Process strengthening method for improving radiation resistance of DIP device

Abstract

The invention belongs to the technical field of anti-radiation reinforcement of spaceflight components, and discloses a process reinforcement method for improving the anti-radiation capability of a DIP device. And obtaining the anti-radiation index of the chip in the DIP device, and calculating the thickness of the tantalum sheet based on the anti-radiation index of the chip. And obtaining the size of a chip in the DIP device and the position of the chip relative to the device, and bonding the tantalum sheet above the DIP device according to the size and the position of the chip in the DIP device. According to the method, quantitative calculation of anti-radiation design is provided, and the tantalum sheet thickness required by radiation resistance of the DIP device can be accurately obtained. The tantalum sheet is bonded above the DIP device, so that the anti-radiation performance of the DIP device is greatly improved, the cost is low, the operation is simple, the defect of the anti-radiation performance of the DIP device is overcome, and the selectable range of devices required by spaceflight products is greatly expanded.

Description

Technical Field

[0001] The present invention belongs to the technical field of radiation resistance reinforcement of aerospace components, and specifically relates to a process reinforcement method for improving the radiation resistance of DIP components. Background Art

[0002] The space radiation environment is a critical environmental factor facing spacecraft during in-orbit operation. According to relevant domestic and international statistics, approximately 40% of spacecraft electronic failures are caused by space radiation. To improve device radiation resistance, in addition to device inherent radiation resistance design, appropriate radiation resistance processes can also be implemented during device operation. Because the chip's lateral area is very small, the underlying packaging and printed circuit board also block radiation, so the chip's exposure primarily originates from above the device.

[0003] Chinese patent publication number CN109548311, "A method for strengthening components against radiation," strengthens components against radiation through steps such as PCB design, forming radiation-resistant materials, pre-fixing, trial assembly, welding, and reinforcement. The patented technology is simple and highly operational, but does not provide a method for calculating the size of the radiation-resistant material.

[0004] Existing technologies mostly focus on the radiation-resistant design of device packaging, but there is less focus on the radiation-resistant process design during device use, and there is no quantitative calculation of the corresponding radiation-resistant design. Summary of the Invention

[0005] The present invention provides a process reinforcement method for improving the radiation resistance of DIP devices, which makes up for the insufficient radiation resistance of the devices themselves and solves the problem of insufficient radiation resistance process design and no corresponding quantitative calculation of radiation resistance when the devices are used.

[0006] To achieve the above object, the present invention provides the following technical solutions: A process reinforcement method for improving the radiation resistance of a DIP device, comprising: Obtain the radiation resistance index of the chip in the DIP device and calculate the thickness of the tantalum sheet based on the chip radiation resistance index; Get the chip size in the DIP device and the position of the chip relative to the device; Bond the tantalum sheet to the DIP device based on the chip size within the DIP device and the position of the chip relative to the device; Overall reinforcement of DIP components and tantalum sheets.

[0007] Preferably, the step of calculating the thickness of the tantalum sheet based on the chip radiation resistance index is specifically as follows: Calculate the total ionizing radiation dose based on the chip's radiation resistance index; Based on the total ionizing radiation dose-depth data curve, the aluminum shielding thickness is obtained according to the total ionizing radiation dose; Calculate the thickness of the tantalum sheet based on the thickness of the aluminum shield.

[0008] Preferably, the formula for calculating the total ionizing radiation dose based on the chip radiation resistance index is: D 失效 =RDM×D 环境 Among them, D 环境 is the chip radiation resistance index, RDM is the radiation design margin, D 失效 is the total dose of ionizing radiation.

[0009] Preferably, the formula for calculating the thickness of the tantalum sheet based on the thickness of the aluminum shield is: h 钽 =h 铝 ρ 铝 / ρ 钽 Among them, ρ 铝 is the density of aluminum, ρ 钽 is the density of tantalum, h 铝 is the thickness of aluminum, h 钽 is the thickness of the tantalum sheet.

