A W-band micro-packaged frequency multiplier module

Abstract

The present invention provides a W-band micro-package frequency multiplier module, including a multi-layer printed circuit board, a substrate, a cover plate, a short-circuit waveguide, a bare chip, a radio frequency probe and a passive electronic device; the multi-layer printed circuit board is a frame-type circuit board with a multi-layer step structure, and its bottom end is fixedly connected to the substrate to form a stepped, concave chamber; when working, the power supply and control signal are connected to the corresponding port of the bare chip through the built-in circuit of the multi-layer printed circuit board via the external pad, so that the bare chip works normally, and the radio frequency input signal is connected to the radio frequency signal input port of the bare chip through the external pad, and is output to the outside of the module by the radio frequency output switching structure after frequency multiplication. The multi-layer printed circuit board used in the present invention is small in size, simple in processing and assembly, high in integration and low in cost. The radio frequency switching circuit is mainly a short-circuit waveguide, which has a simple structure and small in size. Compared with the traditional frequency multiplier module, the present invention has the advantages of small size, low cost and easy assembly.

Description

Technical Field

[0001] The invention belongs to the technical field of frequency multiplier module packaging, and in particular relates to a W-band micro-packaged frequency multiplier module. Background Art

[0002] The frequency multiplier module is an important component of various millimeter-wave radars and communication systems. It is used to provide the local oscillator signal for the system. It is generally composed of packaging, bare chips, RF switching circuits, low-frequency switching circuits, etc. The traditional W-band frequency multiplier module packaging is generally a metal cavity, the bare chip is the main active device, the RF switching circuit generally uses a microstrip-waveguide probe based on a metal waveguide cavity, and the low-frequency switching circuit generally uses a glass insulator.

[0003] The package is generally a double-sided open structure with a cover plate at the open cavity to provide protection and support for the entire module. The bare chip, RF switching circuit, low-frequency switching circuit and other parts are all installed on the package structure. The bare chip is generally an active chip that provides a frequency multiplication function so that the output frequency is several times the input frequency. The connection between the bare chip and the external circuit is achieved through the RF switching circuit and the low-frequency switching circuit. The RF switching circuit connects the external input RF signal to the input end of the bare chip, and transfers the output frequency multiplication signal of the bare chip to the outside for system use. The low-frequency switching circuit connects the corresponding pins of the bare chip to the external power supply and control signal, so that the bare chip can work.

[0004] Limited by the metal cavity structure, the traditional W-band frequency multiplier module has many disadvantages: the metal cavity is large and the processing cost is high; the microstrip-waveguide probe is large and difficult to assemble; the glass insulator is large, difficult to assemble and expensive. The traditional W-band frequency multiplier module has the disadvantages of large size, high cost and difficult assembly, which has caused great difficulties in the engineering application of W-band frequency multiplier modules. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a W-band micro-packaged frequency multiplier module, which aims to provide a miniaturized W-band frequency multiplier module and an easily integrated micro-packaged application module solution for terahertz systems, so as to reduce module cost, volume and assembly difficulty, and promote the development of engineering applications of terahertz systems.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A W-band micro-package frequency multiplier module, comprising a multi-layer printed circuit board, a substrate, a cover plate, a short-circuit waveguide, a bare chip, a radio frequency probe, and passive electronic devices;

[0008] The multilayer printed circuit board is a frame-type circuit board with a multilayer step structure, the bottom end of which is fixedly connected to the substrate to form a stepped and concave cavity, the steps of the multilayer printed circuit board located in the cavity are provided with internal pads for radio frequency input signals and a plurality of internal pads for circuit routing, and the top step of the multilayer printed circuit board located outside the cavity is provided with external pads for radio frequency input signals and external pads for low-frequency connection;

