JPH01321646A - Article inspection - Google Patents

Abstract

PURPOSE:To make it possible to shorten inspection time by counting a failure rate of each test item at the time when a specified number of test samples have been inspected and dispensing the test item from inspections that follow if the failure rate is not beyond a specified one. CONSTITUTION:When performing inspection for a plurality of test items in common separately for each test sample flowing down in succession, the failure rate of each test item at the time when a specified number of test samples are measured is sought, and at the after inspection succeeding to it, the measurement is omitted under the specified rule as regards the test item with small failure rate. If this inspection method is applied to the inspection of test samples that the tendency of failure generation rate lowering is seen with a part of test items among plural test items, the test item low in the failure rate can be omitted at the time when a specified number of articles are inspected and the inspection time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for inspecting an article, which is carried out, for example, in the manufacturing process of semiconductor products.

[Conventional technology]

Generally, in the manufacturing process of semiconductor devices, various inspections are performed not only on completed semiconductor products but also on intermediate steps.

FIG. 2 is a flowchart showing a test program of a conventional tester used to test such #-conductor devices. This test program is designed to automatically perform inspections on a plurality of common test items for each product to be inspected that is continuously supplied.

In FIG. 2(a), first, when a start signal is input to the tester from the outside, the item to be inspected is inspected for the items of Test-A (step S1). This inspection is performed by applying specified conditions to the inspected item and comparing the data output from the inspected item with a predetermined reference value. If the product is determined to be defective as a result of this inspection, the execution ends. The inspected product is then rejected as a defective product. On the other hand, if it is determined that the product is non-defective as a result of the inspection in step S1, the execution moves to step S2. In step S2, the test items of the test-B are inspected in the same manner as the test-A items. Thereafter, the test items are similarly inspected and the process moves to step S3. This test 70- is repeated.

FIG. 2(b) shows the register I before the start signal of the tester is input for the test-B test in step S6.
is set to "1", the register is set to "1" in step S5.
Therefore, the inspection of test-B in step S6 is omitted. If register I is set to "O", the flow will be the same as in the case of FIG. 2(a).

[Problem to be solved by the invention]

The test programs of conventional testers are configured to perform inspections using the above-mentioned procedures, so when this is used for intermediate testing in the manufacturing process of semiconductor devices, for example, the test program can be used to omit some of the test items. Because it is necessary to provide the tester with a predetermined amount of human power before executing the test, it is a process in which some test items are omitted even if the defect rate of some test items is extremely low for the continuously flowing products to be inspected. There were problems such as not being able to do the following.

This invention was made in order to solve the above-mentioned problems, and in the middle of the inspection process of continuously flowing products to be inspected, if the test item has a low defect rate, that test item is omitted. The purpose is to obtain a test program that makes it possible to do this.

[Means to solve the problem]

The article inspection method of the present invention is an article inspection method in which a plurality of common test items are inspected for each continuously flowing article to be inspected, and when a predetermined number of articles are inspected, the defective rate of each test item is calculated. For test items whose defect rate is below a certain predetermined defect rate, that inspection is omitted in subsequent inspections of the inspected products.

[For production]

The article inspection method of this invention includes the following among a plurality of test items:
When applied to the inspection of inspected products where the defect rate tends to be low for some test items, the test items with a low defect rate are omitted once a certain number of items have been inspected, reducing inspection time. be done.

〔Example〕

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

FIG. 1 shows a flowchart in which an article inspection method according to an embodiment of the present invention is applied to a test program for an automatic inspection tester. This test program automatically inspects multiple test items that are common to each inspected item that is continuously run, and then tests a predetermined number of items When the number is less than a certain predetermined number Y, the above test items are omitted in subsequent inspections of the inspected items.

In the figure, first, when a start signal is manually input to the tester from the outside, the execution moves to step 511, where the measured number AA of test-A is greater than or equal to a certain predetermined number If the number is equal to or less than Y, the process moves to the next step 315. If the measured number AA is less than or equal to X or the number A of defective pieces is greater than or equal to the predetermined number 1, step
Add 1 to 2 to the number of samples to be measured, and execute the next test-A. If the result of test-A is non-defective, the process moves to step S15, and if it is defective, the process moves to step 514, where the number of defective items A is added by one, and the execution ends.

After this step 815, steps S11 to S5
15.

Number of items measured for one test item (AA, BB.

..., F F ) addition register and number of defective pieces (A, B
,...

F] There is an addition register.

In the above embodiment, the predetermined number of inspected items
..., F), but it is also possible to set the values of X and Y above for each test item, and it is also possible not to omit test items. It is.

〔Effect of the invention〕

As described above, according to the present invention, inspection of a certain test item is omitted if the defect rate of the inspected item is low, so this method can be applied to, for example, a test program of an automatic inspection tester. By applying this method, it is possible to omit some of the test items with a low defective rate among the plurality of test items, which has the effect of significantly shortening the inspection time.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a test program for an automatic inspection tester to which an article inspection method according to an embodiment of the present invention is applied, and FIGS. 2(a) and 2(b) show test programs for a conventional automatic inspection tester. It is a flowchart. In the figure, 51 to 322 are each step of the test program.

Claims (1)

[Claims] In an article inspection method in which a plurality of common test items are inspected for each continuously flowing product to be inspected, the defective rate of each test item is determined when a predetermined number of products are measured, and An article inspection method characterized in that, in the article inspection, measurement of the test items with a low defective rate is omitted according to a predetermined rule.