JP2014003228A - Inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection device which can maintain a high inspection accuracy.SOLUTION: An inspection device 1 performs electrical inspection of an inspected body by bringing an electrode pad formed on the surface of the inspected body in the state of a wafer into contact with the tip of a probe needle 3 attached to a probe card 4. The inspection device 1 includes a housing 2 having an internal space where inspection is carried out, a gas supply section 6 for supplying an antioxidation gas which prevents the oxidation of the tip of the probe needle 3 to the tip of the probe needle 3, and a gas supply line 7 for receiving and supplying the antioxidation gas to the gas supply section 6. The inspection device 1 includes either internal sensors 20, 21 for detecting the amount of a predetermined substance contained in the internal gas of the housing 2, and/or supply sensors 40-42 for detecting the amount of gas passing through the gas supply line 7.

Description

  The present invention relates to an inspection apparatus that performs a probing inspection on an object to be inspected in a wafer state.

  When a chip (inspected object) such as a semiconductor integrated circuit is manufactured, inspection is performed in a wafer state. At this time, the probe needle is brought into contact with the electrode pad formed on the surface of the chip, and an electrical signal is transmitted / received through the probe needle, whereby the electrical inspection of each chip is performed.

  The structure of the inspection apparatus that performs the above inspection will be described with reference to FIG. FIG. 7 is a side view schematically showing a configuration example of a conventional inspection apparatus. In FIG. 7, the internal structure of the housing 101 is shown through.

  As shown in FIG. 7, the inspection apparatus 100 prevents the casing 101 that is inspected in the internal space, the cantilever type probe card 103 to which the probe needle 102 is attached, and the tip of the probe needle 102 from being oxidized. A nozzle 104 that ejects an antioxidant gas (for example, an inert gas such as nitrogen gas) to the tip of the probe needle 102, a gas supply line 105 that receives the antioxidant gas and supplies it to the nozzle 104, and a wafer W are mounted. A movable stage 106, and a test device 107 that generates an electrical signal to be applied to the electrode pad on the chip via the probe needle 102 and determines the quality of the chip by acquiring the electrical signal output to the electrode pad. Prepare. The probe card 103 and the test apparatus 107 are electrically connected by wiring or the like, but are not shown in FIG.

  The probe needle 102 and the movable stage 106 are accommodated in the housing 101, and the wafer W is inspected in the space inside the housing 101. The nozzle 104 prevents oxidation of the tip of the probe needle 102 by blowing an antioxidant gas supplied from the gas supply line 105 to the tip of the probe needle 102 arranged in the space inside the housing 101. To do.

  As such an inspection apparatus, for example, Patent Document 1 proposes an inspection apparatus that blows nitrogen from the outside of a wafer to a probe needle. For example, Patent Document 2 proposes an inspection apparatus that blows nitrogen from the inside of a wafer to a probe needle.

JP-A-7-273157 JP 2001-7164 A

  The inspection apparatus proposed in Patent Document 2 and the inspection apparatus 100 shown in FIG. 7 include a housing 101 that accommodates the probe needle 102 and the movable stage 106 therein, and performs an inspection in a space inside the housing 101. . For this reason, it is possible to store the antioxidant gas in the space inside the casing 101 to be inspected. Therefore, the concentration of the antioxidant gas contained in the gas inside the housing 101 can be easily increased.

  However, if for some reason the gas inside the casing 101 enters a state where the inspection accuracy can be lowered, the inspection is continued in that state, which causes a problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an inspection apparatus capable of maintaining high inspection accuracy.

  In order to achieve the above object, the present invention provides an electrode pad formed on a surface of an object to be inspected in a wafer state and a tip of a probe needle attached to a probe card, thereby contacting the electric power of the object to be inspected. And a gas supply unit for supplying an antioxidation gas for preventing oxidation of the tip of the probe needle to the tip of the probe needle. A gas supply line that receives the antioxidant gas and supplies the antioxidant gas to the gas supply unit, an internal sensor that detects the amount of a predetermined substance contained in the gas inside the housing, and the gas supply There is provided an inspection apparatus comprising at least one of a supply sensor for detecting the amount of gas passing through a line.

  According to the inspection apparatus having the above characteristics, it is possible to confirm whether or not the gas in the housing is suitable for inspection by referring to the detection result of at least one of the internal sensor and the supply sensor.