[0010] Preferably, the steps of obtaining the chip size and position in the DIP device are as follows: Place the DIP device horizontally on the X-ray inspection equipment platform, adjust the imaging angle to 90°, identify the DIP device outline and the chip outline through grayscale contrast, calculate the chip outline dimensions based on the DIP device outline dimensions, and determine the position of the chip outline center relative to the DIP device outline.

[0011] Preferably, the steps of bonding the tantalum sheet to the DIP device are as follows: The outer dimensions of the tantalum sheet are determined according to the outer dimensions of the chip outline, and a tantalum sheet of the outer dimensions is obtained by wire cutting. The surface of the tantalum sheet is cleaned with a non-woven fabric dipped in anhydrous ethanol, and the tantalum sheet is bonded to the top of the DIP device using epoxy resin. The center position of the tantalum sheet is the same as the position of the center of the chip outline relative to the device outline.

[0012] Preferably, the outer dimensions of the tantalum sheet are larger than the outer dimensions of the chip outline.

[0013] Preferably, the bonded tantalum sheet and DIP device are cured at 50±5° C. for 4 to 6 hours.

[0014] Preferably, the steps of integrally reinforcing the DIP device and the tantalum sheet are as follows: The tantalum sheet and the DIP device are integrally reinforced using silicone rubber. After the reinforcement is completed, excess glue is wiped off with a non-woven fabric dipped in anhydrous ethanol. The tantalum sheet and the DIP device integrally reinforced with silicone rubber are cured at 23±5° C. for more than 72 hours.

[0015] Preferably, the reinforcement method is a cross reinforcement method.

[0016] Compared with the existing technology, the present invention has the following beneficial effects: The present invention provides a process reinforcement method for improving the radiation resistance of DIP devices, obtains the radiation resistance index of the chip in the DIP device, and calculates the thickness of the tantalum sheet based on the chip radiation resistance index. The chip size in the DIP device and the position of the chip relative to the device are obtained, and the tantalum sheet is bonded to the top of the DIP device according to the chip size and position in the DIP device. This method provides quantitative calculation of radiation resistance design and can more accurately obtain the thickness of the tantalum sheet required for the radiation resistance of the DIP device. Bonding the tantalum sheet on the top of the DIP device greatly improves the radiation resistance of the DIP device, is low in cost, and simple to operate, which makes up for the shortcomings of the radiation resistance of the DIP device itself and greatly increases the range of options for devices required for aerospace products; Furthermore, silicone rubber is used to reinforce the tantalum sheet and the DIP device as a whole, which not only strengthens the fastening between the tantalum sheet and the DIP device, but also improves the connectivity between the DIP device and the printed circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a process reinforcement method for improving the radiation resistance of DIP devices according to the present invention; Figure 2 An X-ray image of a DIP device and a chip inside the DIP device according to an embodiment of the present invention; Figure 3 This is a cross-shaped diagram of the silicone rubber reinforcement of the DIP device and the tantalum sheet in an embodiment of the present invention; In the figure, 1-DIP device outline, 2-DIP device chip outline, 3-printed circuit board, 4-DIP device, 5-tantalum sheet, 6-epoxy resin, 7-silicone rubber. DETAILED DESCRIPTION

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0021] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0022] like Figure 1 As shown, the present invention provides a process reinforcement method for improving the radiation resistance of DIP devices, comprising: S1 obtains the radiation resistance index of the chip in the DIP device and calculates the thickness of the tantalum sheet based on the chip radiation resistance index; According to the chip radiation resistance index D in the DIP device 环境 , calculate the corresponding total ionizing radiation dose D by formula (1) 失效 ,

[0023] RDM is the radiation design margin, which is generally 2.5~3.

[0024] By consulting the total ionizing radiation dose-depth data curve, the ionizing radiation dose value D can be obtained. 失效 The corresponding aluminum shield thickness h 铝 .

