a through-hole array is formed on the first substrate using a glass through-hole process, and the through-holes are metallized to form conductive through-holes; S2: Metal deposition is performed on the top surface of the first substrate to form a metal stack, and the metal stack is patterned to form an exploded bridge foil array; S3: A flyer layer is generated on the top surface of the first substrate by spin coating or by laminating a dry film profile on the top surface of the first substrate. S4: An acceleration bore is processed on the second substrate, and the second substrate is wafer-bonded to the flyback layer to obtain a wafer stack; S5: The wafer stack is cleaned and cut to obtain an independent impact detonation device assembly.

[0008] Furthermore, step S1 includes the following sub-steps: S11: Using photoresist as a mask, deep reactive ion etching or picosecond laser drilling is used to etch an array of through holes through the first substrate. S12: Sputter an adhesion layer and a seed layer onto the surface of the first substrate and the surface of each via by physical vapor deposition; S13: The copper plating process is used to completely fill each through hole and to plate copper on the surface of the first substrate; S14: Perform chemical mechanical polishing on the surface of the first substrate to remove the copper plating layer.

[0009] Furthermore, the via array includes two or two sets of vias symmetrically arranged along the central axis of the first substrate, each via having a cross-sectional dimension of 80 micrometers × 400 micrometers.

[0010] Furthermore, step S2 includes the following sub-steps: S21: Using magnetron sputtering, metal is deposited on the top surface of the first substrate to form a metal stack; S22: The metal stack is patterned using standard photolithography and ion beam etching or metal stripping processes to form a dumbbell-shaped exploded bridge foil array.

[0011] Furthermore, the explosive bridge foil array is arranged along the central axis of the first substrate, and the pad areas at both ends of the explosive bridge foil array are covered with two or more sets of through holes, so that the two or more sets of through holes are connected.

[0012] Furthermore, the process of generating a flyback layer on the top surface of the first substrate via spin coating includes the following sub-steps: S31: Spin-coat the liquid polyimide precursor onto the top surface of the first substrate; S32: Control the spin coating time and pattern selection speed so that the spin coating layer reaches the preset thickness and completely covers the exploded bridge foil array; S33: The first substrate is placed in an oven for heating and curing, so that the spin coating layer forms a fly sheet layer.

[0013] Furthermore, the thickness of the flyer layer is 25 micrometers.

[0014] Furthermore, the heating and curing process is a multi-stage heating process.

[0015] Furthermore, step S4 includes the following sub-steps: S41: Select a second substrate of the same thickness according to the preset acceleration bore thickness; S42: Accelerated boring holes are etched on the second substrate using photolithography, deep reactive ion etching, sandblasting, or laser processes; S43: The second substrate is wafer-bonded to the flyback layer to obtain a wafer stack.

[0016] Furthermore, the accelerating boring hole is arranged along the central axis of the second substrate, and the central axis of the accelerating boring hole and the explosive bridge foil array are collinear.

[0017] The present invention provides a low-cost method for fabricating impact sheet components based on three-dimensional integration of glass substrates, which has at least the following beneficial effects: 1. Significantly improves product consistency and reliability. By replacing traditional multi-stage spin-coating thick film processes with microelectronic techniques (such as photolithography and etching), the dimensions (such as thickness and bore diameter) and geometry (such as bore wall perpendicularity) of key structures like the accelerator chamber can be precisely controlled. This effectively solves the problem of batch product performance consistency.

[0018] 2. Effectively reduces production costs. Microelectronic processes facilitate mass production and wafer-level manufacturing, enabling the parallel fabrication of numerous identical functional structures on a single substrate. This significantly reduces the manufacturing cost of individual components and eliminates tedious manual alignment and bonding steps in traditional assembly, simplifying the production process and saving labor costs. Furthermore, improved process consistency directly leads to higher product yields, reduced scrap losses, and further optimized overall costs.

[0019] 3. Significantly improve production efficiency. This solution adopts highly automated planar manufacturing technology, which enables fast and continuous assembly line operations. It fundamentally changes the situation of long cycles and slow speed caused by traditional multi-step spin coating and multiple curing, and significantly shortens the production cycle. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the structure of the impact plate detonation device of the present invention.