  Furthermore, in the inspection apparatus having the above characteristics, as the internal sensor, the concentration of the antioxidant gas in the gas inside the housing and the oxidizing gas that oxidizes the tip of the probe needle in the gas inside the housing It is preferable to provide a gas sensor that detects at least one of the concentration.

  According to the inspection apparatus having the above characteristics, the concentration of the antioxidant gas in the gas inside the housing is insufficient, and the oxidation in the gas inside the housing causes the oxidation of the tip of the probe needle, which can reduce the inspection accuracy. It becomes possible to detect at least one of the excessive concentration of the sex gas.

  Furthermore, in the inspection apparatus having the above characteristics, it is preferable that a dust sensor for detecting the concentration of dust contained in the gas inside the housing is provided as the internal sensor.

  According to the inspection apparatus having the above characteristics, it is possible to detect an excessive concentration of dust in the gas inside the housing, which is a cause of dust adhesion to the wafer, which can reduce the inspection accuracy.

  Furthermore, in the inspection apparatus having the above characteristics, it is preferable that the internal sensor is disposed at a plurality of different locations inside the housing.

  According to the inspection apparatus having the above characteristics, it is possible to detect the concentration distribution of the substance contained in the gas inside the housing.

  Furthermore, in the inspection apparatus having the above characteristics, it is preferable that a flow rate sensor that detects a flow rate of the antioxidant gas passing through the gas supply line is provided as the supply sensor. In the inspection apparatus having the above characteristics, it is preferable that a pressure sensor for detecting the pressure of the antioxidant gas passing through the gas supply line is provided as the supply sensor.

  According to the inspection apparatus having the above characteristics, it is possible to check a supply failure of the antioxidant gas (for example, insufficient flow rate or insufficient pressure), which causes the oxidation of the tip of the probe needle, which can reduce the inspection accuracy. .

  Furthermore, in the inspection apparatus having the above characteristics, a control apparatus that determines whether or not an abnormal state is a state in which the inspection accuracy can be lowered based on a detection result of at least one of the internal sensor and the supply sensor. Further, it is preferable to further provide.

  According to the inspection apparatus having the above characteristics, it is possible to automatically and continuously monitor whether or not an abnormal state has occurred. For example, an abnormal state is an insufficient concentration of the antioxidant gas in the gas inside the housing, an excessive concentration of oxidizing gas in the gas inside the housing, or an excessive concentration of dust in the gas inside the housing. The supply of antioxidant gas is poor.

  Furthermore, the inspection device having the above characteristics further includes a notification device that notifies the user, and when the control device determines that the abnormal state is present, the control device controls the notification device to the user. It is preferable to notify the abnormal state.

  According to the inspection apparatus having the above characteristics, when an abnormal state occurs, it is possible to notify the user to that effect. Then, it is possible to prevent a decrease in inspection accuracy by performing an appropriate operation for eliminating the abnormal state by the notified user.

  Furthermore, in the inspection apparatus having the above characteristics, the inspection apparatus further includes a supply controller that adjusts the amount of the antioxidant gas that passes through the gas supply line, and when the control device determines that the abnormal state is present, the abnormal state It is preferable to control the supply controller so that the above is eliminated.

  According to the inspection apparatus having the above characteristics, when an abnormal state occurs, the abnormal state can be resolved by automatically adjusting the supply of the antioxidant gas.

  Furthermore, in the inspection apparatus having the above characteristics, it is preferable that a flow rate controller for adjusting a flow rate of the antioxidant gas passing through the gas supply line is provided as the supply controller. Moreover, in the inspection apparatus having the above characteristics, it is preferable that a pressure controller for adjusting the pressure of the antioxidant gas passing through the gas supply line is provided as the supply controller.

  According to the inspection apparatus having the above characteristics, when an abnormal state occurs, it is possible to eliminate the abnormal state by adjusting the flow rate and pressure of the antioxidant gas to be supplied.

  As described above, according to the inspection apparatus of the present invention, since it is possible to confirm whether or not the gas in the housing is suitable for inspection, the gas in the housing can be maintained in a state suitable for inspection. . Therefore, high inspection accuracy can be maintained.

