JPH0714604U - Chip type variable temperature fixed attenuator - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a chip-type temperature variable fixed attenuator which is composed of a single temperature variable attenuator for temperature compensation and which can be easily surface-mounted on a substrate and has excellent practicality. . [Structure] A first substrate having negative temperature characteristics on the surface of a rectangular substrate 1.
A resistor 2A and a second resistor 2B having a negative temperature characteristic are coated in a mutually insulating state, a first electrode 3A is formed on one side of the rectangular substrate 1, and a second electrode is formed on one end of the other side. 3B, a third electrode 3C is formed on the other end, and the first electrode 3A and the second electrode 3B and the first electrode 3A and the third electrode 3C are respectively brought into contact with the first resistor 2A to be electrically connected. Then, the second electrode 3B and the third electrode 3C are brought into contact with and electrically connected to the second resistor 2B.
The temperature characteristics of the second resistor 2B and the second resistor 2B are set to be positive and negative, and a π-type temperature compensating circuit is formed, and the second electrode 3B and the first electrode 3A are used as input ends, and the third electrode 3C and the first electrode Chip type temperature variable fixed attenuator with 3A and output.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chip-type variable temperature fixed attenuator.

[0002]

[Prior art]

 With the spread of portable communication devices, there is a demand for miniaturization and higher performance. For communication devices and the like, amplifiers using high-performance GaAs semiconductor elements are used. This semiconductor element has the property that its output changes depending on the ambient temperature in use, and temperature variable attenuators have been developed to correct this and downsize and stabilize the equipment.

However, in the conventional temperature variable attenuator, a temperature sensor is generally used to form a temperature compensation circuit using several to ten or more electronic components to compensate for the temperature characteristic of the semiconductor element and further fix it. Used to form a circuit that either performs the damping function or compensates the input current.

[0004]

[Problems to be solved by the device]

 However, in such a conventional method, a large number of components are used, so that the ratio of the board to be mounted is large and a complicated circuit design is unavoidable, and it is necessary to reduce the weight and size of the circuit to save labor. It is difficult, and therefore the number of parts used is currently required to be reduced.

In view of the above situation, the present invention comprises a temperature variable attenuator for temperature compensation, which is composed of only one component, and can be easily surface-mounted on a substrate. The purpose is to provide an attenuator.

[0006]

[Means for Solving the Problems]

 The gist of the present invention will be described with reference to the accompanying drawings.

Two kinds of first resistor 2A and second resistor 2B having different properties are formed on the surface of the rectangular substrate 1 so as to be insulated from each other, and the first electrode 3A is formed on one side of the rectangular substrate 1. The second electrode 3B is formed at one end on the other side, and the third electrode 3C is formed at the other end, and the first electrode 3A and the second electrode 3B, the first electrode 3A and the third electrode 3C, and the second electrode 3B are formed. The electrode 3B and the third electrode 3C are brought into contact with and electrically connected to the first resistor 2A or the second resistor 2B, and the second electrode 3B and the first electrode 3A are used as input ends, and the third electrode 3C And a first electrode 3A as an output end form a π-type or T-type attenuator circuit, and the resistance film having a positive temperature characteristic in which the resistance value of the first resistor 2A increases as the temperature rises. In contrast, the attenuating circuit is configured as a temperature compensating circuit by using the second resistor 2B as a resistance film having a temperature negative characteristic in which the resistance value decreases with increasing temperature. The present invention relates to a chip type variable temperature fixed attenuator, characterized in that a protective coat 4 is coated on the coating surfaces of the body 2A and the second resistor 2B.

