A target support structure for laser fusion ignition and its MEMS processing method

Abstract

The present invention provides a target support structure for laser fusion ignition and a MEMS processing method thereof, comprising: a lower compression cone support plate, which is located at the bottom and is provided with a lower compression cone assembly hole and a clamping end; an upper compression cone support plate, which is parallel to the lower compression cone support plate and is provided with an upper compression cone assembly hole; an ignition cone support plate, which is vertically arranged to connect the lower compression cone support plate and the upper compression cone support plate, and is provided with an ignition cone assembly hole; a supporting plate, which is vertically arranged to connect the lower compression cone support plate and the upper compression cone support plate, and is provided with an adjustment observation hole; and all the assembly holes are provided with a glue groove. The modular design of the present invention meets the high flexibility requirements of target processing in target shooting experiments, MEMS processing technology solves the problem of high dimensional accuracy, and the use of SOI silicon wafers achieves high uniformity of processing results of parts from different batches from a technical level. A reliable technical circuit is formed for the target support structure to meet the flexible requirements and mass production requirements of ignition experiments for targets of various parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of laser fusion ignition targets, and in particular to a target support structure for laser fusion ignition and a MEMS processing method thereof. Background Art

[0002] Laser inertial confinement fusion (ICF), considered the pinnacle of human engineering physics, presents numerous highly complex intrinsic physics challenges. There is an urgent need to simplify the process, both physically and technically, and reduce the total input laser energy. The double-cone collision ignition scheme proposed by Academician Zhang Jie of the Chinese Academy of Sciences simplifies the implosion process, effectively decomposing the complex physics and reducing the compression and ignition laser energies, significantly accelerating the fusion process.

[0003] After searching and comparing existing technologies, a Chinese invention patent with authorization publication number CN111681783B discloses a laser fusion ignition device and fusion ignition method. This patent describes a laser fusion ignition device consisting primarily of two coaxial, metal compression cones with opposing apexes, as well as an ignition assembly for heating the fuel. This laser fusion ignition device requires high component positioning accuracy.

[0004] Chinese invention patent application number CN202111438179.5 discloses a three-cone laser fusion ignition target, assembly device, and assembly method. The patent focuses on high-precision assembly of the three-cone laser fusion ignition target, overcoming the low efficiency and poor precision of traditional manual assembly processes. However, the patent mentions that the target support frame is produced using 3D printing, which has the disadvantages of low flexibility, low dimensional accuracy, and poor uniformity. Summary of the Invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a target support structure for laser fusion ignition and a MEMS processing method thereof.

[0006] According to a first aspect of the present invention, a target support structure for laser fusion ignition is provided, comprising four parts, namely:

[0007] A lower compression cone support piece, the lower compression cone support piece is located at the bottom and is provided with a lower compression cone assembly hole and a clamping end;

[0008] an upper compression cone support piece, the upper compression cone support piece being parallel to the lower compression cone support piece and being provided with an upper compression cone assembly hole;

[0009] An ignition cone support plate, which is vertically arranged to connect the lower compression cone support plate and the upper compression cone support plate, and is provided with an ignition cone assembly hole;

[0010] A supporting plate, which is vertically arranged and parallel to the ignition cone supporting plate, connects the lower compression cone supporting plate and the upper compression cone supporting plate, and is provided with an adjustment observation hole;

[0011] Glue dispensing grooves are arranged on the outer sides of the lower compression cone assembly hole, the upper compression cone assembly hole and the ignition cone assembly hole.

[0012] Preferably, the target support structure is manufactured by modular design, and the lower compression cone support plate, upper compression cone support plate, ignition cone support plate and supporting plate are respectively manufactured by MEMS technology, and then the target support structure is formed by assembly.

[0013] Preferably, the lower compression cone support plate, the upper compression cone support plate, the ignition cone support plate and the supporting plate need to be processed using SOI silicon wafers.

[0014] Preferably, the thickness of the top silicon layer of the SOI silicon wafer is 50 nm to 100 μm, and the thickness of the buried oxide layer of silicon dioxide is 0.2 to 5 μm.

[0015] Preferably, the depth of the dispensing groove is 50 nm to 100 µm, which is the same as the thickness of the top silicon layer of the SOI silicon wafer.

