Radiation hardening structure and design method of silicon-based chip based on local protection

Abstract

The application provides a local protection-based lightweight structure of a silicon-based chip against radiation, comprising a PCB mainboard, a silicon-based chip, non-radiation-sensitive devices and a local anti-radiation shielding shell; the PCB mainboard has a central region and an edge region distributed around the central region; the silicon-based chip is arranged in the central region; the non-radiation-sensitive devices are arranged in the edge region; the local anti-radiation shielding shell is an independent metal shell covering only the chip mounting area and is fixed on the PCB mainboard through fasteners; the non-radiation-sensitive devices in the edge region are exposed outside the local anti-radiation shielding shell. In this way, the application adopts a partition layout, sets a local shielding only for the radiation-sensitive silicon-based chip, and does not protect the non-radiation-sensitive devices, thereby reducing the overall structure weight under the premise of ensuring the anti-radiation index unchanged, limiting the connector plugging, and solving the problems of heavy weight, serious redundant protection and inconvenient connector disassembly of the existing fully-enclosed shell anti-radiation scheme.

Description

Technical Field

[0001] This invention relates to the field of spaceborne electronic equipment structure design technology, and in particular to a radiation-resistant and lightweight structure and design method for spaceborne PCB silicon-based chips based on local protection. Background Technology

[0002] During satellite operation, circuit boards are exposed to a complex space radiation environment for extended periods. High-energy protons, high-energy electrons, and heavy ions in orbit continuously act on the onboard electronic components. Silicon-based chips are susceptible to radiation damage such as total dose effect, single-event upset, and single-event latch-up, leading to logic errors and, in severe cases, permanent device failure, thus reducing the reliability and service life of onboard equipment.

[0003] To mitigate the effects of radiation, conventional spaceborne PCB radiation-hardening designs generally employ a fully enclosed metal casing: enclosing the entire PCB motherboard and all electronic components within the shielding shell. However, while this method offers stable overall shielding, it has significant drawbacks:

[0004] First, the shielding shell has a large overall volume, uses a lot of shielding material, and has a relatively high overall weight. Satellite payloads have strict requirements for weight reduction, and an excessively heavy structure will reduce the payload's weight margin.

[0005] Second, the connectors and passive components such as resistors and capacitors on the circuit board have excellent radiation resistance and are not radiation-sensitive components. The overall enclosed protection is a redundant design, which further increases the structural weight.

[0006] Third, the entire casing completely surrounds the circuit board, and the connectors on the edge of the board are blocked by the casing, making cable plugging and unplugging cumbersome, and the shielding casing needs to be removed during maintenance and disassembly.

[0007] Fourth, the sealed casing hinders heat dissipation from the circuit board, causing the heat generated by the chip to accumulate inside the casing. Long-term high temperature combined with radiation environment accelerates device aging.

[0008] Therefore, there is a need to provide a lightweight radiation-resistant structure and design method for silicon-based chips based on local protection, which can fundamentally solve the technical problems of existing fully enclosed radiation-resistant solutions, such as large weight, serious redundant protection, and inconvenient connector assembly and disassembly. Summary of the Invention

[0009] This invention provides a lightweight radiation-resistant structure and design method for silicon-based chips based on local protection. It adopts a partitioned layout, setting local shielding only for radiation-sensitive silicon-based chips, while leaving non-radiation-sensitive devices unprotected. Under the premise of ensuring that the radiation resistance index remains unchanged, the overall structural weight is reduced, and the connector insertion and removal are not restricted. This solves the technical problems of existing fully enclosed radiation-resistant solutions, such as large weight, serious redundant protection, and inconvenient connector disassembly and assembly.

[0010] According to one aspect of the present invention, a radiation-resistant lightweight structure for silicon-based chips based on local protection is provided, comprising: a PCB motherboard, a silicon-based chip, a non-radiation-sensitive device, and a local radiation-resistant shielding shell;

[0011] The PCB motherboard has a central region and an edge region distributed around the central region;

[0012] The silicon-based chips are centrally arranged in the central area to form a chip mounting area;

[0013] The non-radiation-sensitive device is disposed in the edge region;

[0014] The partial radiation shielding housing is configured as an independent metal housing that only covers the chip mounting area, and the partial radiation shielding housing is fixed to the PCB motherboard by fasteners.

[0015] The projection of the envelope of the localized radiation shielding shell onto the horizontal plane falls entirely within the central region of the PCB motherboard, so that non-radiation-sensitive devices in the edge region are exposed outside the localized radiation shielding shell.

