JPH0681103U - Isolator - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an isolator in which a grounding conductor is formed on a substrate surface by using a technique of directly bonding a copper plate to the substrate, and the number of components and the number of steps are small. [Structure] A ferrimagnetic substrate 1 having a surface conductor 2 for a transmission line on the front surface and a ground conductor 3 on the back surface, and the surface conductor 2
And a grounding conductor 7 for grounding the resistor 5, and a means for applying a magnetic field substantially perpendicularly to the ferrimagnetic substrate 1. The resistor 5 is grounded. The conductor 7 for grounding is formed on the ferrimagnetic substrate 1 by a technique of directly joining the copper plate and the ferrimagnetic substance.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a stripline type isolator used for microwave integrated circuits and the like.

[0002]

[Prior art]

 In recent years, the scale of integration of microwave integrated circuits has increased. Along with this, there is an increasing demand for so-called drop-in type isolators that can be easily connected to circuits. The most commonly used line structure is the stripline type.

Here, a conventional stripline type isolator will be described with reference to FIGS. 3 to 6. In each drawing, (a) is a perspective view and (b) is a side view thereof, and the same portions are denoted by the same reference numerals.

In FIG. 3, reference numeral 1 is a ferrimagnetic substrate (hereinafter referred to as a substrate), a surface conductor 2 for a transmission line is formed on the front surface of the substrate 1, and a ground conductor 3 is formed on the back surface. The surface conductor 2 is composed of a central joint portion 2a and transmission lines 2b, 2c and 2d extending in three directions from the joint portion 2a. The ground conductor 3 is fixed to the carrier plate 4 by soldering or the like. A magnet (not shown) is placed on the joint 2a of the surface conductor 2 to apply a DC magnetic field in the direction of the joint 2a.

When the circulator having the above-mentioned configuration is used as an isolator, one of the transmission lines 2b, 2c and 2d is terminated.

For example, one end of the resistor 5 is connected to one transmission line 2c, and the other end of the resistor 5 is connected to the ground terminal 6. Then, using the grounding conductor 7, the ground terminal 6 is connected to the grounding conductor 3 on the rear surface of the substrate 1 and terminated.

[0007]

[Problems to be solved by the device]

 As described above, when connecting the ground terminal 6 and the ground conductor 3, the ground conductor 7 is used. As a method of forming the grounding conductor 7, there are methods such as soldering and welding of metal foil, vapor deposition of metal, printing of metal paste and firing. However, the method using soldering or welding of metal foil increases the number of parts such as metal foil, and also increases the number of steps such as soldering.

Further, the method of depositing a metal on the side surface of the substrate has complicated steps and processes, and there is concern about the electrical conductivity.

In addition, the method of printing and firing the metal paste also involves a complicated process and process, like the vapor deposition of the metal, and there is concern about the electrical conductivity.

If there is a problem with the conductivity of the grounding conductor 7, the characteristics as an isolator deteriorate, and the wire may break during use due to changes in the environment.

In FIG. 4, the resistor 5 connected to the transmission line 2c is arranged on the side surface of the substrate 1, and the resistor 5 terminates the transmission line 2c. In this case, since the grounding conductor is not used, the number of parts and the number of steps are reduced. However, such a structure can be adopted only when the thickness of the substrate 1 and the height of the resistor 5 are substantially equal to each other, and the adoption is restricted.

In FIG. 5, a resistor paste is printed and fired on the upper surface of the substrate 1 to form the resistor 5, and the resistor 5 is connected to the carrier plate 4 on the back surface of the substrate 1 by using the grounding conductor 7. There is. In this case, since the resistor in the form of one element is not used, the number of parts and the number of steps are reduced accordingly. However, the formation of the grounding conductor 7 has the same drawbacks as in the case of FIG.

In FIG. 6, a part of the carrier plate 4, for example, the left side is at the same height as the surface of the substrate 1, and a resistor 5 is connected between the surface conductor 2 and the carrier plate 4. In this case, since the grounding conductor is not required, the number of parts and the number of steps are reduced. Instead, the carrier plate 4 needs to be processed, which is not preferable from the viewpoint of supplying an inexpensive isolator.

The present invention solves the above-mentioned drawbacks, and provides an isolator in which a grounding conductor is formed on a substrate surface by using a technique of directly joining a copper plate to the substrate and the number of components and the number of steps are small. With the goal.

[0015]

[Means for Solving the Problems]

 According to the present invention, a ferrimagnetic substrate having a surface conductor for a transmission line on the front surface and a ground conductor on the back surface, a resistor connected to the surface conductor, a grounding conductor for grounding the resistor, and the ferrimagnetic material. In the isolator comprising means for applying a magnetic field almost perpendicularly to the magnetic substrate, the ferrimagnetic material is formed by directly bonding the grounding conductor for grounding the resistor body to the copper plate and the ferrimagnetic material. Formed on the body substrate.

[0016]

[Action]

 One of the methods for fixing the copper plate and the ferrimagnetic material is the Direct Bond Copper (hereinafter referred to as DBC) technology.

