JPH07130902A - Ceramic package body for integrated circuits - Google Patents

Abstract

(57) [Abstract] [Purpose] To enable wire bonding of an integrated circuit with fine pitch pads in a glass seal type package body without being restricted by the mutual pitch of the inner ends of the metal leads. . [Structure] Glass layer 3a on peripheral surface 3 of package body 1
Inside, the relay line 4 for electrically connecting the pads 8 of the integrated circuit 7 to be housed and the metal leads 9 for external connection is provided. In each relay line 4, the mutual interval P2 between the outer ends 6 is the same as the mutual interval between the inner ends 10 of the metal leads 9, and the mutual interval P1 between the inner ends 5 is the mutual distance between the pads 8 of the integrated circuit 7. It is made smaller according to the interval P1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic package body for integrated circuits (hereinafter, also simply referred to as a package).

[0002]

2. Description of the Related Art Glass seal type packages such as sir dip and sir quad are widely used because of their advantages such as low cost. On the other hand, recently, in order to handle a large number of input / output signals, a space between input / output terminals (also called bonding pads or simply pads) formed on an integrated circuit chip called IC, LSI, VLSI or the like. (Pitch) is becoming finer and finer. This tendency also applies to the glass seal type package. This type is constructed as shown in FIG. That is, the integrated circuit 33 is accommodated (mounted) in the die attach portion 32 of the package 31, and the pad 34 of the integrated circuit 33 and the inner end portion 36 of the external metal lead (frame terminal) 35 are bonded by the metal wire 37, Then, the glass layer 38 on the peripheral surface is covered with a lid (not shown) to sandwich the metal lead 35, and the integrated circuit 33 is sealed by glass welding. Further, in this structure, as shown in FIG. 3, the distance P between the pads 34 of the integrated circuit 33 and the distance between the inner end portions 36 of the external metal leads 35 are substantially the same.

[0003]

The metal lead 35 is made of 42 alloy (Fe-Ni alloy) or Kovar (F).
Since the thin plate of (e-Ni-Co alloy) is manufactured by punching and etching by a press, its inner end portion 36
The mutual pitch P is generally about 0.25 mm as a manufacturing limit. This is because, for example, a normal metal lead material has a thickness of about 0.15 mm, and in order to punch this out by press molding or etching, the width of the punched portion (gap between terminals) is equal to the plate thickness. That is, at least 0.
This is because about 15 mm is necessary, and if the lead width is set to about 0.1 mm, which is the minimum, the distance between the leads (hereinafter, also referred to as pitch) is at least 0.25 mm.

Therefore, the glass seal type package cannot generally accommodate an integrated circuit having pads with a pitch smaller than this size. That is, in FIG. 3, the mutual pitch of the inner end portions 36 of the metal leads 35 is 0.25 mm, whereas when the pitch of the pads 34 of the integrated circuit 33 is 0.2 mm or less, both pitches do not match. The inner end 3 of the metal lead
6 and the pad 34 of the integrated circuit cannot be brought close to each other by wire bonding. On the other hand, if the distance from the pad of the integrated circuit to the inner end of the metal lead is made large, the pitch mismatch can be absorbed, but the bonding wire becomes large and the wire is slackened. The problem that occurs easily occurs. Thus, conventional glass seal type packages are limited to integrated circuits with pad pitches that are approximately equal to the mutual pitch of the inner ends of the metal leads used, and thus integrated with fine pitch pads. There was a problem that the circuit was not suitable. The present invention is
The present invention has been devised in order to solve such problems, and an object thereof is to provide a technique capable of responding to a demand for a fine pitch integrated circuit in a glass seal type package.

[0005]

In order to achieve the above-mentioned object, the present invention is a ceramic package body for an integrated circuit having a glass layer on its peripheral surface, which is formed on an integrated circuit chip to be housed. A plurality of relay lines for electrically connecting the bonded bonding pad and the metal lead for external connection fixed to the peripheral surface by the glass layer are provided inward from the mutual distance between the outer ends that are outward. The inner ends of the eggplant are formed with a small distance between them, and are formed inside the glass layer on the peripheral surface.

[0006]

With the above structure, the inner end portion of the metal lead is
It is possible to wire bond the outer ends of the relay line having a large pitch, and the pads of the integrated circuit can be wire bonded to the inner ends of the relay line having a small pitch. Therefore, it is possible to accommodate an integrated circuit having pads with a pitch smaller than the mutual pitch of the inner ends of the metal leads. That is, when forming the relay line, the distance between the outer ends of the relay line is matched with the distance between the inner ends of the metal leads to be used, and the distance between the inner ends is accommodated in the pad of the integrated circuit. By forming them to be small in accordance with the mutual intervals, it is possible to electrically connect the integrated circuit having the fine pitch pads and the metal leads. Thus, in the glass seal type integrated circuit device, even if the metal leads (frames) have a relatively large pitch as in the conventional one, a fine pitch integrated circuit can be mounted without causing the length of the bonding wire to increase.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a package according to the present invention is embodied will be described in detail with reference to FIGS.
That is, the package main body 1 in the present example is formed as follows mainly by the ceramic substrate 2 having a substantially square shape with the center of the upper surface being recessed. The ceramic substrate 2 is
In this example, it is made by firing 90% alumina by press molding, and a glass layer 3a (low melting point) forming an insulating layer is applied to the outer periphery of the peripheral surface 3 on the upper surface with a predetermined width. . However, the glass layer 3a is formed by screen-printing a glass paste formed by mixing glass powder with a predetermined solvent or the like.

On the other hand, inside the glass layer 3a, relay lines (metallized wiring portions) 4, 4 are formed substantially radially from the inside to the outside of the package body 1 and the inner end portion 5 is an inner portion. A large number of pitches P2 of the outer end portions 6 that are outward of the pitch P1 are formed, and the inner and outer end portions 5 and 6 are formed to form bonding pads, respectively. In this example, the relay lines 4 and 4 are linear with a width of about 50 μm and are formed by Au plating on a thin film of Ti or Pd by a sputtering method with Ni plating as a base. It serves as a conductive path for electrically connecting the pad 8 of the circuit 7 and the metal lead 9. In addition,
The interval (pitch) P1 between the inner ends 5 of the relay line 4 is set to be the same as the pitch of the pads 8 of the integrated circuit 7. On the other hand, the pitch P2 of the outer ends is set to be the same as the distance between the inner ends (pads) 10 of the metal leads 9. By the way, in this example, P1 is 0.08 m
m, and P2 is 0, 3 mm.

In the package body 1 of this example thus formed, metal leads 9 are placed on the glass layer 3a of the peripheral surface 3, and the inner end 10 thereof is the outer end 6 of the relay line 4.
The metal leads 9 are fixed by melting the glass by temporarily fixing and heating so that the metal leads 9 face each other. Next, the integrated circuit 7 is housed in the die attach portion 11 so that the pad 8 thereof and the inner end portion 5 of the relay line 4 face each other and attached to the bottom portion. The metal lead 9 shown in the drawing is made by etching a 42 alloy thin plate (thickness 0.15 mm) by a method similar to the conventional one. It is vapor-deposited or Au-plated.

Ultrasonic waves are passed between the pad 8 of the integrated circuit 7 and the inner end 5 of the relay line 4 and between the outer end 6 of the relay line 4 and the inner end 10 of the metal lead 9. Wire bonding may be performed by a method or the like. As a result, the pad 8 of the integrated circuit 7 and the inner end 10 of the metal lead 9 can be connected via the relay line 4 without increasing the length of the bonding wire W. After that, by covering the ceramic substrate 2 with the ceramic lid 12 having the glass layer on the peripheral surface facing the glass layer 3a in the same manner as in the conventional case, heating and fusing the glass layers together, Seal the integrated circuit. After the hermetic sealing, the metal film oxidized by heating is washed with an acid to remove the oxide film, and nickel plating or solder plating is performed to obtain a desired integrated circuit package.