[0016] As a further explanation of the present invention, preferably, the non-radiation-sensitive device includes a connector and a passive device;

[0017] The connectors are distributed along the outline of the PCB motherboard in the edge region, and the insertion and removal directions and insertion and removal ports of the connectors are located outside the envelope of the local anti-radiation shielding shell.

[0018] As a further explanation of the present invention, preferably, the local radiation-resistant shielding housing is disposed on at least one of the upper and lower sides of the PCB motherboard.

[0019] As a further explanation of the present invention, preferably, the localized radiation-resistant shielding shell is an aluminum alloy shell;

[0020] The thickness of the local anti-radiation shielding shell is calculated based on the target orbital irradiation dose according to the wide beam radiation attenuation formula, and is used to reduce the irradiation dose at the silicon-based chip to below the design threshold.

[0021] The formula for wide-beam radiation attenuation is: ;

[0022] in, This represents the final irradiation dose at the location of the silicon-based chip after shielding attenuation.

[0023] The unattenuated incident radiation dose; It is a cumulative factor; It is a natural constant; This represents the linear attenuation coefficient of the aluminum alloy for the corresponding energy radiating particles. This refers to the thickness of the localized radiation-resistant shielding shell.

[0024] As a further explanation of the present invention, preferably, the fastener is a screw;

[0025] The edge of the partial radiation shielding shell is integrally formed with a flange edge that fits the PCB motherboard. The flange edge has mounting holes, and the screw passes through the mounting holes to fix the partial radiation shielding shell onto the PCB motherboard.

[0026] As a further explanation of the present invention, preferably, the base of the partial radiation shielding shell is provided with a heat dissipation protrusion, the heat dissipation protrusion is integrally formed on the inner side of the base of the partial radiation shielding shell, and the heat dissipation protrusion is disposed opposite to the back of the silicon-based chip for conducting the heat generated by the silicon-based chip.

[0027] As a further explanation of the present invention, preferably, a thermally conductive medium layer is disposed between the heat dissipation protrusion and the silicon-based chip, and the heat dissipation protrusion is thermally coupled to the silicon-based chip through the thermally conductive medium layer;

[0028] The thermally conductive medium layer is either a thermally conductive pad or a thermally conductive insulating layer.

[0029] As a further explanation of the present invention, preferably, the connector insulator is made of polyphenylene sulfide material or alumina ceramic material;

[0030] The connector's contacts are copper alloy contacts with a gold plating thickness ≥2μm;

[0031] The connector's plug and socket are sealed with a metal-ceramic brazing structure, and the connector's outer shell is a stainless steel shielding layer used to attenuate incident gamma rays and secondary electrons.

[0032] As a further explanation of the present invention, preferably, the distance from any position in the central region to the edge of the PCB motherboard is ≥20mm.

[0033] Furthermore, to achieve the above objectives, this invention also proposes a design method for a radiation-resistant and lightweight silicon-based chip structure based on local protection, the method comprising:

[0034] Centralized layout steps: Silicon-based chips are centrally arranged in the central area of ​​the PCB motherboard to form a chip mounting area, and connectors and passive devices are arranged in the edge area of ​​the PCB motherboard; wherein, the silicon-based chips are radiation-sensitive devices, and the connectors and passive devices are non-radiation-sensitive devices;

[0035] Steps for determining shielding parameters: Based on the target orbital irradiation dose, determine the material and thickness of the local radiation-resistant shielding shell according to the wide-beam radiation attenuation formula;

[0036] Shielding housing setup steps: Set the local radiation-resistant shielding housing as an independent metal housing that only covers the chip mounting area, and fix the local radiation-resistant shielding housing to the PCB motherboard with fasteners, so that the connectors and passive devices in the edge area are exposed outside the local radiation-resistant shielding housing.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] 1. Achieve lightweight design: Only the central area where the silicon-based chip is located is partially shielded, and non-radiation-sensitive devices in the edge area are no longer redundantly protected. The amount of shielding material used is greatly reduced, and the overall structural weight is significantly reduced, which meets the strict weight reduction requirements of satellites.

[0039] 2. Precise and reliable radiation protection: The silicon-based chips are centrally located on the circuit board, relying on the surrounding structure to achieve natural radiation attenuation in the radiation area, while keeping them away from secondary radiation generated by the connector; the thickness of the shielding shell is quantitatively calculated based on orbital radiation, precisely controlling the radiation dose at the chip. The connector itself adopts a radiation-resistant structure, further improving the on-orbit stability of edge components.

[0040] 3. Convenient assembly and maintenance: The edge connector is not obstructed by the shielding housing, and the cable can be directly plugged in and unplugged. There is no need to disassemble the shielding housing during later debugging and maintenance. The shielding housing is assembled using flange screws, making disassembly and assembly simple.

[0041] 4. Excellent heat dissipation performance: The shielding shell only covers the center of the circuit board, and most of the board surface directly exchanges heat with the cabin environment. The heat of the silicon-based chip is conducted to the shielding shell through the heat dissipation protrusion, avoiding the problem of heat accumulation in the overall sealed shell. The heat dissipation efficiency is improved by 5% compared with the traditional structure under full load conditions. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is one of the structural schematic diagrams of a silicon-based chip radiation-resistant lightweight structure based on local protection provided in the embodiments of the present invention;

[0044] Figure 2This is the second schematic diagram of the radiation-resistant and lightweight silicon-based chip structure based on local protection provided in the embodiments of the present invention;

[0045] Figure 3 This is one of the structural schematic diagrams of the heat dissipation boss of the silicon-based chip radiation-resistant lightweight structure based on local protection provided in the embodiments of the present invention;

[0046] Figure 4 This is one of the flowcharts of the design method for a radiation-resistant lightweight silicon-based chip structure based on local protection provided in the embodiments of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Please see Figures 1 to 3 , Figure 1 This is one of the structural schematic diagrams of the radiation-resistant and lightweight silicon-based chip structure based on local protection provided in the embodiments of the present invention, and it is a three-dimensional view; Figure 2 This is the second schematic diagram of the radiation-resistant and lightweight silicon-based chip structure based on local protection provided in this embodiment of the invention, which is a top view; Figure 3 This is one of the structural schematic diagrams of the heat dissipation boss of the silicon-based chip radiation-resistant lightweight structure based on local protection provided in the embodiments of the present invention.

[0049] Yes, it is understandable. Non-radiation-sensitive devices refer to components that will not experience functional failure due to high-energy protons, electrons, or heavy ions under the radiation environment of the target orbit. These mainly include connectors and various passive devices. The silicon-based chip in this application is a radiation-sensitive device, which is prone to total dose effect and single-event effect.

[0050] In this invention, a partitioned layout is adopted, which protects only the radiation-sensitive silicon-based chips on the PCB motherboard, while not providing additional shielding protection for non-radiation-sensitive devices such as connectors and passive components on the PCB motherboard, thus achieving a lightweight design of "key protection and non-sensitive exemption".

[0051] like Figure 1 As shown, the silicon-based chip radiation-resistant lightweight structure 100 based on local protection in this invention includes a PCB motherboard 1, a silicon-based chip (not shown in the figure), a non-radiation-sensitive device 3, and a local radiation-resistant shielding shell 4.

[0052] The PCB motherboard 1 is a rectangular board structure, having a central area (not shown in the figure) and edge areas (not shown in the figure) distributed around the central area. For example, the central area may occupy 49% of the total area of ​​the PCB motherboard 1. The central area has reserved chip mounting areas (not shown in the figure).

[0053] The silicon-based chips are centrally located within the chip mounting area of ​​the PCB motherboard 1.

[0054] The non-radiation-sensitive device 3 is located in the edge region, away from the central chip mounting area.

[0055] The localized radiation shielding housing 4 is configured as an independent metal housing that only covers the chip mounting area, and the localized radiation shielding housing 4 is fixed to the PCB motherboard 1 by fasteners 5. The projection of the envelope of the localized radiation shielding housing 4 onto the horizontal plane falls entirely within the central area of ​​the PCB motherboard 1, so that the non-radiation-sensitive devices 3 in the edge area are exposed outside the localized radiation shielding housing 4.

[0056] In this way, the present invention adopts a partitioned layout, setting up local radiation-resistant shielding shells only for radiation-sensitive silicon-based chips on the PCB motherboard for shielding protection, while not providing additional shielding protection for non-radiation-sensitive devices such as connectors and passive components on the PCB motherboard. This achieves a lightweight design of "key protection and non-sensitive exemption", reducing the overall structural weight while ensuring that the radiation resistance index remains unchanged.

[0057] like Figure 2 As shown, the non-radiation sensitive device 3 in this invention includes a connector 31 and a passive device (not shown in the figure).

[0058] The connectors 31 are distributed along the outline of the PCB motherboard 1 in the edge region, and the insertion and removal directions and ports of the connectors 31 are located outside the envelope of the local radiation shielding housing 4. Passive devices are also arranged in the edge region and are not blocked by the local radiation shielding housing.

[0059] With the above arrangement, non-radiation sensitive devices such as connector 31 and passive devices do not require additional shielding protection, and connector insertion and removal are not restricted. This avoids the design of traditional fully enclosed housing solutions that require opening connector through holes in the housing and additional radiation sealing, and significantly reduces structural weight while ensuring radiation resistance performance.

[0060] In this embodiment, the projection of the envelope of the localized radiation-resistant shielding shell 4 onto the horizontal plane falls entirely within the central region of the PCB motherboard 1. This ensures that the localized radiation-resistant shielding shell 4 can completely shield and protect the silicon-based chip located within the central region, shielding only the core sensitive area rather than the entire PCB motherboard, thereby exposing the non-radiation-sensitive devices 3 in the edge regions to the outside of the localized radiation-resistant shielding shell 4.

[0061] In this embodiment, the positional relationship between the localized radiation shielding shell 4 and the PCB motherboard 1 can be that the localized radiation shielding shell 4 is disposed on the upper side of the PCB motherboard 1, or on the lower side of the PCB motherboard 1, or both the upper and lower sides of the PCB motherboard 1 can be disposed simultaneously. The specific placement is based on the relative relationship between the silicon-based chip and the PCB motherboard 1. If the silicon-based chip is disposed on the upper side of the PCB motherboard 1, then the localized radiation shielding shell 4, which only covers the silicon-based chip, is disposed on the upper side of the PCB motherboard 1; if the silicon-based chip is disposed on the lower side of the PCB motherboard 1, then the localized radiation shielding shell 4, which only covers the silicon-based chip, is disposed on the lower side of the PCB motherboard 1. The specific placement is not limited in this embodiment.

[0062] In this embodiment, all silicon-based chips are concentrated in the central area of ​​the PCB motherboard, which has significant advantages compared to arranging them in other areas:

[0063] When radiation particles (gamma rays, neutrons, high-energy protons) are incident from the outside, they must pass through multiple layers of material, including the device casing and PCB edges, to reach the central region. The longer the path, the higher the probability of the particles being scattered or absorbed. According to the shielding attenuation formula... The central region has an equivalent metal shielding path that is approximately 2–3 mm longer than the peripheral region, which can reduce the gamma-ray and neutron doses reaching the chip by 30%–60%, and significantly decrease the single-event upset rate. It should be noted that the shielding attenuation formula... Since this is existing technology, it will not be described in detail here.

[0064] If silicon-based chips are placed in the edge region, radiation particles can directly enter the environment simply by passing through the outer casing, without any additional shielding path, and the dose rate is 2 to 3 times that of the central region.

[0065] In this embodiment, any position in the central region is ≥20mm from the edge of the PCB motherboard 1, which is used to extend the equivalent shielding path of the radiating particles and move them away from the secondary radiation source generated by the connector 31 located in the edge region.

[0066] Because connectors, plugs, and other non-radiation-sensitive devices generate secondary electrons and scattered neutrons when bombarded by high-energy particles, these secondary particles pose a far greater threat to silicon-based chips in terms of single-event effects (SEU / SEL) than the primary radiation. In this embodiment, the lateral distance from any position in the central region to the edge of the PCB motherboard 1 is ≥20mm, significantly reducing the range coverage of secondary particles and avoiding the risk of localized high dose rates and single-event latch-up (SEL) caused by "close-range bombardment."

[0067] With silicon-based chips concentrated in the center, the wiring lengths of the edge connectors are more uniform and shorter. The wiring length in the central area is 30% to 50% shorter than that in the edge area, and the signal transmission delay variation rate is reduced by more than 40%, effectively reducing timing errors and data transmission errors caused by irradiation.

[0068] In this embodiment, the localized radiation-resistant shielding shell 4 is an aluminum alloy shell; the thickness of the localized radiation-resistant shielding shell 4 can be determined according to the target orbital radiation dose, based on the wide-beam radiation attenuation formula. The calculations show that the irradiation dose at the silicon-based chip is reduced to below the design threshold.

[0069] Understandably, the design threshold refers to the maximum total ionization dose that a silicon-based chip can withstand during the satellite's design lifespan, and is usually provided by the chip manufacturer or determined through irradiation tests.

