JP2669892B2 - Package for storing semiconductor devices - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package, and more particularly to a semiconductor element housing package for housing a semiconductor element.

[Conventional technology and its problems]

As a package for accommodating a semiconductor element, there is already known a package including a ceramic base body in which the semiconductor element is arranged in the central portion and a ceramic frame body provided on the ceramic base body so as to surround the semiconductor element. .

As shown in FIG. 4, the conventional semiconductor element housing package has a strip line 53 formed on a ceramic base 52 in the terminal mounting portion 51. In addition, the ceramic base 52 is sandwiched so that the strip line 53 is sandwiched from both sides.
A ground pattern 54 is formed on top. The ground pattern 54 is connected to the metal heat dissipation plate 56 via a through hole 55 formed in the ceramic base 52. Further, the ground pattern 54 is connected to the sealing metallization layer 59 formed on the upper surface of the ceramic frame 57 through the through hole 58 formed in the ceramic frame 57. Here, the strip line 53 is surrounded by the ground pattern 54, the through holes 55 and 58, the metal heat dissipation plate 56, and the sealing metallization layer 59, and as a result, the strip line 53 is shielded.

However, in the above-mentioned conventional structure, it is necessary to form a small through hole in the ceramic base body / frame body, which is not easy to manufacture. Moreover, in the shield by the through hole,
In plan view, the radiation loss is larger than that of the shield. Further, in this configuration, the distance from the strip line to the shield becomes relatively long, so that the dielectric loss due to the ceramic is inevitably large.

On the other hand, it is already known that the base body and the frame body are made of metal, a cutout is provided in the lower portion of the frame body, and a small ceramic member having a strip line is inserted into the cutout.

With this conventional configuration, radiation loss and dielectric loss can be reduced, but it is necessary to fit a small ceramic member in the notch formed in the frame with high precision. Therefore, high processing accuracy is required, assembly becomes difficult, and mass productivity decreases.

An object of the present invention is to provide a semiconductor element housing package that is easy to manufacture, has high mass productivity, and can reduce radiation loss and dielectric loss.

[Means for Solving the Problems]

A semiconductor element housing package according to the present invention includes a ceramic base having a terminal mounting portion, a ceramic frame body provided on the ceramic base, and a metal radiator plate mounted under the ceramic base. The terminal mounting portion includes a metal layer for terminal mounting formed in the ceramic base, notches formed at intervals on both sides of the metal layer for terminal mounting, and metal heat dissipation through the notch from the upper surface of the ceramic base. And a shield metal layer reaching the plate.

[Action]

In the package for accommodating semiconductor elements according to the present invention, the metal layer for terminal attachment is formed in the ceramic base,
The metal layer for terminal attachment is shielded by the metal layer for shielding which reaches from the upper surface of the ceramic substrate to the metal heat dissipation plate through the notch. Therefore, the metal layer for attaching terminals can be surrounded by the planar shield layer, and the radiation loss is reduced. Moreover, since the distance between the metal layer for attaching the terminal and the metal layer for shielding becomes close, the dielectric loss is reduced by the ceramic member. Moreover, according to this configuration, it is not necessary to process the small ceramic member with high precision or to form a small through hole, which facilitates manufacturing and improves mass productivity.

〔Example〕

FIG. 1 shows a semiconductor element housing package for housing a field effect transistor as an embodiment of the present invention. In FIG. 1, this semiconductor element housing package includes a rectangular flat ceramic base 1, a ceramic frame 2 provided on the ceramic base 1, and a metal lid that can be fixed to the upper surface of the ceramic frame 2. 3 and a metal heat dissipation plate 4 fixed to the lower surface of the ceramic substrate 1. A hole 5 for accommodating a field effect transistor (not shown) is formed in the center of the ceramic base 1, and the heat sink 4 is exposed upward from the hole 5. The frame 2 is arranged at a position surrounding the hole 5 at a constant interval. A pair of terminal mounting portions 6 is arranged between the long side of the ceramic base 1 and the hole 5. The terminal mounting portions 6 are arranged in the central portion of the ceramic base body 1 so as to face each other.

As shown in FIG. 2, the terminal mounting portion 6 includes an external terminal mounting concave portion 11 arranged on the outside of the package and an internal terminal mounting concave portion 12 provided on the hole 5 side at a position corresponding to the concave portion 11. And have. Grooves 13 and 14 extending in the up-and-down direction are formed on both sides of the surface recessed portion 11 at intervals.
Is arranged. The lower ends of the grooves 13 and 14 are closed by the heat dissipation plate 4.