Two kinds of first resistor 2A and second resistor 2B having different properties are formed on the surface of the rectangular substrate 1 so as to be insulated from each other, and the first electrode 3A is formed on one side of the rectangular substrate 1. The second electrode 3B is formed at one end on the other side, and the third electrode 3C is formed at the other end, and the first electrode 3A, the second electrode 3B, the first electrode 3A, and the third electrode 3C are formed, respectively. The first resistor 2A is contacted and electrically connected, and the second electrode 3B and the third electrode 3C are contacted with the second resistor 2B and electrically connected, the second electrode 3B and the first electrode 3B are electrically connected. 3A is used as an input end, and the third electrode 3C and the first electrode 3A are used as output ends to form a π-type attenuator circuit. This first resistor 2A has a temperature positive characteristic in which the resistance value increases as the temperature rises. The π-type attenuating circuit is configured as a temperature compensating circuit as a resistance film, and the second resistor 2B is a resistance film having a temperature negative characteristic in which the resistance value decreases with an increase in temperature. First resistor 2A, it relates to a chip-type temperature variable fixed attenuator, characterized in that coated with protective coating 4 on the film surface of the second resistor 2B.

In the device according to claim 1 or 2, the first resistor 2A is a resistance film having a temperature negative characteristic rather than a temperature positive characteristic, and the second resistor 2B is a temperature positive characteristic rather than a temperature negative characteristic. The present invention relates to a chip-type temperature variable fixed attenuator, which is characterized by using a resistive film having characteristics.

It is characterized in that the absolute values of the resistance temperature coefficient of the first resistor 2A between the electrodes having positive and negative temperature characteristics and the resistance temperature coefficient of the second resistor 2B between the electrodes are set to be substantially equal to each other. The present invention relates to the chip-type temperature variable fixed attenuator according to claim 1, claim 2 or claim 3.

[0011]

[Action]

 Although which side is used as the input end or the output end can be changed as appropriate (the expression of the input and the output is a descriptive distinction, and it can be said that there is no functional difference), for example, the second electrode 3B Assuming that the first electrode 3A and the first electrode 3A are input ends and the third electrode 3C and the first electrode 3A are output ends, the present device becomes a π-type temperature compensation circuit as shown in FIG.

The impedance of the input / output depends on the resistance value of the first resistor 2A, and the resistance between the input and output depends on the resistance value of the second resistor 2B. Therefore, for example, according to claim 1 or claim 2, In the device, the first resistor 2A has a positive temperature characteristic and the second resistor 2B has a negative temperature characteristic, so that the negative gain (-At) as an attenuator decreases as the temperature rises as shown in FIG. (The gain (At) as an amplifier rises as the temperature rises. Since the vertical axis in FIG. 4 is shown as −db, the graph drops as a negative gain.).

On the contrary, if the temperature characteristics of the first resistor 2A and the second resistor 2B are set oppositely as in the invention of claim 3, the gain (At) as shown by the dotted line in FIG. 4 is obtained. The temperature characteristics of are the opposite, and the negative gain (-At) rises as the temperature rises.

Therefore, as shown by the solid line in FIG. 4, the temperature characteristic of the gain shows a positive characteristic, and the chip type temperature variable fixed attenuator (this device) according to the invention of claim 1 or 2 is shown in FIG. When connected to the amplifier 5 as shown, it works as follows.

Assuming that, for example, a high-performance GaAs semiconductor element is used as the amplifier 5 as described above, the gain G'decreases as the temperature rises, as shown in FIG.

On the other hand, the gain At of this device increases as the temperature rises as described with reference to FIG. 4 (in FIG. 4, the vertical axis is −dB, but in FIG. The graph rises.)

Therefore, the total gain G is compensated by the temperature negative characteristic of the gain At of this device as shown in FIG. 5, and it becomes possible to obtain the gain (total gain) G which does not change due to the temperature change.

Similarly, if the temperature characteristic of the amplifier is a positive characteristic, it can be compensated by connecting the main unit according to claim 3 having a negative temperature characteristic, and the total gain G can be changed with temperature. In the same way, it can be stabilized so that it does not change.