In this example, the relay line 4 has a pitch P2 between the outer ends 6 thereof set to 0.3 mm, and a pitch P2 between the inner ends 5 thereof set to 0.08 mm. However, in the present invention, this size is adjusted to the pad pitch of the integrated circuit to be mounted,
It goes without saying that it may be set appropriately. However,
The pitches P1 and P2 of the outer end portion and the inner end portion of the relay line are preferably formed to match the pitches of the inner end portion of the external metal lead and the pad of the integrated circuit as much as possible.

In the above-mentioned embodiment, the case where the relay line is formed by the sputtering method suitable for the fine pitch is illustrated, but the present invention is not limited to this. The material may be an appropriate metal, for example, Ti for thin film,
In addition to Pd, Mo, Cu, Cr, etc. may be used.
An example is a case of applying Ni underlayer Au plating or Cu underlayer Au plating. That is, it is sufficient that each pad of the integrated circuit and the metal lead for external connection are metalized so that they can be electrically connected (wiring).
A thin film may be formed by D, plating or the like, and depending on the pitch, a thick film forming technique may be used to bake a metal paste such as Au or Ag, or a tungsten or molybdenum paste may be printed on the package body before firing and baked. (Cofier), and then Ni or Au may be plated.

Needless to say, the number of relay lines depends on the number of pads. The length of the relay line may be set appropriately according to the pitch, the size of the package body, and the like, but the bonding wire may be set as short as possible. The present invention can be embodied by forming a relay line inside the glass layer in a glass seal type package such as a conventional sir dip or sir quad.

[0014]

As is apparent from the above description, in the package body according to the present invention, the relay line is provided between the pad of the integrated circuit and the inner end portion of the metal lead without directly connecting them with the bonding wire. By interposing, the distance between the inner and outer ends of the relay line is made smaller by making the inner end on the pad side of the integrated circuit smaller than the outer end on the metal lead side for wire bonding. is there. Therefore, when forming the relay line, the distance between the outer ends is adjusted to the distance between the inner ends of the metal leads to be used, and the distance between the inner ends is adjusted so that the pads of the integrated circuit are By reducing the size according to the distance, it is possible to accommodate and wire bond an integrated circuit having fine pitch pads without increasing the length of the bonding wire. As a result,
Even in the glass seal type package, it is possible to obtain an integrated circuit package in which an integrated circuit having fine pitch pads is mounted as long as the distance between the inner ends of the relay lines can be formed at a fine pitch.

[Brief description of drawings]

FIG. 1 is an enlarged plan view of essential parts for explaining an embodiment in which a ceramic package body for integrated circuits according to the present invention is embodied.

FIG. 2 is a partial cross-sectional view illustrating a state in which an integrated circuit is fixed and wired to the package body of FIG.

FIG. 3 is an enlarged plan view of an essential part for explaining a conventional ceramic glass seal type package main body for accommodating integrated circuits.

[Explanation of symbols]

 1 Package Main Body 3 Peripheral Surface 3a Glass Layer 4 Relay Line 5 Inner End of Relay Line 6 Outer End of Relay Line 7 Integrated Circuit 8 Pads of Integrated Circuit 9 Metal Leads for External Connections 10 Metal Leads for External Connections Inner end P1 Distance between inner ends of relay line P2 Distance between outer ends of relay line

Claims (1)

[Claims] 1. A ceramic package body for an integrated circuit, comprising a glass layer on a peripheral surface thereof, the bonding pad being formed on an integrated circuit chip to be housed, and for external connection fixed to the peripheral surface by a glass layer. A plurality of relay lines for electrically connecting to the metal leads of the outer peripheral end portions of the outer side of the glass, the inner side end portions of the inner side portions of the inner side portions of the inner side portions of the outer side of the outer side of the outer side portion of the glass of A ceramic package body for an integrated circuit, which is formed inside the layer.