JPS64843B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a microwave integrated circuit having microwave striplines.

Figure 1 shows the amplification transistor TR, strip lines L ₁ , L ₂ , resistors R ₁ , R ₂ , R ₃ , capacitances C ₁ , C ₂ ,
A microwave amplification circuit consisting of C ₃ , C ₄ , and C ₅ is shown, but a part of the structure when this amplification circuit is formed using a microwave integrated circuit using thick film technology is shown in the second diagram.
As shown in the figure.

In FIG. 2, a ground conductor _a1 is provided on one surface of the dielectric D, and conductors and components are provided on the ground. Although the same symbols as in FIG. 1 are used in FIG. 2, chip parts are used as the resistors and capacitors. Note that parts a ₂ , a ₃ , and a ₄ are electrodes for mounting parts. strip line
As is well known, the dimension of L ₁ is determined inversely proportional to the square root of the dielectric constant of the dielectric D sandwiched between the ground conductor a ₁ and the stripline L ₁ .

Microwave striplines for such integrated circuits are formed by printing or vapor depositing conductors on both sides of a dielectric substrate, or by printing or etching a double-sided copper-clad laminate. In all conventional examples, the dielectric D serves as a substrate and also mechanically holds the circuit. Therefore, mechanically fragile materials cannot be used as the dielectric, and there are restrictions from this point of view.
Therefore, it is often impossible to use a material with a large dielectric constant, and the stripline (and thus the microwave integrated circuit) cannot be miniaturized. Further, since a dielectric substrate cannot be made extremely large, it is impossible to continuously feed the substrate in an almost endless manner during the manufacturing process (divide it later), resulting in poor manufacturing efficiency.

The present invention proposes a novel and effective method for manufacturing microwave integrated circuits devised to eliminate these drawbacks.

The embodiments will be described in detail below according to the embodiments shown in the drawings.

In the present invention, as shown in FIG. 3, a plate-shaped ground conductor 1 such as a metal plate is used as a substrate, and a dielectric material 2,
3 and conductors 8 and 9 provided thereon to form a stripline. In this way, in the present invention, striplines can be formed on both sides of the substrate by using the ground conductor as the substrate instead of using the dielectric as the substrate.
Therefore, FIG. 3 shows a case where microwave integrated circuits are formed on both surfaces A and B of the ground conductor 1. Third
In the figure, 10 and 11 are solder resists, 12 is adhesive, 13 and 14 are chip parts, 15 and 16 are electrodes of chip parts, 17 is solder, 18 is cream solder or conductive adhesive, and 19 is a circuit on both sides. It is a conductor for grounding.

Next, the procedure for creating a microwave integrated circuit as shown in FIG. 3 will be explained with reference to FIG. 4.

In [ ] of FIG. 4, holes indicated by H ₁ and H ₂ are formed in the ground conductor 1 made of a metal plate. hole
_H1 is provided to connect the circuits formed above and below the ground conductor 1, and the hole _H2 is provided to ground each circuit (therefore, connect it to the ground conductor 1). .

In [], a paste-like dielectric material 2 is applied or printed on the ground conductor 1. At this time, holes H ₁ and H ₂
Paste-like dielectric material 2 drips into the parts 2a and 2b.
It will be like this.

At [], a squeegee such as 6 is moved in the direction of the arrow while applying a predetermined pressing force to the ground conductor 1.

In [], as a result of [], the holes H ₁ and H ₂ are completely filled with the dielectric 2.

In [], after the dielectrics 2a and 2b are dry to the touch, the dielectrics 2 are applied or printed at predetermined locations to a required thickness.

In [], after the dielectric 2 applied to the predetermined locations is dry to the touch, the dielectric 3 is similarly coated or printed on the B side of the ground conductor 1 and dried to the touch.

In [], holes are made by pressing or other methods.
Drill holes in H ₁ and H ₂ parts. At this time, care must be taken to ensure that sufficient dielectric material is present on the wall surface of the hole _H1 .
The other hole _H2 is made to its original size. That is,
Remove all dielectric in _H2 . In this state, the dielectrics 2 and 3 are fired. Next, the whole is immersed in a catalyst solution, and a thin layer of metal (for example, copper) is applied by electroless plating. (not shown).

In [ ], plating resists 4 and 5 are applied by printing or the like to the parts except for the places where strip lines and connection electrodes are to be created, the holes H ₁ for connecting the circuits on sides A and B, the ground holes H ₂ , etc.

At [ ], electrolytic plating is performed to provide metal (for example, copper) 8 and 9 of a predetermined thickness. At this time, a grounding metal 19 is further attached to the exposed part of the grounding conductor 1. Next, the plating resists 4 and 5 are peeled off, and then, unnecessary electroless plating portions are removed by light etching.

In [ ], solder resists 10 and 11 are provided on both sides A and B as shown.

In [XI], adhesive 12 is applied between the electrodes by printing or using a dispenser. This adhesive is thermosetting.

In [XII], chip parts 13 such as chip resistors, chip capacitors, microtransistors, mini-mold semiconductors, etc. are mounted on the adhesive 12, the adhesive 12 is cured by heating, and the chip parts 13 are temporarily fixed. .

At [ ], the ground conductor 1 is reversed and cream solder or conductive adhesive 18 is applied to the electrode by printing or using a dispenser.

At [ ], the chip part 14 is installed,
The electrode 16 and the cream solder or conductive adhesive 18 are heated and melted so as to overlap, and then the B side is immersed in a molten solder bath to form the chip part 13.
A sufficient electrical connection between the electrode 15 and the electrode 9 on the ground conductor 1 is achieved by solder 17.

Through the above steps, a microwave integrated circuit as shown in FIG. 3 can be created. Note that the method for creating the circuit shown in Figure 3 is not limited to the method shown in Figure 4, as it is also possible to form the metals in (), (), and () above by vapor deposition or the like instead of by electroless or electrolytic plating. I can't wait to say it.

According to the present invention, the microwave stripline does not use a dielectric as a substrate as in the past, but uses a ground conductor as a substrate, so it can have sufficient mechanical strength, and the dielectric used as a dielectric Materials with high coefficients can be used, and therefore the dimensions of the strip wave line can be made considerably smaller, and the overall size of the circuit can be reduced.
Moreover, since circuits can be provided on both sides of the ground conductor, the size can be further reduced. In addition, the grounding conductor can be realized with a metal plate, and even if it is quite long, it has great strength, so it is possible to use a method in which the metal plate is continuously fed in the production line, and then divided and taken out one after another in the final process. The present invention is extremely effective as it also has the effect of dramatically improving manufacturing efficiency.

Furthermore, the present invention allows the thickness of the dielectric layer to be freely selected when a paste-like dielectric is used. For example, by making the paste coating thickness different on the upper and lower surfaces of the ground conductor, different dielectric layers can be formed on the upper and lower surfaces. A low frequency and high frequency microwave integrated circuit can be formed on both sides of the same substrate, respectively.

[Brief explanation of drawings]

FIG. 1 is a drawing showing a microwave amplifier circuit, and FIG. 2 is a perspective view showing the structure of a part of a conventional microwave integrated circuit. FIG. 3 is a sectional view of a microwave integrated circuit embodying the present invention, and FIG. 4 is a drawing for explaining a manufacturing method in one embodiment of the present invention. 1... Ground conductor, 2, 3... Dielectric material, 8, 9... Conductor.

Claims (1)

[Claims] 1. A step of forming a through hole in a ground conductor made of a metal plate, and applying a paste-like dielectric material to a predetermined thickness on both surfaces of the ground conductor and on the inner surface of the through hole continuous to both surfaces. forming a conductive layer on the upper surface of the dielectric and on both surfaces of the substrate and the inner surface of the through hole continuous to both surfaces; soldering an electrical component onto the conductive layer; A method for manufacturing a microwave integrated circuit comprising: