Back-to-back double-layer schottky diode and preparation method thereof

Abstract

The application provides a back-to-back double-layer Schottky diode and a preparation method, and belongs to the technical field of semiconductor microwave frequency multiplication, and comprises a first Schottky diode and a second Schottky diode connected back to back; wherein a first cathode of the first Schottky diode is connected to a first bus bar through a first lead wire, and a second cathode of the second Schottky diode is connected to the first bus bar through first conductive glue; a first anode of the first Schottky diode is connected to a second bus bar through a second lead wire, and a second anode of the second Schottky diode is connected to the second bus bar through second conductive glue. The electrodes of two Schottky diodes connected back to back are synchronously connected to the bus bar, and the parallel connection or symmetric configuration of two single tubes in the circuit is formed in essence, thereby providing strong support for the high power bearing capacity and high output power of the frequency multiplier and the frequency mixer.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor microwave frequency multiplication technology, specifically relating to a back-to-back double-layer Schottky diode used in frequency multipliers and mixers and its preparation method. Background Technology

[0002] Frequency multipliers and mixers are core components in radio frequency (RF) communication systems, widely used in critical stages such as signal frequency conversion and high-frequency signal generation. Their performance directly determines the communication quality, signal stability, and energy efficiency of the entire RF communication system. Schottky diodes, as a core component of frequency multipliers and mixers, are crucial in their structural design and performance parameters, significantly impacting device efficiency, frequency response, and power consumption control.

[0003] However, existing Schottky diode technologies used in frequency multipliers and mixers have many limitations. Traditional Schottky diodes mostly adopt a single-layer structure design, which is prone to limited power handling capability under high-frequency conditions. Specifically, for frequency multipliers, the single-layer structure makes it difficult to achieve efficient harmonic generation and stable output, resulting in low frequency multiplication efficiency. For mixers, the noise figure during signal conversion is high, affecting the signal-to-noise ratio of the received signal, and the device is prone to damage when high-power signals are input.

[0004] In summary, the current single-layer structure of Schottky diodes limits the power handling and output power of frequency multipliers and mixers, thus affecting the design freedom of frequency multipliers and mixers. Summary of the Invention

[0005] This invention provides a back-to-back double-layer Schottky diode and its fabrication method, aiming to improve the power handling and output power of frequency multipliers and mixers, and to increase the design freedom of frequency multipliers and mixers.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, a back-to-back double-layer Schottky diode is provided, comprising: a first Schottky diode and a second Schottky diode connected back-to-back; In this configuration, the first cathode of the first Schottky diode is connected to the first busbar via a first lead, and the second cathode of the second Schottky diode is connected to the first busbar via a first conductive adhesive, thereby enabling synchronous current merging of the cathode electrodes of the first Schottky diode and the second Schottky diode. The first anode of the first Schottky diode is connected to the second busbar via a second lead, and the second anode of the second Schottky diode is connected to the second busbar via a second conductive adhesive, thereby achieving synchronous current merging of the anode electrodes of the first Schottky diode and the second Schottky diode.

[0007] In conjunction with the first aspect, in one feasible manner, the initial substrates of the first Schottky diode and the second Schottky diode are thinned and then bonded back to back, with the thickness of the thinned substrate being 1 / 6 to 1 / 3 of the thickness of the initial substrate; the two thinned substrates and the adhesive layer bonded between them constitute a common substrate.

[0008] In conjunction with the first aspect, in one feasible manner, the connection between the first Schottky diode and the second Schottky diode is achieved using a high-temperature silicone adhesive or a cyanoacrylate-modified adhesive.

[0009] Secondly, embodiments of the present invention also provide a method for fabricating a back-to-back double-layer Schottky diode, the method comprising: The initial substrates of the first Schottky diode and the second Schottky diode are thinned respectively; After uniformly applying an adhesive layer to the thinned substrate of the first Schottky diode or the second Schottky diode, they are bonded back to back. A pressure plate is used to press and fix the back-to-back bonded double-layer Schottky diodes. After curing in a drying oven, cool to room temperature. Remove the pressure plate and perform wire bonding to achieve synchronous current collection of the double-layer Schottky diode electrodes.

[0010] In conjunction with the second aspect, in one feasible manner, after thinning the initial substrates of the first Schottky diode and the second Schottky diode, the thickness of the common substrate formed by back-to-back connection is not greater than the initial substrate thickness of the first Schottky diode or the second Schottky diode.

[0011] In conjunction with the second aspect, in one feasible method, the first Schottky diode and the second Schottky diode have the same structure. When they are bonded back to back, an optical alignment platform is used, with the anode edge contour and / or cathode edge contour of the first Schottky diode and the second Schottky diode as the alignment reference. After bonding, the orthographic projections of the anodes of the two Schottky diodes on the horizontal plane coincide, and the orthographic projections of the two cathodes on the horizontal plane coincide.

[0012] In conjunction with the second aspect, in one feasible method, the process of placing the glued and pressed double-layer Schottky diode into a drying oven for heat curing includes: A stepped heating curing method is adopted. First, the temperature is raised to 80±5℃ and held for 30±5 minutes to remove volatile solvents from the adhesive layer. Then, the temperature is raised to 150±5℃ and held for 60±5 minutes to achieve preliminary curing of the adhesive layer. Finally, the temperature is raised to 180±5℃ and held for 90±5 minutes to complete the full curing of the adhesive layer.

[0013] In conjunction with the second aspect, in one feasible manner, during the stepped temperature curing process, a vacuum environment is maintained inside the drying oven to prevent the formation of air bubbles in the adhesive layer.

[0014] In conjunction with the second aspect, in one feasible manner, the vacuum level inside the drying oven is ≤10Pa.

[0015] In conjunction with the second aspect, in one feasible manner, the thickness of the adhesive layer is 1.5-3µm, and the adhesive material of the adhesive layer is a high-temperature resistant silicone adhesive or a cyanoacrylate modified adhesive.

[0016] The back-to-back double-layer Schottky diode provided by this invention has the following advantages compared with the prior art: For frequency multipliers, this invention employs a back-to-back double-layer Schottky diode structure. By synchronously merging the anodes and cathodes of the two Schottky diodes, it essentially forms two single transistors connected in parallel or symmetrically in the circuit. This structure effectively increases the overall area of ​​the device, thereby improving power handling capability. In frequency multiplication applications, higher power handling capability means that larger input signals can be driven without breakdown, making nonlinear effects more significant and thus exciting richer harmonic components. Simultaneously, the double-layer structure design helps balance the internal electric field distribution of the device, reducing performance fluctuations caused by local overheating or electric field concentration, making the harmonic generation process more stable and controllable. Because the two diodes work together, the equivalent series resistance is reduced, and conduction losses are decreased, thus improving the frequency multiplication efficiency.

[0017] For mixers, this technical solution reduces the equivalent series resistance and parasitic parameters of individual diodes through a back-to-back double-layer structure. During mixing, the reduction in series resistance directly reduces the contribution of thermal noise, thereby effectively reducing the overall noise figure and improving the signal-to-noise ratio of the received signal. Furthermore, since the two diodes share the input signal power, especially under high-power signal input, the voltage swing and current density borne by each individual diode are significantly reduced, avoiding the risk of localized overheating or avalanche breakdown, and greatly improving the reliability of the device.

[0018] In frequency multipliers and mixers, to address the issue of limited power handling capacity under high-frequency operating conditions, this invention integrates two Schottky diodes back-to-back, effectively increasing the junction perimeter and heat dissipation path within the same unit area. When a high-power signal is input, the input power is evenly distributed across the two diodes, significantly reducing the power density handled by a single device. This power-sharing mechanism directly increases the overall device's burn-out threshold (i.e., power handling capacity). Simultaneously, the double-layer structure provides greater thermal mass, facilitating rapid heat dissipation and preventing performance degradation due to heat accumulation. This allows for higher-power input signals, increasing the power handling capacity of the frequency multiplier and mixer.