[0009] The bare chip comprises a radio frequency signal input port and a radio frequency signal output port, which are used to provide a frequency multiplication function so that the frequency of the output radio frequency signal is several times of the radio frequency input signal; the radio frequency signal input port is electrically connected to the internal pad of the radio frequency input signal through a gold wire / gold belt, and the radio frequency signal output port is electrically connected to the radio frequency probe;

[0010] The substrate is a metal sheet. A short-circuit waveguide, a bare chip, a radio frequency probe and a passive electronic device are fixedly installed on one side of the substrate located inside the chamber. An opening is provided on the substrate at a position corresponding to the end of the radio frequency probe. The short-circuit waveguide is located at the upper part of the opening and a notch is provided on the side facing the radio frequency probe. The end of the radio frequency probe enters the semi-enclosed cavity formed by the short-circuit waveguide and the opening through the notch, so that the radio frequency output signal is output from the opening in a waveguide mode. The short-circuit waveguide, the substrate opening and the radio frequency probe together constitute a radio frequency output switching structure.

[0011] The passive electronic device is electrically connected to a number of internal pads for circuit routing, external pads for low-frequency connection, and ports related to the bare chip through gold wires / gold ribbons, so that the bare chip can work normally;

[0012] The cover plate is fixed above the chamber by utilizing the limiting effect of the upper step of the multi-layer printed circuit board to protect the circuit components in the chamber;

[0013] When working, the power supply and control signal are connected to the corresponding ports of the bare chip through the external solder pads for low-frequency connection via the built-in circuits of the multi-layer printed circuit board, so that the bare chip can work normally. The RF input signal is connected to the RF signal input port of the bare chip through the external solder pads of the RF input signal via the built-in circuits of the multi-layer printed circuit board. After the bare chip is multiplied, the RF output signal is formed and output to the outside by the RF output adapter structure.

[0014] Furthermore, the short-circuit waveguide is a cap-shaped metal shell, the internal dimensions of which meet the short-circuit waveguide dimension requirements of the operating frequency, and the short-circuit waveguide is plated with gold or silver.

[0015] Furthermore, the passive electronic components are components required for connecting the bare chip and the pads of the multi-layer printed circuit board, including resistors, capacitors and inductors, and their quantity and specifications are determined according to the specific circuit design.

[0016] Furthermore, the radio frequency probe refers to a microstrip-waveguide transition probe, which is a hard insulating substrate with a metal film attached to the surface.

[0017] Furthermore, the gold wire / gold ribbon is used for circuit connection and is assembled using an ultrasonic bonding process.

[0018] Furthermore, the number, model and layout of the bare chips are adjusted according to the specific circuit design. By changing the circuit design, the applicable coverage frequency of the multiplier module includes but is not limited to the W band.

[0019] The present invention provides a W-band micro-package frequency multiplier module, which adopts a multi-layer printed circuit board as the main body of the package with small volume, simple processing and assembly, high integration and low cost. The radio frequency switching circuit is mainly a short-circuit waveguide with simple structure, small volume and low cost. Therefore, compared with the traditional frequency multiplier module, the present invention has the advantages of small volume, low cost and easy assembly, is easy to be integrated in a micro-package system, can be applicable to millimeter waves or higher frequencies, and supports the terahertz frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the module of the present invention;

[0021] Figure 2 is a top view of the module of the present invention;

[0022] Among them, 101 is a cover plate, 102 is a short-circuit waveguide, 103 is a multilayer printed circuit board, 104 is a substrate, 105 is a bare chip, 106 is a gold wire / gold ribbon, 107 is an external pad, 108 is an internal pad, 109 is a passive electronic device, and 110 is a radio frequency probe. DETAILED DESCRIPTION

[0023] The present invention will now be described in further detail with reference to the accompanying drawings.

[0024] The W-band micro-package frequency multiplier module of the present invention is composed of a package, a bare chip, a radio frequency switching circuit, etc. The package is mainly composed of a multi-layer printed circuit board, and realizes the functions of low-frequency switching and partial radio frequency switching. The radio frequency switching circuit is mainly a short-circuit waveguide, which cooperates with the package to realize radio frequency switching.

