JPH048961B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a module equipped with a strip line, particularly a slot line, used as a transmission line in the microwave band and millimeter wave band.

Lines used as transmission lines for transmitting microwaves, such as transmitting devices and receiving devices of communication devices that utilize microwave bands and millimeter wave bands (hereinafter referred to as microwaves), need to be made smaller, lighter, and simpler in structure. Microstrip lines are being used due to demands such as

A circuit pattern is formed on the top surface of the dielectric substrate,
A circuit board with a full-surface ground conductor layer formed on the back side is formed into a module by soldering a ground conductor layer to the top surface of the metal board and conductively bonding it with a conductive adhesive. These modules are configured into functional units such as oscillators, circulators, variable attenuators, amplifiers, filters, modulators, and mixers, depending on the circuit configuration formed on the circuit board. The metal substrates are installed in a vertical line inside a box-shaped housing, and the metal substrates are individually screwed and fixed to the bottom of the housing, and the circuits are connected to each other. Signals are connected to predetermined locations by signal lines that pass through the case, and power supplies are connected to predetermined locations by power lines that also pass through the case.After comprehensive adjustment is made, the case opening is covered with a metal cover. The high-frequency section of the device is configured by fixing with screws.

(b) Prior Art and its Problems Among the above-mentioned element modules, for example, a mixer uses a semiconductor element, but the semiconductor element is required to be hermetically sealed so that it does not come into contact with air. Conventionally, packaged semiconductor elements were placed on a module circuit board, and circuit connections were made via the package's electrodes. Since the package is mounted on the circuit board in this way, it is unavoidable to increase the size of the package, and when used in the high frequency range, it is difficult to achieve good matching, making it difficult to obtain the required frequency characteristics. A number of problems arose.

(c) Purpose of the Invention In view of the above-mentioned conventional problems, the present invention has been devised to provide a method for incorporating chip-shaped semiconductor elements into conventional modules so as to obtain good frequency characteristics without increasing the size and without deteriorating chip-shaped semiconductor elements. Our objective is to provide an implemented strip line module.

(d) Structure of the Invention In order to achieve the above object, the present invention provides a method in which a part of the back surface of a dielectric substrate having a pattern such as a microstrip line as a signal transmission path on the top surface is tightly attached to the top surface of a metal substrate. In the module that will be made,
A slot line pattern is provided on the back surface of the dielectric substrate and a semiconductor element is mounted thereon.
A recess is provided on the back surface of the metal substrate, a window hole through which the slot line surface of the dielectric substrate can be seen is provided at the bottom of the recess, and an airtight terminal inserted into the recess is provided to lead the semiconductor element and the terminal. The recessed opening of the metal substrate is sealed with a cover.

(e) Embodiments of the invention Hereinafter, embodiments of the invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which A is a perspective view of a microstrip line module, B is a perspective view seen from the back, C is a longitudinal cross-sectional view of an exploded state, and D is an assembled FIG. 2 is a vertical sectional view showing another example of the terminal extraction position, and FIG. 2 is a perspective view of the circuit board viewed from the back side on the element mounting side, that is, the slot line side.

In the figure, 1 is a circuit board, and a microstrip line 3 is patterned on one side of a dielectric substrate 2 made of ceramic, sapphire, quartz, etc., for example, the upper surface of the figure, and on the other side, for example, A slot line 4 is patterned on the back surface at the bottom of the figure.

The microstrip line 3 and the slot line 4 are patterned by a known method such as metal vapor deposition. Further, on the back surface on the side of the slot line 4, chip-shaped semiconductor elements 5, for example, four beam lead type diodes, are mounted.
A gold wire or ribbon 6 is connected to the ground conductor layer through a connecting conductor pattern P formed on the ground conductor layer to form a mixer in this embodiment. A high frequency signal and a local oscillation signal are input to the microstrip line 3, and these are coupled to the slot line to extract signal components. This circuit board 1 is mounted on a metal board 7 as a carrier. The metal substrate 7 is entirely made of one metal plate, and has a recess 8 on the back side.
A window hole of a required size is formed through the opening step 9 and the bottom of the recess 8. Further, as shown in A and B, screw insertion holes for mounting are bored at both left and right ends.

The back surface of the circuit board 1 is mounted on the upper surface of the metal substrate 7 in close contact with the hole 10 so as to close the hole 10, and is bonded and sealed by brazing or the like with a ground conductor layer around the slot line at the sealing portion 11. That is, the slot line 4, the semiconductor element 5, the connecting conductor pattern P
is looking into the recess 8 through the window hole 10. The size of the window hole 10 is determined to satisfy this relationship.

Next, the wire 6 of the semiconductor element 5 is connected to the inner end of the hermetic glass terminal 12 inserted through the case 7, and then, with the recess 8 filled with an inert gas such as nitrogen gas, the stepped portion is A cover 13 made of a metal plate is fitted to 9, and the joint part 14 is brazed and sealed, so that the bottom surface becomes flat as shown in D. Note that the hermetic glass terminal for signal output can also be inserted in parallel to the cover 13 as shown at 15 in E.

In FIG. 2, a coplanar line may be formed on the surface opposite to the slot line 4 instead of the microstrip line 3.

Although the above is an example in which semiconductor elements are mounted only on one side of the circuit board, it is also possible to mount semiconductor elements on both the upper and lower sides of the circuit board 1 as shown in FIG. FIG. 3 shows a second embodiment of the present invention, in which A is an exploded perspective view and B is a longitudinal sectional view. circuit board 1
is the same as the examples shown in FIGS. 1 and 2 in that a microstrip line 3 or a coplanar line is patterned on the front surface, and a slot line 4 is patterned on the back surface. However, the semiconductor elements are mounted on the back surface on the slot line 4 side as shown at 5, and also on the surface on the microstrip line 3 or coplanar line side as shown at 16. The manner in which the circuit board 1 is mounted on the metal substrate 7 is also the same as the example shown in FIG. In order to hermetically seal the semiconductor element 16 on the front side,
Case 17 is used.

The case 17 is formed into a rectangular frame shape from ceramic material or the like, and required surfaces such as the outer wall are metallized with gold or the like to form a metal surface 18. This frame-shaped case 17 is mounted on the metal substrate 7 so as to surround the circuit board 1, and the joint portion 19 is joined with adhesive, wax, or the like. Next, the cover 20 is filled with an inert gas such as nitrogen gas inside the case 17.
, and the joint portion 21 is joined with adhesive or wax.
Reference numeral 22 denotes a lead terminal to the semiconductor element 16 on the front surface, which is pulled out from the non-metalized side surface of the case 17 so as not to come into contact with the metal substrate 7.

According to the above configuration, the semiconductor element 5 on the back side of the circuit board 1 is kept airtight in the metal substrate 7, and the semiconductor element 16 on the front side is kept airtight in the case 17. In this way, if the semiconductor elements on both sides are hermetically sealed, it is possible to mount semiconductor elements that require hermetic sealing on both sides of the circuit board 1, allowing for higher-density mounting than the example shown in FIG. This is extremely effective for devices that require In this example, the hermetic glass terminal can also be arranged parallel to the cover 13, as in the case shown in FIG. 1E.

Contrary to the example in FIG. 1, when mounting a semiconductor element that requires hermetic sealing only on the front side of the circuit board 1,
In the example shown in FIG. 3, only the case 17 on the front side has an airtight sealing structure, and the metal substrate 7 on the back side does not have an airtight sealing structure, but is simply a mounting board.

(f) Effects of the Invention As described above, according to the present invention, semiconductor elements that require hermetic sealing in a metal substrate for mounting a strip line module can be mounted on the back side of the same substrate to effectively hermetically seal them. can do. In addition, the structure is simple, airtightness can be maintained reliably, the module itself has the same dimensions and shape as the conventional one without having to be enlarged, and the compatibility is good.

[Brief explanation of drawings]

The drawings show embodiments of the strip line module according to the present invention. FIG. 1 is a perspective view and a sectional view showing the first embodiment, FIG. 2 is a perspective view of a circuit board, and FIG. 3 is a strip line module according to the present invention. FIG. 7 is an exploded perspective view and a vertical cross-sectional view of the second embodiment in an assembled state. In the figure, 1 is a circuit board, 2 is a dielectric substrate,
3 is a microstrip line, 4 is a slot line, 5 and 16 are semiconductor elements, 7 is a metal substrate, 8 is a recess, 9 is a step, 10 is a window hole, 11, 14, 1
9 and 21 are joint parts, 12, 15 and 22 are hermetic glass terminals, 13 and 20 are covers, and 17 is a case, respectively.

Claims (1)

[Scope of Claims] 1. A module in which a part of the back surface of a dielectric substrate having a pattern such as a microstrip line as a signal transmission path on the top surface is closely attached to the top surface of a metal substrate, A slot line pattern is provided on the back surface of the metal substrate and a semiconductor element is mounted thereon, and a recess is provided on the back surface of the metal substrate, and a window hole through which the slot line surface of the dielectric substrate can be seen is inserted into the recess at the bottom of the recess. A hermetically sealed terminal is provided, and the semiconductor element and the terminal are connected with a lead wire.
A strip line module characterized by having a recessed opening in a metal substrate sealed with a cover.