A method for manufacturing a ceramic composite silicon-based circulator and its application

Abstract

The present invention relates to the field of circulator technology, in particular to the field of IPC H04B, and more specifically to a method for manufacturing a ceramic composite silicon-based circulator and its application. The present invention obtains a ceramic composite silicon-based circulator by cutting through eight steps: deep silicon etching through holes, making ferrite discs, preparing composite substrates, making dielectric bridges, photolithography patterns, vacuum coating, photoresist stripping, and scribing and slicing. The present invention adopts a silicon wafer commonly used in semiconductor technology, embeds a ferrite ceramic disc in the middle of each silicon wafer through hole, connects them into a completed circuit substrate substrate through a specific adhesive material, and then manufactures a microstrip circulator through a semiconductor thin film process. Dielectric bridge metallization technology is used at the connection between the two materials to ensure the continuity and reliability of the circuit connection. The circulator has a wide operating frequency band, high power resistance, good consistency, easy integration, and low cost. It is very suitable for use in isolators, duplexers, reflection amplifiers and other fields.

Description

Technical Field

[0001] The present invention relates to the field of circulator technology, in particular to the field of IPC H04B, and more specifically to a method for manufacturing a ceramic composite silicon-based circulator and applications thereof. Background Art

[0002] Traditional all-ferrite microstrip circulators are made by thin-film processing on all-ferrite materials. Due to material limitations, the operating frequency band of the microstrip circulator cannot be very wide, the power resistance is poor, and the consistency is not very good. In addition, the substrate material is generally 2 to 4 inches, and the production cost using semiconductor thin-film technology is relatively high.

[0003] In the prior art, patent document CN111403884A discloses a method for manufacturing a chip circulator. By injection molding metal, the chip circulator prepared has high manufacturing efficiency and assembly accuracy, but it does not significantly improve the width of the circulator's operating frequency band and power resistance.

[0004] The patent document with application publication number CN102629705A discloses a C-band high-power circulator and its manufacturing process. The process can increase the operating temperature range, improve temperature performance, and has low cost, but it does not significantly improve the width of the circulator's operating frequency band and power resistance. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method for manufacturing a ceramic composite silicon-based circulator in the first aspect. The method flow chart is as follows: Figure 1 As shown, the following steps are included:

[0006] S1. Deep silicon etching through hole: multiple circular through holes are etched on the silicon wafer by deep silicon etching;

[0007] S2. Making ferrite discs: Grinding the ferrite rod to the diameter of the circular through hole, cutting out a number of circular slices and then grinding and polishing them to make ferrite discs;

[0008] S3. Preparation of composite substrate: ferrite discs are embedded in the through holes respectively, and the ferrite discs are embedded in the silicon wafer using adhesive material. The bonded silicon wafer and ferrite discs are then placed in a fixture and sintered at high temperature to obtain the composite substrate;

[0009] S4, dielectric bridge fabrication: spin-coating a polyimide coating on the composite substrate, and then fabricating a polyimide dielectric bridge using a photolithography / etching process;

[0010] S5. Photolithography pattern: Use photolithography to make circuit patterns on the surface of the polyimide dielectric bridge;

[0011] S6, vacuum coating: using magnetron sputtering process, coating on the side with polyimide dielectric bridge;

[0012] S7, photoresist stripping: using lift-off process to strip the photoresist;

[0013] S8. Slicing and cutting: Use a high-precision dicing machine to cut the prepared composite substrate circuit into several independent unit devices.

[0014] There is no specific limitation on the deep silicon etching process described in step S1 of the present application.

[0015] In some preferred schemes, the specific process of deep silicon etching in step S1 is: placing the silicon wafer into the etcher chamber, the working chamber pressure is 0.1-0.5Pa, SF6 gas is introduced, the SF6 gas flow rate is 50-80sccm, the protective gas O2 flow rate is 5-15sccm, the upper electrode power is 400-600W, the lower electrode power is 20-40W, each etching is 8-12min, and three cycles are performed to obtain the result.

[0016] In some preferred embodiments, the silicon wafer is purchased from ultra-thin polished silicon wafers produced by China Silicon Semiconductor Co., Ltd.

[0017] Preferably, the through hole has a diameter of 2-5 mm.

[0018] Preferably, the ferrite rod is one or more of magnesium-manganese ferrite rod, garnet ferrite rod, and nickel-zinc ferrite rod; more preferably, it is garnet ferrite rod.

[0019] In some preferred embodiments, the garnet ferrite rods are purchased from Nanjing Bio Electronics.

[0020] Preferably, the thickness of the ferrite sheet is the same as the thickness of the silicon sheet.

[0021] Preferably, the diameter tolerance of the ferrite rod is controlled within ±5 μm of the grinding hole diameter; and the thickness tolerance is controlled within ±2 μm of the target thickness.

[0022] The applicant has found that by embedding specific garnet ferrite discs in silicon wafers, the width of the operating frequency band of the manufactured microstrip circulator can be increased while also improving its power resistance and consistency. This may be due to the synergistic effect between the silicon wafer and the garnet ferrite disc. The composite substrate formed by their combination can, on the one hand, make up for the narrower operating frequency band of the all-ferrite microstrip circulator due to material limitations, and on the other hand, it can also meet the integrity of the circuit substrate substrate, saving the amount of ferrite and reducing the preparation cost of the circulator. However, in order to ensure that the ferrite and silicon wafers are tightly bonded, ordinary glue either has poor temperature resistance and is prone to voids during the substrate sintering preparation process, affecting the consistency of the substrate, or the bonding strength is insufficient and the ferrite and silicon wafer cannot be tightly bonded.

[0023] Preferably, the adhesive material is one or more of wood adhesive material, stone adhesive material, wallpaper adhesive, and glass adhesive; more preferably, it is glass adhesive.

[0024] Preferably, the glass glue is any one of modified silicone glue and polyurethane glue; more preferably, it is modified silicone glue.

[0025] Preferably, the modified silicone adhesive is prepared by mixing silicone adhesive and silicone oil uniformly, adding filler and continuing to mix uniformly, then adding silane coupling agent and continuing to mix for 20-40 minutes to obtain the modified silicone adhesive.

[0026] Preferably, the shear strength of the silicone adhesive is 1.0-2.0 MPa, and the tensile strength is 0.5-1.5 MPa; further preferably, the shear strength of the silicone adhesive is 1.4 MPa, and the tensile strength is 1.2 MPa.

[0027] In some preferred embodiments, the silicone adhesive is purchased from silicone adhesive SY-428 produced by Dongguan Shin-Etsu Electronic Materials Co., Ltd.

[0028] Preferably, the silicone oil is selected from one or more of vinyl silicone oil, polymethylhydrogensiloxane, methyl-terminated silicone oil, and methyl silicone oil; more preferably, it is methyl silicone oil.

[0029] Preferably, the kinematic viscosity of the methyl silicone oil at 25°C is 5-15 mm 2 / s, and a flash point of 140-160°C; further preferably, the kinematic viscosity of the methyl silicone oil at 25°C is 10 mm 2 / s, flash point is 155℃.

[0030] In some preferred embodiments, the methyl silicone oil is purchased from methyl silicone oil 201-10 produced by Shandong Longhui Chemical Co., Ltd.

[0031] Preferably, the filler is one or more of calcium carbonate, barium sulfate, bentonite, silicon dioxide, titanium dioxide, talc, white carbon black, and aluminum oxide; more preferably, it is calcium carbonate.

[0032] Preferably, the calcium carbonate is one or more of activated calcium carbonate, nano calcium carbonate, activated nano calcium carbonate, heavy calcium carbonate, and light calcium carbonate; more preferably, it is activated nano calcium carbonate.

[0033] Preferably, the average particle size of the active nano-calcium carbonate is 10-100 nm, and the calcium carbonate content is ≥95 wt %; further preferably, the average particle size of the active nano-calcium carbonate is 50 nm, and the calcium carbonate content is ≥98.5 wt %.

[0034] The active nano-calcium carbonate was purchased from Shanghai Yuanjiang Chemical Co., Ltd.

