Multi-chip micro-assembled broadband distributed amplifier and manufacturing method thereof

Abstract

The invention discloses a multi-chip micro-assembled broadband distributed amplifier which comprises a carrier flange, a plurality of amplifiers connected with one another through metal leads are arranged on the carrier flange, the input ends of the amplifiers are connected with laminated ceramic plate networks, and the laminated ceramic plate networks are connected with one another through metal leads. The laminated ceramic plate network comprises a ceramic substrate, the upper surface of the ceramic substrate extends inwards to form a first metal layer with a certain distance away from the edge, a dielectric layer and an upper metal layer are sequentially arranged above the middle of the first metal layer, the dielectric layer is made of a high-dielectric-constant material, thin-film resistors are arranged at the corners of the first metal layer, and the upper metal layer is made of a high-dielectric-constant material. One end of the thin-film resistor is connected with the first metal layer, and the other end is connected with the lead pad. According to the distributed amplifier, the area of a high-cost semiconductor chip can be reduced, the cost is greatly reduced, debugging is more convenient, and the working bandwidth of the distributed amplifier can be further improved by adding the laminated ceramic plate network.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency and microwave circuits, and particularly relates to a low-cost broadband distributed amplifier with multi-chip micro-assembly and a manufacturing method thereof. Background Art

[0002] The working principle of a distributed amplifier is to use the parasitic capacitance of transistors to form an artificial transmission line, thereby being able to break through the limitation of the gain-bandwidth product of traditional amplifiers and obtain a large flat gain within a very wide frequency band (up to multiple frequencies or even more than ten times the frequency). This has important academic value in the research field of broadband amplifiers for radio frequency and microwave circuits. The application fields of distributed amplifiers include high-speed links, broadband wireless transceivers, high-resolution radars, imaging systems, etc. There is a large demand for them in both military and civilian markets. For example, the broadband power amplifiers of series chips such as HMC459, HMC464, HMC930, and HMC1022 of Hittite microwave company are realized by using distributed amplifiers.

[0003] Currently, distributed amplifiers generally adopt the MMIC (Monolithic Microwave Integrated Circuit) method. MMIC is to manufacture passive and active components on a semi-insulating semiconductor substrate by a series of semiconductor process methods and connect them to form a functional circuit applied to the microwave (even millimeter wave) frequency band. However, although the MMIC method has certain advantages, its manufacturing cost is high, the use of on-chip inductors is not conducive to the debugging of the amplifier, and the working bandwidth is limited to a certain extent.

[0004] The present invention thus comes into being. Summary of the Invention

[0005] Aiming at the above existing technical problems, the object of the present invention is to provide a broadband distributed amplifier with multi-chip micro-assembly and a manufacturing method thereof, which can reduce the area of high-cost semiconductor chips, greatly reduce the cost, use packaged metal leads instead of on-chip inductors in the MMIC method to make the debugging more convenient, and further improve the working bandwidth of the distributed amplifier by adding a stacked ceramic plate network.

[0006] To solve these problems in the prior art, the technical solution provided by the present invention is: A broadband distributed amplifier for multi-chip micro-assembly includes a carrier flange, on which a plurality of amplifiers interconnected by metal leads are provided. The input end of the amplifier is connected to a stacked ceramic plate network, and the stacked ceramic plate networks are interconnected by metal leads. The stacked ceramic plate network includes a ceramic substrate. A first metal layer extends inward from the edge of the upper surface of the ceramic substrate at a certain distance. Above the middle of the first metal layer, a dielectric layer and an upper metal layer are sequentially arranged. The dielectric layer is made of a high dielectric constant material. Thin film resistors are arranged at the corners of the first metal layer. The thin film resistors are used to provide the gate voltage for the amplifier chip and make the power supply network have an open-circuit effect on the radio frequency signal. One end of the thin film resistor is connected to the first metal layer, and the other end is connected to a lead pad. The metal lead serves as the transmission line of the broadband distributed amplifier.

[0007] In a preferred technical solution, the first metal layer, the dielectric layer, and the upper metal layer form a DC blocking capacitor, and the capacitance value of the DC blocking capacitor is 0.5 pF - 3 pF.

[0008] In a preferred technical solution, two thin film resistors are provided, symmetrically distributed on both sides of the DC blocking capacitor, and the resistance value of the thin film resistor is 50 Ohm - 200 Ohm.

[0009] In a preferred technical solution, the ceramic substrate is made of alumina, and a second metal layer is provided on the lower surface of the ceramic substrate.

[0010] In a preferred technical solution, the equivalent capacitance formed by the parasitic capacitance of the upper metal layer to the ground in parallel with the parasitic capacitance of the first metal layer to the ground and then in series with the DC blocking capacitor makes the input capacitance of the amplifier chip smaller, thereby increasing the cut-off frequency of the distributed amplifier.

[0011] In a preferred technical solution, a termination absorption resistor and a grounding capacitor are connected in series at the input end of one of the stacked ceramic plate networks.

[0012] In a preferred technical solution, the width of the first metal layer is slightly larger than the width of the DC blocking capacitor, and the size is 50 um - 150 um.

[0013] The present invention also discloses a manufacturing method for a broadband distributed amplifier for multi-chip micro-assembly, including the following steps: S01: Mount a plurality of amplifiers on the carrier flange and interconnect the plurality of amplifiers through metal leads; S02: A stacked ceramic plate network is connected to the input end of the amplifier. Multiple stacked ceramic plate networks are interconnected through metal leads. The stacked ceramic plate network includes a ceramic substrate. A first metal layer extends inward from the upper surface of the ceramic substrate at a certain distance from the edge. A dielectric layer and an upper metal layer are sequentially arranged above the middle of the first metal layer. The dielectric layer is made of a high dielectric constant material; S03: A thin film resistor is prepared by a deposition process at the corners of the first metal layer. The thin film resistor is used to provide a gate voltage for the amplifier chip and make the power supply network have an open - circuit effect on the radio frequency signal. One end of the thin film resistor is connected to the first metal layer, and the other end is connected to a lead pad. The metal lead serves as a transmission line of the broadband distributed amplifier.

[0014] In the preferred technical solution, it further includes connecting a terminal absorption resistor and a grounding capacitor in series at the input end of one of the stacked ceramic plate networks.

[0015] Compared with the solutions in the prior art, the advantages of the present invention are: 1. The broadband distributed amplifier of the present invention reduces the area of high - cost semiconductor chips, greatly reducing the cost. Using packaged metal leads instead of on - chip inductors in the MMIC method, compared with MMIC, the debugging is more convenient. Only by changing the line height and line length can the debugging effect be achieved, and there is no need to spend a lot of time on re - tape - out. Using metal leads can effectively reduce circuit losses and improve the power amplifier efficiency.

[0016] 2. By introducing a stacked ceramic plate network with a DC - blocking capacitor and a bias resistor, the convenience of wire bonding can be increased, the cost can be reduced, and the input capacitance of the radio frequency signal entering the active chip can be effectively reduced, thereby increasing the cut - off frequency of the distributed amplifier to achieve the purpose of increasing the amplifier bandwidth.

[0017] 3. This method has a high degree of freedom. Compared with the MMIC method where the circuit elements are fixed after manufacturing and cannot be changed, this method can adjust the absorption resistor at the input end of the distributed amplifier by replacing and attaching resistors with different numerical values. Even if the input capacitance of a certain unit chip is large, good gain flatness can still be achieved. It is convenient for mass production and has good consistency. In particular, it can be applied to broadband distributed amplifiers in the lower frequency band (below 6 GHz) and has a wide range of application prospects. Description of the Drawings

[0018] The present invention will be further described below in conjunction with the drawings and embodiments: Figure 1 It is a connection schematic diagram of a GaN 100 MHz - 6200 MHz 10 W amplifier according to an embodiment of the present invention; Figure 2 It is a structural schematic diagram of the stacked ceramic plate network of the present invention; Figure 3 This is the equivalent circuit diagram of the stacked ceramic plate network of the present invention; Figure 4 This is the flowchart of the manufacturing method of the broadband distributed amplifier of the multi-chip micro-assembly of the present invention. Detailed implementation manners

[0019] The above solution will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are for illustrating the present invention and not for limiting the scope of the present invention. The implementation conditions adopted in the embodiments can be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are usually those in conventional experiments.

[0020] Embodiment

[0021] As Figure 1 、 2 shown, a broadband distributed amplifier of multi-chip micro-assembly includes a carrier flange 100. A plurality of amplifiers 30 interconnected by metal leads 10 are arranged on the carrier flange 100. The input end of the amplifier 30 is connected to a stacked ceramic plate network 20. The stacked ceramic plate networks 20 are interconnected with each other through metal leads 10. The stacked ceramic plate network 20 includes a ceramic substrate 200. A first metal layer 21 extends inward from the upper surface of the ceramic substrate 200 at a certain distance from the edge. A dielectric layer 201 and an upper metal layer 202 are sequentially arranged above the middle of the first metal layer 21. The dielectric layer 201 is made of a high dielectric constant material. A thin film resistor 22 is arranged at the corner of the first metal layer 21. The thin film resistor 22 is used to provide the gate voltage for the amplifier chip and make the power supply network have an open-circuit effect on the radio frequency signal. One end of the thin film resistor 22 is connected to the first metal layer 21, and the other end is connected to a lead pad 25. The metal lead 10 is used as the transmission line of the broadband distributed amplifier.