In this device, an attenuation circuit is formed on the rectangular substrate 1. For example, when the electrodes 3A, 3B, 3C are connected by the resistors 2A, 2B as in the invention described in claim 2, as shown in FIG. A π-type attenuation circuit as shown is constructed.

In such a π-type attenuator circuit, the attenuation amount of the electric energy transmitted from the input to the output is expressed as the attenuation amount of the attenuator, and when the circuit of the target impedance is connected to the output side, The resistance value measured on the input side is the impedance with the attenuator connected, but the impedance seen from the input should ideally be the same as the output impedance regardless of whether the attenuator is connected or not. If it changes due to connection, reflection will occur in the circuit and the characteristics will deteriorate. Therefore, the attenuator is designed so that the impedance of the output is equal to the impedance seen by the input (for example, if the output is 50Ω, connect the attenuator so that it is 50Ω when seen from the input). ).

Further, as the characteristic of the temperature variable attenuator, it is possible to obtain the attenuation amount change only by the change of the second resistor 2B in FIG. 3, but if only the second resistor 2B is changed, the resistance balance is broken. The circuit impedance changes. For example, if the temperature characteristic of the second resistor 2B is negative, the decrease in attenuation and the decrease in impedance occur simultaneously with the rise in temperature. In order to avoid this, the first resistor 2A having a positive temperature characteristic for increasing the resistance value of the first resistor 2A is required. In addition, since the change in impedance changes the amount of attenuation during operation, it becomes difficult to obtain the change in attenuation with respect to the desired temperature change. Therefore, if the absolute values of the temperature coefficient of resistance of the first resistor 2A between the electrodes having positive and negative temperature characteristics and the temperature coefficient of resistance of the second resistor 2B between the electrodes are set to be approximately equal, the impedance due to temperature change It is possible to keep the change small, and a characteristic is achieved in which only the amount of attenuation depends on temperature. In addition, by suppressing the impedance change, it is possible to suppress the attenuation change due to impedance imbalance during use, making it easier to obtain the desired attenuation change.

[0022]

【Example】

 The present embodiment is constructed in a π-type temperature compensation circuit which belongs to the invention defined in claim 2, and is produced by the following procedure.

(1) A first resistor 2A having a positive temperature coefficient is vapor-deposited as a multilayer metal thin film on the upper surface of a ceramic rectangular substrate 1 having excellent thermal conductivity and mechanical strength.

(2) Further, a multi-component alloy mainly composed of copper for forming electrodes is vapor-deposited on the entire surface.

(3) Since this copper-based film is used for the electrode, unnecessary parts are removed by etching.

(4) The first resistor 2A of the metal thin film exposed by the etching of (3) is formed into a pattern shape having a predetermined attenuation amount and a characteristic impedance by etching.

(5) (4) is washed, dried and killed in a special atmosphere furnace.

(6) Using a pre-prepared alloy ink, printing on a mask with a predetermined attenuation and characteristic impedance on (5), and then printing in a special atmosphere furnace at a relatively low temperature. To form a second resistor 2B having a negative temperature characteristic, and further special trimming correction is performed by a laser. For example, a π type as in the present embodiment or a T type which acts equivalently to this or Formed in an H-shaped attenuator.

(7) After being exposed, the surface of the first and second resistors 2A and 2B of the thin film is coated with a protective coat 4 which is rich in moisture resistance and excellent in high temperature and high insulation properties.

(8) The rectangular substrate 1 formed as described above is cut into, for example, a shape that serves as a standard standard of a square plate chip resistor so that it can be mounted on an automatic machine.

(9) A copper-based alloy is vapor-deposited at predetermined positions on the cutting end surface so as to cover the upper surface, the side surface, and the lower surface to form the first electrode 3A, the second electrode 3B, and the third electrode 3C. To do. (10) The surfaces of the first electrode 3A, the second electrode 3B, and the third electrode 3C are coated with solder to ensure surface mounting.

