JPS5814071B2 - Electrode extraction structure of semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure in which electrodes are drawn out from the back side of a semiconductor element fixed to a ceramic-based stage.

Particularly in MOSICs, etc., bias electrodes are drawn out from the back of the semiconductor element fixed to the stage.
The exposed surface of the stage after the element is fixed is narrow, the material is different from that of the lead, and there is a step between the stage and the top surface of the base, making it difficult to pull out the electrodes from the stage using metallization, etc., and problems such as wire breakage are likely to occur.

In order to solve this problem, as described in Japanese Patent Application Laid-Open No. 51-81573, a semiconductor element is fixed to a stage in a recessed hole made with an insulating material, and the step between the stage and the top surface of the base is sloped. A semiconductor device has been proposed in which a lead-out conductor for the stage is provided through the inclined surface.

However, with this configuration, it is difficult to connect the lead conductor and the lead terminal in a device having a structure in which a glass layer is provided for fixing the lead and the sealing cap.

Therefore, it can only be applied to devices that do not require a glass layer for adhesion.

An object of the present invention is to realize an electrode lead-out structure that can be applied to a semiconductor device having a structure in which lead terminals and caps are bonded with a glass layer.

In order to achieve this object, the present invention forms a stage by making a recessed hole in an insulator base, fixes a semiconductor element in this stage, and slopes the step between the stage and the top surface of the paste. In a semiconductor device in which a stage lead-out conductor is provided through this inclined surface. A glass layer is provided on the upper surface of the base on which the lead-out conductor is provided, a window hole is formed in the glass layer through which the lead-out conductor is partially exposed, and the lead-out conductor and the lead are connected in this window hole. ing.

Next, how the electrode lead-out structure of a semiconductor device according to the present invention is actually implemented will be explained using examples.

FIG. 1 is a perspective view showing an electrode lead-out structure of a semiconductor device according to the present invention, and FIG. 2 is an enlarged perspective view of the main part thereof.

Reference numeral 1 denotes a base (package board) made of an insulator such as ceramic, and a stage 3 is formed by making a recessed hole at a location where a semiconductor element 2 such as an IC is to be attached.

Apply gold paste 3' etc. to the stage surface,
A conductive treatment is applied, a silicon chip of a semiconductor element is placed on top of it, and the gold-silicon is fixed by heating.

Aluminum-clad leads 5...5l are fixed to the surface of the substrate via a glass layer 4.

Each electrode pad on the surface of the element 2 is connected to the leads 5 by wire bonding of aluminum wire.

The stage 3 is connected to the lead 5' in the following manner, and electrodes are drawn out from the back surface of the element 2.

Step portion 12 between stage 3 of base 1 and base surface 11
A sloped portion 13 is formed in the slanted portion 13, and an electrode lead-out conductor 6 connected to the stage 3 is provided through the sloped portion 13.

The lead-out conductor 6 may be metalized with paste or the like, or an aluminum-clad conductor plate or foil.

The base of the lead-out conductor 6 is connected to the conductor 3' of the stage, and an auxiliary land 61 is formed at the other end.

The lead conductor 6 is connected to the lead 5' at an auxiliary land 61.

After installing the drawer conductor 6, screen print the glass 4 on the base 1, and place the lead frame 5 on top of it.
Place it on top and heat it to make it stick.

During glass printing, only the top of the auxiliary land 61 is masked, and a window hole 41 is opened so that the auxiliary land 61 is exposed through the window hole 41.

The auxiliary land 61 and the lead 5' are connected in the window hole 41. If the auxiliary land 61 is made of aluminum cladding or other material to facilitate aluminum bonding, the auxiliary land 61 can be connected with the aluminum wire 7 as shown in FIG. land 61
and lead 5' can be wire bonded.

Or, as shown in Fig. 4, the auxiliary lead 51 is attached to the lead 5'.
' is formed, and the auxiliary lead 51' and the auxiliary land 61
may be bonded using conductive paste 8, welding, or the like.

As described above, according to the present invention, a window hole is made in the glass layer on the base where the lead-out conductor is provided, the stage section is pulled out to this window hole, and bonding with the lead is performed on the auxiliary land with a wide space. , workability is good, and the auxiliary land is easy to process so that it can be easily bonded to the lead of the aluminum cladding, and other great effects can be obtained.

Therefore, according to the present invention, a structure in which the back surface of a semiconductor element provided in a recessed hole and the top surface of a base are connected by a lead-out conductor passing through an inclined surface is replaced with a structure in which leads and a cap are bonded through a glass layer. It can also be applied to other semiconductor devices.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an electrode lead-out structure of a semiconductor device according to the present invention, FIG. 2 is an enlarged perspective view of the main part thereof, FIG. 3 is a perspective view showing a connection structure between an auxiliary land and a lead, and FIG. In another example of the same connection structure, the figure A is a perspective view, and the figure at the front is a sectional view. In the figure, 1 is a ceramic base, 12 is a stepped portion, and 13 is a ceramic base.
2 is a semiconductor element, 3 is a stage, 4 is a glass layer, 41 is a window hole, 5...5 is a lead, 6 is a stage lead-out conductor, and 61 is an auxiliary land.

Claims (1)

[Claims] 1. A stage is formed by making a recessed hole in an insulator base, a semiconductor element is fixed in this stage, and a stepped portion between the stage and the top surface of the base is sloped, and a stage is formed through the sloped surface. In a semiconductor device provided with a stage lead-out conductor, a glass layer is provided on the upper surface of the base on which the lead-out conductor is provided, a window hole is formed in this glass layer through which a part of the lead-out conductor is exposed, and a window hole is formed in the window hole. An electrode lead-out structure for a semiconductor device characterized by connecting a lead-out conductor and a lead.