JPS58123472A - Semiconductor characteristics measuring apparatus - Google Patents

Abstract

PURPOSE:To prevent misjudgement of characteristics of a semiconductor element due to poor contact between leads thereof and a handler measuring element by checking for poor contact between the leads of the semiconductor element and the measuring element, evaluating the level of components of a test signal with a specified frequency, which is applied to the input of the semiconductor element. CONSTITUTION:A test signal is applied to the input of a semiconductor element from an oscillator 23 for generating a sine wave signal with the frequency higher than the frequency of noise to be detected with a noise detection circuit 16 as contact testing signal and the level of the test signal components contained in the output of the element is evaluated in the route of an amplifier 15 a band filter 24 an AC/DC converter 25 comparator 26 to detect the propriety of contact between leads of the semiconductor and a measuring element 12. When the contact is defective a handler interface 22 prohibits the sorting output from an analog comparator 17 and another sorting output (defective contact signal) D' is sent to a handler 10. This prohibits the sorting by the handler 10 in response to any poor contact thereby elimiating missorting confusing the judgement of the quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a semiconductor characteristic measuring device used when manufacturing semiconductor devices to automatically measure their electrical characteristics using an automatic sorting device (hereinafter referred to as "nola"). .

TECHNICAL BACKGROUND OF THE INVENTION A conventional device of this type is constructed as shown in FIG. That is, in the handler 10, 1 is the device under test, such as a transistor, and 12 is the transistor under test 1.
This is a contact element (hereinafter referred to as a probe) that comes into contact with the sensor. 131
~JJ.

are first to third measuring terminals, which are respectively connected to the collector, pace, emitter, and terminal of the transistor 11 via the probe 12. When measuring the noise voltage of the transistor 11, the second measurement terminal 13 connected to the base is grounded via the signal source resistor 14, and the first measurement terminal 13 connected to the collector and emitter is grounded via the signal source resistor 14. ．． The third measurement terminal '3te13sIfi is connected to the input terminal of the amplifier 15. This amplifier 15Fi has a signal input (noise signal) from the transistor 11 of 10 to 1
This is for amplifying up to about 1,000 mV. 16
is a noise detection circuit that integrates the output noise signal of the amplifier 15 over a certain period of time and converts it into a DC level. 17 compares and classifies to which of the first to third classifications the output level of the noise detection circuit 16 corresponds, and classifies the first to third classification outputs A, B, and C (these are non-defective products, Defective products on the low level side,
This is an analog comparator that generates a defective product (representing a defective product on the level side). A handler interface 18 sends the classification output from the comparator 17 to the handler 10, and the handler 10 selects the transistor under test based on this input classification signal.
1K-Classify. 1. Problems with the Background Art In the semiconductor characteristic measuring device described above, when the handler J (+ probe 12 and the transistor under test 11 come into contact with each other), the leads of the transistor under test 11 may come into contact with each other by mistake, or this lead may contact the handler 10. The noise voltage of the test transistor 11 cannot be measured correctly if it contacts the metal of the chute and short-circuits, or if the contact between the probe 12 and the lead is poor, or if it remains open without contact. In the case of the above contact failure, the noise level of the amplifier 15 is usually smaller than the noise input level during normal contact, so the analog comparator 17 outputs a signal indicating a defective product on the low level side. K so that the 2-classification signal B is output.

However, in the case of such a poor contact, the contact state between the lead of the test transoster 11 and the probe 12 is unstable, so that the noise voltage output signal of the test transistor 11 is superimposed on the noise voltage output signal. At this time, K is the analog comparator 1. Since the input level of the analog comparator 17 becomes high, the first classification signal erroneously indicating a good product may be output.

Purpose of invention The present invention has been made in view of the above circumstances.

An object of the present invention is to provide a semiconductor characteristic measuring device that can prevent erroneous determination of device characteristics due to poor contact between a semiconductor device lead and a handler side piece.

Summary of the Invention That is, the present invention applies a test signal of a predetermined frequency to an element input, separates the element output signal into the test signal component and a noise signal component, and determines the level of the test signal component to determine the level of the element lead. The system detects the presence or absence of poor contact with the probe, and uses the classification output based on the level judgment of the noise signal component only when there is no contact. When there is poor contact, the classification output is not used, so it is possible to avoid errors. classification judgment will not be performed.