[0022] The specific wire bonding positions of the stacked ceramic plate network 20 are as Figure 2 shown, specifically including one end of the upper metal layer 202, one end of the first metal layer 21, and on the lead pad 25.

[0023] The metal lead here can be a gold wire or an aluminum wire, and the metal lead can be welded by a wire bonder, such as a Wire Bond device.

[0024] The length of the metal lead can be obtained through simulation calculation.

[0025] In a preferred embodiment, the first metal layer 21, the dielectric layer 201, and the upper metal layer 202 form a DC-blocking capacitor 23, and the size of the DC-blocking capacitor 23 is 0.5 pF - 3 pF. It can reduce the cost and effectively reduce the input capacitance of the radio frequency signal entering the active chip.

[0026] The metal layer on the upper surface of the ceramic substrate 200, i.e., the first metal layer 21, is slightly wider than the width of the DC-blocking capacitor 23, and the size range is between 50um and 150um.

[0027] In a preferred embodiment, two thin-film resistors 22 are provided, symmetrically distributed on both sides of the DC-blocking capacitor 23, and the size of the thin-film resistor is 50Ohm - 200Ohm. It is convenient for wire bonding.

[0028] In a preferred embodiment, the ceramic substrate 200 is made of alumina, a second metal layer is provided on the lower surface of the ceramic substrate 200, and the ceramic substrate 200 is mounted on the carrier flange 100.

[0029] In a preferred embodiment, as Figure 3 shown, the equivalent capacitance formed by the parasitic capacitance 33 formed by the upper metal layer 202 to the ground in parallel with the parasitic capacitance 32 formed by the first metal layer 21 to the ground and then in series with the DC-blocking capacitor 23 makes the input capacitance of the amplifier chip smaller, improving the cut-off frequency of the distributed amplifier.

[0030] In a preferred embodiment, at the input end of one of the stacked ceramic board networks 20, a termination absorption resistor 40 and a ground capacitor 50 are connected in series. The absorption resistor 40 is less than or equal to 50Ω, and the absorption resistor 40 plays a role in improving the input standing wave and gain flatness, and the ground capacitor 50 plays a DC-blocking role, with a typical value of 1000pF.

[0031] In another embodiment, as Figure 4 shown, a manufacturing method of a multi-chip micro-assembled broadband distributed amplifier includes the following steps: S01: Mount multiple amplifiers on the carrier flange and connect the multiple amplifiers to each other through metal leads; S02: A stacked ceramic board network is connected to the input end of the amplifier, and multiple stacked ceramic board networks are connected to each other through metal leads. The stacked ceramic board network includes a ceramic substrate. A first metal layer extends inward from a certain distance from the edge on the upper surface of the ceramic substrate. A dielectric layer and an upper metal layer are sequentially arranged above the middle of the first metal layer. The dielectric layer is made of a high-dielectric-constant material; S03: Prepare a thin-film resistor at the corner of the first metal layer by a deposition process. The thin-film resistor is used to provide the gate voltage for the amplifier chip and make the power supply network open-circuit to the RF signal. One end of the thin-film resistor is connected to the first metal layer, and the other end is connected to the lead pad. The metal lead serves as the transmission line of the broadband distributed amplifier.

[0032] In a preferred embodiment, after step S03, it further includes connecting a termination absorption resistor and a ground capacitor in series at the input end of one of the stacked ceramic board networks.

[0033] The present invention is mainly used for GaN HEMT devices, and can also be used for GaAs FETs, LDMOS, etc. Below, the GaN HEMT device will be taken as an example for illustration. Transistors with other structures also have similar structures.

[0034] To obtain a higher working bandwidth, the stacked ceramic plate network 20 of the DC-blocking capacitor and the bias resistor as shown in Figure 2 is introduced. 200 is a ceramic substrate, and the typical material of its dielectric is alumina. Its lower surface is a gold-plated metal layer to facilitate mounting on the carrier flange 100. 21 is the gold-plated metal layer on the upper surface, but the area is slightly smaller than the upper surface area of the substrate. This is to reduce the parasitic capacitance formed by the upper surface metal plate to the ground. At the same time, 21 provides the capacitance lower plate support and electrical connection for the mounted stacked DC-blocking capacitor 23. 23 is a ceramic DC-blocking capacitor, and both the upper and lower surfaces have gold-plated metal layers for easy mounting and electrical connection. The substrate material is a high dielectric constant material to provide capacitance. 22 is a thin-film bias resistor manufactured by a deposition process. The two ends of the resistor are respectively connected to the upper metal layer 21 of the ceramic support plate and the lead pad of the metal wire 24. The lead pad and the upper metal layer 21 of the ceramic support plate are metal layers made of the same material and process. 24 is the connected metal wire, and the gold wire is welded to the lead pad by a ball bonder for electrical connection.