[0035] Preferably, the silane coupling agent is one or more of vinyltrichlorosilane, 3-aminopropyltriethoxysilane, γ-glycidylpropyl-trimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, bis(3-trimethoxysilylpropyl)amine, N-(2-N-benzylaminoethyl)-3-aminopropyltrimethoxysilane, anilinemethyltriethoxysilane, and 3-(methacryloyloxy)propyltrimethoxysilane; further preferably, 3-aminopropyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane.

[0036] Preferably, the weight ratio of the 3-aminopropyltriethoxysilane to the 3-(methacryloyloxy)propyltrimethoxysilane is (1-2):(1-2); more preferably, it is 1:1.

[0037] Preferably, the weight ratio of the silicone adhesive to the silicone oil is (2-4):1; more preferably, it is 3:1.

[0038] Preferably, the weight ratio of the silicone adhesive to the filler is 1:(1-2); more preferably, it is 2:3.

[0039] Preferably, the weight of the silane coupling agent accounts for 0.5-2% of the total weight of the modified silicone adhesive; more preferably, it is 1%.

[0040] The applicant unexpectedly discovered that by selecting a specific silicone adhesive as the bonding material and modifying this silicone adhesive, it is possible to firmly bond the silicon wafer and ferrite while being less likely to develop holes or ferrite detachment during the subsequent sintering process, thereby improving the integrity of the composite substrate. This may be because although silicone adhesive has good high-temperature resistance, its bonding strength and tensile strength are still insufficient for application in this system. Ordinary silicone adhesives are prone to forming holes between the ferrite and the silicon wafer at high temperatures. The applicant unexpectedly discovered that by modifying the silicone adhesive, the addition of a silane coupling agent in a specific weight ratio improves the tensile properties of the silicone adhesive, and the two different silane coupling agents have a synergistic effect, which can improve the bonding strength of the modified silicone adhesive. The addition of specific fillers and methyl silicone oil can, on the one hand, weaken the intermolecular forces of polydimethylsiloxane in the silicone adhesive, thereby increasing the mobility of the polymer molecular chains, giving the modified silicone adhesive good elasticity and further improving its sealing effect. On the other hand, it can improve the tear resistance of the modified silicone adhesive, thereby improving the safety of the composite substrate.

[0041] Preferably, the high temperature sintering process in step S3 is: heating the bonded silicon wafer and ferrite material to 500-600° C. and sintering for 10-50 hours.

[0042] Further preferably, the high-temperature sintering process in step S3 is: heating the bonded silicon wafer and ferrite material to 100°C at 10°C / min, and keeping warm for 5 hours; heating to 200°C at 10°C / min, and keeping warm for 5 hours; heating to 300°C at 10°C / min, and keeping warm for 5 hours; heating to 400°C at 10°C / min, and keeping warm for 5 hours; heating to 500°C at 10°C / min, and keeping warm for 5 hours; heating to 600°C at 10°C / min, and keeping warm for 10 hours; cooling to room temperature with the furnace to obtain a composite substrate.

[0043] The applicant unexpectedly discovered that, during the preparation of a composite substrate, a specific sintering method can improve the integrity of the resulting composite substrate, thereby enhancing the consistency and frequency range of the subsequently fabricated circulator. This is likely due to the stepped, heat-insulating sintering method, which reduces the internal stress of polyimide dehydration polymerization, thereby preventing voids during the sintering process while maintaining the bond strength between the ferrite and silicon wafer. This also improves the composite substrate's environmental stability, such as acid and alkali resistance, thereby increasing the width and consistency of the resulting circulator's operating frequency band and enhancing its power handling capability.

[0044] Preferably, the spin coating process in step S4 is: a rotation speed of ≤5000 rad, and an acceleration of 5000 rad / min.

[0045] Preferably, the thickness of the polyimide coating is 5-15 μm; more preferably, it is 10 μm.

[0046] Preferably, the polyimide coating has a melting temperature of 300-400° C. and a tensile strength of 90-115 MPa; further preferably, the polyimide coating has a melting temperature of 352° C. and a tensile strength of 107 MPa.

[0047] In some preferred solutions, the polyimide coating is purchased from PI polyimide resin TP-2875 produced by DuPont.

