RU2556271C1 - Microwave integrated circuit - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: microwave integrated circuit comprises a dielectric substrate made of diamond, elements of the integrated circuit - active and passive elements, transmission lines, outputs; at the reverse side of the dielectric substrate there is metallised coating, at that the elements of the integrated circuits are connected electrically and grounded as per its electrical circuit. At the face of the above dielectric substrate there is an additional layer of crystalline semi-insulating silicon with the thickness of less than 10 mcm and the elements of the integrated circuit - active and passive elements, transmission lines, outputs are made at the surface of the above layer. The elements of the integrated circuit are monolithic, in the above dielectric substrate and the layer of crystalline semi-insulating silicon there are plated-through holes and the integrated circuit is grounded by means of the above plated-through holes.

EFFECT: improved electrical performance and their improved reproducibility, improved reliability, reduced weight and dimensions, reduced labour intensity for manufacturing of the microwave integrated circuit.

6 cl, 7 dwg, 1 tbl

Description

The invention relates to electronic equipment, namely microwave integrated circuits, and can be widely used in microwave electronic equipment, in particular in radar stations with phased antenna arrays (PAR).

The main characteristics of the microwave integrated circuit and especially in the latter case of its application are the output power, efficiency (Efficiency) and weight and size characteristics.

A known microwave integrated circuit containing a dielectric board with coplanar lines, passive and active elements placed on one side thereof, mounted on a metal base, and conclusions, in which, in order to simplify the design, reduce cost, improve electrical characteristics, the dielectric board is mounted on the metal base containing coplanar lines [1].

This microwave integrated circuit, due to the presence of a coplanar transmission line, makes it easy to turn on passive elements, including shunts without wire connections, and thereby partially, but partially, reduce the number and length of wire connections, thereby partially reducing the spread of electrical characteristics and, as the consequence is an increase in their reproducibility and an increase in the reliability of the microwave integrated circuit.

A known microwave integrated circuit containing a dielectric substrate, on the front side of which are made passive elements, including shunt - capacitors and resistors, coplanar transmission lines and conclusions and installed active elements.

In this integrated circuit, in order to improve the electrical characteristics, the active components are mounted on the dielectric board with the front side, and on the front side of the dielectric board at the junction of the shunt elements and at the points of heat removal from the active components, metal poles with a section and height of 40-50 μm are made, by the dielectric board is installed face-down on the metal base, and the recess in the metal base is made only under the active components [2].

The presence and indicated location of the mentioned metal poles in the microwave integrated circuit allowed:

firstly, to almost completely eliminate wire connections and thereby minimize the spread of electrical characteristics and, as a result, increase their reproducibility and increase the reliability of the microwave integrated circuit,

secondly, to remove heat from active elements in the shortest way and thereby improve heat dissipation and, as a result, improve electrical characteristics and increase the reliability of the microwave integrated circuit.

A known microwave integrated circuit containing a dielectric substrate on the front side of which is made only of passive elements or passive elements, transmission lines, terminals and mounted active elements, while the elements are electrically connected, the integrated circuit is grounded, in which, in order to improve electrical characteristics, increase reliability, reducing the overall dimensions, the dielectric substrate is made of a diamond plate with a thickness of 100-200 μm, which has a metallization coating, while the lamination coating is made in the form of a continuous layer on the back and end sides and a local layer on the front side of the said dielectric substrate, wherein said layers are made of the same thickness equal to each 3-7 depths of the skin layer, and the grounding of the integrated circuit is made by the said metallization coating, and mounted active elements are made on a crystal with a thickness of 100 μm [3] - a prototype.

This microwave integrated circuit with sufficiently high electrical characteristics is widely used in amplifiers and microwave generators, various microwave conversion circuits, including radar stations with phased antenna arrays, which include many (about a thousand) identical elements.

However, the above advantages of this design in some cases (high-power amplifiers, high-power switches, powerful protective devices) are insufficient when required:

firstly, more efficient heat dissipation,

secondly, a significant increase in the reproducibility of electrical characteristics,

thirdly, a significant decrease in weight and size characteristics.

This is due to both the minimum possible crystal thickness of the active element, which is about 100 μm, and the accuracy and quality of its mounting on a dielectric substrate.

The technical result is to improve electrical characteristics and increase their reproducibility, increase reliability, reduce weight and size characteristics, reduce the complexity of manufacturing an integrated circuit microwave.