[0035] The equivalent circuit is as shown in Figure 3 . 31 is the required main capacitor, that is, the DC-blocking capacitor 23. 32 and 33 are parasitic capacitances, that is, the capacitances formed by the first metal layer 21 of the ceramic substrate and the upper plate of the DC-blocking capacitor 23 to the ground. 34 is the bias isolation resistor. By placing the above device at the input end of the active GaN amplifier chip, wire bonding can be facilitated, the cost can be reduced, and the input capacitance of the RF signal entering the active chip can be effectively reduced, thereby increasing the cut-off frequency of the distributed amplifier to achieve the purpose of increasing the amplifier bandwidth.

[0036] It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modification examples falling within the scope and boundary of the appended claims, or equivalent forms of such scope and boundary.

Claims

1. A broadband distributed amplifier with multi-chip micro-assembly, comprising a carrier flange, on which a plurality of amplifiers interconnected by metal leads are provided, characterized in that, The input end of the amplifier is connected to a stacked ceramic plate network, and the stacked ceramic plate networks are interconnected through metal leads. The stacked ceramic plate network includes a ceramic substrate. A first metal layer extends inward from the upper surface of the ceramic substrate at a certain distance from the edge. A dielectric layer and an upper metal layer are sequentially arranged above the middle of the first metal layer. The dielectric layer is made of a high dielectric constant material. Thin film resistors are arranged at the corners of the first metal layer. The thin film resistors are used to provide the gate voltage for the amplifier chip and make the power supply network have an open - circuit effect on the radio - frequency signal. One end of the thin film resistor is connected to the first metal layer, and the other end is connected to the lead pad. The metal lead serves as the transmission line of the broadband distributed amplifier.

2. The broadband distributed amplifier with multi-chip micro-assembly according to claim 1, characterized in that, The first metal layer, the dielectric layer and the upper metal layer form a DC - blocking capacitor, and the capacitance value of the DC - blocking capacitor is 0.5 pF - 3 pF.

3. The broadband distributed amplifier with multi-chip micro-assembly according to claim 2, characterized in that, There are 2 thin film resistors, symmetrically distributed on both sides of the DC - blocking capacitor, and the resistance value of the thin film resistor is 50 Ohm - 200 Ohm.

4. The broadband distributed amplifier with multi-chip micro-assembly according to claim 1, characterized in that, The ceramic substrate is made of alumina, and a second metal layer is arranged on the lower surface of the ceramic substrate.

5. The broadband distributed amplifier with multi-chip micro-assembly according to claim 2, characterized in that, The parasitic capacitance formed by the upper metal layer to the ground and the parasitic capacitance formed by the first metal layer to the ground are connected in parallel and then in series with the DC - blocking capacitor. The equivalent capacitance makes the input capacitance of the amplifier chip smaller, and improves the cut - off frequency of the distributed amplifier.

6. The broadband distributed amplifier with multi-chip micro-assembly according to claim 1, characterized in that, A termination absorption resistor and a ground capacitor are connected in series at the input end of one of the stacked ceramic plate networks.

7. The broadband distributed amplifier with multi-chip micro-assembly according to claim 1, characterized in that, The width of the first metal layer is slightly larger than the width of the DC - blocking capacitor, and the size is 50 um - 150 um.

8. A manufacturing method of a broadband distributed amplifier with multi-chip micro-assembly, characterized in that, Including the following steps: S01: Mount multiple amplifiers on the carrier flange and connect the multiple amplifiers to each other through metal leads; S02: The input end of the amplifier is connected to a stacked ceramic plate network. Connect multiple stacked ceramic plate networks to each other through metal leads. The stacked ceramic plate network includes a ceramic substrate. A first metal layer extends inward from the upper surface of the ceramic substrate at a certain distance from the edge. A dielectric layer and an upper metal layer are sequentially arranged above the middle of the first metal layer. The dielectric layer is made of a high dielectric constant material; S03: Prepare thin film resistors at the corners of the first metal layer by a deposition process. The thin film resistors are used to provide the gate voltage for the amplifier chip and make the power supply network have an open - circuit effect on the radio - frequency signal. One end of the thin film resistor is connected to the first metal layer, and the other end is connected to the lead pad. The metal lead serves as the transmission line of the broadband distributed amplifier.

9. The manufacturing method of a broadband distributed amplifier with multi-chip micro-assembly according to claim 8, characterized in that, It also includes connecting a termination absorption resistor and a ground capacitor in series at the input end of one of the stacked ceramic plate networks.

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