Mitsubishi Denki Kabushiki Kaisha

Ryouichi Takagi

Tetsuo Tada

Hiroshi Noda

Masanobu Kohara

Toshiyuki Tsujii

Masahiko Hyozo

Mikio Asai

To provide a substantially flat surface, a semiconductor device includes a first insulating film formed on one main surface of a semiconductor substrate, and a first lead layer buried in the first insulating film. A first bonding pad is formed in contact with the first lead layer. A second insulating film is formed on the first insulating film and the first lead layer. A second lead layer is formed on the second insulating film, and a second bonding pad includes part of the second lead layer. The height of the surface of the second lead layer is substantially equal to the height of the surface of the first bonding pad respectively from the one main surface of the semiconductor substrate. The first lead layer can be formed on the first insulating film in which case the second insulating film is formed on the first insulating film and the first lead layer such that a first bonding pad is buried in part in the second insulating film in contact with the first lead layer and is exposed in part out of the second insulating film. A second lead layer is formed on the second insulating film, and a height of a top surface of the second lead layer is substantially equal to a height of a top surface of the first bonding pad. A second bonding pad is constituted by part of the second lead layer. The first lead layer and the second lead layer can overlap each other at least in part via the second insulating film.

Semiconductor device

A bare chip (1) is rectangular, and has a front surface (1a) on the center of which semiconductor elements are integrated and a back surface. Notches (2) are formed on a side of the bare chip (1) according to the kind of the semiconductor elements integrated on the bare chip (1). The notches (2) are oblong and extend through the bare chip (1) from the front surface (1a) to the back surface. For example, assuming that the notch (2) represents '1' and a portion without the notch (2) represents '0', one-bit information is obtained according to the presence or absence of the notch (2). When detection of several portions is made, binary information according to a detection result, i.e., information regarding the type of the bare chip (1), is obtained. For detection of the presence or absence of the notch (2), the bare chip (1) is irradiated with light, and then whether the light goes through the notch (2) or is intercepted by the bare chip (1) is detected. Thus, a semiconductor device which allows easy identification of its type is provided.

Semiconductor device with identification function

A test apparatus for a semiconductor device is provided to be used for testing, wafer by wafer, a semiconductor device formed on a semiconductor wafer. The test apparatus for a semiconductor device comprises a test head, a probe card and a selection circuit. The probe card has an insulating transparent base plate, and protruding parts are formed on the main surface of the base plate corresponding to electrode pads on a test object semiconductor wafer, and conductive layer forming a prober for the electrode pad is formed on the surface of each of these protruding parts. A wiring layer is formed on the surface opposite to the main surface. The wiring layer and the probers are connected electrically through the through holes provided on the base plate. A prober to be connected to the test head is switched electrically, which makes it possible to test a semiconductor device without moving the corresponding semiconductor wafer.

Probe plate used for testing a semiconductor device, and a test

A probing card for wafer testing has a plurality of probes arranged so as to correspond to and come in contact with a plurality of bonding pads of semiconductor devices fabricated on a semiconductor wafer. The probing card comprises a base plate, contact fingers and wiring sections. The base plate is formed of photosensitive glass. The base plate defines through holes extending from one of its main surfaces to the other. The contact fingers are formed as columnar elements filling the through holes and having a cross-sectional area decreasing from opposite ends to an intermediate position thereof. Each contact finger has one end thereof projecting from one of the main surfaces of the base plate. This projecting end of each contact finger at least defines a substantially planar end face. The wiring sections comprise conductive layers formed in a predetermined pattern on the other main surface of the base plate and connected respectively to the other ends of the contact fingers. The through holes are formed in the photosensitive glass base plate by photolithography. The contact fingers may be positioned with high precision relative to a plurality of bonding pads. A stable contact is secured between the bonding pads and contact fingers.

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Hyogo, Japan

Ryouichi Takagi