[0019] In frequency multipliers and mixers, output power is often limited by the parasitic parameters of the devices. The dual-layer structure in this invention, through parallel / symmetrical configuration, effectively reduces the overall equivalent series resistance. For frequency multipliers, lower series resistance means that during harmonic generation, less energy is dissipated as heat across the parasitic resistance, and more energy is converted into the desired harmonic components for output, thereby increasing output power. For mixers, this low-loss characteristic allows for more efficient coupling of the local oscillator signal and the RF signal, reducing conversion losses and consequently increasing the intermediate frequency output power.

[0020] Traditional single-layer Schottky diodes, due to their small power capacity, often require a trade-off between optimal power delivery and preventing device breakdown during circuit matching, thus limiting the design of the matching network. This invention, with its significantly increased power capacity, allows for greater freedom in selecting the impedance matching point to achieve optimal frequency doubling efficiency or the lowest noise figure, and even good matching over a wider frequency band. This greatly simplifies the design of the peripheral circuitry, thereby increasing the design freedom of the frequency multiplier.

[0021] In mixer design, dynamic range is a key performance indicator. Traditional single-layer structures often saturate or fail first under large signal input, limiting the receiver's maximum input level. The dual-layer structure of this invention effectively widens the linear operating region of the device by increasing power handling capacity. Therefore, this characteristic can be used to design mixers with a larger dynamic range without the need for additional limiting protection circuitry. This allows the receiver design to adapt to more diverse application scenarios, thereby increasing the design freedom of the mixer.

[0022] Therefore, by adopting a back-to-back double-layer Schottky diode structure, this invention improves the limitations of traditional single-layer diodes in power handling capability, enhances the power handling capacity and output power of frequency multipliers and mixers, and broadens their design freedom.

[0023] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0025] Figure 1 A three-dimensional structural diagram (top view) of a back-to-back double-layer Schottky diode applied to a frequency multiplier, provided in an embodiment of the present invention. Figure 2 A three-dimensional structural diagram (view from below) of a back-to-back double-layer Schottky diode used in a frequency multiplier, provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the front view structure of a back-to-back double-layer Schottky diode used in a frequency multiplier, provided in an embodiment of the present invention. Figure 4 for Figure 3 A rear view schematic diagram of the back-to-back double-layer Schottky diode provided in the embodiment; Figure 5 for Figure 4 A top view of the back-to-back double-layer Schottky diode provided in the embodiment; Figure 6 for Figure 4 A bottom view of the back-to-back double-layer Schottky diode provided in the embodiment; Figure 7 A three-dimensional structural diagram (top view) of a back-to-back double-layer Schottky diode applied to a mixer, provided in an embodiment of the present invention. Figure 8 This is a schematic diagram of the front view structure of a back-to-back double-layer Schottky diode applied to a mixer, provided in an embodiment of the present invention. Figure 9 A top view of the back-to-back double-layer Schottky diode used in a mixer, as provided in an embodiment of the present invention; Figure 10 A three-dimensional structural diagram of a back-to-back double-layer Schottky diode applied to a mixer provided in an embodiment of the present invention (a bottom view after removing the base plate, showing the second Schottky diode).

[0026] Explanation of reference numerals in the attached figures: 1. First Schottky diode; 11. First anode; 12. First cathode; 13. First lead; 14. Second lead; 2. Second Schottky diode; 21. Second cathode; 22. First conductive adhesive; 23. Second anode; 24. Second conductive adhesive; 3. First busbar; 4. Second busbar; 5. Adhesive layer; 6. Common substrate; 7. Thinned substrate. Detailed Implementation

[0027] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0028] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims, description, and accompanying drawings of this invention is for distinguishing different objects and not for describing a specific order.

[0029] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0030] In the claims, description and accompanying drawings of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0031] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," etc., used in the description of the embodiments of this application should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0032] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0033] It should also be understood that the term “and / or” as used in this application specification means any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0034] The design concept of this invention is to add a back-to-back Schottky diode layer symmetrical to the original Schottky diode onto a traditional Schottky diode substrate: For a frequency multiplier, the anode of the first Schottky diode is connected to the same gold plate via a Beaufort wire and the anode of the second Schottky diode via conductive adhesive. Simultaneously, the corresponding cathodes on both sides of the first Schottky diode are also connected to the same gold plate via Beaufort wires and the cathodes of the second Schottky diode via conductive adhesive, achieving synchronous current convergence of the two diode electrodes; For a mixer, the corresponding cathodes on both sides of the first Schottky diode and the cathode of the second Schottky diode are connected to the same gold plate, achieving synchronous current convergence of the two diode electrodes.

[0035] It should be noted that, Figures 1 to 6 The diagram shows the structure of the present invention applied to a frequency multiplier, where both the cathodes and anodes of the two Schottky diodes need to be connected. Figures 7 to 10 This is a schematic diagram of the structure of the present invention applied to a mixer. The cathodes of the two Schottky diodes need to be connected, while the anodes do not.

[0036] Please see Figures 1 to 6As shown, the back-to-back double-layer Schottky diode provided by the present invention will now be described. The back-to-back double-layer Schottky diode includes: a first Schottky diode 1 and a second Schottky diode 2 connected back-to-back; wherein, the first cathode 12 of the first Schottky diode 1 is connected to the first busbar 3 via a first lead 13, and the second cathode 21 of the second Schottky diode 2 is connected to the first busbar 3 via a first conductive adhesive 22, thereby achieving synchronous current convergence of the anode electrodes of the first Schottky diode 1 and the second Schottky diode 2; the first anode 11 of the first Schottky diode 1 is connected to the second busbar 4 via a second lead 14, and the second anode 23 of the second Schottky diode 2 is connected to the second busbar 4 via a second conductive adhesive 24, thereby achieving synchronous current convergence of the cathode electrodes of the first Schottky diode 1 and the second Schottky diode 2.

[0037] For ease of description and labeling, the cathode of the first Schottky diode 1 is defined as the first cathode 12, and the anode is defined as the first anode 11. The anode of the second Schottky diode 2 is defined as the second anode 23, and the cathode is defined as the second cathode 21.

[0038] This invention employs a back-to-back double-layer Schottky diode structure. By synchronously connecting the anodes of the two Schottky diodes through leads or directly through conductive adhesive, and synchronously connecting the cathodes through leads and conductive adhesive, it essentially forms two single diodes in parallel or symmetrical configuration in the circuit. This provides strong support for achieving high power handling capacity and high output power in frequency multipliers and mixers, and broadens their design freedom. A detailed analysis follows: In frequency multipliers and mixers, to address the issue of limited power handling capacity under high-frequency operating conditions, this invention integrates two Schottky diodes back-to-back, effectively increasing the junction perimeter and heat dissipation path within the same unit area. When a high-power signal is input, the input power is evenly distributed across the two diodes, significantly reducing the power density handled by a single device. This power-sharing mechanism directly increases the overall device's burn-out threshold (i.e., power handling capacity). Simultaneously, the double-layer structure provides greater thermal mass, facilitating rapid heat dissipation and preventing performance degradation due to heat accumulation. This allows for higher-power input signals, increasing the power handling capacity of the frequency multiplier and mixer.

[0039] In frequency multipliers and mixers, output power is often limited by the parasitic parameters of the devices. The dual-layer structure in this invention, through parallel / symmetrical configuration, effectively reduces the overall equivalent series resistance. For frequency multipliers, lower series resistance means that during harmonic generation, less energy is dissipated as heat across the parasitic resistance, and more energy is converted into the desired harmonic components for output, thereby increasing output power. For mixers, this low-loss characteristic allows for more efficient coupling of the local oscillator signal and the RF signal, reducing conversion losses and consequently increasing the intermediate frequency output power.

[0040] Traditional single-layer Schottky diodes, due to their small power capacity, often require a trade-off between optimal power delivery and preventing device breakdown during circuit matching, thus limiting the design of the matching network. This invention, with its significantly increased power capacity, allows for greater freedom in selecting the impedance matching point to achieve optimal frequency doubling efficiency or the lowest noise figure, and even good matching over a wider frequency band. This greatly simplifies the design of the peripheral circuitry, thereby increasing the design freedom of the frequency multiplier.

[0041] In mixer design, dynamic range is a key performance indicator. Traditional single-layer structures often saturate or fail first under large signal input, limiting the receiver's maximum input level. The double-layer Schottky diode structure provided by this invention effectively widens the linear operating region of the device by increasing its power handling capacity. Therefore, this characteristic can be used to design mixers with a wider dynamic range without the need for additional limiting protection circuitry. This allows the receiver design to adapt to more diverse application scenarios, thereby increasing the design freedom of the mixer.

[0042] In some embodiments, see Figures 1 to 4 , Figure 7 and Figure 8 As shown, the initial substrates of the first Schottky diode 1 and the second Schottky diode 2 are thinned and then bonded back-to-back. The thickness of the thinned substrate is 1 / 6 to 1 / 3 of the thickness of the initial substrate. In this embodiment, the initial substrates of the two Schottky diodes are thinned. The initial substrate thickness of the Schottky diodes prepared by conventional processes is generally 25 μm to 30 μm. The thickness of the thinned substrate is 4-10 µm. The thickness of the common substrate 6 formed by bonding the two thinned substrates 7 is 10-22 µm (including the thickness of the adhesive layer 5). This satisfies the high compatibility requirement of the double-layer structure without affecting the parameter performance of the diode.

[0043] Specifically, after thinning the initial substrates of the first Schottky diode 1 and the second Schottky diode 2, the thickness of the common substrate 6 formed by connecting them back-to-back is no greater than the initial substrate thickness of either the first Schottky diode 1 or the second Schottky diode 2. That is, the thickness of the common substrate 6 is essentially equivalent to the thickness of the initial substrate of a single Schottky diode.

[0044] In some embodiments, see Figures 1 to 4 As shown, the connection between the first Schottky diode 1 and the second Schottky diode 2 is made of high-temperature silicone adhesive or cyanoacrylate modified adhesive.

[0045] Specifically, the connection between the first Schottky diode 1 and the second Schottky diode 2 can be made using Fuji Red Adhesive NE8800T, which is produced by Fuji Chemical Industries, Ltd. of Japan and has high temperature resistance and low dielectric loss, as the substrate connection material. Alternatively, silicone high temperature resistant adhesive SE4486 (Dow Corning) or cyanoacrylate modified adhesive LOCTITE 3090 (Loctite) can be used as alternative adhesives.

[0046] Fuji Red Glue is a thermosetting epoxy resin adhesive primarily used in SMT (Surface Mount Technology) electronic manufacturing. Its core component is epoxy resin. It is a one-component, heat-curing adhesive, appearing as a red, viscous liquid or paste before curing, turning dark red or reddish-brown after curing. It requires heating to approximately 150°C for curing, with a relatively short curing time (approximately 1-2 minutes). It exhibits excellent adhesive strength, electrical insulation properties, temperature and moisture resistance, and good storage stability.

[0047] SE4486, a high-temperature resistant silicone adhesive, is a high-performance, one-component, room-temperature (RTV) thermally conductive adhesive primarily used in electronic devices where efficient heat dissipation and reliable bonding are required. Its core function is to provide excellent heat transfer capabilities, while also exhibiting good electrical insulation and environmental resistance.

[0048] LOCTITE 3090, a cyanoacrylate-modified adhesive, is a two-component, fast-curing gap-filling adhesive. Its core component is cyanoacrylate, but its performance has been modified through an innovative two-component formulation, overcoming the limitations of traditional one-component instant adhesives in terms of heat resistance, impact resistance, and bonding range. It is specifically designed for industrial applications requiring high reliability, rapid positioning, and the ability to handle irregular gaps.