[0048] In some preferred schemes, by selecting a specific polyimide coating and using a spin coating process and metal dielectric bridge technology, the gaps that may exist between the ferrite and the silicon wafer can be filled and the continuity of the circuit can be ensured, thereby compensating for the defects of incompleteness or holes in the composite substrate during the sintering process, thereby improving the integrity of the composite substrate, and further improving the operating frequency range and signal integrity of the prepared circulator, while reducing insertion loss and energy loss caused by signal transmission on different media.

[0049] There is no specific limitation on the photolithography / etching process described in step S4 of the present application.

[0050] In some preferred solutions, the specific steps of the photolithography / etching process in step S4 are:

[0051] The radio frequency power is set to 30-50W, the etching gas component is O2, the gas flow rate is 40-70sccm, the etching rate is 0.05-0.2μm / min, and the polyimide dielectric layer is etched until the composite substrate with a pattern shape is exposed.

[0052] There is no specific limitation on the photolithography process described in step S5 of this application.

[0053] In some preferred embodiments, the photolithography process in step S5 is as follows: coating the surface of the polyimide dielectric layer with photoresist and then exposing the layer to light, wherein the exposure time is 1-3 seconds and the development time is 50-70 seconds, and the pattern is engraved on the polyimide dielectric layer by photolithography.

[0054] The photoresist is not particularly limited.

[0055] In some preferred embodiments, the photoresist is purchased from RDN-2025P photoresist produced by Suzhou Yancai Micro-Nano Technology Co., Ltd.

[0056] Preferably, in step S6, the metal plating layers are chromium layer, copper layer and gold layer in order from the polyimide dielectric bridge layer upwards.

[0057] The thicknesses of the chromium layer, copper layer and gold layer are 80-100 nm, 2-4 μm and 0.5-1 μm respectively.

[0058] There is no specific limitation on the magnetron sputtering process described in step S6 of the present application.

[0059] In some preferred embodiments, the plating process of the chromium layer is as follows: chromium target, back vacuum 5×10 -3 Pa, pass argon until the vacuum is between 0.1-0.5 Pa, then apply a DC voltage of 500 V to start deposition, and the deposition time is 5 minutes.

[0060] The copper layer plating process is as follows: copper target, back vacuum 5×10 -3 Pa, argon gas was passed until the vacuum was between 0.1-0.5 Pa, and then a DC voltage of 500 V was applied to start deposition, and the deposition time was 100 min.

[0061] The plating process of the gold layer is as follows: gold target, back vacuum 5×10 -3 Pa, pass argon until the vacuum is between 0.1-0.5 Pa, then apply a DC voltage of 500 V to start deposition, and the deposition time is 20-30 minutes.

[0062] The lift-off process described in step S7 of the present application is not specifically limited.

[0063] In some preferred solutions, the lift-off process in step S7 is:

[0064] 1) After applying photoresist on the surface of the metal coating, it is exposed for 1-3 seconds and developed for 50-70 seconds. The pattern is transferred to the metal coating by photolithography.

[0065] 2) Remove the gold layer with etching solution;

[0066] 3) Set the etching gas to O2 and Ar, the oxygen flow rate to 40-60 sccm, the Ar flow rate to 1 sccm, the etching gas pressure to 1-3 Pa, the RF power to 40-60 W, the ICP power to 200-400 W, the etching time to 1-3 min, and remove the photoresist;

[0067] 4) using inductively coupled plasma etching, setting the etching gases to CH3F and Ar, a CH3F flow rate of 2-8 sccm, an Ar flow rate of 40-60 sccm, an etching gas pressure of 0.1-1.0 Pa, a radio frequency power of 200-300 W, an ICP power of 10-30 W, and an etching time of 2-10 min to remove the polyimide dielectric layer;

[0068] 5) Use a cleaning agent to remove the photoresist and the gold dielectric layer thereon.

[0069] The corrosive liquid and cleaning agent described in step S7 of the present application are not specifically limited.

[0070] In some preferred embodiments, the etching solution is prepared by mixing 115 g KI, 65 g I2, and 100 ml water.

[0071] In some preferred embodiments, the cleaning agent is NMP cleaning agent produced by Shanghai Ruiyi Trading Co., Ltd.