[0016] According to a second aspect of the present invention, a method for processing a target support structure MEMS for laser fusion ignition is provided, comprising:

[0017] Take the SOI wafer, spin-coat photoresist on the front side, and form a mask by photolithography patterning;

[0018] Using photoresist as a mask, the top silicon layer of SOI is patterned by etching, and then the photoresist is removed;

[0019] Spin-coat photoresist on the front side and form a mask by photolithography patterning;

[0020] Using photoresist as a mask, the buried oxide layer of SOI is patterned by dielectric etching, and then the photoresist is removed;

[0021] Spin-coat photoresist on the front side as a front protective glue for back etching;

[0022] Depositing a dielectric layer on the back side;

[0023] Spin-coat photoresist on the back side and pattern it by photolithography to form a mask;

[0024] Using photoresist as a mask, the deposited dielectric layer is patterned by dielectric etching;

[0025] Using the dielectric layer as a mask, the underlying silicon of the SOI is patterned by etching;

[0026] After backside etching to form through holes, the individual support sheets or carriers are released from the wafer, the photoresist is finally removed, and the four parts of the support structure are assembled.

[0027] Preferably, the dielectric layer deposited on the back side is any one of a hard mask of silicon dioxide and silicon nitride.

[0028] Preferably, the method of etching the top silicon and silicon dioxide is any one of sputtering etching, plasma etching and reactive ion etching; and the method of etching the bottom silicon to form the through hole is deep reactive ion etching.

[0029] Preferably, the four parts of the support structure are fixed using UV curing glue during assembly.

[0030] Preferably, the process of assembling the compression cone or the ignition cone support piece with the compression cone or the ignition cone support piece is as follows:

[0031] Use a microscope to observe and determine the location of the assembly holes;

[0032] Use UV curing glue to dispense a small amount of glue into the dispensing slot;

[0033] Assemble the compression cone or ignition cone into the assembly hole, observe and adjust the position of the compression cone and ignition cone through the adjustment observation hole on the support plate, and finally cure the glue by ultraviolet irradiation.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a target support structure for laser fusion ignition and a MEMS processing method thereof. The support structure consists of four parts: a lower compression cone support plate, an upper compression cone support plate, an ignition cone support plate, and a support plate. The modular design meets the high flexibility required for target processing in target shooting experiments. MEMS processing technology solves the problem of high dimensional accuracy. The use of SOI silicon wafers technically achieves high uniformity in component processing results across different batches. This establishes a reliable technical circuit for the target support structure, meeting the flexible requirements for various target parameter requirements and the mass production requirements of ignition experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0037] Figure 1 A schematic diagram of a target support structure according to a preferred embodiment of the present invention;

[0038] Figure 1The middle numbers represent: lower compression cone support plate 101; upper compression cone support plate 102; ignition cone support plate 103; supporting plate 104

[0039] Figure 2 A schematic diagram of various parts of a target support structure according to a preferred embodiment of the present invention;

[0040] Figure 2 The middle numbers represent: lower compression cone assembly hole 201; clamping end 202; upper compression cone assembly hole 203; ignition cone assembly hole 204; adjustment observation hole 205; glue dispensing groove 206;

[0041] Figure 3 Schematic diagram of each step of a MEMS processing method for a target support structure according to a preferred embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the steps of assembling a compression cone or an ignition cone to a compression cone support plate or an ignition cone support plate according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0044] See Figure 1 In one embodiment of the present invention, a target support structure for laser fusion ignition is provided. The support structure consists of four parts, namely a lower compression cone support plate 101, an upper compression cone support plate 102, an ignition cone support plate 103 and a supporting plate 104.

[0045] See Figure 2The lower compression cone support plate 101 is provided with a lower compression cone assembly hole 201 for assembling the lower compression cone and a clamping end 202 for integrally clamping the target in the target chamber. The upper compression cone support plate 102 is provided with an upper compression cone assembly hole 203. The ignition cone support plate 103 is provided with an ignition cone assembly hole 204. The support plate 104 is provided with an adjustment observation hole 205. The support plate serves two purposes: firstly, it ensures the stability of the entire target support structure; secondly, the adjustment observation hole 205 on it allows for the position adjustment and observation of the cone during assembly. Glue dispensing grooves 206 are provided on the outer sides of the lower compression cone assembly hole 201, the upper compression cone assembly hole 203, and the ignition cone assembly hole 204, while the support plate does not require a glue dispensing groove. The glue dispensing groove can hold a certain amount of glue, ensuring that the cone is firmly fixed in the hole after installation, effectively avoiding the unstable contact state between the two, which plays a vital role in the stability of the target in the later stage and is indispensable.