The DBC technique is a method in which a copper plate is brought into close contact with a ferrimagnetic substrate and then passed through an electric furnace having an atmosphere with an appropriate temperature and oxygen concentration. At this time, only the surface of the copper plate is melted and the ferrimagnetic substrate surface Get into the unevenness of. Then, when the molten copper is cooled, the copper plate and the ferrimagnetic material substrate 1 are fixed and directly bonded.

The present invention uses the above-mentioned DBC technique to form a grounding conductor for grounding the resistor on the ferrimagnetic substrate.

Since the grounding conductor can be formed on the surface of the magnetic substrate at the same time as another conductor, for example, a surface conductor or a ground conductor, no additional process is required. In addition, since the grounding conductor is strongly fixed to the magnetic substrate, the conductivity is good and the grounding is reliable as compared with the method of vapor deposition of metal or the method of printing and firing metal paste.

[0020]

【Example】

 An embodiment of the present invention will be described with reference to FIG.

1 (a), (b), (c), and (d) are a perspective view, a side view, an assembly view, and a perspective view, respectively, and the same parts as those in FIGS. is there.

As shown in FIG. 1C, a copper plate having a shape in which the surface conductor 2, the ground terminal 6, the grounding conductor 7, and the grounding conductor 3 are connected by a bridge 8 is manufactured. The surface conductor 2 is composed of a central joint portion 2a and transmission lines 2b, 2c, 2d extending in three directions from the joint portion 2a.

Thereafter, the grounding terminal 6 and the grounding conductor 7 are bent, and the surface conductor 2 is placed on the front surface side of the substrate 1 and the grounding conductor 3 is placed on the back surface side of the substrate 1 as shown in FIG. 1D. So that the copper plate and the substrate 1 are brought into close contact with each other.

Then, in a state where the copper plate and the substrate 1 are in close contact with each other, they are passed through an electric furnace under appropriate conditions, and the surface conductor 2, the ground conductor 3, the earth terminal 6 and the like are fixed to the substrate 1 by the DBC technique. The bridge 8 part is cut off after the direct joining.

After the ground conductor 3 and the ground terminal 6 are directly joined, the substrate 1 is fixed on the carrier plate 4 by soldering as shown in FIG. Then, the resistor 5 is soldered to the position where the bridge 8 is cut off.

According to the above configuration, the ground terminal 6 and the grounding conductor 7 that ground the resistor 5 are integrally fixed to the substrate 1 at the same time as the grounding conductor 3. Therefore, it is not necessary to ground the grounding terminal 6 and the grounding conductor 7 later, and it is not necessary to separately prepare a component used for the grounding conductor 7. Therefore, the number of parts and the number of processes are reduced, and the conductivity is certain. Also, the carrier plate 4 may be inexpensively pressed. Further, since the surface conductor 2, the ground terminal 6, and the ground conductor 3 are integrally formed in one step, the ground terminal 6 can be arranged at a fixed position of the surface conductor 2. 2 shows another embodiment of the present invention, in which the same parts as those in FIG. 1 are designated by the same reference numerals, and the duplicated description will be omitted.

FIG. 2A shows an example in which only the ground terminal 6 for grounding the resistor 5 and the grounding conductor 7 are joined by the DBC technique. In this case, the ground terminal 6 and the grounding conductor 7 are formed so that a part thereof projects from the outer periphery of the substrate 1. When the isolator is used, the resistor 5 is connected between the transmission line 2c and the ground terminal 6 as shown in FIG. 2 (b), and the grounding conductor 7 is bent to form the grounding conductor 3 or the carrier plate 4. Connect by soldering.

Also in this case, when the resistor 5 is grounded, the portion protruding from the outer periphery of the substrate 1 can be used, and it is not necessary to separately prepare a component used for grounding. Further, the step of forming the grounding component on the side surface of the substrate is not necessary.

Therefore, manufacturing is facilitated, and grounding is more reliable than when grounding is performed using metal vapor deposition or the like.

In the above-described embodiment, the ground terminal 6 and the grounding conductor 7 are separately shown. However, since both are usually integrally formed, the grounding terminal 6 and the grounding conductor 7 are combined. The combined conductor may be treated as the grounding conductor 7.

[0031]

[Effect of device]

 According to the present invention, it is possible to provide an isolator having a small number of parts and a small number of steps.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram illustrating another embodiment of the present invention.

FIG. 3 is a diagram illustrating a conventional example.

FIG. 4 is a diagram illustrating a conventional example.

FIG. 5 is a diagram illustrating a conventional example.

FIG. 6 is a diagram illustrating a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ferrimagnetic substance substrate 2 ... Surface conductor 3 ... Grounding conductor 4 ... Carrier plate 5 ... Resistor 6 ... Grounding terminal 7 ... Grounding conductor 8 ... Bridge

Claims (1)

[Scope of utility model registration request] 1. A ferrimagnetic substrate having a front surface conductor for a transmission line and a back surface having a ground conductor, a resistor connected to the front conductor, a grounding conductor for grounding the resistor, and the ferrimagnetic material. In the isolator comprising means for applying a magnetic field substantially perpendicularly to the magnetic substrate, the ferrimagnetic substrate is formed by a technique in which a grounding conductor for grounding the resistor directly joins the copper plate and the ferrimagnetic substance. An isolator characterized by being formed in.