Embodiment of the Invention Hereinafter, an embodiment of the present invention will be explained in detail with reference to FIG. The semiconductor characteristic measuring device shown in FIG.
In addition to the element input by applying voltage to the second measurement terminal 13 via the handler interface 22 in response to the detection output of good or bad contact from the circuit 20,
〜3rd classification output AI, B/, σ and 4th classification output (contact failure signal) D't-The difference is that it is selectively output), and the others are the same, so 1st in Fig. 2 The same parts as those in the figures are given the same reference numerals and the explanation thereof will be omitted.

The contact failure detection circuit 20 operates at a frequency higher than the noise frequency detected by the noise detection circuit 16 (for example, 50 k
An oscillator 23 that generates a sine wave signal (Hz) as a contact test signal, a band F wave generator 24 that separates the test signal component from the output signal of the amplifier 15, and an AC/DC converter for the output signal of the P wave generator 24. AC/DC converter 2 to convert
The output level of the pin parter 25 of 5 and 5 is compared with a predetermined reference level, and depending on whether the judgment result is above the reference level or not, a good contact state between the element lead and the probe 12 in the handler 1o is determined. , a converter 26 that generates a contact state detection output indicative of a defect, and a low-frequency p-wave generator (the cutoff frequency is, for example, Approximately 2
0 ki(z) 27.

In the semiconductor characteristic measuring device having the above configuration, the noise signal contained in the element output is detected in the path from the half driver 10 to the amplifier 15 to the low-frequency P wave generator 27-+noise detection circuit 16 to the analog comparator 17. Classify and judge the level of non-defective products and low-level defective products.

1, outputs classification signals A, B, and C for defective products on the level side.

- On the other hand, since the test signal from the generator 23 is added to the element input, the test signal component included in the element output is transferred from the amplifier 15 to the impedance p wave generator 24 to the C/υC converter 25.
→The level is determined by one pass of the converter/converter 26, and the quality of the contact between the element needle and the probe 12 is detected.

And the handler interface? 2Fi, when a good contact detection output is led from the poor contact detection circuit 20, a classification output corresponding to the classification signal from the analog comparator Noah is sent to the controller 10, and a poor contact detection output is led. When there is a classification output 1 according to the classification signal from the analog comparator 17! - prohibit and send the fourth classification output (bad contact signal) D' to the handler 10;

Therefore, classification in the handler 10 is prohibited in the case of a contact failure, and classification in the case of a contact failure as described above in the conventional example is prohibited.
Misclassification caused by erroneously determining a defective product as a non-defective product using the dike signal does not occur.

The contact failure detection circuit 20 in the above embodiment not only detects the contact failure as described above, but also appropriately sets the test signal to be added as an element input, the measurement form of the test signal separated from the X output, etc. By doing so, it is possible to implement a significant modification that also has the function of measuring the characteristics of the element.

Effects of the Invention As described above, according to the semiconductor characteristic measuring device of the present invention,
The handler is configured to classify devices using the device characteristic classification output only when there is good contact between the probe of the handler and the lead of the test semiconductor device, and not to classify devices when the contact is poor. Therefore, it is possible to prevent misclassification in which a defective product is judged as a non-defective product due to smudging noise or the like when there is a contact failure.

[Brief explanation of drawings]

Figure 1 shows a conventional semiconductor characteristic measuring device.
FIG. 2 is a block diagram showing an embodiment of the semiconductor characteristic measuring device according to the present invention. lO...handler, 11...transistor under test, 1
2... Sensor, 16... Noise detection circuit, 17... Analog comparator, 20... Poor contact detection circuit, 22...
- Handler interface, 23... Oscillator, 24
．． 27...p wave device, 25...AC/DC converter/eta, 26...funno and rater.

Claims (1)

[Claims] An oscillator is connected to the input terminal Km of the semiconductor device under test through the 8111 element of the handler and supplies a test signal of a predetermined wave number to this element, and an output signal from the element obtained via the 3rd element of the handler. an F-wave device that separates the signal into a test signal component and a noise signal component; a classification means that determines the level of the running sound signal separated by the Pt1L device to obtain classification No. 16 representing the characteristic classification of the element; a detection circuit that determines the level of the test signal separated by the device and detects whether the contact state between the lead of the element and the probe is good;
When a good contact output is obtained from this detection circuit, η a signal corresponding to the classification signal by the classification means is sent to the handler, and when a bad contact output is obtained from the detection circuit, a numerator s signal is sent to the handler. A semiconductor characteristic measuring device comprising: a handler interface that prohibits output and outputs a contact failure signal to a handler.