The side view which shows typically the structural example of the inspection apparatus which concerns on embodiment of this invention. The block diagram which shows typically the structural example of the test | inspection apparatus which concerns on embodiment of this invention. The top view shown about the example of arrangement | positioning of an internal sensor. The graph which showed the relationship between the presence or absence of a filter and the density | concentration of dust. The graph which showed about the relationship between the presence or absence of supply of antioxidant gas (nitrogen), and contact resistance. The graph which showed about the relationship between the flow volume of antioxidant gas (nitrogen), and contact resistance. The side view which shows the structural example of the conventional inspection apparatus typically.

<Overall structure>
Hereinafter, an inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view schematically showing a structural example of an inspection apparatus according to an embodiment of the present invention. In FIG. 1, the internal structure of the housing 2 is shown through. Further, FIG. 1 is a schematic diagram, and since the main part is highlighted, the dimensional ratio of each part does not necessarily match the actual inspection apparatus.

  As shown in FIG. 1, the inspection apparatus 1 is provided on a housing 2 in which an inspection is performed in an internal space, a cantilever type probe card 4 to which a probe needle 3 is attached, and a top plate 2 a of the housing 2. A card support portion 5 to which the probe card 4 is fitted and attached to the opened opening, and a nozzle 6 (gas supply portion) for injecting an antioxidant gas to the tip of the probe needle 3 to prevent oxidation of the tip of the probe needle 3 ), A gas supply line 7 that receives the antioxidant gas and supplies it to the nozzle 6, a movable stage 8 on which the wafer W is placed, and the probe card 4 attached to the top plate 2 a of the housing 2. A pogo pin ring 9 that is electrically connected by contacting a connection terminal provided on the upper surface of the substrate, a test head 10 that is electrically connected to the pogo pin ring 9, and an electrode on the chip via the probe needle 3 A test device 11 that generates an electrical signal to be applied to the lid and obtains an electrical signal output to the electrode pad to determine the quality of the chip, and a shield 12 for sealing the space inside the housing 2 And comprising. Note that although the test head 10 and the test apparatus 11 are electrically connected by wiring or the like, illustration of the wiring or the like is omitted in FIG.

  In addition, the inspection apparatus 1 includes internal sensors 20 and 21 that detect the amount of a predetermined substance contained in the gas inside the housing 2, and dust contained in an antioxidant gas that is provided in the gas supply line 7 and is transmitted therethrough. Inspection based on detection results of the filter device 30 to be removed, the supply control units 40 to 42 for detecting and adjusting the amount of gas passing through the gas supply line 7, and the internal sensors 20, 21 and the supply control units 40 to 42 The control device 50 that determines whether or not the accuracy can be lowered (hereinafter referred to as an abnormal state) and the user is notified by giving some stimulus (for example, light, sound, vibration, etc.). And a notification device 51.

  The inspection apparatus 1 illustrated in FIG. 1 includes, as internal sensors 20 and 21, a dust sensor 20 that detects the concentration of dust in the gas inside the housing 2, and an antioxidant gas and an oxidizing property in the gas inside the housing 2. And a gas sensor 21 that detects the concentration of at least one of gas (for example, gas that oxidizes the tip of the probe needle 3 such as oxygen). In addition, the inspection apparatus 1 illustrated in FIG. 1 includes, as the supply control units 40 to 42, a downstream flow meter 40 provided on the nozzle 6 side (hereinafter referred to as a downstream side) when viewed from the filter device 30, and the filter device 30. And an upstream flow meter 41 provided on the antioxidant gas supply source side (hereinafter referred to as upstream side) and a pressure gauge 42 provided on the upstream side of the filter device 30. 1 illustrates the case where the pressure gauge 42 is provided upstream of the upstream flow meter 41, the pressure gauge 42 may be provided downstream of the upstream flow meter 41.

  In this inspection apparatus 1, for example, the test apparatus 11 sequentially contacts the electrode pads provided on the respective chips in the wafer W by controlling the positioning and movement of the movable stage 8 on which the wafer W is placed. Let each chip be inspected. Further, during this inspection, an antioxidant gas is supplied from the nozzle 6 to the tip of the probe needle 3.