[0025] Calculate the thickness h of the tantalum sheet according to formula (2) 钽 ,

[0026] where ρ 铝 is the density of aluminum, unit: g / cm 3 ρ 钽 is the density of tantalum, unit: g / cm 3 ; S2 obtains the chip size and position in the DIP device; Place the DIP device horizontally on the X-ray inspection platform and adjust the imaging angle to 90°. Identify the DIP device outline and the chip outline through grayscale contrast. Calculate the chip outline dimensions L1 and L2 based on the DIP device outline dimensions. Determine the position of the chip outline center relative to the DIP device outline.

[0027] S3 bonds the tantalum sheet to the DIP device according to the size and position of the chip in the DIP device; Determine the tantalum sheet's outer dimensions L according to the chip's outer dimensions L1 and L2. 钽1 、L 钽2 The tantalum sheet has an overall dimension of L 钽1 、L 钽2 Condition L must be met 钽1 ≥L1, L 钽2 ≥L2. A tantalum sheet with the desired dimensions was obtained using wire cutting. The surface of the tantalum sheet was cleaned with a non-woven fabric dipped in anhydrous ethanol. The tantalum sheet was bonded to the DIP device using epoxy resin E51. The center of the tantalum sheet was aligned with the center of the chip outline relative to the device outline described in step 2. The bonded tantalum sheet and DIP device were cured at 50±5°C for 4-6 hours.

[0028] S4 provides overall reinforcement for DIP devices and tantalum sheets.

[0029] The tantalum sheet and DIP device were reinforced with GD-414 silicone rubber using a cross-stitch method. Excess adhesive was removed with a non-woven fabric dipped in anhydrous ethanol. The GD-414 silicone rubber-reinforced tantalum sheet and DIP device were cured at 23±5°C for at least 72 hours.

[0030] An embodiment of the present invention provides a process reinforcement method for improving the radiation resistance of a DIP device, comprising: Step 1: Calculate the thickness of the tantalum sheet According to the chip radiation resistance index D in the DIP device 环境 =440rad, and the corresponding total ionizing radiation dose D is calculated by formula (1) 失效 ,

[0031] RDM is the radiation design margin, which is taken as 2.5.

[0032] By consulting the total ionizing radiation dose-depth data curve, the ionizing radiation dose value D can be obtained. 失效 =1100rad corresponding aluminum shield thickness h 铝 =6mm.

[0033] Calculate the thickness h of the tantalum sheet according to formula (2) 钽 ,

[0034] where ρ 铝 is the density of aluminum, unit: g / cm 3 ρ钽 is the density of tantalum, unit: g / cm 3 ; Step 2: X-ray positioning of the chip size and position in the DIP device Place the DIP device horizontally on the X-ray detection equipment platform and adjust the imaging angle to 90°. Identify the DIP device outline and the chip outline through grayscale contrast. Calculate the chip outline dimensions L1 = 8mm and L2 = 5mm based on the DIP device outline dimensions. Then determine the position of the chip outline center relative to the DIP device outline, as shown in the following example: Figure 2 shown.

[0035] Step 3: Epoxy bonding of tantalum sheet and DIP device According to the chip outline dimensions L1 = 8mm, L2 = 5mm, determine the tantalum sheet dimensions L 钽1 =13mm, L 钽2 =10mm, meeting the condition L 钽1 =13mm>L1=8mm、L 钽2 =10mm>L2=5mm. A tantalum sheet with the desired dimensions was obtained using wire cutting. The surface of the tantalum sheet was cleaned with a non-woven fabric dipped in anhydrous ethanol. The tantalum sheet was bonded to the DIP device using epoxy resin E51. The center of the tantalum sheet was aligned with the center of the chip outline relative to the device outline as described in step 2. The bonded tantalum sheet and DIP device were cured at 50°C for 5 hours.

[0036] Step 4: Silicone rubber reinforcement of tantalum sheet and DIP device The tantalum sheet and the device were reinforced with GD-414 silicone rubber using a cross-reinforcement method. After reinforcement, excess adhesive was wiped off with a non-woven fabric dipped in anhydrous ethanol. The tantalum sheet and the DIP device, reinforced with GD-414 silicone rubber, were cured at 25°C for 72 hours.

