CN114499452A - Miniaturized temperature compensation crystal oscillator - Google Patents

Abstract

The embodiment of the invention discloses a miniaturized temperature compensation crystal oscillator, which comprises: the temperature compensation device comprises a base, a first crystal resonator component, a second crystal resonator component, a temperature compensation chip and a filter capacitor component, wherein the first crystal resonator component, the second crystal resonator component, the temperature compensation chip and the filter capacitor component are arranged on the base and are electrically connected through the base; the first crystal resonator component is complementary to the second crystal resonator component to counteract oscillation; the temperature compensation chip is used for carrying out temperature compensation on the first crystal resonator component and the second crystal resonator component; and the filter capacitor assembly is used for filtering the temperature compensation chip. The two complementary crystal resonators are arranged, so that the phase noise deterioration degree of the crystal resonator under the severe vibration condition is optimized, the requirements of electronic equipment on miniaturization, high precision and vibration resistance of the temperature compensation crystal oscillator are met, and the crystal resonator has a wide application prospect.

Description

A miniaturized temperature compensated crystal oscillator

technical field

The present invention relates to the technical field of oscillators. More specifically, it relates to a miniaturized temperature compensated crystal oscillator.

Background technique

With the wide application of high-precision temperature-compensated crystal oscillators in electronic equipment, higher requirements have been placed on temperature-compensated crystal oscillators in terms of volume, temperature, frequency-temperature stability, vibration resistance and shock resistance. It is designed in terms of high precision and anti-vibration performance to achieve miniaturization, high index and high reliability of products, and to meet the relevant requirements of electronic equipment.

In the traditional temperature-compensated crystal oscillator in a working environment with severe vibration, the vibration transmitted to the crystal oscillator will affect the stability of the output signal, resulting in deviation of the output frequency, system performance degradation, and abnormal operation of the electronic system may occur in severe cases. . Therefore, it cannot meet the high-precision requirements of temperature-compensated crystal oscillators under severe vibration conditions.

SUMMARY OF THE INVENTION

In order to solve at least one of the above problems, the present application proposes a miniaturized temperature compensated crystal oscillator, comprising: a base, a first crystal resonator assembly, a second crystal resonator assembly, a temperature compensated chip, and filter capacitor assembly, wherein,

The first crystal resonator assembly, the second crystal resonator assembly, the temperature compensation chip, and the filter capacitor assembly are electrically connected through the base;

The first crystal resonator component and the second crystal resonator component are complementary to cancel oscillation;

The temperature compensation chip is used to perform temperature compensation on the first crystal resonator assembly and the second crystal resonator assembly;

The filter capacitor component is used for filtering the temperature compensation chip.

In a specific embodiment, the first crystal resonator assembly includes: a first crystal ceramic base, a first crystal quartz wafer, a first crystal gold electrode and a first crystal metal cover plate.

In a specific embodiment, the second crystal resonator assembly includes: a second crystal ceramic base, a second crystal quartz wafer, a second crystal gold electrode and a second crystal metal cover plate.

In a specific embodiment, the first crystalline gold electrode is disposed on the first crystalline quartz wafer through a coating process to form a first crystalline quartz oscillator;

The first crystal quartz oscillator is bonded to the first crystal ceramic base through conductive glue;

The first crystal metal cover plate is welded to the first crystal ceramic base by a parallel soldering packaging technology to form a first crystal resonator assembly.

In a specific embodiment, the second crystalline gold electrode is disposed on the second crystalline quartz wafer through a coating process to form a second crystalline quartz oscillator;

The second crystal quartz oscillator is bonded to the second crystal ceramic base through conductive glue;

The second crystal metal cover plate is welded to the second crystal ceramic base by the parallel soldering packaging technology to form a second crystal resonator assembly.

In a specific embodiment, the filter capacitor assembly includes: a first filter capacitor, a second filter capacitor and a third filter capacitor, wherein the filter capacitor assembly is adhered to the capacitor pad of the base through conductive glue to filter the temperature compensation chip.

In a specific embodiment, the temperature compensation chip is adhered to the groove in the base by conductive glue;

The pins of the temperature compensation chip and the pads of the base are electrically connected by gold wire bonding.

In a specific embodiment, the first crystal resonator and the second crystal resonator are bonded to the pads of the base through conductive glue, so as to complete the assembly of the miniaturized temperature compensated crystal oscillator.

In a specific embodiment, the models of the first crystal ceramic base and the second crystal ceramic base are SMD3225 crystal bases.

In a specific embodiment, the model of the base is SMD7050 crystal base.

The beneficial effects of the present invention are as follows:

Aiming at the existing problems at present, the present application formulates a miniaturized temperature-compensated crystal oscillator. By setting two complementary crystal resonators, the phase noise deterioration degree under severe vibration conditions is optimized, which satisfies the requirements of electronic equipment for temperature-compensated crystal oscillators. The demand for miniaturization, high precision and vibration resistance has a wide range of application prospects.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 shows a schematic structural diagram of a miniaturized temperature-compensated crystal oscillator according to an embodiment of the present application.

FIG. 2 shows a schematic structural diagram of a first crystal resonator assembly according to an embodiment of the present application.

FIG. 3 shows a schematic structural diagram of a second crystal resonator assembly according to an embodiment of the present application.

FIG. 4 shows a schematic diagram of a packaged temperature compensated crystal oscillator according to an embodiment of the present application.

Detailed ways

In order to illustrate the present application more clearly, the present application will be further described below with reference to the preferred embodiments and the accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present application.

In order to meet the requirements of high stability of temperature-compensated crystal oscillator products under severe vibration conditions and the requirements of product miniaturization, it is necessary to design the product in terms of miniaturization and high precision. The present invention proposes a miniaturized temperature-compensated crystal oscillator, such as As shown in Figure 1, the temperature compensated crystal oscillator includes:

The base 10 , the first crystal resonator assembly 20 , the second crystal resonator assembly 30 , the temperature compensation chip 40 , and the filter capacitor assembly 50 disposed on the base 10 .

In this embodiment, the base 10 is used to place the first crystal resonator assembly 20 , the second crystal resonator assembly 30 , the temperature compensation chip 40 , and the filter capacitor assembly 50 , and to electrically connect the components and provide final input and output. port. The first crystal resonator assembly 20 , the second crystal resonator assembly 30 , the temperature compensation chip 40 , and the filter capacitor assembly 50 are electrically connected through the base 10 .

Those skilled in the art can understand that the miniaturization of the surface mount dual-crystal thermocompensated ceramic base determines the final size. Therefore, in this embodiment, the miniaturization of the surface mount dual-crystal resonator thermocompensated ceramic base is the basis for the product to realize the SMD7050 package. In other words, the model of the base is SMD7050 crystal base.

In an optional example, as shown in FIG. 2 , the first crystal resonator assembly 20 includes: a first crystal ceramic base 200 , a first crystal quartz wafer 202 , a first crystal gold electrode 204 and a first crystal metal cover board 206, wherein, in a specific manufacturing process,

First, a first crystalline gold electrode 204 is disposed on the first crystalline quartz wafer 202 through a coating process to form a first crystalline quartz resonator.

That is to say, the first crystalline gold electrode 204 is used as the electrode of the first crystalline quartz wafer 202 to make the first crystalline quartz oscillator. It should be noted that the electrode film layer produced by traditional evaporation coating has poor adhesion, and there is a large stress inside the electrode film, between the electrode film and the wafer, which affects the aging rate of the product. By using the high vacuum ion beam sputtering coating process, the vacuum degree is higher than the traditional evaporation coating, the coating firmness is improved, the film stress is reduced, the film adhesion of the electrode film on the wafer surface is enhanced, and the stress is reduced. The long-term stability of the product makes the aging performance of the product better. In this example, ion etching is used for fine-tuning, that is, ion beam is used to etch the electrode material in a small amount, and the frequency is adjusted in a small amount. The etching and fine-tuning can avoid the adhesion and film stress caused by the secondary evaporation, thereby reducing the aging rate of the product. .

In this example, a first crystalline gold electrode is plated on the first crystalline quartz wafer 202 for cooperating with the temperature compensation chip to generate an oscillation circuit. Due to the method of using the register to control the coefficients of multiple terms, the required control voltage can only be formed according to the polynomial smooth curve, which cannot compensate for the sudden jump of the resonator attached to the smooth curve. Therefore, it is required that the frequency temperature characteristic curve is smooth, and the frequency jump point should not exceed 1/2 of the required temperature frequency difference. By adjusting the cutting angle of the first quartz wafer, the frequency and temperature stability characteristics of the first quartz oscillator are optimized, so that it better matches the compensation algorithm curve of the temperature compensation chip, and by adjusting the width-thickness ratio of the wafer, the quartz oscillator is reduced. The frequency jump variable generated with temperature changes optimizes the frequency temperature stability characteristics of the product, so that the frequency jump point is less than ±0.5ppm.

