CN107946712B

CN107946712B - Temperature compensation attenuator

Info

Publication number: CN107946712B
Application number: CN201711110391.2A
Authority: CN
Inventors: 廖进福; 沓世我; 付振晓; 杨曌; 罗俊尧; 李保昌
Original assignee: Guangdong Fenghua Advanced Tech Holding Co Ltd
Current assignee: Guangdong Fenghua Advanced Tech Holding Co Ltd
Priority date: 2017-11-09
Filing date: 2017-11-09
Publication date: 2020-12-25
Anticipated expiration: 2037-11-09
Also published as: CN107946712A

Abstract

The invention relates to a temperature compensation attenuator, which comprises a substrate, wherein a first thermistor, a second thermistor, a signal electrode and a ground electrode are arranged on the substrate, and the first thermistor is a thin film PTC (positive temperature coefficient) thermistor; the second thermistor is formed by alternately stacking at least one conductive layer and at least one thin film NTC thermistor, and the conductive layer at the bottommost layer is arranged between the substrate and the thin film NTC thermistor at the bottommost layer; the signal electrode is respectively electrically connected with the first thermistor and the thin-film NTC thermistor, and the ground electrode is electrically connected with the first thermistor or the thin-film NTC thermistor. The second thermistor is formed by alternately stacking at least one conducting layer and at least one thin film NTC thermistor, so that the overall resistance value and the resistance temperature coefficient can be flexibly adjusted in a large range, and the thinning and the serialization of the temperature compensation attenuator are realized.

Description

Temperature compensation attenuator

Technical Field

The invention relates to an attenuator, in particular to a temperature compensation attenuator.

Background

Temperature compensated attenuators (or "temperature variable attenuators") are a class of devices used to stabilize the gain of radio frequency/microwave amplifiers against temperature variations. The gains of GaAs Field Effect Transistors (FETs) and High Electron Mobility Transistors (HEMTs) may vary significantly with temperature. Therefore, for many applications, in order to avoid system anomalies caused thereby, it is necessary to effectively compensate for temperature drift. Methods of temperature compensation can be divided into three categories, including Automatic Level Control (ALC)/Automatic Gain Control (AGC), offset compensation, and the use of temperature compensated attenuators. The ALC/AGC circuit structure is relatively complex, the design and implementation cost is high, the response speed is low, and the reliability is poor; the method of offset compensation requires a separate analysis design for a specific amplifying circuit; the passive temperature compensation attenuator based on the thermistor and the constant value resistor network has the advantages of simple design, low cost, high reliability, high response speed, no frequency distortion and the like, and becomes the primary choice of most radio frequency engineers.

A typical temperature-compensated attenuator is a T-type or Π -type two-port network (as shown in fig. 14) formed by thermistors, wherein the series thermistors and the parallel thermistors respectively have Temperature Coefficients of Resistance (TCR) with opposite signs, so that the attenuation amount changes approximately linearly with the temperature according to a specific slope, and the characteristic impedance is kept substantially constant. Two key performance parameters of a temperature compensated attenuator are the amount of attenuation and its Temperature Coefficient (TCA). The temperature compensation attenuator with proper attenuation and TCA is selected according to the gain and temperature coefficient of the radio frequency amplifier, and the temperature compensation attenuator are connected in series through the transmission line, so that the temperature compensation of the gain of the amplifier can be realized. Due to the different performance parameters of the radio frequency amplifiers, the attenuation of the temperature compensation attenuator and the TCA are required to be serialized. The attenuation and TCA are mainly determined by the resistance value of the thermistor and TCR thereof, for typical attenuation, the resistance value of the thermistor covers the range of several ohms to hundreds of ohms, and the corresponding surface resistivity is between tens of mega ohm/□; for different TCAs, the TCR of the thermistor also covers a wide range, up to thousands of ppm/DEG C. Therefore, the prerequisite for realizing the product serialization is a thermistor material system and a matching process, wherein the thermistor material system has (room temperature) resistivity and TCR (T cell temperature) which can be flexibly adjusted in a large range.

At present, all passive temperature compensation attenuators are manufactured by adopting a thick film process. The American EMC Technology company has the first invention patent of a passive temperature compensation attenuator (US5332981), thick-film Positive Temperature Coefficient (PTC) and Negative Temperature Coefficient (NTC) thermistors and corresponding conductor paste are adopted, devices are manufactured through a screen printing process, two adjacent pastes are selected from the serialized thermistor paste and mixed according to different proportions to adjust the resistivity and TCR, and therefore different attenuation amounts and TCA combinations are obtained. The thick film process has its unique advantages: the attenuation and the temperature coefficient thereof are easy to serialize, the cost is low, and the method is suitable for large-scale production. On the other hand, the thick film process has the following problems: the controllability, repeatability and consistency of the process and performance are low, and the main reason is that the thickness and the line width/line distance precision of the graph are not high enough; the glass phase in the thick film paste generally contains lead, so that the thick film paste is not environment-friendly; meanwhile, the addition of the glass phase obviously improves the resistivity of the material, and obvious parasitic capacitive reactance is easily introduced to influence the high-frequency performance of the device.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the film temperature compensation attenuator with more excellent performance and good consistency, the temperature compensation attenuator can flexibly adjust the integral resistance value and the resistance temperature coefficient in a larger range, and the thinning and the serialization of the temperature compensation attenuator are realized.

In order to achieve the purpose, the invention adopts the technical scheme that: a temperature compensation attenuator comprises a substrate, wherein a first thermistor, a second thermistor, a signal electrode and a ground electrode are arranged on the substrate, and the first thermistor is a thin film PTC thermistor; the second thermistor is formed by alternately stacking at least one conductive layer and at least one thin film NTC thermistor, and the conductive layer at the bottommost layer is arranged between the substrate and the thin film NTC thermistor at the bottommost layer;

the signal electrode is respectively electrically connected with the first thermistor and the thin-film NTC thermistor, and the ground electrode is electrically connected with the first thermistor or the thin-film NTC thermistor.

As a preferred embodiment of the temperature compensation attenuator of the present invention, the conductive layer and the thin film NTC thermistor are both 1 layer or both 2 layers.

As a preferred embodiment of the temperature compensation attenuator, the material of the conducting layer is a metal conductor, and the ratio of the resistivity of the conducting layer to the resistivity of the thin-film NTC thermistor is less than 10^-6(ii) a Or the material of the conducting layer is oxide, and the ratio of the resistivity of the conducting layer to the resistivity of the thin-film NTC thermistor is 3 multiplied by 10^-5～7×10^-4In the meantime.

As a more preferable embodiment of the temperature compensating attenuator of the present invention, the metal conductor is Pt, Au or Pd; the thin-film NTC thermistor is made of a material with the resistivity of 1-100 omega-cm and the thermal sensitive constant (

B value) is 10³A K-order Mn-Co-Cu-O system; the oxide is SnO₂Antimony doped SnO₂、ITO、RuO₂、RhO₂、ReO₂、ReO₃、IrO₂、MRuO₃、LaMnO3、LaCoO₃、LaNiO₃、LaCrO₃、CaVO₃、SrVO₃、SrMoO₃；MRuO₃Wherein M is Sr, Pb, Bi, Ca or Ba.

As a preferred embodiment of the temperature compensating attenuator of the present invention, the temperature compensating attenuator further includes a protective layer covering the first thermistor and the thin-film NTC thermistor.

As a preferred embodiment of the temperature-compensated attenuator of the present invention, an adhesive layer is further provided on the substrate, and the adhesive layer is provided below the conductive layer at the lowermost layer.

As a preferred embodiment of the temperature compensating attenuator of the present invention, the substrate is provided with 2 first thermistors, 1 second thermistors, 2 signal electrodes and 1 ground electrode, wherein 2 signal electrodes respectively cover two side edges of the second thermistors, and 2 signal electrodes respectively cover top edges of 2 first thermistors; the ground electrode covers the bottom edges of 2 first thermistors at the same time.

As a preferred embodiment of the temperature compensating attenuator of the present invention, there are 1 first thermistor, 2 second thermistors, 2 signal electrodes and 1 ground electrode on the substrate, wherein 2 signal electrodes respectively cover two sides of the first thermistor, and 2 signal electrodes respectively cover the top side of 2 second thermistors; the ground electrode covers the bottom edges of 2 second thermistors at the same time.

As a preferred embodiment of the temperature compensating attenuator of the present invention, the substrate is provided with 1 first thermistor, 2 second thermistors, 3 signal electrodes and 1 ground electrode, wherein the 3 signal electrodes are a first end signal electrode, a second end signal electrode and a middle signal electrode in sequence; the first end signal electrode and the second end signal electrode respectively cover the outer side edges of the 2 second thermistors, and the middle signal electrode simultaneously covers the inner side edges of the 2 second thermistors and the top edge of the first thermistor; the ground electrode covers a bottom edge of the first thermistor.

As a preferred embodiment of the temperature compensating attenuator of the present invention, the substrate is provided with 2 first thermistors, 1 second thermistors, 3 signal electrodes and 1 ground electrode, wherein the 3 signal electrodes are a first end signal electrode, a second end signal electrode and a middle signal electrode in sequence; the first end signal electrode and the second end signal electrode respectively cover the outer side edges of the 2 first thermistors, and the middle signal electrode simultaneously covers the inner side edges of the 2 first thermistors and the top edge of the second thermistor; the ground electrode covers a bottom edge of the second thermistor.

Compared with the prior art, the invention has the beneficial effects that: the second thermistor is formed by alternately stacking at least one conducting layer and at least one thin film NTC thermistor, so that the overall resistance value and the resistance temperature coefficient can be flexibly adjusted in a large range, and the thinning and the serialization of the temperature compensation attenuator are realized.

Drawings

FIG. 1 is a schematic structural diagram of a temperature-compensated attenuator in accordance with embodiment 1 of the present invention;

FIG. 2 is a schematic view showing the structure of a temperature compensating attenuator of example 1 of the present invention without a protective layer;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1 in accordance with the present invention;

FIG. 4 is a cross-sectional view taken along line B-B of FIG. 1 in accordance with the present invention;

FIG. 5 shows the total resistance and the resistivity ρ of the conductive layer in example 1 of the present invention₁And resistivity ρ of NTC thermistor₂A relation curve chart of the ratio of (1);

fig. 6 is a resistance temperature characteristic graph of the total resistance of the NTC thermistor of the four-layer stacked structure in embodiment 3 of the present invention;

FIG. 7 is a schematic view showing a structure of a temperature compensating attenuator of example 4 of the present invention without a protective layer;

FIG. 8 is a schematic structural diagram of a temperature-compensated attenuator in accordance with embodiment 5 of the present invention;

FIG. 9 is a schematic view showing the structure of a temperature compensating attenuator of example 5 of the present invention without the protective layer;

FIG. 10 is a cross-sectional view taken along line A-A of FIG. 8 in accordance with the present invention;

FIG. 11 is a cross-sectional view taken along line B-B of FIG. 8 in accordance with the present invention;

FIG. 12 is a schematic view showing the structure of a temperature compensating attenuator of example 6 of the present invention without the protective layer;

FIG. 13 is a typical resistance temperature characteristic graph of a thin film NTC thermistor of a stacked structure in example 12 of the present invention;

FIG. 14 is a schematic diagram of a typical temperature-compensated attenuator.

The chip comprises a substrate 1, a substrate 2, a first thermistor 3, a second thermistor 31, a conducting layer 32, a thin film NTC thermistor 4, a signal electrode 41, a first end signal electrode 42, a second end signal electrode 43, an intermediate signal electrode 5, a ground electrode 6 and a protective layer.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to the accompanying drawings and specific embodiments.

In the invention, the thin film PTC thermistor refers to a positive temperature coefficient thermistor which is prepared by a vacuum deposition process and the resistance value of which is increased along with the temperature rise, and the thin film NTC thermistor refers to a negative temperature coefficient thermistor which is prepared by a vacuum deposition process and the resistance value of which is decreased along with the temperature rise.

Example 1

As shown in fig. 2, a temperature compensating attenuator according to an embodiment of the present invention includes a substrate 1, wherein the substrate 1 is provided with a first thermistor 2, a second thermistor 3, a signal electrode 4 and a ground electrode 5, and the first thermistor 2 is a thin-film PTC thermistor; as shown in fig. 3, the second thermistor 3 is formed by stacking a conductive layer 31 and a thin-film NTC thermistor 32, with the conductive layer 31 interposed between the substrate 1 and the thin-film NTC thermistor 32; as shown in fig. 2, 3 and 4, the signal electrode 4 is electrically connected to the first thermistor 2 and the thin-film NTC thermistor 32, respectively, and the ground electrode 5 is electrically connected to the first thermistor 2 or the thin-film NTC thermistor 32.