[0049] Using the above-mentioned adhesive materials can ensure that the connection between two Schottky diodes is stable and reliable, with good electrical insulation and heat resistance.

[0050] Preferably, the first Schottky diode 1 and the second Schottky diode 2, connected back-to-back, have identical structures. Therefore, by adding a back-to-back Schottky diode layer symmetrical to the original Schottky diode onto a conventional Schottky diode substrate, this invention effectively improves the power handling capacity and output power of frequency multipliers and mixers, increases the design freedom of frequency multipliers, and provides strong support for achieving high power handling capacity and high output power in frequency multipliers and mixers with the addition of a diode layer.

[0051] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0052] Based on the same inventive concept, this application also provides a method for fabricating a back-to-back double-layer Schottky diode, which is used for connecting the back-to-back double-layer Schottky diode.

[0053] Example 1, applied to a frequency multiplier, combined with Figures 1 to 6 The understanding is as follows: S100, Material Selection: Gallium arsenide is selected as the substrate material for Schottky diodes that are traditionally used in frequency multipliers and mixers. Two Schottky diodes are fabricated according to the conventional Schottky diode fabrication process.

[0054] S200, the initial substrates of the first Schottky diode 1 and the second Schottky diode 2 are thinned respectively, reducing the initial substrate thickness from the conventional specification to 4µm.

[0055] S300, a 1.5-3µm adhesive layer 5 is formed by uniformly applying high-temperature resistant silicone adhesive SE4486 (Dow Corning) to the thinned substrate of the first Schottky diode 1, and then bonding them back to back.

[0056] The S400 uses a pressure plate to press and fix a double-layer Schottky diode bonded back to back; the contact surface between the pressure plate and the Schottky diode is treated with an anti-sticking agent to effectively prevent electrode misalignment.

[0057] S500 is placed in a drying oven for curing and then cooled to room temperature.

[0058] S600: Remove the pressure plate and perform wire bonding to achieve synchronous current connection of the double-layer Schottky diode electrodes.

[0059] It should be noted that the structures of the two Schottky diodes in Example 1 may be different. However, since the cathodes and anodes of the two Schottky diodes need to be connected to the same busbar, in order to save materials and reduce costs, the back-to-back Schottky diodes are selected. It should be considered that after the back-to-back connection, the anode distance of the two diodes is similar and the cathode distance of the two diodes is similar. This can reduce the size of the busbar, making the structure compact and saving materials in the bus connection.

[0060] Example 2, applied to a frequency multiplier, combined with Figures 1 to 6 The understanding is as follows: S100, Material Selection: Gallium arsenide is selected as the substrate material for Schottky diodes traditionally used in frequency multipliers and mixers. Two Schottky diodes with completely identical structures are fabricated according to the conventional Schottky diode fabrication process to ensure that the anode and cathode plate dimensions, electrode positions, and diode parameters of the two are exactly the same, laying the foundation for subsequent back-to-back assembly.

[0061] S200, the initial substrates of the first Schottky diode 1 and the second Schottky diode 2 are thinned respectively, reducing the thickness of the initial substrates from the conventional specifications to 5µm.

[0062] S300, Fuji red adhesive NE8800T is uniformly applied to the thinned substrate of the first Schottky diode 1 to form a 2µm adhesive layer 5. Using a high-precision optical alignment platform, with the anode and cathode edge contours and electrode pad center of the Schottky diode as the alignment reference, the second Schottky diode 2 is aligned and bonded back to back: the back sides of the thinned substrate 7 of the two Schottky diodes are tightly bonded through the adhesive layer 5, and the orthogonal projections of the anodes of the two diodes on the horizontal plane are coincident, and the orthogonal projections of the cathodes of the two diodes on the horizontal plane are coincident, that is, the positions of the anode and cathode electrodes of the two Schottky diodes correspond one-to-one.

[0063] The S400 uses a quartz clamp to press and fix a double-layer Schottky diode bonded back to back; the contact surface between the quartz clamp and the Schottky diode is treated with an anti-sticking treatment to effectively prevent electrode misalignment.

[0064] S500: The back-to-back double-layer diode assembly, which has been temporarily pressed and fixed, is placed in a precision hot air drying oven for drying and solidification. A stepped heating and curing process is adopted. First, the temperature is raised to 80℃ and held for 30 minutes to remove volatile solvents in the adhesive layer 5. Then, the temperature is raised to 150℃ and held for 60 minutes to achieve preliminary curing of the adhesive. Finally, the temperature is raised to 180℃ and held for 90 minutes to complete the full curing of the adhesive. During the curing process, a vacuum environment (vacuum degree ≤10Pa) is maintained in the drying oven to avoid the formation of air bubbles in the adhesive layer 5.

[0065] After the S600 module has cooled to room temperature naturally, the quartz sheet is removed, and wire bonding is performed to achieve synchronous current collection of the double-layer Schottky diode electrodes.

[0066] The anode of the first Schottky diode 1 is connected to the first busbar 3 via a beam wire, and the anode of the second Schottky diode 2 is directly bonded to the first busbar 3 using conductive adhesive. At the same time, the cathodes of the two Schottky diodes are connected to the second busbar 4 to achieve synchronous current merging of the electrodes of the two Schottky diodes.

[0067] Both busbars are gold-plated, and the bonding wires used are beamleads. Beamlead is one of the core technologies in microelectronic packaging in the field of electronics, mainly used for electrical interconnection between integrated circuit chips and substrates. This technology forms a cantilevered lead structure on the surface of semiconductor devices through a metallization process, which can replace traditional bonding wires to achieve high-density packaging.

[0068] Example 3 (Applied to a mixer) See Figures 7 to 10 As shown, the difference from Embodiments 1 and 2 is that it is only necessary to connect the cathodes of the two Schottky diodes to the second busbar 4 to achieve synchronous busing of the cathode electrodes of the first Schottky diode 1 and the second Schottky diode 2.

[0069] The optical alignment platform used is described as follows: The optical alignment platform is an indispensable key equipment in high-end manufacturing and is widely used in scenarios with extremely high precision requirements.

[0070] An optical alignment platform is an automated device that integrates machine vision technology and a precision motion control system. It is primarily used in industrial production to achieve high-precision spatial positioning and attitude adjustment of workpieces, ensuring micron-level alignment accuracy for multiple components during assembly, processing, or inspection. It is an intelligent system containing a closed-loop "sensing-computation-execution" process. Its core function is to automatically identify the target position and drive the platform to make precise corrections, thereby eliminating human error and improving production yield and efficiency.

[0071] The main application areas of optical alignment platforms are as follows: Semiconductor manufacturing: wafer dicing, photolithography, chip packaging, defect detection, etc., where errors need to be controlled at the micrometer or even nanometer level.

[0072] PCB (Printed Circuit Board) production: Ensuring precise alignment of pads and components in screen printing, SPI (Soldering Paste Inspection), SMT (Surface Mount Technology), and AOI (Automated Optical Inspection).

[0073] Display panel manufacturing: Precise positioning, bonding, and testing of LCD / LED panels.

[0074] Precision optics and optical communication: fiber alignment, laser packaging, and optical lens assembly.

[0075] Consumer electronics assembly: high-precision bonding of micro-components such as mobile phone camera modules and sensors.

[0076] Therefore, based on the characteristics and application fields of the optical alignment platform, and since the optical alignment platform is an indispensable key equipment in high-end manufacturing, its operation and use can be obtained from publicly available information by those skilled in the art. As a semiconductor device, the present invention enables those skilled in the art to achieve accurate alignment of two Schottky diodes using the optical alignment platform.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A back-to-back double-layer Schottky diode, characterized in that, include: A first Schottky diode (1) and a second Schottky diode (2) are connected back to back; Wherein, the first cathode (12) of the first Schottky diode (1) is connected to the first busbar (3) through the first lead (13), and the second cathode (21) of the second Schottky diode (2) is connected to the first busbar (3) through the first conductive adhesive (22), so as to realize the synchronous current collection of the cathode electrodes of the first Schottky diode (1) and the second Schottky diode (2); The first anode (11) of the first Schottky diode (1) is connected to the second busbar (4) through the second lead (14), and the second anode (23) of the second Schottky diode (2) is connected to the second busbar (4) through the second conductive adhesive (24), so as to realize the synchronous busbar connection of the anode electrodes of the first Schottky diode (1) and the second Schottky diode (2).

2. The back-to-back double-layer Schottky diode as described in claim 1, characterized in that, The initial substrates of the first Schottky diode (1) and the second Schottky diode (2) are thinned and then bonded back to back. The thickness of the thinned substrate (7) formed after thinning is 1 / 6 to 1 / 3 of the thickness of the initial substrate. The two thinned substrates and the adhesive layer bonded between them constitute a common substrate (6).

3. The back-to-back double-layer Schottky diode as described in claim 1, characterized in that, The connection between the first Schottky diode (1) and the second Schottky diode (2) is made of silicone high-temperature resistant adhesive or cyanoacrylate modified adhesive.

4. A method for fabricating a back-to-back double-layer Schottky diode, used to fabricate the back-to-back double-layer Schottky diode as described in any one of claims 1-3, characterized in that, The method includes: The initial substrates of the first Schottky diode (1) and the second Schottky diode (2) are thinned respectively; After uniformly applying adhesive layer (5) to the thinned substrate of the first Schottky diode (1) or the second Schottky diode (2), they are bonded back to back. A pressure plate is used to press and fix the back-to-back bonded double-layer Schottky diodes. After curing in a drying oven, cool to room temperature. Remove the pressure plate and perform wire bonding to achieve synchronous current collection of the double-layer Schottky diode electrodes.

5. The method for fabricating a back-to-back double-layer Schottky diode as described in claim 4, characterized in that, After thinning the initial substrates of the first Schottky diode (1) and the second Schottky diode (2), the thickness of the common substrate (6) formed by back-to-back connection is not greater than the initial substrate thickness of the first Schottky diode (1) or the second Schottky diode (2).

6. The method for fabricating a back-to-back double-layer Schottky diode as described in claim 4, characterized in that, The first Schottky diode (1) and the second Schottky diode (2) have the same structure. When they are bonded back to back, an optical alignment platform is used. The anode edge contour and / or cathode edge contour of the first Schottky diode (1) and the second Schottky diode (2) are used as alignment references. After bonding, the orthographic projections of the anodes of the two Schottky diodes on the horizontal plane coincide, and the orthographic projections of the cathodes on the horizontal plane coincide.

7. The method for fabricating a back-to-back double-layer Schottky diode as described in claim 4, characterized in that, The process of placing the glued and pressed double-layer Schottky diode into a drying oven for heating and curing includes: A stepped heating curing method is adopted. First, the temperature is raised to 80±5℃ and held for 30±5min to remove the volatile solvent in the adhesive layer (5); then the temperature is raised to 150±5℃ and held for 60±5min to achieve the initial curing of the adhesive layer (5); finally, the temperature is raised to 180±5℃ and held for 90±5min to complete the complete curing of the adhesive layer (5).

8. The method for fabricating a back-to-back double-layer Schottky diode as described in claim 7, characterized in that, During the stepped heating and curing process, the drying oven maintains a vacuum environment to prevent air bubbles from forming in the adhesive layer (5).

9. The method for fabricating a back-to-back double-layer Schottky diode as described in claim 8, characterized in that, The vacuum level inside the drying oven is ≤10Pa.

10. The method for fabricating a back-to-back double-layer Schottky diode as described in claim 4, characterized in that, The thickness of the adhesive layer (5) is 1.5-3µm, and the adhesive material of the adhesive layer (5) is a high-temperature resistant silicone adhesive or a cyanoacrylate modified adhesive.

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