Next, the first crystal quartz oscillator is bonded to the first crystal ceramic base 200 by conductive glue. The first crystal ceramic base is an SMD3225 surface mount crystal ceramic base, which is used to place the first crystal quartz oscillator and the first crystal metal cover plate, and to electrically connect each part and provide the final input and output ports.

Finally, the first crystalline metal cover plate 206 is soldered to the first crystalline ceramic base 200 by parallel soldering packaging technology to form the first crystal resonator assembly 20 .

In an optional example, as shown in FIG. 3 , the second crystal resonator assembly 30 includes: a second crystal ceramic base 300 , a second crystal quartz wafer 302 , a second crystal gold electrode 304 and a second crystal metal cover board 306, wherein, in a specific manufacturing process,

First, a second crystalline gold electrode 304 is disposed on the second crystalline quartz wafer 302 through a coating process to form a second crystalline quartz oscillator;

That is to say, a second crystal gold electrode is plated on the second crystal quartz wafer, which is used to cooperate with the temperature compensation chip to generate an oscillation circuit; Two crystal quartz oscillator.

Next, the second crystal quartz oscillator is bonded to the second crystal ceramic base through conductive glue; the second crystal ceramic base is an SMD3225 surface mount crystal ceramic base, which is used to place the second crystal quartz oscillator and the second crystal metal cover, and make electrical connections to various parts and provide final input and output ports.

It should be noted that since the low acceleration sensitivity dual crystal resonator is the core component of the entire crystal oscillator, two first crystal resonator assemblies 20 and second crystal resonator assemblies 30 with similar acceleration sensitivity performance must be selected for symmetry. combination so that their acceleration sensitivities cancel each other, in other words, the first crystal resonator assembly 20 and the second crystal resonator assembly 30 are complementary. The crystal quartz wafer 302 is assembled in the opposite direction, so as to cancel the oscillation and optimize the degree of phase noise deterioration under severe vibration conditions, so as to meet the requirements of electronic equipment in terms of miniaturization, high precision and vibration resistance of temperature compensated crystal oscillators .

Finally, the second crystal metal cover plate is welded to the second crystal ceramic base by parallel soldering packaging technology to form a second crystal resonator assembly.

In an optional example, the temperature compensation chip 40 is used to perform temperature compensation on the first crystal resonator assembly 20 and the second crystal resonator assembly 30 . In other words, the temperature compensation chip 40 is used to cooperate with the first crystal resonator and the second crystal resonator to generate an oscillation circuit, perform temperature compensation calculation on the two crystal resonators, and finally output a high-precision frequency signal.

In this embodiment, in order to realize the miniaturization of the crystal quartz oscillator, each part of the circuit adopts an integrated design, in which the main oscillator circuit, the filter circuit and the compensation network are integrated on a temperature compensation chip. By designing the compensation algorithm curve of the higher order term , greatly improves the accuracy of temperature compensation, so that the crystal oscillator can achieve the frequency stability of ≤±1ppm in the wide temperature range of -55℃～+85℃.

It should also be noted that the temperature compensation chip is bonded to the groove in the base through conductive glue; the pins of the temperature compensation chip and the pads of the base are bonded by gold wire. Electrical connections. In order to protect the temperature compensation chip, epoxy resin is filled into the groove in the ceramic base of the temperature compensation crystal oscillator through the glue filling process, and the temperature compensation chip is sealed and protected.

In an optional example, the filter capacitor component 50 is used to filter the temperature compensation chip 40 . As shown in FIG. 1 , it includes: a first filter capacitor 500 , a second filter capacitor 502 and a third filter capacitor 503 , wherein the filter capacitor component is adhered to the capacitor pad of the base through conductive glue to realize Filtering the temperature compensation chip.

It should be noted that the present application does not limit the number of filter capacitors, as long as the filter capacitor assembly 50 can realize the function of filtering the temperature compensation chip 40 .

In this embodiment, the first crystal resonator component, the second crystal resonator component, and the filter capacitor component are bonded to the pads of the base through conductive adhesive, and the The temperature compensation chip is assembled in the base to complete the assembly of the miniaturized temperature compensation crystal oscillator, forming a miniaturized low acceleration sensitivity temperature compensation crystal oscillator product in physical form as shown in Figure 4. Its external dimensions are SMD7050, length × width × height : 7mm×5mm×2mm(max), the product adopts ceramic metal package, which is a split TCXO structure. The split TCXO structure resonator and oscillation circuit chip are packaged separately. The upper part is the dual crystal resonator and the capacitor, and the lower part is the ceramic base packaged with the temperature compensation chip. The two parts are bonded by conductive glue. assembled.

After the assembly is completed, debug and test the temperature compensated crystal oscillator, such as wide temperature compensation. After debugging, test the electrical performance index and frequency temperature stability at room temperature, and eliminate the products with unqualified electrical performance index and frequency temperature stability index, so that the normal temperature electrical performance and frequency temperature stability of the crystal oscillator meet the target requirements, so as to make the product stability It is better than ±1ppm in the range of -55℃～+85℃, and its phase noise deterioration degree is optimized under severe vibration conditions.

By setting two complementary crystal resonators, the present application optimizes the degree of phase noise deterioration under severe vibration conditions, and meets the requirements of electronic equipment for miniaturization, high precision and vibration resistance of temperature-compensated crystal oscillators, and has a wide range of applications. application prospects.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Changes or changes in other different forms cannot be exhausted here, and all obvious changes or changes derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims (10)

1. A miniaturized temperature-compensated crystal oscillator, comprising: a base, a first crystal resonator assembly, a second crystal resonator assembly, a temperature-compensated chip, and a filter capacitor assembly arranged on the base, in, The first crystal resonator assembly, the second crystal resonator assembly, the temperature compensation chip, and the filter capacitor assembly are electrically connected through the base; The first crystal resonator component and the second crystal resonator component are complementary to cancel oscillation; The temperature compensation chip is used to perform temperature compensation on the first crystal resonator assembly and the second crystal resonator assembly; The filter capacitor component is used for filtering the temperature compensation chip. 2 . The temperature compensated crystal oscillator according to claim 1 , wherein the first crystal resonator assembly comprises: a first crystal ceramic base, a first crystal quartz wafer, a first crystal gold electrode and a first crystal metal cover plate. 3 . The temperature compensated crystal oscillator according to claim 2 , wherein the second crystal resonator assembly comprises: a second crystal ceramic base, a second crystal quartz wafer, a second crystal gold electrode and a second crystal metal cover plate. 4. temperature compensated crystal oscillator according to claim 2, is characterized in that, The first crystalline gold electrode is disposed on the first crystalline quartz wafer through a coating process to form a first crystalline quartz oscillator; The first crystal quartz oscillator is bonded to the first crystal ceramic base by conductive glue; The first crystal metal cover plate is welded to the first crystal ceramic base by a parallel soldering packaging technology to form a first crystal resonator assembly. 5. temperature compensated crystal oscillator according to claim 3, is characterized in that, The second crystal gold electrode is disposed on the second crystal quartz wafer through a coating process to form a second crystal quartz oscillator; The second crystal quartz oscillator is bonded to the second crystal ceramic base through conductive glue; The second crystal metal cover plate is welded to the second crystal ceramic base by the parallel soldering packaging technology to form a second crystal resonator assembly. 6 . The temperature compensated crystal oscillator according to claim 1 , wherein the filter capacitor component comprises: a first filter capacitor, a second filter capacitor and a third filter capacitor, wherein the filter capacitor component is glued by conductive glue. 7 . The capacitor pad connected to the base is used to filter the temperature compensation chip. 7. temperature compensated crystal oscillator according to claim 1, is characterized in that, The temperature compensation chip is bonded to the groove in the base through conductive glue; The pins of the temperature compensation chip and the pads of the base are electrically connected by gold wire bonding. 8 . The temperature compensated crystal oscillator according to claim 1 , wherein the first crystal resonator and the second crystal resonator are bonded to the pads of the base through conductive glue to complete miniaturized temperature compensation. 9 . Assembly of the crystal oscillator. 9 . The temperature compensated crystal oscillator according to claim 2 , wherein the models of the first crystal ceramic base and the second crystal ceramic base are SMD3225 crystal bases. 10 . 10 . The temperature compensated crystal oscillator according to claim 2 , wherein the model of the base is an SMD7050 crystal base. 11 .

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