[0021] Figure 2 This is a process flow diagram of the low-cost impact sheet assembly fabrication method based on three-dimensional integration of glass substrates according to the present invention.

[0022] Figure 3 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S1.

[0023] Figure 4 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S2.

[0024] Figure 5 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S3.

[0025] Figure 6 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S4.

[0026] Explanation of reference numerals in the attached figures: First substrate-1; conductive via-2; explosion bridge foil array-3; flyer layer-4; second substrate-5; accelerated boring-6. Detailed Implementation

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] Please see Figure 1 This is a schematic diagram of the structure of the impact plate initiating device of the present invention. The specific structure of the impact plate initiating device of this solution, from top to bottom, may include: First substrate 1: The first substrate 1 is a glass substrate; the first substrate 1 can be made of materials such as borosilicate glass (Borofloat 33) or quartz glass, and the thickness can be selected according to design requirements, such as 400 micrometers.

[0029] Conductive vias 2: Two or more sets of conductive vias 2 are symmetrically arranged within the first substrate 1, penetrating the upper and lower surfaces of the first substrate 1. The cross-sectional dimensions of the conductive vias 2 can be selected according to actual needs, such as 80 micrometers × 400 micrometers. These conductive vias 2 can be fabricated in the first substrate using TGV (Through Glass Via) technology. In this embodiment, the cross-sectional dimensions of the vias are 80 micrometers × 400 micrometers, symmetrically arranged on both sides of the substrate. The vias are filled with a highly conductive metal, such as copper (Cu).

[0030] Explosion bridge foil array 3: disposed on the upper surface of the first substrate 1, with its two ends electrically connected to the two sets of conductive vias 2 respectively; this explosion bridge foil array 3 can be disposed on the upper surface of the first substrate, is a metal film, and has a total thickness of approximately 3-10 micrometers. Its shape is dumbbell-shaped, with wider pad areas at both ends precisely covering the top of the conductive vias, and a narrow bridge area in the middle.

[0031] Flying foil layer 4: A polymer film layer covering the upper surface of the explosion bridge foil and the first substrate 1; this flying foil layer 4 can be made of high-toughness polymer materials such as polyimide (PI), formed by spin coating or film lamination process, with uniform thickness, for example 25 micrometers. This layer completely covers the explosion bridge foil.

[0032] Second substrate 5 (acceleration chamber): The second substrate 5 is a glass substrate with through holes extending through its upper and lower surfaces to form an acceleration chamber structure. The second substrate 5 is fixed to the upper surface of the flyer layer 4 by a bonding process, and the central axis of the acceleration chamber is collinear with the center of the explosive bridge foil. This second substrate 5 can also be made of borosilicate glass or quartz glass, and its thickness determines the acceleration distance of the flyer layer 4, for example, 400 micrometers. A through-hole 6 for the acceleration chamber is formed in its central region. The second substrate 5 is firmly fixed to the flyer layer 4 by a bonding process. The center of the acceleration chamber 6 is precisely aligned with the center of the bridge area of ​​the explosive bridge foil array 3.

[0033] Please see Figure 2 This is a flowchart illustrating the low-cost impact sheet assembly fabrication method based on three-dimensional integration of a glass substrate according to the present invention. The method specifically includes: Please see Figure 3 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S1. S1: A first substrate 1 is provided, and a through-hole array is formed on the first substrate 1 using a glass through-hole process. The through-holes are then metallized to form conductive through-holes 2.

[0034] This S1 step may include the following sub-steps: S11: Using photoresist as a mask, deep reactive ion etching or picosecond laser drilling is used to etch a through-hole array on the first substrate 1, which penetrates the first substrate 1; wherein, the through-hole array includes two or two sets of through holes symmetrical along the central axis of the first substrate 1, and the cross-sectional size of each through hole can be 80 micrometers × 400 micrometers.

[0035] S12: An adhesive layer and a seed layer are sputtered onto the surface of the first substrate 1 and the surface of each via by physical vapor deposition; wherein the adhesive layer and the seed layer may be made of Ti / Cu metal.