In the above structure, the thin film NTC thermistors R in two thickness directions₂、R₃And resistance R of the conductive layer₄Forming a series structure. Wherein, because the gap of the part of the signal electrode 4 covering the NTC thermistor 32 is much larger than the thickness of the thin film NTC thermistor 32, the resistance R of the thin film NTC thermistor 32 parallel to the thin film surface direction₁The resistance value of (A) is as large as the approximate value of an open circuit, so most of the resistance values come from the resistors R in two thickness directions of the thin film NTC thermistor 32₂、R₃And/or resistance R of conductive layer 31₄. This configuration has a total resistance value (resistance R in both thickness directions of the thin film NTC thermistor 32) under typical dimensional parameters₂、R₃And resistance R of the conductive layer₄Sum) versus the ratio of the resistivities of the two layers is shown in figure 5. It is apparent that the total resistance value is a function of the resistivity ρ of the conductive layer 31₁Monotonically increases. Wherein the resistivity p of the conductive layer 31₁And resistivity p of the thin film NTC thermistor 32₂Is less than 10^-6The total resistance hardly follows rho₁And (4) changing. And rho₁/ρ₂At 3X 10^-5～7×10^-4In between, the total resistance value is between 10 and 100 omega.

Due to the adoption of the second thermistor 3 with the laminated structure, the integral resistance value and the resistance temperature coefficient can be flexibly adjusted in a large range, so that the thinning and the serialization of the temperature compensation attenuator are realized.

The thin film laminated NTC thermistor structure is suitable for various types of temperature compensation attenuators, such as T-type, pi-type, bridge T-type, balance T-type or balance pi-type. The temperature compensation attenuator of the present embodiment is a pi-type structure with negative TCA (temperature coefficient), specifically, as shown in fig. 2, 3 and 4, 2

first thermistors

2, 1

second thermistors

3, 2

signal electrodes

4, 1

ground electrode

5, 2 signal electrodes 4 respectively covering two sides of the

second thermistors

3, and 2 signal electrodes 4 respectively covering top edges of the 2 first thermistors 2; the ground electrode 5 covers the bottom sides of the 2 first thermistors 2 at the same time.

It should be noted that the conductive layer and the thin film NTC thermistor are not limited to 1 layer, and the second thermistor may be formed by alternately stacking 2 or more conductive layers and 2 or more thin film NTC thermistors, and when both the conductive layer and the thin film NTC thermistor are 2 or more layers, the lowermost conductive layer is disposed between the substrate and the lowermost thin film NTC thermistor.

In the present invention, the first thermistor 2 may be made of a conductive oxide material having metal conductivity and a high TCR, and preferably, the material of the first thermistor 2 is RuO₂、MRuO₃、RhO₂、ReO₂、ReO₃Or IrO₂And the like. These materials have moderate resistivity and excellent high temperature stability, and different sheet resistance and TCR combinations can be obtained by selecting different material systems and doping, adjusting the film deposition process and heat treatment process parameters. Of these materials, RuO₂Commonly used as base material for resistors and thermistors, for RuO₂The copper-doped PTC thermistor with higher TCR can be prepared.

Because the thin-film NTC thermistor 32 needs to be subjected to high-temperature heat treatment at 500-900 ℃, the material of the conductive layer 31 must have good high-temperature resistance, and maintain good conductivity and relatively smooth surface morphology after the heat treatment, so as to avoid forming obvious 'hillocks' and a partial short circuit of the signal electrode 4 covering the NTC thermistor 32. Preferably, the material of the conductive layer 31 is a high temperature resistant metal conductor, and the resistivity ρ of the conductive layer 31₁Resistivity p of the thin film NTC thermistor 32₂Is less than 10^-6. At this time, the resistance R of the conductive layer 31₄As small as the short-circuit approximation possible, and the NTC thermistor 32 has a resistance R parallel to the film surface₁Can be approximated by an open circuit, so that the total resistance value is mainly determined by the resistance value R in the thickness direction of the thin film NTC thermistor 32₂、R₃And (6) determining. By reducing the area S of the portion of the signal electrode 4 covering the NTC thermistor 32 directly facing the conductive layer 31 or increasing the thickness of the NTC thermistor, the total resistance can be increased within a certain range. Thus, the structure can obtain a small-sized, low-resistance, high-B-value thin-film NTC thermistor.

Preferably, the metal conductor is Pt, Au or Pd; the thin film NTC thermistor 32 is made of a material having a resistivity of 1 to 100. omega. cm and a thermal constant of 10³Mn-Co-Cu-O system with K order of magnitude.