  The probe card 4 has an opening 4a at the center, and the probe needle 3 extends obliquely downward from the outer periphery of the opening 4a. The antioxidant gas supplied from the nozzle 6 is sprayed to the tip of the probe needle 3 through the opening 4 a of the probe card 4.

  Since the probe card 4 has the opening 4a, the space inside the housing 2 communicates with the space above the probe card 4 through the opening 4a. A pogo pin ring 9 and a test head 10 are provided at the top of the probe card 4. There is a gap between the pogo pins, and the test head 10 is provided with an opening 10 a for inserting the nozzle 6. Therefore, in this state, the space above the probe card 4 is not sealed, and the space inside the housing 2 communicating with the space is not sealed. Therefore, in the inspection apparatus 1, a shield 12 is provided on the upper surface of the probe card 4 in order to seal the space above the probe card 4.

  The shield 12 is formed of an airtight material and includes a side wall portion and a lid portion. The lower end portion of the side wall portion is in close contact with the upper surface of the outer peripheral portion of the opening 4a of the probe card 4, and the upper end portion of the side wall portion is in close contact with the outer peripheral end of the lid portion. The lid is provided with an opening through which the nozzle 6 penetrates closely. Thus, since the space inside the housing 2 and the space above the probe card 4 are sealed, it has a structure in which dust and oxidizing gas do not easily enter and exit from the outside.

  As a supply source of the antioxidant gas connected to the upstream side of the gas supply line 7, for example, a gas cylinder filled with the antioxidant gas, a generation device that generates an antioxidant gas (for example, nitrogen) from air, or the like is used. be able to. As the antioxidant gas, for example, an inert gas such as nitrogen or a rare gas, a reducing gas such as hydrogen, or the like can be used.

<Response to abnormal conditions>
The inspection apparatus 1 has a configuration for dealing with an abnormal state. Hereinafter, a configuration for dealing with this abnormal state will be described with reference to the drawings. FIG. 2 is a block diagram schematically showing a configuration example of the inspection apparatus according to the embodiment of the present invention.

  As shown in FIG. 2, the inspection apparatus 1 includes a dust sensor 20, a gas sensor 21, a downstream flow meter 40, an upstream flow meter 41, a pressure gauge 42 as a configuration for dealing with an abnormal state, A control device 50 and a notification device 51 are provided.

  The dust sensor 20 detects the concentration of dust in the gas inside the housing 2. The dust sensor 20 includes, for example, an optical particle counter, and detects the concentration of dust in the gas inside the housing 2 by counting the number of dust contained in a predetermined volume of gas. .

  The gas sensor 21 includes an antioxidant gas sensor 21a that detects the concentration of the antioxidant gas in the gas inside the housing 2, an oxidizing gas sensor 21b that detects the concentration of the oxidizing gas in the gas inside the housing 2, and Is provided. Each sensor 21a, 21b may be any detection type sensor such as a semiconductor type or a galvanic cell type.

  An example of the arrangement of the internal sensors 20 and 21 will be described with reference to FIG. FIG. 3 is a plan view showing an arrangement example of the internal sensors. The plane shown in FIG. 3 is perpendicular to the side surface shown in FIG. Moreover, in FIG.1 and FIG.3, although the antioxidant gas sensor 21a and the oxidizing gas sensor 21b are illustrated as one gas sensor 20, you may arrange | position these separately as a different body.

  As shown in FIG. 3, a plurality of internal sensors 20 and 21 are arranged at different locations inside the housing 2 such as the periphery of the movable stage 8 and the inner wall of the housing 2. When the internal sensors 20 and 21 are arranged in this way, it becomes possible to detect the concentration distribution of the substance contained in the gas inside the housing 2. From the viewpoint of maintaining high inspection accuracy, it is particularly preferable to arrange the internal sensors 20 and 21 near the tip of the probe needle 3 to be actually inspected (around the movable stage 8).

  The downstream flow meter 40 includes a flow sensor 40a (corresponding to a supply sensor) and a flow controller 40b (corresponding to a supply controller). Similarly, the upstream flow meter 41 also includes a flow sensor 41a (corresponding to a supply sensor) and a flow controller 41b (corresponding to a supply controller). The pressure gauge 42 includes a pressure sensor 42a (corresponding to a supply sensor) and a pressure controller 42b (corresponding to a supply controller).

  The flow rate sensors 40 a and 41 a detect the flow rate of the antioxidant gas passing through the gas supply line 7. The pressure sensor 42 a detects the pressure of the antioxidant gas that passes through the gas supply line 7.

  The flow controllers 40b and 41b control the flow rate of the antioxidant gas that passes through the gas supply line 7 so that the flow rate is set in advance or the flow rate set by the control device 50, for example. Further, the pressure controller 42b controls the pressure of the antioxidant gas passing through the gas supply line 7 so that the pressure is set in advance or the pressure set by the control device 50, for example.

  The control device 50 acquires the detection results of the dust sensor 20, the gas sensor 21, the flow sensors 40a and 41a, and the pressure sensor 42a, and determines whether or not an abnormal state is met. For example, the control device 50 stores a threshold value for the detection result of each sensor in advance, and determines that the state is abnormal if any one (or a plurality of) detection results exceed the threshold value. If the control device 50 determines that it is in an abnormal state, the control device 50 controls at least one of the flow controllers 40b and 41b and the pressure controller 42b to eliminate the abnormal state.

  Specifically, for example, the control device 50 determines the concentration of the dust in the gas inside the housing 2 that causes the dust to adhere to the wafer W, which may reduce the inspection accuracy, based on the detection result of the dust sensor 20. When the excess is confirmed, it is determined that the state is abnormal. The control device 50 increases the flow rate set in the flow rate controllers 40b and 41b in order to promote the supply of the antioxidant gas to the inside of the housing 2 and to reduce the concentration of dust in the gas inside the housing 2. Or increase the pressure set in the pressure controller 42b.

  Further, for example, the control device 50 lacks the concentration of the antioxidant gas in the gas inside the housing 2 that causes the oxidation of the tip of the probe needle 3 that can reduce the inspection accuracy based on the detection result of the gas sensor 21. In addition, when it is confirmed that the concentration of the oxidizing gas in the gas inside the housing 2 is excessive, it is determined that the state is abnormal. Then, the control device 50 promotes the supply of the antioxidant gas to the inside of the housing 2 to increase the concentration of the antioxidant gas in the gas inside the housing 2 or the oxidizing gas in the gas inside the housing 2. In order to reduce the concentration, the flow rate set in the flow rate controllers 40b and 41b is increased, or the pressure set in the pressure controller 42b is increased.

  Further, for example, the control device 50 determines that the state is abnormal when the supply of the antioxidant gas (for example, insufficient flow or insufficient pressure) is confirmed based on the detection results of the flow sensors 40a and 41a and the pressure sensor 42a. To do. Then, the control device 50 changes the flow rate set in the flow rate controllers 40b and 41b and the pressure set in the pressure controller 42b in order to eliminate the supply failure of the antioxidant gas.

  Further, when the control device 50 confirms the abnormal state as described above, the control device 50 controls the notification device 51 to notify the user of the abnormal state. For example, the notification device 51 includes a light emitting device such as a light emitting diode, a sounding device such as a speaker, a vibration motor, and the like, and is abnormal to the user by giving the user a stimulus such as light, sound, and vibration. Inform you. In FIG. 1, the notification device 51 is illustrated as if fixed to the inspection device 1, but the notification device 51 is portable such as a portable terminal owned by a user or the like. Also good. In this case, the portable terminal which comprises the alerting | reporting apparatus 51 receives the predetermined | prescribed radio signal which the control apparatus 50 which confirmed that it was in an abnormal state, and the said portable terminal alert | reports to a user. Further, when the control device 50 controls the flow rate controllers 40b and 41b and the pressure controller 42b described above, the notification device 51 may be controlled when the abnormal state is still not resolved.

  As described above, in the inspection apparatus 1, whether or not the gas in the housing 2 is suitable for inspection by referring to the detection result of at least one of the internal sensors 20 and 21 and the supply control units 40 to 42. It becomes possible to confirm. Therefore, the gas in the housing 2 can be maintained in a state suitable for inspection, and high inspection accuracy can be maintained.