[0032]

[Effect of device]

 Since the present invention is configured as described above, it becomes a chip-type temperature variable attenuator that is extremely small and easy to manufacture, and suitable for mass production. Moreover, the surface mounting technology of chip resistors is used to make the surface very easy. It can be mounted, and as in the example, the electrode can be formed in a U shape that extends over the upper surface, the side surface, and the lower surface, which increases reliability and makes it possible to mount without distinguishing the front and back sides. It is a temperature-variable fixed attenuator that is extremely excellent and can provide stable output regardless of ambient temperature.

[Brief description of drawings]

FIG. 1 is a schematic configuration perspective view of a present embodiment.

FIG. 2 is a schematic configuration plan view of the present embodiment.

FIG. 3 is an equivalent circuit diagram of the present embodiment.

FIG. 4 is a characteristic graph showing a negative gain of this embodiment.

FIG. 5 is a characteristic graph for explaining the operation showing the temperature compensation of the gain of the present embodiment.

[Explanation of symbols]

 1 Square substrate 4 Protective coat 2A 1st resistor 2B 2nd resistor 3A 1st electrode 3B 2nd electrode 3C 3rd electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keigo Inomata, 537 Suzawa, Ome-cho, Nishikubiki-gun, Niigata Yokohama Electron Seiko Co., Ltd. Niigata Plant (72) Masato Nakao 12229 Nakamiwa, Minowa-cho, Kamiina-cho, Nagano Prefecture Inside Shinsei Electronics Co., Ltd.

Claims (4)

[Scope of utility model registration request] 1. A rectangular substrate is provided with two kinds of first resistors and second resistors having different properties, which are insulatively coated on each other, and a first electrode is formed on one side of the rectangular substrate. The second electrode is formed at one end on the other side, and the third electrode is formed at the other end,
The first electrode and the second electrode, the first electrode and the third electrode, and the second electrode and the third electrode are brought into contact with and electrically connected to the first resistor or the second resistor, and the second electrode and A π-type or T-type attenuation circuit having the first electrode as an input end and the third electrode and the first electrode as an output end is configured, and the resistance value of the first resistor increases as the temperature rises. The attenuating circuit is configured as a temperature compensating circuit as a resistance film having a temperature positive characteristic, and the second resistor is a resistance film having a temperature negative characteristic in which the resistance value decreases conversely with temperature rise. A chip type variable temperature fixed attenuator, characterized in that a protective coat is coated on the coating surface of the second resistor. 2. A rectangular substrate having two kinds of first resistors and second resistors having different properties formed on the surface of the rectangular substrate so as to be insulated from each other, and a first electrode is formed on one side of the rectangular substrate. The second electrode is formed at one end on the other side, and the third electrode is formed at the other end,
The first electrode and the second electrode and the first electrode and the third electrode are brought into contact with and electrically connected to the first resistor, respectively, and the second electrode and the third electrode are brought into contact with the second resistor. Electrically connected,
The second electrode and the first electrode are used as input ends, and the third electrode and the first electrode are used as output ends to form a π-type attenuating circuit, and the resistance value of the first resistor increases as the temperature rises. The π-type attenuating circuit is configured as a temperature compensating circuit as a resistance film having a positive characteristic, and the second resistor is conversely a resistance film having a temperature negative characteristic in which the resistance value decreases as the temperature rises. A chip type variable temperature fixed attenuator having a protective coat on the surface of the second resistor. 3. The device according to claim 1 or 2, wherein the first resistor is a resistance film having a temperature negative characteristic instead of a temperature positive characteristic, and the second resistor is not a temperature negative characteristic but a temperature positive characteristic. A variable temperature fixed attenuator of chip type, which is a resistance film having 4. A first electrode between electrodes having positive and negative temperature characteristics.
The chip type temperature variable fixing according to claim 1, 2 or 3, wherein the absolute values of the resistance temperature coefficient of the resistor and the resistance temperature coefficient of the second resistor between the electrodes are set to be substantially equal. Attenuator.