The specified technical result is achieved by the claimed microwave integrated circuit containing a dielectric substrate made of diamond, integrated circuit elements are active and passive elements, transmission lines, leads, a metallization coating is made on the reverse side of the dielectric substrate, while the integrated circuit elements are electrically connected and grounded according to its electrical circuit, in which on the front side of said dielectric substrate an additional layer of crystalline semi-insulated is made total silicon with a thickness of not more than 10 μm,

and elements of the integrated circuit - active and passive elements, transmission lines, conclusions are made on the surface of this layer of crystalline semi-insulating silicon,

while the elements of the integrated circuit are made integrally,

through said dielectric substrate and a layer of crystalline semi-insulating silicon, through metallized holes are made,

and the integrated circuit is grounded through these through metallized holes.

The dielectric substrate can be made of natural diamond or artificial, including polycrystalline CVD diamond.

The metallization coating is made in the form of a direct sequence of a system of well-conducting metals, for example, nickel-gold, or titanium-molybdenum-nickel-gold, or titanium-tungsten-nickel-gold with an adhesive sublayer.

The microwave integrated circuit can be performed, for example, in the form of a microwave power amplifier, microwave power switch, driver.

The active element is made, for example, in the form of gallium or silicon nitride field effect transistor or diode.

The transmission lines can be made in the form of coplanar, or microstrip, or slot.

Disclosure of the invention.

The set of essential features of the declared microwave integrated circuit, namely when:

on the front side of said dielectric substrate, a layer of crystalline semi-insulating silicon with a thickness of not more than 10 μm is additionally made,

and integrated circuit elements - active and passive elements, transmission lines, conclusions are made on the surface of this layer of crystalline semi-insulating silicon and in the aggregate when the dielectric substrate is made of diamond, which is the best dielectric material known today and at the same time has the best thermal conductivity (coefficient thermal conductivity of diamond - (1001-2600) W / (m × K)

while the elements of the integrated circuit are made integrally,

through metallized holes are made in a dielectric substrate made of diamond and a layer of crystalline semi-insulating silicon.

This will provide:

firstly, the ability to produce on this layer of crystalline semi-insulating silicon all the elements of the integrated circuit - active elements (field effect transistors and diodes), passive elements, outputs and through metallized holes in a dielectric substrate made of diamond, and a layer of crystalline semi-insulating silicon monolithically - a single technological cycle, including in conditions of mass production and, as a result, improved reproducibility of electrical characteristics and reduced labor intensity laziness;

secondly, the planarity of the structure necessary for the application of modern methods of photolithography, projection lithography, electron lithography, molecular beam and gas-phase epitaxy, etc. in the manufacture of microwave integrated circuits and, as a result, improved reproducibility of electrical characteristics, reduced mass and size characteristics and the complexity of manufacturing ;

thirdly, an improvement in heat removal, primarily from active elements, and, as a result, a significant improvement in the electrical characteristics and reliability of the microwave integrated circuit by lowering the temperature of the active elements.

The implementation of a layer of crystalline semi-insulating silicon with a thickness of more than 10 microns is undesirable, as it leads to:

firstly, to the deterioration of heat removal from active elements,

secondly, to increase weight and size characteristics.

The gain in heat removal efficiency can be estimated based on the thermal conductivity of the crystal material of the active element and its structural thickness.

Proceeding from this, the gain for gallium nitride transistors compared to the prototype is about 3 times for silicon carbide, and 10 times for silicon transistors (their thermal conductivity is (490, 150 W / (m × K, respectively).

The implementation of through metallized holes in a dielectric substrate of diamond and a layer of crystalline semi-insulating silicon provides grounding of the terminals of each of the elements provided by the electrical circuit in the shortest way and, as a result, improves electrical characteristics, increases their reproducibility and reduces the overall dimensions of the microwave integrated circuit.

So, the claimed microwave integrated circuit will fully provide the claimed technical result, namely, improving electrical characteristics and increasing their reproducibility, increasing reliability, reducing weight and size characteristics, reducing the complexity of manufacturing an integrated microwave circuit.

The claimed invention is illustrated by drawings.

Figure 1 gives the topology of the claimed integrated circuit microwave, where:

- dielectric substrate - 1,

- active and passive elements - 2 and 3, respectively,

- transmission lines - 4,

- conclusions - 5,

- metallization coating - 6,

- a layer of crystalline semi-insulating silicon - 7,

- through metallized holes - 8.

Figure 2 (a, b), 3 (a, b), 4 (a, b) shows the topology of particular cases of the implementation of the claimed integrated circuit - a single-stage microwave power amplifier, microwave power switch and driver, and their electrical circuits, respectively.

Figure 5 (curves a, b) shows the dependence on the operating frequency of the output power and the gain of a single-stage microwave power amplifier, respectively.

Figure 6 (curves a, b) depending on the operating frequency of the output power and efficiency of a single-stage microwave power amplifier, respectively.

In Fig. 7 (curves a, b), the direct and reverse losses of the microwave power switch, respectively, at an input power of 5 watts, depending on the operating frequency.

Examples of specific performance of the claimed integrated circuit microwave and special cases of its implementation.

