JP2008261678A - Inspection probe contact detection mechanism and circuit board inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection probe contact detection mechanism and a circuit board inspection device capable of performing accurate inspection accurately by allowing an inspection probe to be in contact more surely with a pattern to be measured on a circuit board. <P>SOLUTION: A circuit board device 41 is equipped with at least a central processing means 42 for performing general control of the whole device, and a probing control means 43 for controlling probing operation based on an electric signal detected by the inspection probe contact detection mechanism 11, other than the inspection probe contact detection mechanism 11 for detecting electrically contact with the pattern to be measured of the inspection probe 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides an inspection probe contact detection mechanism and a circuit board inspection for accurately inspecting an inspection probe used when performing a necessary inspection by bringing it into electrical contact with a measured pattern of a circuit board more reliably. It is a technology related to equipment.

  The inspection probe provided in the circuit board inspection device normally ensures electrical contact by making pressure contact by pressing further against the biasing force of the built-in spring when it comes into contact with the pattern to be measured on the circuit board. Can be made to.

  In this case, the inspection probe is pushed in by moving in the Z-axis direction by a predetermined stroke amount determined based on a set value that is held in advance as software, and when the stroke amount is reached, the necessary inspection is performed. Will be started.

Also, various methods for detecting whether or not the inspection probe has come into contact with the pattern to be measured on the circuit board have been proposed. For example, as shown in Patent Document 1 below, the elasticity of the inspection probe during probing is proposed. A method for detecting contact by optically detecting the amount of deformation has also been proposed by the present applicant.
Japanese Patent Laid-Open No. 2005-233738

  However, the surface position of the circuit board on which the pattern to be measured is located is not always constant according to the set value because the surface position fluctuates due to warpage or swell due to solder. For example, there is an inconvenience that the contact state cannot always be accurately detected only by optically detecting the amount of elastic deformation of the inspection probe by the method disclosed in Patent Document 1.

  For this reason, in order to ensure the contact of the inspection probe, the stroke amount is inevitably increased more than necessary, and this extra stroke amount is a waste of time and shortens the inspection time. There was a defect that became an obstacle.

  The present invention provides an inspection probe contact detection mechanism and a circuit board inspection apparatus capable of accurately inspecting an inspection probe by making it contact with a measured pattern of a circuit board more reliably in view of the above-described problems of the prior art. There is a purpose.

  The present invention has been made to achieve the above object, and a first invention (inspection probe contact detection mechanism) includes at least two inspection probes and these inspection probes on a circuit board to be inspected. At least a probe moving unit that freely holds simultaneous contact with the same pattern to be measured, and a measurement circuit that measures a resistance value between the inspection probes in the pattern to be measured, the probe moving unit being measured The most important feature is that the measurement circuit can freely detect the state of reliable contact with the measurement pattern by pushing each inspection probe until the resistance value is equal to or less than the allowable resistance value required for inspection. To do.

  According to a second invention (inspection probe contact detection mechanism), a plurality of four-terminal measurement probes, which are inspection probes, and each of the four-terminal measurement probes are in contact with each measured pattern on a circuit board to be inspected. Each probe moving means that is freely held separately, and a current application side terminal and a voltage detection side terminal in each four terminal measurement probe when each of the four terminal measurement probes is brought into contact with the pattern to be measured. And at least a measurement circuit for detecting a conduction state between each of the four-terminal measurement probes via the measurement circuit. Main features.

  A third invention (inspection probe contact detection mechanism) includes one inspection probe, probe moving means for freely holding the inspection probe in contact with a pattern to be measured on a circuit board to be inspected, and the probe moving means. At least a pair of electrode portions that are arranged in a freely spaced manner and electrically fixed to each other in the initial state via a conductive portion provided in the device, and a measurement circuit that is connected to the electrode portion and detects current And the current flowing between the electrode parts via the conductive part causes the probe moving means to be deformed and separated from the electrode part side by contact pressure received when the inspection probe is brought into contact with the pattern to be measured. The main feature is that the flow of the inspection probe is cut off so that the measurement circuit can freely detect the contact of the inspection probe with the pattern to be measured.

  According to a fourth aspect of the present invention (circuit board inspection apparatus), the inspection probe contact detection mechanism according to any one of claims 1 to 3, central processing means for overall control, and electricity detected by the inspection probe contact detection mechanism. The main feature is that at least probing control means for controlling the probing operation based on the target signal is provided.

  In this case, the probing control means detects the difference between the planned stop position that is the contact detection position of the inspection probe to the pattern to be measured and the stop command position at which the probe is actually stopped, and corrects the position data by the difference. The probing operation may be stopped.

  According to the first aspect of the present invention, each inspection probe is pushed by the probe moving means until the measured resistance value is equal to or less than the allowable resistance value required for the inspection, whereby the inspection probe is applied to the measured pattern on the circuit board. Whether or not they are in contact can be accurately detected as an electrical signal immediately by the measurement circuit.

  According to the invention described in claim 2, the conduction state between the current application side terminal and the voltage detection side terminal when the four-terminal measurement probe is brought into contact with the pattern to be measured is accurately obtained as an electrical signal by the measurement circuit. By detecting, the presence or absence of contact can be immediately detected.

  According to the third aspect of the present invention, the pair of electrode portions that are disposed in a fixed manner while being electrically spaced apart from each other in the initial state via the conductive portion provided in the probe moving means, and the electrodes And a measuring circuit connected to the part for detecting the current, so that the current is cut off when the probe moving means is deformed and separated from the electrode part side by the contact pressure received when the inspection probe is brought into contact with the pattern to be measured. It can be accurately detected as an electrical signal by the measurement circuit, and the presence or absence of contact can be immediately detected.

  According to the invention described in claim 4, since the inspection probe contact detection mechanism capable of accurately detecting as an electric signal immediately whether or not the inspection probe is in contact with the pattern to be measured of the circuit board is provided, Even if the pattern to be measured is warped or swelled by solder, a motor stop signal can be immediately sent to the motor via the probing control means. Therefore, the circuit board can be inspected at a high speed and in a short time without causing a time delay.

  According to the fifth aspect of the present invention, there is a difference between the planned stop position as the contact detection position obtained by the inspection probe contact detection mechanism and the actual stop command position at which the motor stop signal is received. However, since the probing control unit can detect the difference and correct the position data and then stop the probing operation, the inspection can be performed at a higher speed in a shorter time.

  FIG. 1 is an explanatory view showing an example of the first invention (inspection probe contact detection mechanism). The inspection probe contact detection mechanism 11 includes inspection probes 12 each composed of a main probe 12a and an auxiliary probe 12b, and these inspection probes. For example, the inspection probe 12 is configured to include at least probe moving means 22 as shown in FIG. 5 for freely holding the inspection probe 12 in the XY and Z axis directions.

  In this case, the main probe 12a and the auxiliary probe 12b are held on the probe moving means 22 side so that they can simultaneously contact the same measured pattern 53 on the circuit board 51 to be inspected.

  Further, the main probe 12a and the auxiliary probe 12b are provided with a measurement circuit 33 for measuring the resistance value between them, for example, as shown in FIG. The resistance value can be detected.

  Further, the inspection probe moving unit 22 sets the main probe 12a and the auxiliary probe 12b to a predetermined stroke amount until the resistance value obtained via the measurement circuit 33 becomes equal to or less than the allowable resistance value required for the inspection. Until the resistance value is equal to or less than the allowable resistance value, the movement is stopped. For example, the main probe 12a is brought into electrical contact with the pattern 53 to be measured, and the process proceeds to the original electrical inspection. Be able to.

  FIG. 2 is an explanatory view schematically showing an example of the second invention (inspection probe contact detection mechanism). The inspection probe contact detection mechanism 11 includes a four-terminal measuring probe 13 as the inspection probe 12 and the four probes. For example, the probe moving means 22 as shown in FIG. 5 and the four-terminal measuring probe 13 to be measured hold the terminal measuring probe 13 freely in contact with the measured pattern 53 on the circuit board 51 to be inspected. For example, a measurement circuit 33 as shown in FIG. 5 detects the conduction state between the current application side terminal 13a and the voltage detection side terminal 13b in the four-terminal measurement probe 13 when being brought into contact with the pattern 53. At least. Note that the inspection probe contact detection mechanism 11 in the third invention can be arranged as a plurality of units as shown in FIG.

  In this case, the measurement circuit 33 detects the current flowing between the current application side terminal 13 a and the voltage detection side terminal 13 b in the four-terminal measurement probe 13, so that the measurement pattern 53 of the four-terminal measurement probe 13 is detected. The presence or absence of contact can be detected.

  FIG. 3 is an explanatory view showing an example of the third invention (inspection probe contact detection mechanism), in which (a) is a perspective view of the main part, and (b) is an enlarged view of a broken-line surrounding part in (a). (C) shows a state explanatory view after the deformation in relation to (b).

  Referring to FIG. 5, the inspection probe contact detection mechanism 11 freely holds one inspection probe 12 and the inspection probe 12 in contact with the pattern 53 to be measured on the circuit board 51 to be inspected. A pair of electrode portions that are fixedly spaced apart from each other in the initial state via a probe moving means 22 as shown and a conductive portion 29 provided in the probe moving means 22 in an initial state. 38 and 39 at least.

  In this case, the probe moving means 22 is provided with a pair of support portions 26 and 27 that protrude in a bowl shape from the main body portion 23 side at a constant interval, and the open ends of these support portions 26 and 27 are mutually connected. The inspection probe 12 is held via a holding portion 28 connected and disposed therebetween.

  In the illustrated example, the conductive portion 29 is on the support portion 26 positioned above, and a conductive sheet made of a conductive material such as a copper material is attached to the opposite surface 26a side of the other support portion 27. Or copper plating.

  Further, the pair of electrode portions 38 and 39 includes a lead wire (not shown) connected for power feeding, and a measurement circuit 33 as shown in FIG. 5 for detecting the presence / absence of current via the lead wire. It has.

  In addition, the pair of electrode portions 38 and 39 are illustrated in an arrangement state in which they are electrically connected via the conductive portion 29 in the initial state before entering the inspection shown in FIGS. The position is fixed, for example, by supporting it on the main body side.

  The current flowing between the electrode portions 38 and 39 through the conductive portion 29 in the initial state causes the probe moving means 22 to be brought into contact with the electrode portions 38 and 39 by the contact pressure received when the inspection probe 12 is brought into contact with the pattern 53 to be measured. As shown in FIG. 3C, the flow is blocked by the deformation from the 39 side, so that the presence or absence of contact of the inspection probe 12 with the pattern 53 to be measured can be detected by the measurement circuit 33. .

  FIG. 4 shows a fourth invention (circuit board inspection) constructed by incorporating the inspection probe contact detection mechanism shown in FIG. 3 of the third invention among the inspection probe contact detection mechanisms according to the first to third inventions. It is a block diagram which shows an example of an apparatus.

  According to the figure, the circuit board inspection apparatus 41 receives the inspection probe contact detection mechanism 11 shown in FIG. 3, central processing means (CPU) 42 that controls the entire apparatus, and control signals from the CPU 42. And a probing control means 43 for generating a control signal necessary for driving the inspection probe contact detection mechanism 11.

  Among these, the inspection probe contact detection mechanism 11 is arranged separately in pairs in relation to the measured pattern 53 drawn out from the measured element 52 included in the circuit board 51 to two places, of which The four-terminal measurement probe 13 provided on one side is used as the H side, and the four-terminal measurement probe 13 provided on the other side is used as the L side.

  Each inspection probe contact detection mechanism 11 includes a four-terminal measurement probe 13 and probe moving means 22 that freely holds the four-terminal measurement probe 13 in contact with the measured pattern 53 on the circuit board 51. ing.

  In this case, as shown in FIG. 4, the probe moving means 22 has a movable arm portion 24 provided on its main body portion 23, which can be freely moved up and down by an appropriate motor 25 including a servo motor. The four-terminal measuring probe 13 is detachably held via the support arm portion 24.

  In addition, the measurement circuit 33 determines whether or not there is current flowing through each measurement line 34 from the current application side terminal 13a side to the voltage detection side terminal 13b side of the four-terminal measurement probe 13 in each inspection probe contact detection mechanism 11. To detect.

  The probing control means 43 is for controlling the drive of the motor 25 provided on the main body 23 side of the probe moving means 22, and based on the control signal generated by the CPU 42 based on the presence or absence of the current detected by the measurement circuit 33. A control signal is sent to the motor 25.

  FIG. 5 is a flowchart showing a processing procedure of inspection performed by applying to the circuit board inspection apparatus 41 shown in FIG. According to the figure, when the inspection is started, the probing control means 43 receives a control signal from the CPU 42 and sends a drive control signal to the motor 30 provided in the probe moving means 22 to start its movement. The four-terminal measurement probe 13 is lowered toward a predetermined pattern 53 to be measured on the circuit board 51 after moving toward the target position.