[0070] The wide beam radiation attenuation formula middle:

[0071] This represents the final irradiation dose at the location of the silicon-based chip after shielding attenuation.

[0072] Outside the shielding shell, the target orbit represents the unattenuated incident radiation dose;

[0073] This is a cumulative factor used to correct for the dose enhancement effect caused by radiation scattering, secondary particles, and oblique particle incidence. Its value is generally 1.1-1.35 under aluminum alloy shielding structures.

[0074] It is a natural constant;

[0075] The linear attenuation coefficient of the aluminum alloy for corresponding energy radiating particles, in cm. -1 ;

[0076] This refers to the thickness of the localized radiation-resistant shielding shell.

[0077] The space environment is characterized by wide-beam radiation. High-energy particles colliding with aluminum alloy materials produce secondary electrons and scattered neutrons. Furthermore, the radiation is not incident perpendicularly; therefore, if a shielding attenuation formula is used… Calculations can lead to biases, so a cumulative factor is introduced. After engineering modifications, the wide-beam radiation attenuation formula used in this embodiment is obtained.

[0078] When designing the localized radiation-resistant shielding housing 4, the maximum radiation threshold that the silicon-based chip can withstand is taken as... The required thickness of the local radiation-resistant shielding shell is calculated by reverse engineering. .

[0079] Compared to the traditional fully enclosed aluminum shell solution, the centralized shielding solution in this embodiment can reduce the amount of shielding material used by 50.8%, while avoiding assembly errors and weight redundancy problems caused by dispersed shielding; moreover, the thermal management of centralized shielding is easier to control, and local overheating will not occur due to dispersed shielding layers.

[0080] In this embodiment, in order to fix the local radiation shielding shell 4 to the PCB motherboard 1, the edge of the local radiation shielding shell 4 is integrally formed with a flange edge (not shown in the figure) that fits the PCB motherboard 1. The flange edge is provided with a mounting hole (not shown in the figure). The fastener 5 is a screw. The screw is passed through the mounting hole, so that the local radiation shielding shell 4 can be fixed to the PCB motherboard 1.

[0081] In some optional embodiments, an insulating gasket (not shown in the figure) may also be provided between the flange edge and the PCB motherboard 1 to avoid short circuit between the local radiation shielding housing 4 and the circuit on the PCB motherboard 1.

[0082] This screw-fixing method makes the installation and removal of the localized radiation-resistant shielding housing 4 convenient, facilitating the repair and replacement of silicon-based chips on the PCB motherboard 1. Simultaneously, the one-piece molded flange structure ensures a tight fit between the localized radiation-resistant shielding housing 4 and the PCB motherboard 1, preventing radiation leakage caused by shielding gaps.

[0083] like Figure 3 As shown, in order to enhance heat dissipation performance, the silicon-based chip radiation-resistant lightweight structure 100 based on local protection in this invention also includes a heat dissipation boss 6. The heat dissipation boss 6 is disposed on the base 7 of the local radiation-resistant shielding shell 4. The base 7 is provided with screw holes 8 that cooperate with the fastener 5, so that the local radiation-resistant shielding shell 4 fixed on the PCB motherboard 1 can also be fixed on the base 7.

[0084] The heat dissipation protrusion 6 is integrally formed inside the base 7 of the local anti-radiation shielding shell 4, and the heat dissipation protrusion 6 is disposed opposite to the back of the silicon-based chip to conduct heat generated by the silicon-based chip.

[0085] A thermally conductive medium layer (not shown in the figure) is disposed between the heat dissipation protrusion 6 and the silicon-based chip. The heat dissipation protrusion 6 is thermally coupled to the silicon-based chip through the thermally conductive medium layer to conduct heat generated by the silicon-based chip. The thermally conductive medium layer can be a thermally conductive insulating layer or a thermally conductive pad. For example, a 1mm thermally conductive pad is disposed between the heat dissipation protrusion 6 and the silicon-based chip to conduct heat generated by the silicon-based chip.

[0086] The heat dissipation efficiency of this solution can be improved by about 5% compared to the traditional fully enclosed housing solution. At the same time, the setting of the heat dissipation protrusion 6 effectively avoids the formation of a thermal barrier by the local radiation-resistant shielding housing 4, ensuring the thermal reliability of the silicon-based chip under high power operation.