[0072] The second aspect of the present invention provides applications of the ceramic composite silicon-based circulator of the present invention, which can be applied to fields such as isolators, duplexers, and reflection amplifiers.

[0073] Beneficial effects:

[0074] 1. The present invention adopts a method of embedding a specific garnet ferrite disc in a silicon wafer, which can increase the width of the operating frequency band of the manufactured microstrip circulator while also improving its power resistance and consistency.

[0075] 2. The present invention selects a specific silicone adhesive as the bonding material and modifies the silicone adhesive. While being able to firmly bond the silicon wafer and the ferrite, it is still not easy to have holes or ferrite detachment during the subsequent sintering process, thereby improving the integrity of the composite substrate.

[0076] 3. This application uses a specific sintering method to improve the integrity of the prepared composite substrate, thereby improving the consistency and frequency range of the circulator prepared subsequently.

[0077] 4. This application improves the integrity of the composite substrate by selecting a specific polyimide coating and using a spin coating process and metal dielectric bridge technology, thereby improving the operating frequency range and signal integrity of the prepared circulator while reducing insertion loss and energy loss caused by signal transmission on different media.

[0078] 5. The present invention utilizes silicon wafers commonly used in semiconductor processes, embeds a ferrite ceramic disc in the middle of each silicon wafer through-hole, connects them to form a complete circuit substrate using a specific adhesive material, and then manufactures a microstrip circulator using a semiconductor thin film process. Dielectric bridge metallization technology is used at the junction of the two materials to ensure circuit connection continuity and reliability. The circulator has a wide operating frequency band, high power resistance, good consistency, easy integration, and low cost, making it very suitable for applications in isolators, duplexers, reflection amplifiers, and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 This is a flow chart of the method for manufacturing the ceramic composite silicon-based circulator described in this application;

[0080] Figure 2-Figure 7 4 is a process flow chart of a ceramic composite silicon-based circulator according to an embodiment of the present invention. DETAILED DESCRIPTION

[0081] Example

[0082] Example 1

[0083] Example 1 provides a method for manufacturing a ceramic composite silicon-based circulator, comprising the following steps:

[0084] S1, deep silicon etching through hole: through deep silicon etching, multiple circular through holes are etched on the silicon wafer ( Figure 2 );

[0085] S2. Making ferrite discs: Grind the ferrite rod to the diameter of the circular through hole, cut out several circular slices and then grind and polish them to make ferrite discs ( Figure 3 );

[0086] S3. Preparation of composite substrate: embed the ferrite discs into the through holes respectively, embed the ferrite discs into the silicon wafer with adhesive material, and then put the bonded silicon wafer and ferrite discs into the fixture, and sinter at high temperature to obtain the composite substrate ( Figure 4 );

[0087] S4, dielectric bridge fabrication: Spin-coat polyimide coating on the composite substrate, and then use photolithography / etching process to fabricate a polyimide dielectric bridge ( Figure 5 );

[0088] S5. Photolithography pattern: Use photolithography to make circuit patterns on the surface of the polyimide dielectric bridge;

[0089] S6, vacuum coating: using magnetron sputtering process, coating on the side with polyimide dielectric bridge;

[0090] S7, photoresist stripping: Use lift-off process to strip the photoresist ( Figure 6 );

[0091] S8, Slicing and Cutting: Use a high-precision dicing machine to cut the prepared composite substrate circuit into several independent unit devices. Figure 7 ).

[0092] The specific process of deep silicon etching in step S1 is as follows: placing the silicon wafer into the etcher chamber, the working chamber pressure is 0.2 Pa, introducing SF6 gas, the SF6 gas flow rate is 70 sccm, the protective gas O2 flow rate is 10 sccm, the upper electrode power is 500 W, the lower electrode power is 30 W, each etching is 10 minutes, and the cycle is repeated three times.

[0093] The silicon wafers were purchased from ultra-thin polished silicon wafers produced by China Silicon Semiconductor Co., Ltd.

[0094] The through hole has a diameter of 3 mm.

[0095] The ferrite rod is a garnet ferrite rod.

[0096] The garnet ferrite rods were purchased from Nanjing Bio Electronics.

[0097] The thickness of the ferrite sheet is the same as that of the silicon sheet.

[0098] The bonding material is glass glue.

[0099] The glass glue is modified silicone glue.

[0100] The preparation method of the modified silicone adhesive comprises the following steps: uniformly stirring silicone adhesive and silicone oil, adding filler and continuing to uniformly stir, then adding silane coupling agent and continuing to stir for 30 minutes to obtain the modified silicone adhesive.

[0101] The shear strength of the silicone adhesive is 1.4 MPa, and the tensile strength is 1.2 MPa.

[0102] The silicone adhesive was purchased from Dongguan Shin-Etsu Electronic Materials Co., Ltd. as silicone adhesive SY-428.

[0103] The silicone oil is methyl silicone oil.

[0104] The kinematic viscosity of the methyl silicone oil at 25°C is 10 mm 2 / s, flash point is 155℃.

[0105] The methyl silicone oil was purchased from methyl silicone oil 201-10 produced by Shandong Longhui Chemical Co., Ltd.

[0106] The filler is calcium carbonate.

[0107] The calcium carbonate is active nano calcium carbonate.

[0108] The average particle size of the active nano-calcium carbonate is 50 nm, and the calcium carbonate content is ≥98.5 wt %.

[0109] The active nano-calcium carbonate was purchased from Shanghai Yuanjiang Chemical Co., Ltd.

[0110] The silane coupling agents are 3-aminopropyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane.

[0111] The weight ratio of the 3-aminopropyltriethoxysilane to the 3-(methacryloyloxy)propyltrimethoxysilane is 1:1.

[0112] The weight ratio of the silicone glue to the silicone oil is 3:1.

[0113] The weight ratio of the silicone adhesive to the filler is 2:3.

[0114] The weight of the silane coupling agent accounts for 1% of the total weight of the modified silicone rubber.

[0115] The high-temperature sintering process described in step S3 is as follows: heating the bonded silicon wafer and ferrite material to 100°C at 10°C / min, and keeping warm for 5 hours; heating to 200°C at 10°C / min, and keeping warm for 5 hours; heating to 300°C at 10°C / min, and keeping warm for 5 hours; heating to 400°C at 10°C / min, and keeping warm for 5 hours; heating to 500°C at 10°C / min, and keeping warm for 5 hours; heating to 600°C at 10°C / min, and keeping warm for 10 hours; cooling to room temperature in the furnace to obtain a composite substrate.

[0116] The spin coating process in step S4 is as follows: the rotation speed is 5000 rad and the acceleration is 5000 rad / min.

[0117] The thickness of the polyimide coating is 10 μm.

[0118] The polyimide coating has a melting temperature of 352° C. and a tensile strength of 107 MPa.

[0119] The polyimide coating was purchased from PI polyimide resin TP-2875 produced by DuPont.

[0120] The specific steps of the photolithography / etching process in step S4 are:

[0121] The radio frequency power is set to 40 W, the component of the etching gas is O2, the gas flow rate is 60 sccm, and the etching rate is 0.1 μm / min. The polyimide dielectric layer is etched away until the composite substrate with a pattern shape is exposed.

[0122] The photolithography process in step S5 is as follows: a photoresist is coated on the surface of the polyimide dielectric layer and then exposed to light, with an exposure time of 2 seconds and a development time of 60 seconds, and a pattern is engraved on the polyimide dielectric layer by photolithography.

[0123] The photoresist was purchased from RDN-2025P photoresist produced by Suzhou Yancai Micro-Nano Technology Co., Ltd.

[0124] In step S6, the metal plating layers are sequentially formed from the polyimide dielectric bridge layer upwards into a chromium layer, a copper layer, and a gold layer.

[0125] The thicknesses of the chromium layer, copper layer and gold layer are 50 nm, 3 μm and 1 μm respectively.

[0126] The plating process of the chromium layer is as follows: chromium target, back vacuum 5×10-3 Pa, argon gas was introduced to the vacuum level of 0.3 Pa, and then a DC voltage of 500 V was applied to start deposition. The deposition time was 5 min.

[0127] The copper layer plating process is as follows: copper target, back vacuum 5×10 -3 Pa, argon gas was introduced to the vacuum level of 0.3 Pa, and then a DC voltage of 500 V was applied to start deposition. The deposition time was 100 min.

