JPH113919A - Ic inspecting method and probe card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid an excess quality, by a method wherein an IC having temperature gradient characteristics is fitted on a probe card as a temperature judgement reference product, so as to decide the testing requirements on the basis of the testing temperature data detected by the characteristics for the testing. SOLUTION: Firstly, a temperature judgement reference product is measured by an LSI tester (process 31). Next, the measured value of the temperature judgement reference product is taken in the LSI tester (process 32). The process for deciding the testing standard is performed on the LSI tester side according to the taken-in measured value, but in that case, the details processed by the LSI tester are programmed in the LSI tester by a test program (process 33). This programmed details once read in the LSI tester are stored in the LSI tester unless they are cancelled. In such a constitution, the measured IC is tested according to the decided testing standard by a series of processing in the LSI tester (process 34).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an IC inspection method and a probe card thereof.

[0002]

2. Description of the Related Art In order to satisfy customer specifications, the characteristics of an IC having a temperature gradient are measured by narrowing inspection standards in consideration of temperature variations in measurement at room temperature. In addition, since the inspection standard is very strict compared to the manufacturing variation, reduction of the yield due to narrowing the inspection standard is inevitable.

[0003]

However, in the conventional test method, as customer requirements for the characteristics of ICs become stricter every year, it is not profitable to simply narrow down the inspection standards in consideration of the inspection temperature variation. The situation is coming.

[0004] In addition, for characteristics that cannot be determined in consideration of the inspection temperature variation, a fuse is added inside the IC to match the characteristics. I
The addition of a fuse inside C causes an increase in cost due to an increase in chip area and a reduction in the degree of freedom in chip layout.

Accordingly, the present invention has been made to solve such a problem. It is an object of the present invention to prevent excessive quality against the increasingly severe characteristics of ICs.
We provide products that meet the specifications.

[0006]

In order to achieve the above object, an IC inspection method and a probe card according to the present invention have a temperature judgment reference product mounted on a probe card, and the inspection temperature is set to an LSI tester. It is characterized in that an inspection standard is determined directly in accordance with processing contents pre-programmed in an LSI tester. That is, according to the present invention, when an IC wafer is mounted on a wafer inspection and transfer device (hereinafter, referred to as a prober) and an electrical test is performed by bringing a probe of a probe card into contact with each electrode of an IC chip in the wafer, An IC having a characteristic having a temperature gradient is mounted on a probe card as a temperature judgment reference product, and test conditions are determined based on inspection temperature data detected based on the characteristic, and a test is performed.

Further, the present invention is characterized in that inspection temperature data is detected by measuring a temperature judgment reference product.

Further, the present invention is characterized in that the inspection temperature data obtained by the temperature judgment reference product is directly taken in from the pins of the LSI tester.

Further, the present invention is characterized in that test conditions are determined by programming on an LSI tester based on inspection temperature data obtained by a temperature judgment reference product.

Further, the present invention has a counter function for counting the number of times the inspection temperature data is detected by the temperature judgment reference product.

The probe card of the present invention is characterized in that an IC having a temperature gradient is mounted as a temperature judgment reference product.

Further, the present invention is characterized in that the temperature judgment reference product is mounted on the IC to be measured.

[0013]

The operation of the inspection temperature detection and mechanism of the present invention will be described. The characteristic value having a temperature gradient of a temperature judgment reference product mounted on a probe card is measured by an LSI tester, and the measured value is directly applied to the LSI tester. The test temperature is determined by this. The test standard is determined by an LSI tester based on the measurement result, and the IC under test is determined.
Perform an inspection.

[0014] In addition, for a temperature judgment reference product, before mounting on a probe card, how much a reference measurement value becomes at a certain temperature is examined in advance, and based on the result of the investigation, an LSI tester is used. Perform programming above.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments thereof.

FIG. 1 is a plan view of a probe card when a temperature judgment reference product according to the present invention is mounted, and FIG. 2 is a sectional view thereof. In FIG. 1, 11 is a probe card, 12 is a probe, 13 is a temperature judgment reference product, and 14 is a wiring land. In FIG. 2, 21 is a probe card,
22 is a probe and 23 is a temperature judgment reference product. As shown in FIG. 1, the temperature judgment reference product is mounted on the probe card outside the portion where the probe is arranged and inside the portion where the pin contacts the LSI tester. Further, as shown in FIG. 2, the mounting place is not on the side of the LSI tester that comes into contact with the pins, but on the side of the IC to be measured. The reason for mounting the temperature judgment reference product in the above-mentioned place is to detect the temperature as close to the measurement atmosphere as possible and to use the LSI.
This is to reduce the wiring of the tester to the pins. It is assumed that the probe card has a structure in which electrical continuity can be established from the wiring land on the side of the IC to be measured to the contact pin to the LSI tester. In addition, in consideration of the height from the probe card to the tip of the probe (L in FIG. 2), the temperature judgment reference product is more SOP than the insertion type package.
(Small Outline Package).

FIG. 3 is a block diagram of the above-described inspection temperature determination method, and the arrows in the block diagram indicate the direction in which the processing is performed. The block diagram will be described below step by step.

First, a temperature judgment reference product is measured from an LSI tester (process 31). Next, the measured value of the temperature judgment reference product is taken into the LSI tester (process 32).
The LSI tester performs processing to determine the inspection standard based on the acquired measurement values.
The contents to be processed by the SI tester are programmed into the LSI tester by a test program (process 33). This programming content exists in the LSI tester once it is read by the LSI tester, unless the content is deleted. Through a series of processes in the LSI tester, the IC under test is inspected according to the determined inspection standard (process 34).

FIG. 4 shows a reference temperature characteristic in the above-mentioned temperature judgment reference product. The temperature characteristics of the temperature determination reference product were previously investigated before mounting on the probe card. At this time, the inspection temperature variation range is set to T
, TN, and the measured values of the corresponding temperature judgment reference products are V1, V2,.
And Note that N is an integer value, and the larger the value, the higher the accuracy of the determined inspection standard.

That is, by examining the temperature characteristics of the temperature judgment reference product, if the measured value is between V (n-1) and Vn, the inspection temperature is between T (n-1) and Tn. It turns out that it is being measured.

The method of determining the inspection standard on the test program is as follows. The measured value of the temperature judgment reference product is V (n-1) to Vn.
If it is determined that the test temperature is within the range, the range of the inspection temperature is determined, and the standard is determined in consideration of the determined inspection temperature and the specification of the IC to be measured.

FIG. 5 is a flowchart showing processing on the programmed LSI tester.
Hereinafter, a series of operations will be described with reference to a flowchart.

First, the number of times of measurement of an IC to be measured is initialized (process 51). The reason for performing the initialization is that if the test temperature determination flow is executed for each IC to be measured, a decrease in throughput is caused, and once the test temperature is determined, the test temperature changes for a certain period of time. It is assumed that there is not. Here, the above-mentioned certain amount of time means that the inspection temperature changes with time,
It is necessary to investigate beforehand how many times the IC under test needs to be determined each time the IC under test is inspected. Based on the frequency of the inspection temperature, the maximum number of times I after which the inspection temperature is determined and how many times the IC under test can be inspected is determined.

After the counter is initialized, the measurement of the temperature judgment reference product is performed (process 52). The measured value is calculated (step 53), and L is calculated according to the contents of the test program.
The inspection standard is determined by the SI tester (process 54). The measured IC is measured based on the determined inspection standard (process 55). After the measurement of the IC to be measured is completed, the counter is incremented (step 56).

Thereafter, the maximum number of times I, at which the IC under test can be measured, is compared with the current counter value based on the above-mentioned one test temperature determination, and the test temperature is determined or not, and the IC under test is determined. Is selected (Step 5)
7).

Thereafter, according to the flowchart shown in FIG.
The same processing is repeated.

[0027]

As described above, according to the inspection temperature detecting method and mechanism of the present invention, it is not necessary to set an inspection standard that is narrowed down in consideration of the inspection temperature variation. It is possible to prevent excess quality due to the measurement in the standard, and it is expected that the yield can be improved by performing the effective inspection.

In addition, since it is not necessary to consider the variation in the inspection temperature at the stage of launching a new product, it is necessary to smoothly determine specifications for characteristics having a temperature gradient and to adjust the characteristics for matching characteristics.
The necessity of the fuse circuit added inside C can be clarified.

[Brief description of the drawings]

FIG. 1 is a plan view of a probe card according to the present invention.

FIG. 2 is a sectional view of a probe card according to the present invention.

FIG. 3 is a block diagram of an inspection temperature determination method according to the present invention.

FIG. 4 shows temperature characteristics of a temperature judgment reference product of the present invention.

FIG. 5 is a flowchart showing a series of processing of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Probe card 12 ... Probe 13 ... Temperature judgment reference product 14 ... Wiring land 21 ... Probe card 22 ... Probe 23 ... Temperature judgment reference product

Claims (7)

[Claims] An IC wafer is transferred to a wafer inspection and transfer device (hereinafter, referred to as a wafer inspection transfer device)
When a probe of a probe card is brought into contact with each electrode of an IC chip in the wafer to perform an electrical test, an IC having a characteristic having a temperature gradient on the probe card is determined. An IC inspection method that is mounted as a reference product, determines test conditions based on inspection temperature data detected based on its characteristics, and performs testing. 2. The IC inspection method according to claim 1, wherein the inspection temperature data is detected by measuring the temperature judgment reference product. 3. The IC inspection method according to claim 1, wherein inspection temperature data obtained by said temperature judgment reference product is directly taken in from a pin of an LSI tester. 4. The IC inspection method according to claim 1, wherein test conditions are determined by programming on an LSI tester based on the inspection temperature data obtained by said temperature judgment reference product. 5. The IC inspection method according to claim 4, further comprising a counter function for counting the number of times inspection temperature data is detected by said temperature judgment reference product. 6. A probe card wherein an IC having a temperature gradient is mounted as a temperature judgment reference product. 7. The probe card according to claim 6, wherein a temperature judgment reference product is mounted on an IC to be measured.