JPH0510391Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an improvement in the mounting structure of a microwave integrated circuit (hereinafter referred to as MIC) board.

(b) Conventional technology Conventionally, the following method has been used to establish electrical continuity between the back surface of the MIC board and the base.

FIG. 3 is a sectional view showing a conventional MIC board mounting structure. In the figure, 11 is a MIC board made of ceramic, and this MIC board 11 has an opening 1.
2 is provided. Further, 13 is a printed circuit board base having a circuit pattern 14 formed on its upper surface, and this printed circuit board base 13 is provided with an opening 15. Reference numeral 18 denotes a metallized layer formed within the MIC substrate 11 and the opening 12.

To attach the MIC board 11 to the printed circuit board base 13, first, a pin 17 made of Cu, stainless steel, etc. is press-fitted into the opening 15 of the printed circuit board base 13. And MIC board 11
The installation is completed by applying a conductive adhesive 16 to the back surface of the pin 17 and press-fitting the portion of the pin 17 exposed from the hole 15 into the hole 12. This mounting structure allows conduction between the metallized layer 18 on the back surface of the MIC board 11 and the surface of the printed circuit board base 13.

Further, FIG. 4 is a sectional view showing another conventional MIC board mounting structure. In the figure, 21 is a MIC board made of ceramic, and this MIC board 21
An opening 22 is provided in the MIC substrate 21, and the opening 22 and the MIC substrate 21 are provided on the back side of the MIC substrate 21.
A metallized layer 23 is provided on a part of the surface (around the opening 22). Moreover, 24 is a die-cast base made of Al, and this die-cast base 24 is provided with an opening 25.

To attach the MIC board 21 to the die-cast base 24, first, a pin 26 made of Cu, stainless steel, etc. is press-fitted into the hole 25 and fixed.
Then, the portion of the pin 26 exposed from the opening 25 is inserted into the opening 22. Note that the opening 22 is connected to the pin 26.
is set sufficiently large compared to . lastly,
A solder portion 27 is placed on the opening 22 portion of the surface of the MIC board 21.
The installation is completed by forming the With this mounting structure, the metallized layer 2 on the back side of the MIC board 21
3 and the die-cast base 24 can be electrically connected to each other.

(c) Problems to be solved by the invention All of the above-mentioned conventional technologies require a pin, which is a separate part, and the work of press-fitting this pin is required, which leads to the problem of high costs. It was hot.

The present invention was devised in view of the above-mentioned problems, and aims to provide an inexpensive mounting structure for a MIC board that can reliably establish electrical continuity between the metallized layer on the back side of the MIC board and the die-cast base. It is something.

(D) Means for solving the problems The present invention is characterized by comprising an MIC substrate made of ceramic and having an opening, a first metallization layer provided on the back surface of the MIC substrate and in the opening, a die-cast base having integrally molded projections that can be inserted into the openings, a second metallization layer formed on the projections and made of a solderable material, and a solder portion that connects the first metallization layer and the second metallization layer.
This is the mounting structure for the MIC board.

(e) Effect Since the present invention is constructed as described above, the MIC board can be fixed by simply inserting the protrusion integrally formed on the die-cast base into the opening of the MIC board and soldering the protrusion. and furthermore, the MIC
Conductivity can be established between the metallized layer on the back of the substrate and the die-cast base.

(f) Embodiment FIG. 2 is a top view of a mounting structure for a MIC board according to an embodiment of the present invention, and FIG. 1 is a sectional view taken along the line -- in FIG.

In the figure, reference numeral 1 denotes an MIC board made of ceramic, and this MIC board 1 is provided with an opening (through hole) 2. Further, a metallized layer (first metallized layer) 3 is provided on the back surface, the front surface (around the opening 2 ), and inside the opening 2 of the MIC substrate 1 . Further, circuit patterns 4a and 4b are provided on the surface of the MIC board 1, and an element 5 is mounted on the circuit pattern 4a.

Note that the circuit pattern 4a shown in FIG. 2 is a partial one. Further, the metallized layer 3 and the circuit patterns 4a and 4b are formed by plating Au or Ni on the MoMn alloy layer.

Reference numeral 6 denotes a die-cast base made of Al, and a protrusion 6a is integrally formed on the die-cast base 6. Further, a Ni layer (second metallized layer) 7 is formed by plating on the die-cast base 6 (including the projections 6a).

To attach the MIC board 1 to the die-cast base 6, after inserting the protrusion 6a into the opening 2 (the opening 2 is sufficiently larger than the protrusion 6a), the Ni layer 7 on the protrusion 6a and the Ni layer 7 on the protrusion 6a are inserted. The solder portion 8 may be provided by soldering the metallized layer 3 on the surface of the MIC substrate 1. This mounting structure allows conduction between the metallized layer 3 on the back surface of the MIC board 1 and the die-cast base 6.

Note that if the metallized layer 3 in the opening 2 and the Ni layer 7 on the protrusion 6a are connected by the solder portion 8, the metallized layer 3 on the MIC substrate 1 is not necessarily necessary. Further, the Ni layer 7 other than the protrusion 6a can be omitted.

In the present invention, the reason why the second metallized layer 7 is formed on the protrusion 6a will be explained below.

The die-cast base 6 is usually made of Al, Zn, etc., and is generally difficult to solder. Therefore, in order to facilitate soldering of the metallized layer 3 to the projection 6a integrally formed on the die-cast base 6, a second metallized layer 7 made of Ni, Au, etc. is formed on the projection 6a.

Next, a description will be given of how the circuit pattern and the die-cast base are electrically connected by the mounting structure of the MIC board as described above.

Below the circuit pattern 4a where element 5 is attached
The MIC board 1 is provided with a through hole 9, and the MIC board 1 is inserted into the through hole 9.
A metallized layer (not shown) is provided to establish electrical conduction between the metallized layer 3 on the back surface and the circuit pattern 4a.

Since the metallized layer 3 on the back surface of the MIC board 1 is electrically connected to the die-cast base 6 through the mounting structure of the present invention, the circuit pattern 4a is also electrically connected to the die-cast base 6 via the through hole 9. There is. Therefore, conduction can be established between the circuit pattern 4a and the die-cast base 6 by simply forming the through hole 9 in which the metallized layer is formed in the circuit pattern 4a.

(g) Effects of the invention As is clear from the above explanation, this invention does not require pins as separate parts, does not require press-fitting of these pins, is inexpensive, and can reliably connect the metallized layer and die-cast layer on the back side of the MIC board. It is possible to establish electrical continuity between the manufactured bases, and the practical effect is extremely large.

[Brief explanation of the drawing]

Figures 1 and 2 both show examples of the present invention.
The mounting structure of the MIC board is shown, and Figure 2 is a top view.
FIG. 1 is a sectional view taken along the - line in FIG. 2.
3 and 4 are cross-sectional views of a conventional MIC board mounting structure. DESCRIPTION OF SYMBOLS 1... MIC board, 2... Opening, 3... First metallized layer, 4a, 4b... Circuit pattern, 5
...Element, 6...Die-cast base, 6a...
...Protrusion, 7...Second metallized layer, 8...Solder part, 9...Through hole.

Claims (1)

[Claims for Utility Model Registration] 1. A microwave integrated circuit board made of ceramic and provided with an aperture, a first metallized layer provided on the back surface of the microwave integrated circuit board and in the aperture, and the a die-cast base integrally formed with a protrusion that can be inserted into the opening; a second metallized layer made of a solderable material formed on the protrusion; the first metallized layer and the second metallized layer; A mounting structure for a microwave integrated circuit board, characterized by comprising: a solder part for connecting layers; 2. The mounting structure for a microwave integrated circuit board according to claim 1, wherein the second metallized layer is made of Ni.