JPS6160571B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a semiconductor device testing device, and particularly to a device for inspecting semiconductor devices, and in particular for detecting alignment between a polarity display mark made on the surface of a main body of a semiconductor device and the polarity of a semiconductor pellet inside. The present invention relates to a semiconductor device testing device that can reliably determine discrepancies.

[Technical background of the invention]

For example, a strip-shaped polarity display mark indicating the polarity of the semiconductor pellet inside is applied to the mold part of an axial lead type semiconductor element near one end of the mold part. This polarity display mark is generally printed through the following steps. That is,
Semiconductor elements are fed into a marking machine at regular intervals, and their polarities are automatically determined. Those with opposite polarities are reversed and sent to the printing mechanism with their polarities aligned in one direction. In the printing mechanism,
A polarity display mark is printed on the surface of the mold part located at a predetermined position, for example, on the cathode side. Thereafter, it is checked again whether the polarity display mark matches the polarity of the semiconductor element itself. In this test, the current direction is determined based on the polarity display mark made in the previous step, and the test current is passed in that direction. Additionally, at the same time as this polarity re-inspection, an appearance inspection is conducted to visually observe the printing condition and eliminate blurred or unclear prints.

[Problems with background technology]

In the above case, the polarity is automatically aligned in one direction before it is supplied to the marking machine and sent to the printing mechanism, and the polarity display mark and the semiconductor element itself are However, the reliability of these inspections is extremely strict, and a non-defective rate of nearly 100% is required.

However, in the conventional process, the polarity automatic alignment process after being supplied to the marking machine, or the re-inspection process after the polarity display printing process, is a few millionths of a millionth.
There was a certain probability that inspections would be missed, and as a result, even stricter quality control was desired.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a semiconductor device inspection device that can completely inspect whether the polarity display mark matches the polarity of the semiconductor device itself or not. .

[Summary of the invention]

That is, the present invention provides at least two methods for detecting polarity display marks provided on the surface of the main body of a semiconductor element.
an energizing current control circuit that determines the direction of a test current flowing through the element based on a combination of optical signals detected by the sensor; and a direction of the test current energized by the circuit; A semiconductor device testing apparatus is characterized in that it has a control signal circuit that issues a non-defective product determination signal only when the polarity display mark matches the polarity display mark, and a control signal circuit that issues a defective product determination signal when they do not match.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a resin molded portion 2 of a semiconductor element 1 is provided with a strip-shaped polarity display mark 3 on one end thereof, that is, for example, on the cathode side.

It is assumed that the semiconductor element 1 described above is supplied with its polarity aligned in a certain direction. At least two optical sensors 41 and 42 are provided adjacent to the resin molded portion 2 of the semiconductor element 1. The optical sensors 41, 42 are formed of, for example, a bundle of optical fibers, and are provided with a light projecting section 43 and a light receiving section 44, as shown in FIGS. 2 to 5.

FIG. 3 shows a cross-sectional view taken along the line A-A in FIG. , a plurality of light projecting sections 43 and light receiving sections 44 are arranged alternately in the horizontal direction, and FIG. shows. Furthermore, in FIG. 5, the light emitting section 43 and the light receiving section 44 are not clearly distinguished as layers as shown in FIGS. It constitutes the light receiving section 44.

The optical sensors 41 and 42 mentioned above are connected to the optical cable 4
It is connected to the optical signal discrimination circuit 5 via. This optical signal discrimination circuit 5 discriminates the combination of optical signals emitted by the light emitters 43 of the optical sensors 41 and 42 and received by the light receiver 44, and an energizing current control circuit connected to the discrimination circuit 5 A signal indicating the direction of energization is sent to 6. For example, in the illustrated state, since the polarity display mark 3 is provided on the cathode side of the resin molded portion 2 of the semiconductor element 1, the optical sensor 4
1 and 42, there is a difference in the amount of input light reflected on the surface of the resin molded part 2. Therefore, in the optical signal discrimination circuit 5, the polarity display mark 3 is applied to the cathode side of the molded part 2. is determined electrically. Therefore, in the energizing current control circuit 6, a current i is passed through the connection 7 to the anode side a of the semiconductor element 1, and is fed back to the control circuit 6 from the cathode side b through the connection 8 to form a closed loop. In this case, since the polarity of the semiconductor element 1 and the display mark 3 match, a specified current flows and it is determined that the semiconductor element is a good product.
Conversely, when the polarity display mark 3 is on the left side in the figure, that is, on the optical sensor 41 side, the control circuit 6
From then on, a current is caused to flow from the cathode side a to the anode side b of the semiconductor element 1 via the connection 8. However, since the current is in the opposite direction to the rectification direction of the semiconductor element 1, no current flows, and the product is determined to be defective. In either case, the polarity indicator mark 3
By connecting the control signal circuit 9 to the control circuit 6, which emits a non-defective product determination signal only when the polarity and the polarity of the semiconductor element 1 themselves match, and which emits a defective product determination signal when they do not match, it is possible to distinguish between non-defective products and defective products. It becomes possible to control the mechanical system that sorts out non-defective products.

As a result of flowing current i in either direction based on the optical signals of optical sensors 41 and 42,
If the energizing current i does not flow in either direction, it indicates that the polarity display mark 3 and the polarity of the semiconductor itself 1 do not match. If the print is not printed at all, or if the print is not printed at all, these can be detected based on the difference in the amount of input light of the optical signal, and the control signal circuit 9 may issue a defective product discrimination signal.

〔Effect of the invention〕

As described above, the present invention detects the polarity display mark printed on the resin molded part of the semiconductor element using at least two optical sensors, determines the current direction based on the combination of the detected optical signals, and displays the polarity. Since the current is passed in the direction that matches the mark, it is possible to conduct highly accurate inspections without omitting inspections, and also to ensure that the polarity of the polarity display mark and the semiconductor element itself match. Regardless, semiconductor devices to be tested can be handled as non-defective products, which would have been excluded in the past due to the difference in the direction in which they are set in the testing apparatus, and the rate of non-defective products can be improved.

In the embodiment of the present invention, an example in which two optical sensors are provided has been described, but the invention is of course not limited to this example, and it is sufficient to provide a plurality of optical sensors.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a semiconductor device testing device according to an embodiment of the present invention, and FIGS. 2 to 5 show a schematic diagram and a cross-sectional view of an optical sensor used in the testing device. 1...Semiconductor element, 2...Resin mold part, 3
...Polarity display mark, 4...Optical cable, 5...
Optical signal discrimination circuit, 6... Energizing current control circuit, 4
1,42...optical sensor.

Claims (1)

[Claims] 1 At least two optical sensors that detect polarity display marks made on the surface of the main body of a semiconductor device, and a combination of optical signals detected by these sensors to determine the direction of the test current flowing through the device. A control signal circuit that issues a non-defective product determination signal only when the direction of the test current applied by this circuit matches the polarity display mark, and issues a defective product determination signal when they do not match. A semiconductor device inspection device comprising: