JP2005049314A - Probing test method and probe condition detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To replace a probe before an inspection result gets unsure, in a probing test method for measuring an electric characteristic by bringing the probe into contact with a terminal of an inspection object. <P>SOLUTION: Monitoring probes 4a-4c are prepared to detect a condition of the measuring probe 1, a monitoring terminal 51 is formed to contact therewith, the monitoring probes 4a-4c are brought into contact with the monitoring terminal 51, and the electric characteristic is measured to detect the condition of the measuring probe 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a probing test method (a method of measuring electrical characteristics by bringing a probe into contact with a terminal to be inspected).

  Conventionally, the probing test is performed for the purpose of inspecting the electrical characteristics of each semiconductor chip of the wafer (in a state where a large number of semiconductor chips are formed) before being divided and the circuit of the mounting substrate as a product. ing. For example, in the case of a mounting board, a probe head in which a large number of probes are arranged in accordance with the circuit to be inspected is prepared, the probe is arranged facing downward, and terminals of the mounting board arranged on the lower side A probe is brought into contact with the electrode to measure the electrical characteristics. Further, this measurement is continuously performed on a large number of mounting boards by automatically arranging the mounting boards to be inspected one after another.

Patent Document 1 listed below describes a probe card for a semiconductor chip used in the probing test method. Patent Document 2 describes a method of applying a resistance measurement method by a four-terminal method or a three-terminal method using a probe as a method for detecting a soldering failure of a mounted component with respect to a mounting board. Patent Document 3 describes a resistance measurement method using a four-terminal method.
JP 2002-164104 A JP-A-7-104026 Japanese Patent Laid-Open No. 11-118850

  In the conventional probing test method, probe replacement is determined to be defective for most products, for example, when the specified number of times of use (the number of times of use where the quality is guaranteed) as suggested by the manufacturer is reached. This was done when the probe was suspected of being deteriorated. That is, it has not been detected whether the probe is deteriorating during continuous use. Therefore, although it is actually a non-defective product, it may be judged as a defective product because it is measured with a deteriorated probe. Therefore, the conventional probing test method has room for improvement in terms of inspection accuracy.

  In each of the above patent documents, there is no proposal to perform a probing test while detecting whether or not the probe is deteriorating.

  An object of the present invention is to perform a probing test while detecting whether or not a probe is deteriorating so that the probe can be exchanged before an inspection result becomes inaccurate.

  In order to solve the above problems, the present invention provides a monitoring probe for detecting the state of a measurement probe used in the measurement in a probing test method in which a probe is brought into contact with a terminal to be inspected to measure electrical characteristics. Prepare the probe, and form the monitor terminal that contacts it on the same side as the terminal to be inspected, contact the monitor probe to the monitor terminal, and measure the electrical characteristics of the circuit that includes them. Provided is a probing test method characterized by detecting a state of a measurement probe based on a measurement value.

  According to the method of the present invention, since the probing test is performed while detecting whether or not the measurement probe is deteriorated, it is possible to replace the measurement probe before the inspection result becomes inaccurate. become able to.

Specific methods included in this method include methods having the following configurations (1) to (5).
(1): Prepare three or more monitoring probes formed in the same manner as the measurement probe.
(2): A monitor circuit comprising the same number of monitor terminals as the monitor probe in (1) and wiring connecting these monitor terminals in parallel is a surface on which the terminals to be inspected are formed. It is formed on the same surface or a surface arranged at the same position.
(3): The monitoring probe of (1) is brought into contact with each corresponding monitoring terminal at the same contact pressure as between the measuring probe and the measuring terminal, and a steady current is introduced between the predetermined monitoring probes. Then, the current value flowing through the “circuit configured by the monitoring probe and the monitoring terminal corresponding to the monitoring probe and the wiring between them” is measured.
(4): On the other hand, the voltage between predetermined monitoring probes is measured.
(5): A contact resistance value between a predetermined monitoring probe and a monitoring terminal is calculated from the measured values of (3) and (4), and the state of the measuring probe is detected based on the resistance value.

  In this method, the contact resistance between a predetermined monitoring probe and the monitoring terminal is measured by a highly accurate resistance measuring method such as a three-terminal method or a four-terminal method. This change in contact resistance indicates a change in the state of the monitoring probe (for example, the resistance measurement value increases when the degree of surface oxidation at the probe tip is high). Further, the monitoring probe and the monitoring terminal are brought into contact with each other with the same contact pressure as that between the measuring probe and the measuring terminal. Therefore, according to this method, the deterioration state of the measurement probe can be accurately detected as a substitute characteristic with the monitor probe.