[0036] S13: Using an electroplating copper process, each through hole is completely filled, and copper is plated on the surface of the first substrate 1; This S13 step uses an electroplating copper process to completely fill the through holes and electroplat a rich copper layer on the surface of the first substrate 1.

[0037] S14: Perform chemical mechanical polishing (CMP) on the surface of the first substrate 1 to remove the surface copper plating layer. This S14 step uses a chemical mechanical polishing (CMP) process to precisely remove excess copper and seed layers from the surface, restoring the wafer surface to a flat surface and retaining only the copper filling inside the vias to form conductive vias. Electrodes are fabricated by etching and electroplating on the back side of the first substrate 1.

[0038] Please see Figure 4 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S2. S2: Metal deposition is performed on the top surface of the first substrate 1 to form a metal stack, and the metal stack is patterned to form an explosion bridge foil array 3; This S2 step may include the following sub-steps: S21: Using magnetron sputtering, metal is deposited on the top surface of the first substrate 1 to form a metal stack; in this S21 step, the metal stack (such as Ti / Cu / Au) required for the explosion bridge foil array 3 is deposited on the upper surface of the first substrate 1 after CMP treatment using PVD sputtering process.

[0039] S22: The metal stack is patterned using standard photolithography and ion beam etching or metal lift-off processes to form a dumbbell-shaped exploded bridge foil array 3. In this S22 step, the metal stack is patterned using standard photolithography and ion beam etching (or metal lift-off) processes to form a dumbbell-shaped exploded bridge foil array 5.

[0040] The explosion bridge foil array 3 is arranged along the central axis of the first substrate 1, and the pad areas at both ends of the explosion bridge foil array 3 are covered with two or two sets of through holes, so that the two or two sets of through holes are connected.

[0041] Please see Figure 5 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S3. S3: The flyer layer 4 is generated on the top surface of the first substrate 1 by spin coating or by laminating a dry film profile on the top surface of the first substrate 1.

[0042] The above-mentioned process of generating the flyer layer 4 on the top surface of the first substrate 1 by spin coating may specifically include the following sub-steps: S31: Spin-coat the liquid polyimide precursor onto the top surface of the first substrate 1; S32: Control the spin coating time and the selection speed so that the spin coating layer reaches the preset thickness and completely covers the explosion bridge foil array 3; S33: The first substrate 1 is placed in an oven for heating and curing to form a flyer layer 4. In this S33 step, the wafer is placed in an oven and subjected to a multi-stage heating and curing process to fully crosslink the PI and form a dense and tough flyer layer 4, the thickness of which is 25 micrometers.

[0043] Please see Figure 6 This is a schematic diagram of the cross-sectional structure of the impact detonator after step S4. S4: Acceleration bores are machined on the second substrate 5, and the second substrate 5 is wafer-bonded to the flyer layer 4 to obtain a wafer stack; This S4 step may include the following sub-steps: S41: Select a second substrate 5 of the same thickness according to the preset thickness of the acceleration bore 6; S42: Using photolithography and deep reactive ion etching (DRIE), sandblasting, or laser processes, an accelerated boring hole 6 is etched on the second substrate 5. This S42 step also uses photolithography and DRIE (or sandblasting, laser) processes to create a through-hole accelerated bore 6 on the second substrate 5. Thanks to the highly mature glass etching process, the size, perpendicularity, and surface finish of the accelerated bore 6 can be precisely controlled. Simultaneously, the accelerated boring hole 6 is positioned along the central axis of the second substrate 5, and the accelerated boring hole 6 and the central axis of the exploded bridge foil array 3 are collinear.

[0044] S43: The second substrate 5 and the flyback layer 4 are wafer-bonded to obtain a wafer stack. The bonding method can be selected as follows: anodic bonding; adhesive bonding using low-release, high-strength intermediate adhesives such as epoxy resin and BCB; or direct bonding, which requires plasma activation treatment of the PI surface.

[0045] S5: The wafer stack is cleaned and diced to obtain an independent impact detonator assembly. After step S5, the obtained impact detonator assembly can be integrated with external circuitry via wire bonding or flip-chip bonding.