Example 1

On the front side of the dielectric substrate made of diamond 1, a thickness of 100 μm made a layer of crystalline semi-insulating silicon 7 with a thickness of 5 μm,

on the front side of which (a layer of crystalline semi-insulating silicon 7) monolithically made - active elements 2 in the form of a high-power gallium nitride field-effect transistor with a Schottky barrier (PTSh) 2, passive elements 3 in the form of inductance, capacitance, resistance, transmission line 4 of the coplanar type , conclusions 5, on the reverse side is a continuous metallization coating 6 in the form of a direct sequence of a system of well-conducting metals titanium-molybdenum-nickel-gold with a total thickness of 3 μm,

wherein the elements are connected electrically by microstrip lines 4 with different wave impedances according to the electrical circuit of the microwave integrated circuit,

in a dielectric substrate made of diamond 1 and a layer of crystalline semi-insulating silicon 7, through metallized holes 8 are made, through which the integrated circuit is grounded according to the electric circuit of the microwave integrated circuit.

At the same time, all of these elements of the microwave integrated circuit are manufactured using thin-film technology (photolithography, projection lithography, electron lithography, molecular beam and gas-phase epitaxy, etc.), which ensures the precision manufacturing of all elements of the microwave integrated circuit in a single technological cycle.

Examples 2, 4, 5, 7, 8.

Analogously to example 1, special cases of the declared microwave integrated circuit according to the topology and electrical circuit of each of the following products are made — microwave power amplifier (example 1, 2), high-power microwave switch (example 4, 5), driver (example 7, 8).

Examples 3, 6, 9 correspond to a prototype sample.

The operation of the claimed microwave integrated circuit is also considered with examples - a single-stage microwave power amplifier, microwave power switch, driver.

One-stage microwave power amplifier.

A single-stage microwave power amplifier is made on the active element - a powerful gallium nitride field-effect transistor with a Schottky barrier (PTSh) 2 according to the scheme with a common source. The circuit contains input matching circuits between cascades and output. Matching is carried out using passive elements 3 - matching capacitors (CC) and segments of the microstrip transmission line (L) 4. For isolation between cascades of direct current and power supply, decoupling capacitors (Cp) are used 3. Blocking capacitors are used to block power supplies (Sb) ) 3. The amplifier is powered by two power sources. One positive polarity feeds the drain circuit of gallium PTSh 2 nitride, the second negative polarity provides the necessary bias voltage on the gates of gallium PTSh 2 gates.

When applying input power to the amplifier input, an amplified signal is obtained at the amplifier output in the frequency range 9-10 GHz.

Microwave power switch.

The microwave power switch is a transistor circuit for switchable gallium nitride PTSH 2. The microwave power switch operates in discrete mode depending on the control voltage U1 and U2 (0 or -40) V supplied to its control contacts.

When applying a constant control voltage U of a value of 0 V to gallium-nitride PTSh 2 gate electrodes, gallium PTSh 2 gates become open, and when a gallium nitride PTSh 2 gate electrodes supply a constant control voltage U of -40 V, gallium nitride PTSh 2 become closed.

The control voltage to the gate electrodes of the gallium nitride PTSh 2 microwave power switches is supplied in antiphase and always one pair of gallium nitride PTSh is closed and the other is open.

When discrete control voltages U1 and U2 (0 and -40) are applied to the control contacts of the microwave power switch, voltage is applied to the gate electrodes of the gallium nitride gates through decoupling resistors (R) 3, the microwave power switch connects the microwave input to microwave output 1 and vice versa when applying to the control contacts of the switch U1 and U2 discrete control voltages (-40 V and 0), the microwave power switch connects the microwave input to the output of microwave 2.

Driver.

The driver is a transistor-diode circuit based on the active elements 2 - silicon PTSh and diodes. The driver operates in discrete mode, depending on the control voltage at its input (0 or +5) V, while at the outputs 1 and 2 the driver gives out two paraphase voltages U1 and U2 (0 and -40) V, necessary for controlling the power switch Microwave The voltage at the gate electrodes of silicon PTSh 2 is supplied through a chain of bias diodes (D) 2, and two paraphase voltages U1 and U2 (0 and -40) are removed from the drains of the output silicon (PTS) 2.

When a voltage of 0 V is applied to the driver input, voltages U1 = 0 V and U2 = -40 V are generated at its two outputs, and vice versa, when a voltage of +5 V is applied to the driver input, voltages U1 = -40 V and U2 = are generated at its two outputs 0 V.

On the samples of the claimed integrated circuit microwave, single-stage microwave power amplifier and microwave power switch were measured:

- depending on the operating frequency of the output power and the gain of a single-stage microwave power amplifier (Fig. 5 curves a, b), respectively,

- depending on the operating frequency of the output power and efficiency of a single-stage microwave power amplifier (Fig.6 curves a, b), respectively,

- depending on the operating frequency of the magnitude of the direct and reverse losses of the microwave power switch (Fig. 7 curves a, b), respectively, with an input power of 5 watts.