  The present invention is also a probe state detection device for detecting the state of the probe, which is used in association with a probing test device for measuring electrical characteristics by bringing a probe into contact with a terminal to be inspected, and is the same as the probe. And a monitoring terminal to be brought into contact with the monitoring probe, and the monitoring probe and the monitoring terminal constitute the probing test apparatus when measuring the electrical characteristics. Provided is a probe state detection device configured to contact at the same contact pressure between a measurement probe and a measurement terminal.

  By using this apparatus attached to a probing test apparatus, the method of the present invention can be easily implemented.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a diagram showing a probing test method performed in this embodiment. FIG. 2 is a plan view showing the monitor circuit formed in this embodiment.

  In this embodiment, a method for inspecting a circuit on a mounting substrate by a probing test method will be described.

  FIG. 1 shows a probe head portion of a probing test apparatus. In this probe head, a large number of measurement probes 1 are arranged in accordance with terminal electrodes (terminals to be inspected) 21 of the circuit of the mounting substrate 2. Each measurement probe 1 has a base end fixed to the plate-like body 3 and extends vertically from the surface of the plate-like body 3.

  The plate-like body 3 was formed larger than the circuit formation surface of the mounting substrate 2. Then, three monitoring probes 4 a to 4 c were attached to a portion 3 a of the plate-like body 3 that is removed from the circuit formation surface of the mounting substrate 2. These monitoring probes 4a to 4c are formed of the same material and in the same shape as the measurement probe 1 by the same method. The monitoring probes 4 a to 4 c were also attached so as to extend vertically from the surface of the plate-like body 3 and to protrude from the surface of the plate-like body 3 by the same length as the measurement probe 1, similarly to the measurement probe 1.

  The wirings 31 from all the measurement probes 1 are respectively connected to circuits that can measure predetermined electrical characteristics. The wiring 41 from the monitoring probes 4a to 4c is connected to a circuit 42 capable of measuring resistance by a three-terminal method. These circuits may be formed on a substrate different from the plate-like body 3 or may be formed as a wiring pattern including the wires 31 and 41 on the surface of the plate-like body 3 on which the probe extends. Also good.

  The monitor terminal 51 with which the monitor probes 4 a to 4 c are brought into contact is formed on one surface of the monitor substrate 5 different from the mounting substrate 2. As shown in FIG. 2, the monitor substrate 5 is formed with a monitor circuit 50 including three monitor terminals 51 and wirings 52 connecting them in parallel. The monitor terminal 51 is formed of the same material and the same thickness as the terminal electrode 21 of the mounting substrate 2.

  The circuit 42 includes a power source 42a, an ammeter 42b, and a voltmeter 42c. The power source 42a introduces a steady current between the monitoring probe 4a and the monitoring probe 4b. The ammeter 42b measures the value of current flowing through a circuit constituted by the monitoring probes 4a and 4b, the monitoring terminals 51 corresponding thereto, and the wiring 52 between them. The voltmeter 42c measures the voltage (variation) between the monitoring probes 4b and 4c.

  In addition, the probing test apparatus includes a resistance calculation device 43 and a display device 44. The resistance calculation device 43 receives the current measurement value I from the ammeter 42b and the voltage measurement value V from the voltmeter 42c, calculates the resistance value R from both measurement values, and obtains the obtained resistance value R Is output to the display device 44.

  Using this probing test apparatus, a probing test is performed by the following method.

  First, the probe head is arranged with the probes 1, 4a to 4c facing downward. Then, the mounting board 2 to be inspected is arranged on the lower side with the circuit forming surface thereof facing up, and each measurement probe 1 is brought into contact with the corresponding terminal electrode 21 with a predetermined contact pressure. At the same time, when the monitor substrate 5 is disposed at the same height at a predetermined position next to the mounting substrate 2 with the surface on which the monitor circuit 50 is formed facing upward, the monitor probes 4a to 4c are Each corresponding monitor terminal 51 is brought into contact with the same contact pressure as described above.

  Along with this, a steady current is introduced from the power source 42a between the monitoring probe 4a and the monitoring probe 4b, the monitoring probes 4a and 4b and the corresponding monitoring terminals 51, and the wiring 52 between them. The current value I flowing through the circuit constituted by the current meter 42b is measured by the ammeter 42b. Further, the voltage value V between the monitoring probes 4b and 4c is measured by the voltmeter 42c. Then, the current measurement value I and the voltage measurement value V are output to the resistance calculation device 43, and the calculated resistance value R is output to the display device 44.

  In addition, the mounting substrate 2 and the monitor substrate 5 are automatically and sequentially arranged at the respective positions, and the above-described terminal and probe are brought into contact with each other. At that time, a different mounting substrate 2 is disposed each time, but the same substrate is disposed each time for the monitor substrate 5.