[0087] In this embodiment, the insulator of the connector 31 is made of polyphenylene sulfide (PPS) material, whose rigid benzene ring-sulfur bond structure has a natural resistance to ionization degradation by gamma rays, and a total dose tolerance of ≥10. 6 rad(Si).

[0088] In some alternative embodiments, the insulator of connector 31 may also be made of alumina ceramic material. (In 1×10...) 4 Gy γ irradiation and 1×10 14 At a neutron flux of n / cm², the insulation resistance remains ≥10. 12 Ω, with no significant degradation in dielectric properties.

[0089] The contacts of the connector 31 are made of copper alloy with a gold plating layer, the plating thickness is ≥2μm, and after irradiation with a total dose of 100kGy, the contact resistance change rate is ≤5%, with no oxidation or migration.

[0090] The connector 31 has a metal-ceramic brazing sealing structure between the plug (not shown) and the socket (not shown), with no organic adhesive at the interface. Under irradiation-temperature cycling (-55℃ to 125℃) coupling environment, the sealing and insulation performance do not degrade.

[0091] The connector 31 has a stainless steel shielding layer that can attenuate ≥30% of incident gamma rays and secondary electrons, thereby reducing the radiation dose to the internal insulation and contacts. The thermal expansion coefficients of the conductor and ceramic insulator are matched (CTE difference ≤3ppm / ℃), suppressing radiation-induced interface stress cracks and improving long-term reliability by ≥5 times.

[0092] The working principle of this invention is as follows:

[0093] This invention categorizes components into radiation-sensitive silicon-based chips and non-radiation-sensitive components consisting of connectors and passive devices. All silicon-based chips are centrally located in the center of the PCB motherboard, while connectors and passive devices are positioned around the perimeter of the circuit board.

[0094] When radiation particles in space are incident on the central region, they first have to pass through the equipment casing, PCB motherboard, and non-radiation sensitive edge devices, resulting in a longer equivalent shielding path and a natural attenuation of radiation dose of 30% to 60%. At the same time, the silicon-based chip is at least 20mm away from the edge connector, avoiding the secondary electrons and scattered neutrons generated after the metal connector is bombarded by radiation, reducing the probability of single-event latch-up and single-event flip.

[0095] An aluminum alloy localized radiation-resistant shielding shell is installed only in the central chip mounting area. The attenuation effect of the shell material reduces the flux of high-energy particles reaching the silicon-based chip, meeting radiation resistance requirements. The thickness of the shielding shell is precisely calculated based on the orbital radiation dose using a wide-beam radiation attenuation formula, accurately controlling the radiation dose at the chip location within the device's tolerance threshold. The shielding shell is secured with flange screws, and a heat dissipation protrusion on the bottom of the shell fits against the chip, effectively dissipating operating heat. The edge connectors are entirely outside the shielding shell, eliminating the need to disassemble the shielding structure when plugging or unplugging cables.

[0096] Non-radiation-sensitive devices in the edge areas are directly exposed to the radiation environment, eliminating the need for additional shielding structures and redundant shielding materials. This also ensures the pluggability of connectors and addresses heat dissipation issues. Compared to traditional fully enclosed shell structures, the overall weight is reduced by 30.9%, the amount of shielding material used is reduced by 50.8%, and the overall heat dissipation efficiency is improved by 5%, meeting the requirements for lightweight and highly reliable assembly of satellite payloads.

[0097] In this embodiment of the invention, a partitioned layout is adopted, with local shielding only for radiation-sensitive silicon-based chips and no protection for non-radiation-sensitive devices. While ensuring that the radiation resistance index remains unchanged, the overall structural weight is reduced, and the connector insertion and removal are not restricted. This solves the technical problems of existing fully enclosed radiation resistance solutions, such as large weight, serious redundant protection, and inconvenient connector disassembly and assembly.

[0098] In addition, Figures 1 to 3 Based on the proposed radiation-resistant and lightweight silicon-based chip structure with localized protection, this invention also proposes a design method for such a structure. Please refer to [link to relevant documentation]. Figure 4 , Figure 4 This is one of the flowcharts illustrating the design steps of a radiation-resistant lightweight silicon-based chip structure based on localized protection, as provided in this embodiment of the invention. For example... Figure 4 As shown, the method includes:

[0099] Step S1: The silicon-based chips are concentrated in the central area of ​​the PCB motherboard to form a chip mounting area, and the connectors and passive devices are arranged in the edge area of ​​the PCB motherboard; wherein, the silicon-based chips are radiation-sensitive devices, and the connectors and passive devices are non-radiation-sensitive devices.

[0100] Yes, it is understandable. Non-radiation-sensitive devices refer to components that will not experience functional failure due to high-energy protons, electrons, or heavy ions under the radiation environment of the target orbit. These mainly include connectors and various passive devices. The silicon-based chip in this application is a radiation-sensitive device, which is prone to total dose effect and single-event effect.

[0101] In this invention, a partitioned layout is adopted, which protects only the radiation-sensitive silicon-based chips on the PCB motherboard, while not providing additional shielding protection for non-radiation-sensitive devices such as connectors and passive components on the PCB motherboard, thus achieving a lightweight design of "key protection and non-sensitive exemption".

[0102] In this embodiment, the PCB motherboard has a rectangular board structure with a central region and peripheral regions surrounding the central region. A chip mounting area is reserved in the central region. The silicon-based chips are centrally located within the chip mounting area of ​​the PCB motherboard. Connectors and passive devices are located in the peripheral regions, away from the central chip mounting area.

[0103] Step S2: Based on the target orbital irradiation dose, determine the material and thickness of the local radiation-resistant shielding shell according to the wide-beam radiation attenuation formula.

[0104] In this embodiment, the wide-beam radiation attenuation formula is: .

[0105] in, This represents the final irradiation dose at the location of the silicon-based chip after shielding attenuation.

[0106] The unattenuated incident radiation dose; It is a cumulative factor; It is a natural constant; This represents the linear attenuation coefficient of the aluminum alloy for the corresponding energy radiating particles. This refers to the thickness of the localized radiation-resistant shielding shell.

[0107] Step S3: Set the local radiation shielding housing as an independent metal housing that only covers the chip mounting area, and fix the local radiation shielding housing to the PCB motherboard with fasteners, so that the connector and the passive device in the edge area are exposed outside the local radiation shielding housing.

[0108] In this way, the present invention adopts a partitioned layout, setting up local radiation-resistant shielding shells only for radiation-sensitive silicon-based chips on the PCB motherboard for shielding protection, while not providing additional shielding protection for non-radiation-sensitive devices such as connectors and passive components on the PCB motherboard. This achieves a lightweight design of "key protection and non-sensitive exemption", reducing the overall structural weight while ensuring that the radiation resistance index remains unchanged.

[0109] Compared with the prior art, the present invention has the following advantages:

[0110] 1. Achieve lightweight design: Only the central area where the silicon-based chip is located is partially shielded, and non-radiation-sensitive devices in the edge area are no longer redundantly protected. The amount of shielding material used is greatly reduced, and the overall structural weight is significantly reduced, which meets the strict weight reduction requirements of satellites.

[0111] 2. Precise and reliable radiation protection: The silicon-based chips are centrally located on the circuit board, relying on the surrounding structure to achieve natural radiation attenuation in the radiation area, while keeping them away from secondary radiation generated by the connector; the thickness of the shielding shell is quantitatively calculated based on orbital radiation, precisely controlling the radiation dose at the chip. The connector itself adopts a radiation-resistant structure, further improving the on-orbit stability of edge components.

[0112] 3. Convenient assembly and maintenance: The edge connector is not obstructed by the shielding housing, and the cable can be directly plugged in and unplugged. There is no need to disassemble the shielding housing during later debugging and maintenance. The shielding housing is assembled using flange screws, making disassembly and assembly simple.

[0113] 4. Excellent heat dissipation performance: The shielding shell only covers the center of the circuit board, and most of the board surface directly exchanges heat with the cabin environment. The heat of the silicon-based chip is conducted to the shielding shell through the heat dissipation protrusion, avoiding the problem of heat accumulation in the overall sealed shell. The heat dissipation efficiency is improved by 5% compared with the traditional structure under full load conditions.

[0114] Please note to all technical personnel: Although the present invention has been described according to the specific embodiments above, the inventive concept of the present invention is not limited to this invention. Any modifications that utilize the inventive concept will be included within the scope of protection of this patent.

[0115] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A radiation-resistant and lightweight silicon-based chip structure based on localized protection, characterized in that, include: PCB motherboard, silicon-based chip, non-radiation-sensitive device, and localized radiation-resistant shielding housing; The PCB motherboard has a central region and an edge region distributed around the central region; The silicon-based chips are centrally arranged in the central area to form a chip mounting area; The non-radiation-sensitive device is disposed in the edge region; The partial radiation shielding housing is configured as an independent metal housing that only covers the chip mounting area, and the partial radiation shielding housing is fixed to the PCB motherboard by fasteners. The projection of the envelope of the localized radiation shielding shell onto the horizontal plane falls entirely within the central region of the PCB motherboard, so that non-radiation-sensitive devices in the edge region are exposed outside the localized radiation shielding shell.