[0046] In a preferred embodiment of the present invention, see Figure 2 The target support structure is manufactured using a modular design. MEMS technology is used to separately machine the lower compression cone support plate 101, upper compression cone support plate 102, ignition cone support plate 103, and support plate 104. These are then assembled to form the target support structure. Modular design and manufacturing offer numerous advantages, ensuring high flexibility in later assembly while allowing for control over the spacing between the cones during assembly to meet the experimental requirements of laser fusion ignition targets with varying parameters. MEMS-manufactured structures exhibit high dimensional accuracy, far exceeding that achieved through 3D printing and precision machining.

[0047] In a preferred embodiment of the present invention, the support frame is fabricated from a SOI silicon wafer with a top silicon layer thickness of 10µm, a buried silicon dioxide layer thickness of 5µm, and a bottom silicon layer thickness of 400µm. The SOI wafer has highly consistent thickness uniformity across its layers, ensuring high uniformity across different target support structures.

[0048] In a preferred embodiment of the present invention, the depth of the glue dispensing groove on the support frame is 10µm. Since the thickness of the glue dispensing groove is formed by etching the top silicon of the SOI silicon wafer, the depth of the glue dispensing groove is the same as the thickness of the top silicon of the SOI silicon wafer.

[0049] See Figure 3 Based on the same inventive concept, in another embodiment of the present invention, a MEMS processing method for a target support structure for laser fusion ignition is provided, which is performed according to the following steps:

[0050] S1: Take SOI wafer ( Figure 3 a), spin-coat 30µm positive photoresist on the front side and pattern it by photolithography to form a mask ( Figure 3b);

[0051] S2: Using the photoresist as a mask, the 10µm top silicon of the SOI is patterned by reactive ion etching, and then the photoresist is washed away with acetone ( Figure 3 c);

[0052] S3: Spin-coat 30µm of positive photoresist on the front side and form a mask by photolithography patterning ( Figure 3 d);

[0053] S4: Using the photoresist as a mask, the 5µm buried oxide layer of SOI is patterned by reactive ion etching, and then the photoresist is washed away with acetone ( Figure 3 e);

[0054] S5: Spin-coat 30µm positive photoresist on the front side as a front protective film for back etching ( Figure 3 f);

[0055] S6: Deposit a 10µm layer of silicon dioxide on the back side by chemical vapor deposition ( Figure 3 g);

[0056] S7: Spin-coat 30µm of positive photoresist on the back side and pattern it by photolithography to form a mask ( Figure 3 h);

[0057] S8: Using photoresist as a mask, the deposited 10µm silicon dioxide is patterned by reactive ion etching ( Figure 3 i);

[0058] S9: Using silicon dioxide as a mask, pattern the 400µm underlying silicon of the SOI by deep reactive ion etching;

[0059] S10: After the backside is etched to form a through hole, the individual support sheets or carrier sheets are released from the wafer, and finally the photoresist is washed away with acetone ( Figure 3 j) and assemble the four parts of the support structure.

[0060] It should be noted that since the support sheet does not need to be provided with a dispensing groove, the processing steps of the support sheet are the same as those of the support sheet, but the top silicon and buried oxide layer of the SOI can be removed successively by only one photolithography, and there is no need to separate them into two steps of photolithography removal.

[0061] In a preferred embodiment of the present invention, the dielectric layer deposited on the back side can be any hard mask such as silicon dioxide, silicon nitride, etc.

[0062] In a preferred embodiment of the present invention, the four parts of the support structure are fixed using UV curing glue during assembly.