On the bottom surfaces of the recesses 11 and 12, one strip-shaped metal layer 15 for attaching terminals is formed. The metal layer 15 continuously extends in the ceramic substrate 1 from the recess 11 side to reach the recess 12.
One end of the input / output terminal 16 is connected to the metal layer 15 in the recess 11. In addition, a terminal of a field effect transistor (not shown) is connected to the metal layer 15 in the recess 12. A shield metal layer 17 is formed on the upper surface of the ceramic substrate 1 between the pair of grooves 13 and 14. Metal layer 17
Surrounds the recess 11 with a slight distance. The metal layer 17 continuously extends from the recess 11 side to the recess 12 side,
It extends to the hole 5 side so as to surround 12. The frame 2
The width of the portion of the metal layer 14 disposed below the is set narrow. This is to improve the fixing strength of the frame body 2 by increasing the contact area between the ceramics of the frame body 2 and the base body 1. The metal layer 17 around the recess 11 is
The side wall surface of the groove 13 continuously extends downward and reaches the metal radiator plate 2. The metal layer 17 around the recess 12 continuously extends downward in the groove 14 and reaches the metal heat dissipation plate 4. As a result, the metal layer 17 is grounded. A metal layer 18 for bonding the heat dissipation plate 4 is formed on the entire lower surface of the ceramic substrate 1. Further, a metal layer 19 for adhering the lid body 3 is provided on the upper end surface of the frame body 2.

The metal layers 15, 17, 18, 19 are made of a high melting point metal such as tungsten, molybdenum, or manganese.

According to the above configuration, the metal layer 15 of the terminal mounting portion 6 is
It is surrounded by metal layers 17 and 18 at a relatively close position. Further, the metal layers 17 and 18 surround the metal layer 15 in a planar shape. Therefore, without using a metal frame,
The radiation loss of the signal can be suppressed as much as possible. Also, the dielectric loss due to the ceramic can be suppressed.

Next, a method for manufacturing the above-mentioned package for housing a semiconductor element will be described.

First, an unfired ceramic substrate (green sheet) formed in a rectangular shape as shown in FIG. 1 is manufactured. In this case, it is manufactured by stacking two green sheets 1a and 1b having holes 5. As shown in FIG. 3, the upper green sheet 1a is provided with holes 5 and notches 11a and 12a for forming recesses. Also, both notches 11a, 12a
Notches 13a and 14a for forming grooves are formed on both sides of the. Furthermore, the upper surface of the green sheet 1a and the notches 13a, 14
A metal layer 17 is formed on the side wall surface of a. On the other hand, the metal sheet 15 is formed at the positions corresponding to the notches 11a and 12a in the green sheet 1b which is superposed on the lower side of the green sheet 1a. Further, notches 13b and 14b are formed at positions corresponding to the notches 13a and 14a. A metal layer 17 is formed on the side wall surfaces of the cutouts 13b and 14b and on the upper surface of the green sheet between the cutouts 13b and 14b. Further, the metal layer 18 is formed on the entire back surface of the green sheet 1b. In addition, a metal layer on top
Ceramic frame 2 coated with 19 and green sheet 1
A metal heat radiating plate 4 having the same size as a and 1b is prepared.

Next, the green sheets 1a, 1b and the frame 2 are superposed and fired to obtain a member in which the base 1 and the frame 2 are integrally fixed. Then, the heat dissipation plate 4 is brazed to the lower surface of the ceramic base 1.

Next, a field effect transistor or the like is housed and fixed in the hole 5, and each electrode of the field effect transistor or the like and the metal layer 15 in the recess 12 are connected by wire bonding.
Further, the input / output terminal 16 is connected to the metal layer 15 in the recess 11 on the outside. Further, the inside of the frame 2 is hermetically sealed by brazing the lid 3 on the upper surface of the frame 2.

In this case, since it is not necessary to provide a small through hole or use a ceramic member that is small and difficult to handle, manufacturing becomes easy and mass productivity is high.

In addition, although the structure in which one terminal is attached to one terminal attachment portion has been described in the above-described embodiment, the present invention can be similarly implemented even in the manufacturing in which a plurality of terminals are attached. In this case, a plurality of structures of the mounting portion shown in FIGS. 1 and 2 are arranged in parallel. If the adhesive strength between the frame body and the base body does not matter, it is not necessary to narrow the width of the metal layer 17 below the frame body 2.

〔The invention's effect〕

According to the semiconductor element housing package of the present invention,
Since the terminal mounting metal layer, the notch, and the shielding metal layer as described above are provided in the terminal mounting portion, the semiconductor element storage package can be manufactured easily and has high mass productivity, and radiation loss and dielectric loss can be reduced. Can be realized.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view of an embodiment of the present invention, FIG. 2 is an enlarged partial view thereof, FIG. 3 is an exploded perspective view of a portion corresponding to FIG. 2, and FIG. It is a figure equivalent to a figure. 1 ... Ceramic substrate, 2 ... Ceramic frame, 4 ...
Heat sink, 6 ... terminal mounting part, 13,14 ... groove, 15 ... terminal mounting metal layer, 17 ... shielding metal layer.

Claims (1)

(57) [Claims] 1. A semiconductor element housing package for housing a semiconductor element, comprising a ceramic base having a terminal mounting portion, a ceramic frame body provided on the ceramic base, and mounted under the ceramic base. A metal heat dissipation plate, the terminal mounting portion, the terminal mounting metal layer formed in the ceramic base, and a notch formed at a distance on both sides of the terminal mounting metal layer, A package for accommodating a semiconductor element, comprising: a metal layer for shielding, which extends from the upper surface of the ceramic base body to the metal heat dissipation plate through the notch.