[0025] Specifically, the present invention is composed of a cover plate, a short-circuit waveguide, a multilayer printed circuit board, a substrate, a bare chip, a gold wire / gold ribbon, a radio frequency probe, a passive electronic device, an internal pad, an external pad and the like. The cover plate and the substrate are two thin metal plates, which are machined and gold-plated or silver-plated on the surface. The cover plate is welded on the top of the multilayer printed circuit board to protect the internal circuit. The substrate is welded on the bottom of the multilayer printed circuit board to carry other components and form electrical and mechanical connections with the outside of the system. The substrate is machined with an opening at the position corresponding to the radio frequency output port, and the shape is a rectangle or a rounded rectangle, so that the signal can be output from the opening in a waveguide mode. The electrical connection between the substrate and the outside of the system is mainly electrical grounding, and the mechanical connection is mainly welding or silver glue bonding. The shape and surface treatment process of the cover plate and the substrate can be adjusted according to the specific design.

[0026] The short-circuit waveguide is a "hat"-shaped metal shell made by high-precision stamping, CNC machining, etc. It can be adjusted according to the specific circuit design, and its internal dimensions meet the short-circuit waveguide size requirements of the operating frequency (approximately 1 / 4 of the waveguide wavelength). The short-circuit waveguide is gold-plated or silver-plated throughout. There is a frame-shaped notch on the side of the short-circuit waveguide facing the RF probe to facilitate the passage of the RF probe. The short-circuit waveguide is located on the upper part of the substrate opening and forms a semi-enclosed cavity together with the opening. The short-circuit waveguide, substrate, and RF probe together constitute the RF output transfer structure.

[0027] A multilayer printed circuit board is a frame-shaped circuit board with circuit lines manufactured using conventional processes, and has a multi-layer step structure inside. Both the internal pads and the external pads are metal contacts formed by the exposed circuit line ends on the multilayer printed circuit board and can be used for gold wire or gold ribbon bonding. The bottom of the multilayer printed circuit board is welded or bonded to the substrate, and together with the substrate, it forms a stepped, concave cavity. Bare chips, passive devices, radio frequency probes, and short-circuit waveguides are all installed at the bottom of the cavity. Compared with the bottom of the cavity, the first step of the multilayer printed circuit board is slightly higher, and the layer where the first step is located and the adjacent layers are arranged with circuit lines for transmitting low-frequency signals. The internal pads of the first step are bonded to the bottom passive devices with gold wire or gold ribbon to form an electrical connection. The internal pads of the radio frequency input signal are also arranged on the first step and connected to the input end of the bare chip through bonding gold wire or gold ribbon. Compared with the bottom of the cavity, the second step of the multilayer printed circuit board is higher than the first step, and pads can be arranged or not arranged. It is mainly used to cooperate with the first step to complete the routing of the circuit lines and limit the cover plate to prevent the cover plate from sinking into the cavity. Relative to the bottom of the cavity, the third step of the multilayer printed circuit board is higher than the second step. It is the top layer of the multilayer printed circuit board. Circuit lines may or may not be laid on the surface. External pads for low-frequency connection and external pads for RF input connection are laid. They are mainly used to limit the cover plate in cooperation with the second step to prevent the cover plate from shifting. Internal pads, external pads, the number of layers of the multilayer printed circuit board, and inner wiring can all be adjusted according to the specific circuit design.

[0028] The bare chip is the functional chip of the frequency multiplier module circuit, which is welded or bonded to the substrate. The number, performance and layout of the bare chips can be adjusted according to the specific circuit design, but the output end faces the direction of the RF probe, the input end faces the direction of the internal pad of the RF input end, and the connection relationship between other low-frequency signal interfaces and internal pads is determined according to the actual circuit design.

[0029] Passive electronic components are components required to connect bare chips and multilayer printed circuit board pads, such as resistors, capacitors, inductors, etc. Passive electronic components are soldered or bonded to the substrate and / or soldered or bonded to the first step of the multilayer printed circuit board. The type, quantity, and specifications of passive electronic components are determined according to the specific circuit design.

[0030] The gold wire / gold ribbon described in the present invention refers to the gold wire or gold ribbon used for connecting the circuit in the module, and is assembled by ultrasonic bonding technology. The radio frequency probe described in the present invention refers to the microstrip-waveguide transition probe used for module output signals, which is generally a hard insulating substrate with metal films processed on the upper and lower surfaces.

[0031] In addition, the size and circuit layout of the present invention can be changed to make it work at different electromagnetic wave frequencies, including but not limited to 40GHz to 110GHz. At different working frequencies, the configuration of the present invention remains unchanged, but the size and circuit layout are changed.

[0032] like Figure 1 As shown, it is a 80GHz-100GHz frequency multiplier module. It consists of a cover plate 101, a short-circuit waveguide 102, a multilayer printed circuit board 103, a substrate 104, a bare chip 105, a gold wire / gold belt 106, a radio frequency probe 107, a passive electronic device 108, an internal pad 109, an external pad 110 and the like. The cover plate 101 and the substrate 104 are two metal thin plates with a thickness of 0.3 mm, which are machined and gold-plated on the surface. The substrate 104 is machined with a rectangular opening with rounded corners (chamfer radius 0.5 mm) at the position corresponding to the radio frequency output port. The short-circuit waveguide 102 is a "cap" type metal shell made by machining. The inner concave depth is 0.75 mm, and the wall thickness of each surface is 0.3 mm. The short-circuit waveguide is gold-plated throughout. There is a frame-shaped notch on the side of the short-circuit waveguide facing the radio frequency probe, and the notch is 0.8 mm wide and 0.7 mm high.

[0033] The multilayer printed circuit board 103 is a frame-type copper-clad circuit board with circuit lines manufactured using conventional processes, with 5 layers of insulating materials inside and 3 steps. The internal pads 108 and the external pads 107 are both exposed gold-plated contacts on the multilayer printed circuit board, and there are multiple of them. The internal pads 108 are located on the first step, and the external pads 107 are located on the third step (the upper surface of the multilayer printed circuit board 103). The pads involved in the radio frequency connection of the internal pads 108 and the external pads 107 are interconnected, and a strip line is used to pass through the multilayer printed circuit board 103.

[0034] The bare chip 105 includes a total of 4 chips based on 100um GaAs process, namely, an amplifier chip, a doubler chip A, a doubler chip B, and a doubler chip C. The amplifier chip is used to amplify the signal power of the RF input signal, and the doubler chip A, the doubler chip B, and the doubler chip C have the same functions but work at corresponding design frequencies.

[0035] The passive electronic device 109 is a plurality of thin film capacitors with a capacitance value of 10pF or 100pF. The gold wire / gold belt 106 includes a plurality of gold wires or gold belts, with 25um gold wires used for low frequency connection and 50um gold belts used for radio frequency connection. The radio frequency probe 110 uses a quartz substrate with a thickness of 0.254 mm, and the upper and lower surfaces are coated with a 2um pure gold circuit film according to the design pattern.

[0036] The implementation steps of this example are as follows:

[0037] Process and purchase various components according to design requirements;

[0038] The multilayer printed circuit board 103 is bonded to the substrate 104 using conductive silver glue;

[0039] The passive electronic device 109 (part), the bare chip 105, and the radio frequency probe 110 are bonded to the corresponding positions of the substrate 104 with conductive silver glue;

[0040] The passive electronic device 109 (part) is bonded to the corresponding position of the multilayer printed circuit board 103 with conductive silver glue;

[0041] Solder the short-circuit waveguide 102 to the corresponding position of the substrate 103 using alloy solder;

[0042] Bond the bare chip 105, the passive electronic device 109, the radio frequency probe 110, the pads of the multilayer printed circuit board 103 with the internal pads 108 and the external pads 107 by gold wire and gold ribbon according to the designed relationship;

[0043] The cover plate is bonded to the multilayer printed circuit board 103 using conductive silver glue.

[0044] At this point, the example structure is complete.

[0045] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0046] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A W-band micro-package frequency multiplier module, It is characterized in that Including multi-layer printed circuit boards, substrates, covers, short-circuit waveguides, bare chips, RF probes, and passive electronic devices; The multilayer printed circuit board is a frame-type circuit board with a multilayer step structure, the bottom end of which is fixedly connected to the substrate to form a stepped and concave cavity, the steps of the multilayer printed circuit board located in the cavity are provided with internal pads for radio frequency input signals and a plurality of internal pads for circuit routing, and the top step of the multilayer printed circuit board located outside the cavity is provided with external pads for radio frequency input signals and external pads for low-frequency connection; The bare chip comprises a radio frequency signal input port and a radio frequency signal output port, which are used to provide a frequency doubling function, the radio frequency signal input port is electrically connected to an internal pad of the radio frequency input signal through a gold wire / gold belt, and the radio frequency signal output port is electrically connected to a radio frequency probe; The substrate is a metal sheet. A short-circuit waveguide, a bare chip, a radio frequency probe and a passive electronic device are fixedly installed on one side of the substrate located inside the chamber. An opening is provided on the substrate at a position corresponding to the end of the radio frequency probe. The short-circuit waveguide is located at the upper part of the opening and a notch is provided on the side facing the radio frequency probe. The end of the radio frequency probe enters the semi-enclosed cavity formed by the short-circuit waveguide and the opening through the notch, so that the radio frequency output signal is output from the opening in a waveguide mode. The short-circuit waveguide, the substrate opening and the radio frequency probe together constitute a radio frequency output switching structure. The passive electronic device is electrically connected to a number of internal pads for circuit routing, external pads for low-frequency connection, and ports related to the bare chip through gold wires / gold ribbons, so that the bare chip can work normally; The cover plate is fixed above the chamber by utilizing the limiting effect of the upper step of the multi-layer printed circuit board to protect the circuit components in the chamber; When working, the power supply and control signal are connected to the corresponding ports of the bare chip through the external solder pads for low-frequency connection via the built-in circuits of the multi-layer printed circuit board, so that the bare chip can work normally. The RF input signal is connected to the RF signal input port of the bare chip through the external solder pads of the RF input signal via the built-in circuits of the multi-layer printed circuit board. After the bare chip is multiplied, the RF output signal is formed and output to the outside by the RF output adapter structure.

2. A W-band micropackage frequency multiplier module as claimed in claim 1, It is characterized in that The short-circuit waveguide is a cap-shaped metal shell, the internal dimensions of which meet the short-circuit waveguide dimension requirements of the operating frequency, and the short-circuit waveguide is plated with gold or silver.

3. A W-band micro-packaged frequency multiplier module as claimed in claim 1, It is characterized in that The passive electronic components are components required for connecting the bare chip and the pads of the multi-layer printed circuit board, including resistors, capacitors and inductors, and their quantity and specifications are determined according to the specific circuit design.

4. A W-band micro-package frequency multiplier module as claimed in claim 1, It is characterized in that The radio frequency probe refers to a microstrip-waveguide transition probe, which is a hard insulating substrate with metal films attached to the upper and lower surfaces respectively.

5. A W-band micro-package frequency multiplier module as claimed in claim 1, It is characterized in that The gold wire / gold ribbon is used for circuit connection and is assembled by ultrasonic bonding process.

6. A W-band micro-package frequency multiplier module as claimed in claim 1, It is characterized in that The number, model and layout of the bare chips are adjusted according to the specific circuit design. By changing the circuit design, the applicable coverage frequency of the multiplier module includes but is not limited to the W band.

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