  While the four-terminal measurement probe 13 is being lowered, the measurement circuit 33 measures the presence or absence of current flowing between the current application side terminal 13a and the voltage detection side terminal 13b via the measurement line 34.

  The CPU 42 detects the current flowing between the current application side terminal 13a and the voltage detection side terminal 13b by the measurement circuit 33 (the current application side terminal 13a and the voltage detection side terminal 13b are in contact with the predetermined measured pattern 53). In this case, a probe stop command signal is issued to the probing control means 43, and a motor stop signal issued by the probing control means 43 that receives the signal is sent to the motor 25 side of the probe moving means 22 to stop the motor 25. When it is determined that no current is detected (the current application side terminal 13a and the voltage detection side terminal 13b are not in contact with the predetermined measured pattern 53), the CPU 42 sets the four-terminal measurement probe 13 in advance. When the target stroke amount is reached, the motor 25 is stopped.

  In this case, the probing control means 43 detects the moment when the four-terminal measurement probe 13 contacts the pattern to be measured 53, and sends a motor stop signal to the motor 25 based on this detection signal. For this reason, the four-terminal measuring probe 13 has a difference between the planned stop position, which is the contact detection position, and the actual stop command position where the motor stop signal is received. The probing control means 43 may stop the probing operation after detecting the difference and correcting the position data.

  After the motor 25 is stopped and the movement of all the four-terminal measurement probes 13 is stopped, the electrical constant of the specific element 52 to be measured between the paired four-terminal measurement probes 13 and 13. The measurement is performed until the target inspection is completed.

  FIG. 6 is a block diagram showing another example of the fourth invention (circuit board inspection apparatus), and the hardware configuration is the same as the example shown in FIG. It differs from the software processing of FIG. 4 in that it is a hardware processing that sends signals directly to the means 43.

  FIG. 7 is a flowchart showing a processing procedure of inspection performed by applying to the circuit board inspection apparatus 41 shown in FIG. According to the figure, when the inspection is started, the probing control means 43 receives a control signal from the CPU 42 and sends a drive control signal to the motor 25 of the probe moving means 22 to start its movement, and is predetermined. After being directed to the target position, the four-terminal measurement probe 13 is lowered toward a predetermined pattern 53 to be measured on the circuit board 51.

  The measurement circuit 32 constantly measures the presence / absence of current flowing between the current application side terminal 13a and the voltage detection side terminal 13b of the four-terminal measurement probe 13 via the measurement line 34 (presence of conduction contact).

  When the measurement circuit 32 detects a current that means the conductive contact of the four-terminal measurement probe 13, it directly issues a probe stop command signal to the probing control means 43, and the motor stop generated by the probing control means 43 that receives this signal A signal is sent to the motor 25 side provided in the probe moving means 22 to stop the motor 25. When it is determined that no current is detected (the current application side terminal 13a and the voltage detection side terminal 13b are not in contact with the predetermined measured pattern 53), the measurement circuit 33 performs the measurement until the current is detected. Will continue.

  Also in this example, the probing control means 43 detects the moment when the four-terminal measurement probe 13 contacts the pattern to be measured 53, and sends a motor stop signal to the motor 25 based on this detection signal. For this reason, the four-terminal measuring probe 13 has a difference between the planned stop position, which is the contact detection position, and the actual stop command position where the motor stop signal is received. The probing control means 43 may stop the probing operation after detecting the difference and correcting the position data.

  After the motor 25 is stopped and the movement of all the four-terminal measurement probes 13 is stopped, the electrical constant of the specific element 52 to be measured between the paired four-terminal measurement probes 13 and 13. The measurement is performed until the target inspection is completed.

  Therefore, according to the first to third aspects of the present invention, whether or not the inspection probe 12 constituting the inspection probe contact detection mechanism 11 is in contact with the measured pattern 53 of the circuit board 51 is determined. Immediately detecting it accurately as an electrical signal can contribute to shortening the inspection time.

  Further, according to the fourth invention, the circuit board inspection apparatus 41 can immediately and accurately detect whether or not the inspection probe 12 is in contact with the measured pattern 53 of the circuit board 51 as an electrical signal. Since the contact detection mechanism 11 is provided, a motor stop signal can be immediately sent to the motor 25 via the probing control means 43 even if the measured pattern 53 of the circuit board 51 is warped or swelled by solder. . Therefore, the inspection of the circuit board 51 can be performed at a high speed and in a short time without causing a time delay.

  The above is the description of the present invention based on the illustrated examples, and the specific contents thereof are not limited thereto. For example, the circuit board inspection apparatus 41 shown in FIGS. 4 and 6 may incorporate the inspection probe contact detection mechanism 11 including the inspection probe 12 shown in FIGS. Further, the circuit board inspection apparatus 41 includes a pair of inspection probe contact detection mechanisms 11 having the probe moving means 22 shown in FIG. It may be provided under a plurality of pairs.

Explanatory drawing which shows an example of 1st invention (inspection probe contact detection mechanism). Explanatory drawing which shows typically an example of 2nd invention (inspection probe contact detection mechanism). It is explanatory drawing which shows an example of 3rd invention (inspection probe contact detection mechanism), (a) is a principal part perspective view, (b) is an enlarged view of the broken-line surrounding part in (a), (c) ) Shows a state explanatory diagram after the deformation in relation to (b). Of the inspection probe contact detection mechanisms according to the first to third inventions, an example of the fourth invention (circuit board inspection device) constructed by incorporating the inspection probe contact detection mechanism shown in FIG. FIG. The flowchart figure which shows the process sequence of the test | inspection performed by applying to the circuit board test | inspection apparatus shown in FIG. The block diagram which shows the other example of 4th invention (circuit board inspection apparatus). The flowchart figure which shows the process sequence of the test | inspection performed by applying to the circuit board test | inspection apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Inspection probe contact detection mechanism 12 Inspection probe 12a Main probe 12b Auxiliary probe 13 Four-terminal measurement probe 13a Current application side terminal 13b Voltage detection side terminal 22 Probe moving means 23 Body part 24 Movable arm part 25 Motor 26, 27 Support part 26a Opposing surface 28 Holding portion 29 Conducting portion 33 Measuring circuit 34 Measuring line 38, 39 Electrode 41 Circuit board inspection device 42 Central processing means (CPU)
43 Probing control means 51 Circuit board 52 Element to be measured 53 Pattern to be measured

Claims (5)

At least two inspection probes, probe moving means for freely holding the inspection probes simultaneously on the same measurement pattern on the circuit board to be inspected, and resistance between the inspection probes in the measurement pattern At least a measurement circuit for measuring the value,
The probe moving means can freely detect the reliable contact state of the measurement circuit with the measurement circuit by pushing each inspection probe until the measured resistance value is equal to or less than the allowable resistance value necessary for the inspection. Inspection probe contact detection mechanism characterized by the above. A plurality of four-terminal measuring probes which are inspection probes, and each probe moving means for holding each of the four-terminal measuring probes individually and freely in contact with each measured pattern on the circuit board to be inspected; A measurement circuit for individually detecting a conduction state between a current application side terminal and a voltage detection side terminal in each four-terminal measurement probe when the four-terminal measurement probe is brought into contact with the pattern to be measured. Comprising at least
An inspection probe contact detection mechanism characterized in that it can freely detect the presence or absence of contact of each of the four-terminal measurement probes with each measured pattern via the measurement circuit. One inspection probe, a probe moving means for freely holding the inspection probe in contact with the pattern to be measured on the circuit board to be inspected, and a conductive portion included in the probe moving means are mutually connected in an initial state. At least a pair of electrode portions that are arranged to be electrically spaced apart and fixed in position, and a measurement circuit that is connected to the electrode portions and detects a current;
The current that flows between the electrode parts via the conductive part causes the probe moving means to be deformed and separated from the electrode part side by the contact pressure received when the inspection probe is brought into contact with the pattern to be measured. An inspection probe contact detection mechanism characterized in that, by blocking the flow, the detection circuit can freely detect contact of the inspection probe with the pattern to be measured.   4. The inspection probe contact detection mechanism according to claim 1; central processing means for overall control; and probing control for controlling a probing operation based on an electrical signal detected by the inspection probe contact detection mechanism. And a circuit board inspection apparatus.   The probing control means detects a difference between a stop detection position that is a contact detection position of the inspection probe to the pattern to be measured and a stop command position where the probe is actually stopped, and corrects the position data by the difference before performing a probing operation. The circuit board inspection apparatus according to claim 4, wherein the circuit board inspection apparatus is stopped.

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