Reliability assessment was carried out on samples of a single-stage power amplifier according to the ET-361 method by means of accelerated tests.

The acceleration coefficient is determined by the formula at E a = 0.8 eV:

where E _a is the activation energy,

T _osn.n - temperature of the nominal mode,

T _osn.f - temperature of the forced mode.

The assessment shows that the gain in reliability is more than 20 percent (%).

From the presented dependencies of Fig. 5 (curves a, b), Fig. 6 (curves a, b), Fig. 7 (curves a, b) it can be seen that:

- the gain, output power and efficiency in the working frequency band are resonant in nature and equal to approximately (9-10) dB, (4-5) W and (40-45) percent, respectively, for a single-stage microwave power amplifier (Fig. 5 curves a 6 and 6, curves a, b), respectively,

- the magnitude of direct losses in the working frequency band is approximately (0.9-1.1) dB, the magnitude of the return losses is (25-22) dB in Fig. 7 curves a-b), respectively, at an input power of 5 W.

Thus, the claimed microwave integrated circuit will allow, in comparison with the prototype:

- increase the gain by 30%,

- increase the output power by about 20%,

- increase efficiency by 10%,

- reduce direct losses by 10%,

- increase the return loss by 2 dB,

- increase reliability by about 20%,

- significantly reduce weight and size characteristics by about 2 times.

This microwave integrated circuit with high electrical characteristics, high reliability and small weight and size characteristics is especially in demand in radar stations with phased antenna arrays, which, as indicated above, include many (more than a thousand) identical elements - products.

Information sources

1. RF patent No. 2067362 IPC, priority 05/26/1983, publ. 09/27/1996

2. RF patent №2258330 IPC H05K 3/10, priority 01.08.2003, publ. 08/10/2005

3. RF patent No. 2474921 IPC H01L 27/00, H05K 1/00, priority 08/30/2011, publ. 02/10/2013, the prototype.

Table No. p / p Construction parameters Measured characteristics Amplifier Power switch Driver The thickness of the layer of crystalline semi-insulating silicon, microns Type of execution Ku, db Burst, W Efficiency% Direct loss, dB Return loss, dB Uвx, В U1, B U2, V one 5 monolithic 9-10 4-5 40-45 - - - - - 2 10 monolithic 8.5-9.5 3.5-4.5 35-40 - - - - - prototype absent hybrid monolithic 8-9 3-4 30-35 - - - - - one 5 monolithic - - - 0.9-1.1 25-22 - - - 2 10 monolithic - - - 1-1,2 24-21 - - - prototype absent hybrid monolithic - - - 1.4-1.6 23-20 - - - one 5 monolithic - - - - - 0 0 -40 +5 -40 0 2 10 monolithic - - - - - 0 0 -40 +5 -40 0 prototype absent hybrid monolithic - - - - - 0 0 -40 +5 -40 0

Claims (6)

1. A microwave integrated circuit containing a dielectric substrate made of diamond, integrated circuit elements — active and passive elements, transmission lines, leads, a metallization coating is made on the reverse side of the dielectric substrate, while the integrated circuit elements are electrically connected and grounded according to its electrical circuit characterized in that on the front side of said dielectric substrate, a layer of crystalline semi-insulating silicon with a thickness of not more than 10 μm is additionally made, and nt integrated circuit - active and passive elements, transmission lines, conclusions are made on the surface of this layer of crystalline semi-insulating silicon, while the elements of the integrated circuit are made integrally, in the aforementioned dielectric substrate and the layer of crystalline semi-insulating silicon, through metallized holes are made, and the integrated circuit is grounded by means of these through metallized holes. 2. The microwave integrated circuit according to claim 1, characterized in that the dielectric substrate can be made of natural diamond or artificial, including polycrystalline CVD diamond. 3. The microwave integrated circuit according to claim 1, characterized in that the metallization coating is made in the form of a direct sequence of a system of well-conducting metals, for example, nickel-gold, or titanium-molybdenum-nickel-gold, or titanium-tungsten-nickel-gold with adhesive sublayer. 4. The microwave integrated circuit according to claim 1, characterized in that the microwave integrated circuit can be performed, for example, in the form of a microwave power amplifier, microwave power switch, driver. 5. The microwave integrated circuit according to claim 1, characterized in that the active element is made, for example, in the form of gallium nitride or silicon field-effect transistor or semiconductor diode. 6. The microwave integrated circuit according to claim 1, characterized in that the transmission lines can be made in the form of coplanar, or microstrip, or slotted.

Images