In view of the sensitive characteristics of the thermistor, in order to isolate oxygen and moisture in the environment to slow down the drift of the electrical properties, as shown in fig. 1, the temperature compensating attenuator of the present embodiment further includes a protective layer 6, as shown in fig. 3 and 4, the protective layer 6 covering the first thermistor 2 and the thin-film NTC thermistor 32. The protective layer 6 is an insulating medium, and the material of the insulating medium comprises SiO₂、Si₃N₄And inorganic materials such as SiON, and polymers such as polyimide and epoxy resin. Depending on the material, the insulating medium can be formed by a thin film process such as evaporation, sputtering, Chemical Vapor Deposition (CVD), or a thick film process such as spin coating or screen printing.

In order to increase the adhesion of the conductive layer metal film, the substrate 1 is further provided with an adhesion layer (not shown in the figure) which is arranged below the conductive layer 31 at the lowest layer. The material of the adhesion layer is preferably TiW or NiCr and other metals, and the thickness is 10-100 nm. Preferably, the thickness of the conductive layer 31 is between 100nm and 500nm, and the thickness of the thin film NTC thermistor 32 is between 100nm and 1000 nm. When two sizes Pad _ depth and Pad _ wd of an area of a part of the signal electrode 4 covering the NTC thermistor 32, which is directly opposite to the conducting layer 31, and a Gap _ wd of a part of the signal electrode 4 covering the NTC thermistor 32 are both tens of micrometers, the obtained total resistance value is between 10 and 100 omega; b value-composed NTC thermistorDetermine, still at 10³Of the order of K.

Example 2

The temperature compensation attenuator of the embodiment of the invention is different from the temperature compensation attenuator of the embodiment 1 only in that: in this embodiment, the material of the conductive layer 31 is an oxide, and the ratio of the resistivity of the conductive layer 31 to the resistivity of the thin-film NTC thermistor 32 is 3 × 10^-5～7×10^-4In the meantime. The oxide can adopt binary oxide conductive materials and some composite oxide conductive materials with a perovskite structure, and the oxide needs to have high-temperature resistance. At this time, the resistance of the conducting layer is larger and TCR is smaller, the resistance of the thin film NTC thermistor is smaller and B value is larger, and the conducting layer and the thin film NTC thermistor form a series structure, so that the thin film NTC thermistor with smaller total resistance R and equivalent B value is realized. Fig. 13 is a typical resistance temperature characteristic graph of the thin film NTC thermistor of the stacked structure in this embodiment.

Preferably, the oxide is SnO₂Antimony doped SnO₂、ITO、RuO₂、RhO₂、ReO₂、ReO₃、IrO₂、MRuO₃、LaMnO3、LaCoO₃、LaNiO₃、LaCrO₃、CaVO₃、SrVO₃、SrMoO₃And the like and doped products thereof; MRuO₃Wherein M is Sr, Pb, Bi, Ca or Ba; the thin-film NTC thermistor is made of a material with the resistivity of 1-100 omega-cm and the thermal constant of 10³Mn-Co-Cu-O system with K order of magnitude.

Example 3

The temperature compensation attenuator of the embodiment of the invention is different from the temperature compensation attenuator of the embodiment 1 only in that: in this embodiment, the second thermistor is formed by alternately stacking two conductive layers and two thin-film NTC thermistors, and the lowermost conductive layer is disposed between the substrate and the lowermost thin-film NTC thermistor.

In this embodiment, the thicknesses of the conductive layer and the thin-film NTC thermistor in embodiment 1 are respectively reduced by half, the number of layers is doubled, and alternate deposition is performed to form a four-layer stacked structure, and the sizes of other structures are kept unchanged. Resistance temperature characteristics of the total resistance value of the NTC thermistor of the four-layer stacked structure are shown in fig. 6. As can be seen from comparing fig. 13 and fig. 6, the total resistance of the four-layer stacked structure can be reduced by several Ω on the basis of the two-layer structure, and the equivalent B value can be reduced by several hundreds of K, which is beneficial to better control the microstructure, stress and electrical properties of each layer.

Example 4

The temperature compensation attenuator of the embodiment of the invention is different from the temperature compensation attenuator of the embodiment 1 only in that: the temperature compensation attenuator of the present embodiment is a pi-type structure with positive TCA (temperature coefficient), specifically, as shown in fig. 7, 2

second thermistors

3, 1

first thermistors

2, 2

signal electrodes

4, 1

ground electrode

5, 2 signal electrodes 4 respectively covering two side edges of the

first thermistors

2, and 2 signal electrodes 4 respectively covering top edges of the 2 second thermistors 3; the ground electrode 5 covers the bottom edges of the 2 second thermistors 3 at the same time.

Example 5

The temperature compensation attenuator of the embodiment of the invention is different from the temperature compensation attenuator of the embodiment 1 only in that: the temperature compensation attenuator of the present embodiment is a T-shaped structure with negative TCA (temperature coefficient), specifically, as shown in fig. 8 to 11, a substrate 1 is provided with 1

first thermistor

2, 2 second thermistors 3 (the second thermistor 3 is formed by stacking a conductive layer 31 and a thin film NTC thermistor 32, the conductive layer 31 is disposed between the substrate 1 and the thin film NTC thermistor 32), 3 signal electrodes and 1 ground electrode 5, the 3 signal electrodes are a first end signal electrode 41, a second end signal electrode 42 and a middle signal electrode 43 in this order; the first and second

header signal electrodes

41 and 42 respectively cover the outer sides of the 2 second thermistors 3, and the middle signal electrode 43 simultaneously covers the inner sides of the 2 second thermistors 3 and the top side of the first thermistor 2; the ground electrode 5 covers the bottom side of the first thermistor 2.

Example 6

The temperature compensation attenuator of the embodiment of the invention is different from the temperature compensation attenuator of the embodiment 1 only in that: the temperature compensation attenuator of the present embodiment is a T-shaped structure with positive TCA (temperature coefficient), specifically, as shown in fig. 12, a substrate 1 is provided with 2

first thermistors

2, 1

second thermistors

3, 3 signal electrodes and 1 ground electrode 5, and the 3 signal electrodes are a first end signal electrode 41, a second end signal electrode 42 and an intermediate signal electrode 43 in sequence; the first and second

header signal electrodes

41 and 42 respectively cover the outer sides of the 2 first thermistors 2, and the middle signal electrode 43 simultaneously covers the inner sides of the 2 first thermistors 2 and the top side of the second thermistor 3; the ground electrode 5 covers the bottom side of the second thermistor 3.

The preparation method of the temperature compensation attenuator comprises the following steps:

(1a) depositing the PTC thermistor on the substrate by adopting a thin film process, patterning the PTC thermistor, reserving a part required by design, and carrying out heat treatment on the PTC thermistor;

(2a) depositing at least 1 NTC thermistor and at least 1 conducting layer on the substrate by adopting a thin film process, wherein the NTC thermistor and the conducting layer are alternately stacked, and the conducting layer is in contact with the substrate; patterning the NTC thermistor and the conducting layer, reserving a part required by design, and carrying out heat treatment on the NTC thermistor and the conducting layer;

(3a) depositing a signal electrode and a ground electrode on a substrate by adopting a thin film process, and patterning the signal electrode and the ground electrode;

(4a) covering an insulating medium on the PTC thermistor and the NTC thermistor as protective layers;

(5a) carrying out surface treatment on the unprotected signal electrode and the unprotected ground electrode to obtain a temperature compensation attenuator; or

(1b) Depositing the PTC thermistor on the substrate by adopting a thin film process, patterning the PTC thermistor and reserving a part required by design;

(2b) depositing at least 1 NTC thermistor and at least 1 conducting layer on the substrate by adopting a thin film process, wherein the NTC thermistor and the conducting layer are alternately stacked, and the conducting layer is in contact with the substrate; patterning the NTC thermistor and the conducting layer, and reserving a part required by design;

(3b) simultaneously carrying out heat treatment on the patterned PTC thermistor, the patterned NTC thermistor and the patterned conducting layer;

(4b) depositing a signal electrode and a ground electrode on a substrate by adopting a thin film process, and patterning the signal electrode and the ground electrode;

(5b) covering an insulating medium on the PTC thermistor and the NTC thermistor as protective layers;

(6b) and carrying out surface treatment on the unprotected signal electrode and the unprotected ground electrode to obtain the temperature compensation attenuator.

In the above preparation method, when the two thermistors are simultaneously heat-treated, the deposition and patterning of the NTC thermistor may be performed before the PTC thermistor is manufactured.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A temperature-compensated attenuator, characterized by: the PTC thermistor comprises a substrate, wherein a first thermistor, a second thermistor, a signal electrode and a ground electrode are arranged on the substrate, and the first thermistor is a thin film PTC thermistor; the second thermistor is formed by alternately stacking at least one conductive layer and at least one thin film NTC thermistor, and the conductive layer at the bottommost layer is arranged between the substrate and the thin film NTC thermistor at the bottommost layer;

the number of the signal electrodes is 2 or 3, and the number of the ground electrodes is 1;

the number of the first thermistors and the number of the second thermistors are 3, wherein two ends of one thermistor are respectively electrically connected with the signal electrode, one end of the other thermistor is electrically connected with the signal electrode, and the other end of the other thermistor is electrically connected with the ground electrode, so that a symmetrical resistor network is formed.

2. The temperature-compensated attenuator of claim 1, wherein: the conducting layer and the thin film NTC thermistor are both 1 layer or both 2 layers.

3. The temperature-compensated attenuator of claim 1, wherein: the conducting layer is made of metal conductor, and the ratio of the resistivity of the conducting layer to the resistivity of the thin-film NTC thermistor is less than 10^-6(ii) a Or the material of the conducting layer is oxide, and the ratio of the resistivity of the conducting layer to the resistivity of the thin-film NTC thermistor is 3 multiplied by 10^-5～7×10^-4In the meantime.

4. The temperature-compensated attenuator of claim 3, wherein: the metal conductor is Pt, Au or Pd; the thin-film NTC thermistor is made of a material with the resistivity of 1-100 omega-cm and the thermal constant of 10³A K-order Mn-Co-Cu-O system; the oxide is SnO₂Antimony doped SnO₂、ITO、RuO₂、RhO₂、ReO₂、ReO₃、IrO₂、MRuO₃、LaMnO3、LaCoO₃、LaNiO₃、LaCrO₃、CaVO₃、SrVO₃、SrMoO₃；MRuO₃Wherein M is Sr, Pb, Bi, Ca or Ba.

5. The temperature-compensated attenuator of claim 1, wherein: the temperature compensation attenuator also comprises a protective layer, and the protective layer covers the first thermistor and the thin-film NTC thermistor.

6. The temperature-compensated attenuator of claim 1, wherein: the substrate is further provided with an adhesion layer, and the adhesion layer is arranged below the conductive layer at the bottommost layer.

7. The temperature-compensated attenuator of any one of claims 2 to 6, wherein: the substrate is provided with 2 first thermistors, 1 second thermistor, 2 signal electrodes and 1 ground electrode, wherein the 2 signal electrodes respectively cover two side edges of the second thermistor, and the 2 signal electrodes respectively cover the top edges of the 2 first thermistors; the ground electrode covers the bottom edges of 2 first thermistors at the same time.

8. The temperature-compensated attenuator of any one of claims 2 to 6, wherein: the substrate is provided with 1 first thermistor, 2 second thermistors, 2 signal electrodes and 1 ground electrode, wherein the 2 signal electrodes respectively cover two side edges of the first thermistor, and the 2 signal electrodes respectively cover the top edges of the 2 second thermistors; the ground electrode covers the bottom edges of 2 second thermistors at the same time.

9. The temperature-compensated attenuator of any one of claims 2 to 6, wherein: the substrate is provided with 1 first thermistor, 2 second thermistors, 3 signal electrodes and 1 ground electrode, wherein the 3 signal electrodes are a first end signal electrode, a second end signal electrode and a middle signal electrode in sequence; the first end signal electrode and the second end signal electrode respectively cover the outer side edges of the 2 second thermistors, and the middle signal electrode simultaneously covers the inner side edges of the 2 second thermistors and the top edge of the first thermistor; the ground electrode covers a bottom edge of the first thermistor.

10. The temperature-compensated attenuator of any one of claims 2 to 6, wherein: the substrate is provided with 2 first thermistors, 1 second thermistor, 3 signal electrodes and 1 ground electrode, wherein the 3 signal electrodes are a first end signal electrode, a second end signal electrode and a middle signal electrode in sequence; the first end signal electrode and the second end signal electrode respectively cover the outer side edges of the 2 first thermistors, and the middle signal electrode simultaneously covers the inner side edges of the 2 first thermistors and the top edge of the second thermistor; the ground electrode covers a bottom edge of the second thermistor.