Multi-layer ceramic packaged power amplifier

Abstract

A power amplifier packaged by multiple layers of ceramics comprises a closed tube shell and a power amplifier circuit arranged on a base in the closed tube shell, and is characterized in that the closed tube shell is formed by connecting the base, an outer shell and a cover plate in a sealed mode, the outer shell is made of multiple layers of ceramic materials and internally provided with a plurality of tube shell leading-out ends, a beryllium oxide substrate is fixed on the base, and the beryllium oxide substrate is fixed on the cover plate. An operational amplifier, a triode and a resistor of the power amplifier circuit are respectively adhered to corresponding copper conduction bands through high-thermal-conductivity silver paste and are electrically connected through silicon-aluminum wires, and the copper conduction bands are respectively sintered and fixed on a beryllium oxide substrate. The power amplifier has the advantages that the performance of the power amplifier circuit can be combined with high thermal conductivity, the heat dissipation performance of a product can be effectively improved, and the power amplifier can be suitable for the working environment of-55 DEG C to 125 DEG C; and meanwhile, a lead-free packaging structure is adopted by the closed tube shell, so that the welding space volume of the product can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to a power amplifier, in particular to a multi-layer ceramic packaged power amplifier. Background Art

[0002] Power amplifiers, commonly referred to as "PAs", play a core role in a variety of fields. Their main function is to amplify the amplitude of the input signal to the required level.

[0003] Traditional power amplifiers use metal circular through-hole packages with long tube legs and high tube shell cavity height, requiring additional heat sinks. This leads to problems such as low layout space utilization, large welding volume, and poor heat dissipation. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a multi-layer ceramic packaged power amplifier which has good heat dissipation and can effectively reduce the volume of the product's welding space.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A multi-layer ceramic packaged power amplifier comprises a closed tube shell, and a power amplifier circuit is arranged on a base inside the closed tube shell. The special feature of the power amplifier is that the closed tube shell is formed by sealingly connecting a base, an outer shell and a cover plate, wherein the outer shell is made of a multi-layer ceramic material and has a plurality of tube shell lead terminals built therein, a beryllium oxide substrate is fixed on the base, an operational amplifier, a triode and a resistor of the power amplifier circuit are respectively bonded to corresponding copper conductive strips through high thermal conductivity silver paste and electrically connected through silicon aluminum wires, and the copper conductive strips are sintered and fixed on the beryllium oxide substrate.

[0007] As a further preference, the closed tube shell is filled with high-purity nitrogen.

[0008] As a further preference, a gold layer is plated on the surface of the tube shell lead-out terminal and the copper conductor strip, and the thickness of the gold layer is 0.2 μm to 0.46 μm, so as to facilitate the bonding of the silicon-aluminum wire.

[0009] As a further preference, the base is made of tungsten-copper alloy to enhance thermal conductivity.

[0010] As a further preferred embodiment, the power amplifier circuit includes an operational amplifier U1, a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4 and resistors R1, R2, R3 and R4, wherein the positive and negative power input terminals of the operational amplifier U1 are connected to the positive power supply and the negative power supply respectively through the resistor R2 and the resistor R1, the two signal input terminals of the operational amplifier U1 are electrically connected to the corresponding tube shell lead-out terminals respectively, the collector and emitter of the transistor Q1 are connected to the two ends of the resistor R1 and the collector is electrically connected to the base of the transistor Q2, the collector and emitter of the transistor Q3 are connected to the two ends of the resistor R2 and the collector is electrically connected to the base of the transistor Q4, and the operational amplifier The output end of the amplifier U1 is electrically connected to the collectors of the transistor Q2 and the transistor Q4 through the resistor R3, and the output end of the push-pull circuit is led out; at the same time, the output end of the operational amplifier U1 is grounded through the resistor R4; the emitter of the transistor Q4 is electrically connected to the base of the transistor Q3, and the positive power supply overcurrent protection end is led out and electrically connected to the corresponding tube shell lead-out terminal 1 pin, which is used to perform positive power supply current limiting control according to the actual situation of the whole machine using the power amplifier; the emitter of the transistor Q2 is electrically connected to the base of the transistor Q1, and the negative power supply overcurrent protection end is led out and electrically connected to the corresponding tube shell lead-out terminal 9 pin, which is used to perform negative power supply current limiting control according to the actual situation of the whole machine using the power amplifier.

[0011] As a further preference, the operational amplifier U1 adopts the domestic chip QF741 or the imported chip LM741.