[0063] In a preferred embodiment, the steps of assembling the compression cone or the ignition cone on the compression cone support plate or the ignition cone support plate are as follows:

[0064] S1: Observe and determine the position of the assembly holes under a microscope;

[0065] S2: Use UV curing glue to perform micro dispensing on the dispensing slot;

[0066] S3: Assemble the compression cone or ignition cone into the assembly hole, observe and adjust the position of the compression cone and the ignition cone through the adjustment observation hole on the support plate, and finally cure the glue by ultraviolet irradiation.

[0067] The above embodiment, through modular design and MEMS technology to process various components, features high flexibility, high dimensional accuracy, and high uniformity. This forms a reliable technical circuit for the target support structure, meeting the flexible requirements of ignition experiments for various target parameters and the requirements of mass production.

[0068] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various modifications or variations within the scope of the claims without affecting the essence of the present invention. The above preferred features may be used in any combination as long as they do not conflict with each other.

Claims

1. A target support structure for laser fusion ignition, characterized in that: It consists of four parts: A lower compression cone support piece, the lower compression cone support piece is located at the bottom and is provided with a lower compression cone assembly hole and a clamping end; an upper compression cone support piece, the upper compression cone support piece being parallel to the lower compression cone support piece and being provided with an upper compression cone assembly hole; An ignition cone support plate, which is vertically arranged to connect the lower compression cone support plate and the upper compression cone support plate, and is provided with an ignition cone assembly hole; A supporting plate, which is vertically arranged and parallel to the ignition cone supporting plate, connects the lower compression cone supporting plate and the upper compression cone supporting plate, and is provided with an adjustment observation hole; The outer sides of the lower compression cone assembly hole, the upper compression cone assembly hole and the ignition cone assembly hole are all provided with glue dispensing grooves; The target support structure is manufactured by modular design, and the lower compression cone support piece, upper compression cone support piece, ignition cone support piece and supporting piece are respectively manufactured by MEMS technology, and then assembled to form the target support structure; MEMS processing methods, including: Take the SOI wafer, spin-coat photoresist on the front side, and form a mask by photolithography patterning; Using photoresist as a mask, the top silicon layer of SOI is patterned by etching, and then the photoresist is removed; Spin-coat photoresist on the front side and form a mask by photolithography patterning; Using photoresist as a mask, the buried oxide layer of SOI is patterned by dielectric etching, and then the photoresist is removed; Spin-coat photoresist on the front side as a front protective glue for back etching; Depositing a dielectric layer on the back side; Spin-coat photoresist on the back side and pattern it by photolithography to form a mask; Using photoresist as a mask, the deposited dielectric layer is patterned by dielectric etching; Using the dielectric layer as a mask, the underlying silicon of the SOI is patterned by etching; After backside etching to form through holes, the individual support sheets or carriers are released from the wafer, the photoresist is finally removed, and the four parts of the support structure are assembled.

2. A target support structure for laser fusion ignition according to claim 1, characterized in that: The thickness of the top silicon layer of the SOI wafer is 50nm-100µm, and the thickness of the buried oxide layer silicon dioxide is 0.2-5µm.

3. The target support structure for laser fusion ignition according to claim 2, characterized in that: The depth of the dispensing groove is 50nm to 100µm, which is the same as the thickness of the top silicon layer of the SOI wafer.

4. The target support structure for laser fusion ignition according to claim 1, characterized in that: The dielectric layer deposited on the back side is any one of a hard mask of silicon dioxide and silicon nitride.

5. The target support structure for laser fusion ignition according to claim 1, characterized in that: The method for etching the top silicon and silicon dioxide is any one of sputtering etching, plasma etching and reactive ion etching; the method for etching the bottom silicon to form the through hole is deep reactive ion etching.

6. The target support structure for laser fusion ignition according to claim 1, characterized in that: The four parts of the support structure are fixed using ultraviolet curing glue during assembly.

7. The target support structure for laser fusion ignition according to claim 1, characterized in that: The process of assembling the compression cone or ignition cone to the compression cone support plate or ignition cone support plate is as follows: Use a microscope to observe and determine the location of the assembly holes; Use UV curing glue to dispense a small amount of glue into the dispensing slot; Assemble the compression cone or ignition cone into the assembly hole, observe and adjust the position of the compression cone and ignition cone through the adjustment observation hole on the support plate, and finally cure the glue by ultraviolet irradiation.

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