[0128] The plating process of the gold layer is as follows: gold target, back vacuum 5×10 -3 Pa, pass argon gas to the vacuum of 0.3 Pa, then add a DC voltage of 500 V to start deposition, and the deposition time is 20-30 minutes.

[0129] The lift-off process in step S7 is as follows:

[0130] 1) After applying photoresist on the surface of the metal coating, the exposure time is 2 seconds and the development time is 60 seconds. The pattern is transferred to the metal coating by photolithography.

[0131] 2) Remove the gold layer with etching solution;

[0132] 3) Set the etching gases to O2 and Ar, the oxygen flow rate to 50 sccm, the Ar flow rate to 1 sccm, the etching gas pressure to 2 Pa, the RF power to 50 W, the ICP power to 300 W, the etching time to 2 min, and remove the photoresist;

[0133] 4) Using inductively coupled plasma etching, setting the etching gases to CH3F and Ar, the CH3F flow rate to 4 sccm, the Ar flow rate to 50 sccm, the etching gas pressure to 0.5 Pa, the RF power to 250 W, the ICP power to 20 W, and the etching time to 5 min, to remove the polyimide dielectric layer;

[0134] 5) Use a cleaning agent to remove the photoresist and the gold dielectric layer thereon.

[0135] The preparation method of the etching solution is as follows: take 115g KI, 65g I2, and 100ml water and mix them evenly.

[0136] The cleaning agent is NMP cleaning agent produced by Shanghai Ruiyi Trading Co., Ltd.

[0137] The second aspect of the present invention provides an application of the ceramic composite silicon-based circulator of the present invention, which can be applied to an isolator.

[0138] Example 2

[0139] Example 2 provides a method for manufacturing a ceramic composite silicon-based circulator. The specific implementation method is the same as that of Example 1, except that:

[0140] The through hole has a diameter of 2 mm.

[0141] The weight ratio of the 3-aminopropyltriethoxysilane to the 3-(methacryloyloxy)propyltrimethoxysilane is 1:2.

[0142] The weight ratio of the silicone glue to the silicone oil is 2:1.

[0143] The weight ratio of the silicone adhesive to the filler is 1:1.

[0144] The weight of the silane coupling agent accounts for 0.5% of the total weight of the modified silicone rubber.

[0145] Example 3

[0146] Example 3 provides a method for manufacturing a ceramic composite silicon-based circulator. The specific implementation method is the same as that of Example 1, except that:

[0147] The through hole has a diameter of 5 mm.

[0148] The weight ratio of the 3-aminopropyltriethoxysilane to the 3-(methacryloyloxy)propyltrimethoxysilane is 2:1.

[0149] The weight ratio of the silicone glue to the silicone oil is 4:1.

[0150] The weight ratio of the silicone adhesive to the filler is 1:2.

[0151] The weight of the silane coupling agent accounts for 2% of the total weight of the modified silicone adhesive.

[0152] Comparative Example 1

[0153] Comparative Example 1 provides a high-precision beryllium copper wire and a preparation method thereof, and the specific implementation method is the same as Example 1. The difference is that:

[0154] S1. Making a ferrite sheet substrate: cutting ferrite into several thin slices to obtain a ferrite sheet substrate;

[0155] S2, dielectric bridge fabrication: spin-coating polyimide coating on the ferrite sheet, and then using photolithography / etching process to fabricate the polyimide dielectric bridge;

[0156] S3, photolithography pattern: Use photolithography process to make circuit pattern on the surface of polyimide dielectric bridge;

[0157] S4, vacuum coating: using magnetron sputtering process, coating on the side with polyimide dielectric bridge;

[0158] S5, photoresist stripping: using lift-off process to strip the photoresist;

[0159] S6. Slicing and cutting: Use a high-precision dicing machine to cut the manufactured substrate circuit into several independent unit devices.

[0160] Comparative Example 2

[0161] Comparative Example 2 provides a high-precision beryllium copper wire and a preparation method thereof, and the specific implementation manner is the same as that of Example 1. The difference is that the glass glue is silicone glue.