[0037] So far, the process reinforcement of DIP device against radiation has been completed, such as Figure 3 shown.

[0038] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields. The above-mentioned specific embodiments are merely illustrative and instructive, and are not restrictive. A person skilled in the art, guided by the description, may devise various forms without departing from the scope of protection of the claims of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A process reinforcement method for improving the radiation resistance of DIP devices, characterized in that: include: Obtain the radiation resistance index of the chip in the DIP device and calculate the thickness of the tantalum sheet based on the chip radiation resistance index; Get the chip size in the DIP device and the position of the chip relative to the device; Bond the tantalum sheet to the DIP device based on the chip size within the DIP device and the position of the chip relative to the device; Overall reinforcement of DIP components and tantalum sheets.

2. The process reinforcement method for improving the radiation resistance of DIP devices according to claim 1, characterized in that: The specific steps for calculating the thickness of the tantalum sheet based on the chip's radiation resistance index are: Calculate the total ionizing radiation dose based on the chip's radiation resistance index; Based on the total ionizing radiation dose-depth data curve, the aluminum shielding thickness is obtained according to the total ionizing radiation dose; Calculate the thickness of the tantalum sheet based on the thickness of the aluminum shield.

3. The process reinforcement method for improving the radiation resistance of a DIP device according to claim 2, characterized in that: The formula for calculating the total ionizing radiation dose based on the chip's radiation resistance index is: D 失效 =RDM×D 环境 Among them, D 环境 is the chip radiation resistance index, RDM is the radiation design margin, D 失效 is the total dose of ionizing radiation.

4. The process reinforcement method for improving the radiation resistance of a DIP device according to claim 2, characterized in that: The formula for calculating the thickness of the tantalum sheet based on the thickness of the aluminum shield is: h 钽 =h 铝 r 铝 / r 钽 Among them, ρ 铝 is the density of aluminum, ρ 钽 is the density of tantalum, h 铝 is the thickness of aluminum, h 钽 is the thickness of the tantalum sheet.

5. The process reinforcement method for improving the radiation resistance of DIP devices according to claim 1, characterized in that: The steps to obtain the chip size and position in the DIP device are as follows: Place the DIP device horizontally on the X-ray inspection equipment platform, adjust the imaging angle to 90°, identify the DIP device outline and the chip outline through grayscale contrast, calculate the chip outline dimensions based on the DIP device outline dimensions, and determine the position of the chip outline center relative to the DIP device outline.

6. The process reinforcement method for improving the radiation resistance of a DIP device according to claim 1, characterized in that: The specific steps for bonding the tantalum sheet to the DIP device are as follows: The outer dimensions of the tantalum sheet are determined according to the outer dimensions of the chip outline, and a tantalum sheet of the outer dimensions is obtained by wire cutting. The surface of the tantalum sheet is cleaned with a non-woven fabric dipped in anhydrous ethanol, and the tantalum sheet is bonded to the top of the DIP device using epoxy resin. The center position of the tantalum sheet is the same as the position of the center of the chip outline relative to the device outline.

7. The process reinforcement method for improving the radiation resistance of a DIP device according to claim 6, characterized in that: The outer dimensions of the tantalum sheet are larger than the outer dimensions of the chip outline.

8. The process reinforcement method for improving the radiation resistance of a DIP device according to claim 6, characterized in that: The bonded tantalum sheet and DIP device are cured at 50±5℃ for 4~6 hours.

9. The process reinforcement method for improving the radiation resistance of a DIP device according to claim 1, characterized in that: The specific steps for reinforcing DIP devices and tantalum sheets are as follows: The tantalum sheet and the DIP device are integrally reinforced using silicone rubber. After the reinforcement is completed, excess glue is wiped off with a non-woven fabric dipped in anhydrous ethanol. The tantalum sheet and the DIP device integrally reinforced with silicone rubber are cured at 23±5° C. for more than 72 hours.

10. The process reinforcement method for improving the radiation resistance of a DIP device according to claim 9, characterized in that: The reinforcement method is cross reinforcement.

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