  As a result, the electrical characteristics of the different mounting substrate 2 are inspected each time, and at the same time, the resistance value R of the monitoring probe 4b in contact with the same monitoring terminal 51 is detected and displayed on the display device 44. . Since this resistance value is a value corresponding to the degree of surface oxidation at the tip of the probe, the deterioration state of the monitoring probe 4b can be known from this resistance value. The monitor probe 4b is the same as the measurement probe 1, the monitor terminal 51 is formed of the same material and the same thickness as the measurement terminal 21, and each of the monitor probes 4b has a corresponding monitor terminal. 51 is in contact with the measurement probe 1 and the measurement terminal 21 with the same contact pressure, so that the deterioration state of the monitor probe 4b is substantially the same as the deterioration state of the measurement probe 1.

  Therefore, according to the method of this embodiment, the deterioration state of the measurement probe 1 can be accurately detected by the monitoring probe 4b. As a result, the probing test is performed while detecting whether or not the measurement probe is deteriorated, so that the measurement probe can be replaced before the inspection result becomes inaccurate. .

  In this embodiment, the monitoring probes 4a to 4c are attached to the plate-like object 3 to which the measuring probe 1 is attached. However, the measuring probes 1 are attached to the monitoring probes 4a to 4c. You may attach to the member different from a member. In that case, it is necessary to configure this other member so that the monitoring probes 4a to 4c are arranged at the same position as the measuring probe 1 at the time of measurement.

  Further, in this embodiment, the monitor circuit 52 is formed on the surface of the monitor substrate 5 different from the mounting substrate 2 (surface disposed at the same position as the surface on which the terminals to be inspected are formed). However, the monitor circuit 52 may be formed on an end of the circuit formation surface of each mounting substrate 2 (the same surface as the surface on which the terminals to be inspected are formed) or the like.

  In this embodiment, a method for inspecting a circuit on a mounting board is described. However, the inspection object is not limited to this, and the method of the present invention is obtained by dividing a semiconductor chip on a wafer or a wafer. It can also be applied to inspection of semiconductor chips and the like.

  In addition, the measurement probe and the monitor probe are attached to the same member, a large number of measurement probes are arranged in the center of the member, and the monitor probes are arranged at a plurality of positions around the periphery of the member. At the same time as the measurement of the electrical characteristics of the inspection object, the electrical characteristics may be measured by the monitoring probes at the plurality of locations. Thereby, it can also be detected whether the contact state of many measurement probes and the measurement terminals is uniform within the probe mounting surface.

The figure which shows the probing test method of embodiment. The figure which shows the circuit for a monitor formed in embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Measurement probe, 2 ... Mounting board, 21 ... Circuit terminal electrode (terminal to be inspected), 3 ... Plate body, 31 ... Wiring from measurement probe, 4a-4c ... Monitoring probe, 41 ... Monitor Wiring from the probe for use, 42 ... circuit, 42 a ... power supply, 42 b ... ammeter, 42 c ... voltmeter, 43 ... resistance calculation device, 44 ... display device, 5 ... monitor board, 50 ... monitor circuit, 51 ... monitor Terminal, 52... Wiring constituting a monitor circuit.

Claims (3)

In the probing test method in which the probe is brought into contact with the terminal to be inspected and the electrical characteristics are measured,
While preparing a monitor probe for detecting the state of the measurement probe used in the measurement, forming a monitor terminal to contact this on the same side as the terminal to be inspected,
A probing test method characterized in that a monitor probe is brought into contact with a monitor terminal, an electrical characteristic of a circuit including them is measured, and a state of the measurement probe is detected based on the measured value. Prepare three or more monitoring probes formed in the same way as the measurement probe,
The monitoring circuit comprising the same number of monitoring terminals as these monitoring probes and the wiring connecting these monitoring terminals in parallel is arranged on the same surface as the surface on which the terminals to be inspected are formed, or Formed on the same surface,
These monitoring probes are brought into contact with the corresponding monitoring terminals at the same contact pressure as between the measuring probe and the measuring terminal,
A steady current is introduced between predetermined monitoring probes, and a current value flowing through a circuit constituted by the monitoring probe and a monitoring terminal corresponding to the monitoring probe and a wiring between them is measured,
On the other hand, measure the voltage between the predetermined monitoring probes,
Calculate the contact resistance between a given monitor probe and monitor terminal from these measured values,
2. The probing test method according to claim 1, wherein a state of the measurement probe is detected based on the resistance value. A probe state detection device for detecting the state of the probe, which is used in association with a probing test device that measures electrical characteristics by bringing a probe into contact with a terminal to be inspected, and is formed in the same manner as the probe And a monitoring terminal to be brought into contact with the monitoring probe,
The monitoring probe and the monitoring terminal are configured to contact at the same contact pressure between the measurement probe and the measurement terminal constituting the probing test apparatus when the electrical characteristics are measured. Probe state detection device.

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