[0162] The shear strength of the silicone adhesive is 1.4 MPa, and the tensile strength is 1.2 MPa.

[0163] The silicone adhesive was purchased from Dongguan Shin-Etsu Electronic Materials Co., Ltd. as silicone adhesive SY-428.

[0164] Comparative Example 3

[0165] Comparative Example 3 provides a high-precision beryllium copper wire and its preparation method, with the same specific implementation as Example 1. The difference is that the high-temperature sintering process in step S3 is: heating the bonded silicon wafer and ferrite material to 600°C at 10°C / min, holding the temperature for 35 hours, and then cooling to room temperature to obtain a composite substrate.

[0166] Performance testing methods

[0167] The ceramic composite silicon-based circulators prepared by the processes of Examples 1-3 and Comparative Examples 1-3 were tested for insertion loss, isolation, and standing wave ratio in the 5-13 GHz frequency range and at temperatures between -40°C and 85°C using a network analyzer and a programmable constant temperature and humidity test chamber. The results are recorded in Table 1.

[0168] Table 1

[0169] Frequency range GHz Insertion loss dB Isolation dB Standing Wave Ratio Temperature range ℃ Example 1 5-13 ＜0.7 ＞18 ＜1.35 -40～85 Example 2 5-13 ＜0.7 ＞18 ＜1.34 -40～85 Example 3 5-13 ＜0.7 ＞18 ＜1.34 -40～85 Comparative Example 1 5-13 ＜1.0 ＞11 ＜1.45 -40～85 Comparative Example 2 5-13 ＜0.8 ＞15 ＜1.40 -40～85 Comparative Example 3 5-13 ＜0.9 ＞13 ＜1.41 -40～85

Claims

1. A method for manufacturing a ceramic composite silicon-based circulator, characterized in that: The following steps are involved: S1. Deep silicon etching through hole: multiple circular through holes are etched on the silicon wafer by deep silicon etching; S2. Making ferrite discs: Grinding the ferrite rod to the diameter of the circular through hole, cutting out a number of circular slices and then grinding and polishing them to make ferrite discs; S3. Preparation of composite substrate: ferrite discs are embedded in the through holes respectively, and the ferrite discs are embedded in the silicon wafer using adhesive material. The bonded silicon wafer and ferrite discs are then placed in a fixture and sintered at high temperature to obtain the composite substrate; S4, dielectric bridge fabrication: spin-coating a polyimide coating on the composite substrate, and then fabricating a polyimide dielectric bridge using a photolithography / etching process; S5. Photolithography pattern: Use photolithography to make circuit patterns on the surface of the polyimide dielectric bridge; S6, vacuum coating: using magnetron sputtering process, coating on the side with polyimide dielectric bridge; S7, photoresist stripping: using lift-off process to strip the photoresist; S8, dicing and cutting: Use a high-precision dicing machine to cut the prepared composite substrate circuit into several independent unit devices; The adhesive material is modified silicone adhesive. The preparation method of the modified silicone adhesive is as follows: silicone adhesive and silicone oil are stirred evenly, filler is added and stirred evenly, and then a silane coupling agent is added and stirred for 20-40 minutes to obtain the modified silicone adhesive; the shear strength of the silicone adhesive is 1.0-2.0 MPa and the tensile strength is 0.5-1.5 MPa; the silicone oil is selected from one or more of vinyl silicone oil, polymethyl hydrogen siloxane, methyl-terminated silicone oil, and methyl silicone oil.

2. The method for manufacturing a ceramic composite silicon-based circulator according to claim 1, characterized in that: The through hole has a diameter of 2-5 mm.

3. The method for manufacturing a ceramic composite silicon-based circulator according to claim 2, characterized in that: The ferrite rods are one or more of magnesium-manganese ferrite rods, garnet ferrite rods, and nickel-zinc ferrite rods.

4. The method for manufacturing a ceramic composite silicon-based circulator according to claim 1, characterized in that: The polyimide coating has a melting temperature of 300-400° C. and a tensile strength of 90-115 MPa.

5. An application of the method for manufacturing a ceramic composite silicon-based circulator according to any one of claims 1 to 4, characterized in that: Applied in the fields of isolators, duplexers, and reflection amplifiers.

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