[0012] The beneficial effects of the utility model are:

[0013] The shell of the closed tube shell is made of multilayer ceramic material and has multiple tube shell lead-out terminals built in. The operational amplifier, triode and resistor of the power amplifier circuit are respectively bonded to the corresponding copper conductive strips through high thermal conductivity silver paste and electrically connected through silicon aluminum wire. The copper conductive strips are sintered and fixed on the beryllium oxide substrate arranged on the base. The performance of the power amplifier circuit can be combined with high thermal conductivity, which can effectively improve the heat dissipation of the product and make the power amplifier suitable for the working environment of -55℃~+125℃. At the same time, the closed tube shell adopts a leadless packaging structure, which can effectively reduce the welding space volume of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a circuit schematic diagram of the utility model.

[0015] Figure 2 It is a structural top view of the utility model.

[0016] Figure 3 It is a structural sectional view of the utility model.

[0017] In the figure: outer shell 1, base 2, cover plate 3, silicon aluminum wire 4, beryllium oxide substrate 5, silicon aluminum wire 6, tube shell lead end 7, copper conduction band 8, operational amplifier U1, transistor Q1, transistor Q2, transistor Q3, transistor Q4, resistor R1, resistor R2, resistor R3, resistor R4. DETAILED DESCRIPTION

[0018] The utility model will be further described below in conjunction with the accompanying drawings.

[0019] like Figure 2-3 As shown, the utility model relates to a multi-layer ceramic packaged power amplifier, comprising a closed tube shell, the closed tube shell is formed by connecting a base 2, a shell 1 and a cover plate 3, wherein the shell 1 is made of a multi-layer ceramic material and has a plurality of tube shell lead-out terminals 7 pre-set inside, the tube shell lead-out terminals 7 are made of Kovar alloy 4J42, and high-purity nitrogen is filled in the closed tube shell to achieve an anti-oxidation function. The base 2 is made of tungsten-copper alloy to enhance thermal conductivity.

[0020] A power amplifier circuit is provided on a base 2 in a closed tube shell, and a beryllium oxide substrate 5 is fixedly bonded to the base 2. The operational amplifier, triode and resistor of the power amplifier circuit are respectively bonded to corresponding copper conductive strips 8 through high thermal conductive silver paste and electrically connected through φ40μm silicon aluminum wires 4. The copper conductive strips 8 are respectively sintered and fixed on the beryllium oxide substrate 5 and electrically connected to corresponding tube shell lead-out terminals 7 through φ80μm silicon aluminum wires 6.

[0021] The surfaces of the tube shell lead-out terminal 7 and the copper conductor 8 are plated with a gold layer respectively, and the thickness of the gold layer is 0.2 μm to 0.46 μm, so as to facilitate the bonding of the silicon-aluminum wire.

[0022] like Figure 1 As shown, the power amplifier circuit includes an operational amplifier U1, a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4 and resistors R1, R2, R3 and R4, wherein the positive and negative power input terminals of the operational amplifier U1 are connected to a +15V positive power supply and a -15V negative power supply through resistors R2 and R1 respectively, and the two signal input terminals of the operational amplifier U1 are electrically connected to corresponding shell lead-out terminals 5 and 6 respectively, for external input analog signals;

[0023] The collector and emitter of the transistor Q1 are connected to both ends of the resistor R1, and the collector is electrically connected to the base of the transistor Q2. The collector and emitter of the transistor Q3 are connected to both ends of the resistor R2, and the collector is electrically connected to the base of the transistor Q4. The output end of the operational amplifier U1 is electrically connected to the collectors of the transistors Q2 and Q4 respectively through the resistor R3, and the push-pull circuit output end OUT is led out and electrically connected to the corresponding tube shell lead-out terminal 11 pin;

[0024] The output end of the operational amplifier U1 is electrically connected to the corresponding tube shell lead-out terminal pin 3 through the resistor R4 and is grounded; the output end of the operational amplifier U1 is electrically connected to the corresponding tube shell lead-out terminal pin 2, which is used to lead out the compensation terminal COMP, so as to perform phase margin compensation according to the actual situation of the whole machine using the power amplifier; the pin 1 and pin 5 of the operational amplifier U1 are electrically connected to the corresponding tube shell lead-out terminal pin 7 and pin 8 respectively, which are used to lead out the offset terminal, so as to perform offset adjustment of the operational amplifier U1 according to the actual situation of the whole machine;

[0025] The emitter of the transistor Q4 is electrically connected to the base of the transistor Q3, and the positive power supply overcurrent protection terminal is electrically connected to the corresponding tube shell lead-out terminal 1 pin, which is used to lead out the positive power supply overcurrent protection terminal Isc+, so as to perform positive power supply current limiting control according to the actual situation of the whole machine using the power amplifier; the emitter of the transistor Q2 is electrically connected to the base of the transistor Q1, and the negative power supply overcurrent protection terminal is electrically connected to the corresponding tube shell lead-out terminal 9 pin, which is used to lead out the negative power supply overcurrent protection terminal Isc-, so as to realize negative power supply current limiting control according to the actual situation of the whole machine using the power amplifier.

[0026] The operational amplifier U1 adopts the domestic chip QF741 or the imported chip LM741. The transistors Q1 and Q2 adopt the domestic transistor chip JHAC4793 (NPN) or the imported chip 2SC4793; the transistors Q3 and Q4 adopt the domestic transistor chip JHAC1837 (PNP) or the imported chip 2SA1837.

[0027] The power amplifier circuit can prevent excessive input current through the resistor R1, resistor R2 and transistor Q1 and transistor Q3, and can achieve overload protection for the operational amplifier U1; the push-pull output is formed by the transistor Q2 and the transistor Q4, which enhances the output capacity of the operational amplifier U1, ensuring that the product has the characteristics of higher output current capacity, higher open-loop gain and strong load capacity.

[0028] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multi-layer ceramic packaged power amplifier, comprising a closed tube shell, wherein a power amplifier circuit is arranged on a base inside the closed tube shell, wherein: The closed tube shell is formed by sealingly connecting a base, an outer shell and a cover plate, wherein the outer shell is made of a multilayer ceramic material and has multiple tube shell lead-out terminals built therein, a beryllium oxide substrate is fixed on the base, and the operational amplifier, triode and resistor of the power amplifier circuit are respectively bonded to corresponding copper conductive strips through high thermal conductivity silver paste and electrically connected through silicon aluminum wires, and the copper conductive strips are sintered and fixed on the beryllium oxide substrate.

2. The power amplifier of a multilayer ceramic package according to claim 1, characterized in that: The closed tube shell is filled with high-purity nitrogen.

3. A multi-layer ceramic packaged power amplifier according to claim 1, characterized in that: The surfaces of the tube shell lead-out end and the copper conductor strip are respectively plated with a gold layer, and the thickness of the gold layer is 0.2 μm to 0.46 μm, so as to facilitate the bonding of the silicon-aluminum wire.

4. A multi-layer ceramic packaged power amplifier according to claim 1 or 3, characterized in that: The base is made of tungsten-copper alloy to enhance thermal conductivity.

5. The power amplifier of a multi-layer ceramic package according to claim 1, characterized in that: The power amplifier circuit includes an operational amplifier U1, a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4 and resistors R1, R2, R3 and R4, wherein the positive and negative power input terminals of the operational amplifier U1 are connected to the positive power supply and the negative power supply respectively through the resistor R2 and the resistor R1, the two signal input terminals of the operational amplifier U1 are electrically connected to the corresponding tube shell lead terminals respectively, the collector and emitter of the transistor Q1 are connected to the two ends of the resistor R1 and the collector is electrically connected to the base of the transistor Q2, the collector and emitter of the transistor Q3 are connected to the two ends of the resistor R2 and the collector is electrically connected to the base of the transistor Q4, and the operational amplifier U1 The output end is electrically connected to the collectors of transistor Q2 and transistor Q4 respectively through resistor R3, and the output end of the push-pull circuit is led out; at the same time, the output end of the operational amplifier U1 is grounded through resistor R4; the emitter of the transistor Q4 is electrically connected to the base of the transistor Q3, and the positive power supply overcurrent protection end is led out and electrically connected to the corresponding tube shell lead-out terminal 1 pin, which is used to perform positive power supply current limiting control according to the actual situation of the whole machine using the power amplifier; the emitter of the transistor Q2 is electrically connected to the base of the transistor Q1, and the negative power supply overcurrent protection end is led out and electrically connected to the corresponding tube shell lead-out terminal 9 pin, which is used to perform negative power supply current limiting control according to the actual situation of the whole machine using the power amplifier.

6. The power amplifier of a multi-layer ceramic package according to claim 5, characterized in that: The operational amplifier U1 adopts the domestic chip QF741 or the imported chip LM741.

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