[0046] In summary, this solution discloses a method for improving blind via plating on wafer 1 by enhancing interface wettability. This method not only significantly improves product consistency and reliability, but also, by replacing traditional multi-stage spin-coating thick film processes with microelectronic processes (such as photolithography and etching), precisely controls the dimensions (such as thickness and bore diameter) and geometry (such as bore wall perpendicularity) of key structures like the accelerating bore. This effectively solves the problem of batch product performance consistency and significantly reduces production costs. Microelectronic processes are easy to mass-produce and manufacture at the wafer level, enabling the parallel processing of a large number of identical functional structures on a single substrate, greatly reducing the manufacturing cost of individual components and simplifying the production process by reducing tedious manual alignment and bonding steps in traditional assembly, thus saving labor costs. Simultaneously, the improved process consistency directly leads to higher product yield, reduced scrap losses, and further optimized overall costs. It also significantly improves production efficiency. This solution employs highly automated planar manufacturing technology, enabling rapid and continuous assembly line operations. It fundamentally changes the long cycle and slow speed caused by traditional multi-step spin coating and multiple curing processes, significantly shortening the production cycle.

[0047] The above description merely illustrates preferred embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate, characterized in that, The method includes the following steps: S1: A first substrate is provided, and a through-hole array is formed on the first substrate using a glass through-hole process, and the through-holes are metallized to form conductive through-holes; S2: Metal deposition is performed on the top surface of the first substrate to form a metal stack, and the metal stack is patterned to form an exploded bridge foil array; S3: A flyer layer is generated on the top surface of the first substrate by spin coating or by laminating a dry film profile on the top surface of the first substrate. S4: An acceleration bore is processed on the second substrate, and the second substrate is wafer-bonded to the flyback layer to obtain a wafer stack; S5: The wafer stack is cleaned and cut to obtain an independent impact detonator component chip.

2. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 1, characterized in that, Step S1 includes the following sub-steps: S11: Using photoresist as a mask, deep reactive ion etching or picosecond laser drilling is used to etch an array of through holes through the first substrate. S12: Sputter an adhesion layer and a seed layer onto the surface of the first substrate and the surface of each via by physical vapor deposition; S13: The copper plating process is used to completely fill each through hole and to plate copper on the surface of the first substrate; S14: Perform chemical mechanical polishing on the surface of the first substrate to remove the copper plating layer.

3. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 2, characterized in that, The via array includes two or two sets of vias symmetrically arranged along the central axis of the first substrate, each via having a cross-sectional dimension of 80 micrometers × 400 micrometers.

4. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 3, characterized in that, Step S2 includes the following sub-steps: S21: Using magnetron sputtering, metal is deposited on the top surface of the first substrate to form a metal stack; S22: The metal stack is patterned using standard photolithography and ion beam etching or metal stripping processes to form a dumbbell-shaped exploded bridge foil array.

5. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 4, characterized in that, The explosive bridge foil array is arranged along the central axis of the first substrate, and the pad areas at both ends of the explosive bridge foil array cover two or two sets of through holes, so that the two or two sets of through holes are connected.

6. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 1, characterized in that, The process of generating a flyback layer on the top surface of the first substrate by spin coating includes the following sub-steps: S31: Spin-coat the liquid polyimide precursor onto the top surface of the first substrate; S32: Control the spin coating time and pattern selection speed so that the spin coating layer reaches the preset thickness and completely covers the exploded bridge foil array; S33: The first substrate is placed in an oven for heating and curing, so that the spin coating layer forms a fly sheet layer.

7. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 6, characterized in that, The thickness of the flyback layer is 25 micrometers.

8. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 6, characterized in that, The heating and curing process is a multi-stage heating process.

9. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 1, characterized in that, Step S4 includes the following sub-steps: S41: Select a second substrate of the same thickness according to the preset acceleration bore thickness; S42: Accelerated boring holes are etched on the second substrate using photolithography, deep reactive ion etching, sandblasting, or laser processes; S43: The second substrate is wafer-bonded to the flyback layer to obtain a wafer stack.

10. The method for fabricating a low-cost impact sheet assembly based on three-dimensional integration of a glass substrate as described in claim 9, characterized in that, The accelerated boring hole is arranged along the central axis of the second substrate, and the central axis of the accelerated boring hole and the explosive bridge foil array are collinear.

Images