2. The silicon-based chip radiation-resistant lightweight structure based on localized protection according to claim 1, characterized in that, The non-radiation-sensitive device includes connectors and passive devices; The connectors are distributed along the outline of the PCB motherboard in the edge region, and the insertion and removal directions and insertion and removal ports of the connectors are located outside the envelope of the local radiation shielding shell.

3. The silicon-based chip radiation-resistant lightweight structure based on localized protection according to claim 1, characterized in that, The localized radiation shielding housing is disposed on at least one of the upper and lower sides of the PCB motherboard.

4. The silicon-based chip radiation-resistant lightweight structure based on localized protection according to claim 1, characterized in that, The localized radiation-resistant shielding shell is an aluminum alloy shell; The thickness of the local anti-radiation shielding shell is calculated based on the target orbital irradiation dose according to the wide beam radiation attenuation formula, and is used to reduce the irradiation dose at the silicon-based chip to below the design threshold. The formula for wide-beam radiation attenuation is: ; in, This represents the final irradiation dose at the location of the silicon-based chip after shielding attenuation. The unattenuated incident radiation dose; It is a cumulative factor; It is a natural constant; This is the linear attenuation coefficient of the aluminum alloy for the corresponding energy radiation particles; This refers to the thickness of the localized radiation-resistant shielding shell.

5. The silicon-based chip radiation-resistant lightweight structure based on localized protection according to claim 1, characterized in that, The fastener is a screw; The edge of the partial radiation shielding shell is integrally formed with a flange edge that fits the PCB motherboard. The flange edge has mounting holes, and the screw passes through the mounting holes to fix the partial radiation shielding shell onto the PCB motherboard.

6. The radiation-resistant and lightweight silicon-based chip structure based on localized protection according to claim 1, characterized in that, The base of the partial radiation shielding shell is provided with a heat dissipation protrusion. The heat dissipation protrusion is integrally formed on the inner side of the base of the partial radiation shielding shell and is disposed opposite to the back of the silicon-based chip to conduct heat generated by the silicon-based chip.

7. The silicon-based chip radiation-resistant lightweight structure based on localized protection according to claim 6, characterized in that, A thermally conductive medium layer is disposed between the heat dissipation protrusion and the silicon-based chip, and the heat dissipation protrusion is thermally coupled to the silicon-based chip through the thermally conductive medium layer; The thermally conductive medium layer is either a thermally conductive pad or a thermally conductive insulating layer.

8. The silicon-based chip radiation-resistant lightweight structure based on localized protection according to claim 2, characterized in that, The connector insulator is made of polyphenylene sulfide or alumina ceramic material; The connector's contacts are copper alloy contacts with a gold plating thickness ≥2μm; The connector's plug and socket are sealed with a metal-ceramic brazing structure, and the connector's outer shell is a stainless steel shielding layer used to attenuate incident gamma rays and secondary electrons.

9. The radiation-resistant and lightweight silicon-based chip structure based on localized protection according to claim 1, characterized in that, The distance from any position in the central region to the edge of the PCB motherboard is ≥20mm.

10. A design method for a radiation-resistant lightweight silicon-based chip structure based on local protection, applied to the radiation-resistant lightweight silicon-based chip structure based on local protection as described in any one of claims 1 to 9, characterized in that, The method includes: Centralized layout steps: Silicon-based chips are centrally arranged in the central area of ​​the PCB motherboard to form a chip mounting area, and connectors and passive devices are arranged in the edge area of ​​the PCB motherboard; wherein, the silicon-based chips are radiation-sensitive devices, and the connectors and passive devices are non-radiation-sensitive devices; Steps for determining shielding parameters: Based on the target orbital irradiation dose, determine the material and thickness of the local radiation-resistant shielding shell according to the wide-beam radiation attenuation formula; Shielding housing setup steps: Set the local radiation-resistant shielding housing as an independent metal housing that only covers the chip mounting area, and fix the local radiation-resistant shielding housing to the PCB motherboard with fasteners, so that the connectors and passive devices in the edge area are exposed outside the local radiation-resistant shielding housing.

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