  When the user directly checks the detection results of the internal sensor 20 and the supply control units 40 to 42 and operates the inspection device 1, the control device 50 and the notification device 51 may not be provided. However, if the control device 50 is provided, it is possible to automatically and continuously monitor whether or not an abnormal state occurs. Furthermore, by providing the notification device 51, it becomes possible to notify the user of that fact when an abnormal state occurs. Then, it is possible to prevent a decrease in inspection accuracy by performing an appropriate operation for eliminating the abnormal state by the notified user.

  Moreover, from the viewpoint of detecting an abnormal state, the above-described inspection apparatus 1 may be configured to include only one of the internal sensors 20 and 21 and the supply control units 40 to 42.

  Further, the inspection apparatus 1 may be configured to include only one of the dust sensor 20 and the gas sensor 21. Further, the inspection apparatus 1 may be configured to include only one of the antioxidant gas sensor 21a and the oxidizing gas sensor 21b. Moreover, the test | inspection apparatus 1 may be provided with sensors other than the above as an internal sensor.

  Further, the inspection apparatus 1 may be configured to include only one (or two) of the downstream flow meter 40, the upstream flow meter 41, and the pressure gauge 42. Moreover, the inspection apparatus 1 may include a supply control unit other than the above. Furthermore, in the above-described inspection apparatus 1, the downstream flow meter 40 and the upstream flow meter 41 include flow sensors 40a and 41a and flow controllers 40b and 41b, and the pressure gauge 42 includes a pressure sensor 42a and a pressure controller 42b. Although illustrated, the downstream flow meter 40 and the upstream flow meter 41 may include any one of the flow sensors 40a and 41a and the flow controllers 40b and 41b, and the pressure gauge 42 may be the pressure sensor 42a. And the pressure controller 42b may be provided. Further, the flow sensors 40a and 41a and the flow controllers 40b and 41b are not necessarily integrated devices, and may be separate devices. Similarly, the pressure sensor 42a and the pressure controller 42b are not necessarily integrated devices, and may be separate devices.

<Filter device>
The inspection device 1 includes a filter device 30 in the gas supply line 7. The filter device 30 removes dust by allowing gas to pass through, such as a filtration membrane. First, the effect of providing this filter device will be described with reference to FIG. FIG. 4 is a graph showing the relationship between the presence or absence of a filter and the dust concentration.

  The horizontal axis of the graph shown in FIG. 4 indicates the elapsed time since the start of the supply of the antioxidant gas, and the vertical axis is included in the antioxidant gas at the outlet of the nozzle 6 (immediately before being supplied to the probe needle 3). Count number of dust (a value obtained by counting the number of dust particles having a diameter of 0.3 to 1.0 μm present in a certain volume every minute using an optical particle counter using laser light) Yes. In FIG. 4, the broken line indicates a graph when the filter device 30 is not provided in the gas supply line 7, and the solid line indicates a graph when the filter device 30 is provided in the gas supply line 7. Show. Further, the alternate long and short dash line indicates the reference value of the wafer W in the test environment. Until about 6 minutes have passed since the start of the supply of the antioxidant gas, the state is unsteady due to the influence of the gas existing in the gas supply line 7 and the housing 2 from the start of the supply of the antioxidant gas. ing.

  As shown in FIG. 4, when the filter device 30 is not provided in the gas supply line 7, dust is contained in the antioxidant gas supplied from the nozzle 6 to the probe needle 3, so that the count number of dust is less than the reference value. It becomes difficult to make. The dust mixed in the gas supply line 7 may be, for example, dust generated due to deterioration of a metal or resin pipe constituting the gas supply line 7, or dust generated from an antioxidant gas supply source (not shown). It is done.

  On the other hand, when the filter device 30 is provided in the gas supply line 7, the dust can be removed by the filter device 30, so the count number of dust in the antioxidant gas supplied from the nozzle 6 to the probe needle 3 is It becomes possible to make it below the reference value. In particular, the count number of dust in a steady state after 7 minutes can be continuously and stably kept below the reference value.

  By the way, when using such a filter apparatus 30, an abnormal state resulting from the filter apparatus 30 is concerned. Specifically, for example, there is a concern that clogging of the filter device 30 may reduce the flow rate of the antioxidant gas downstream of the filter device 30 and oxidize the tip of the probe needle 3 to reduce the inspection accuracy.

  Here, the relationship between the supply of the antioxidant gas and the inspection accuracy will be described with reference to the drawings. FIG. 5 is a graph showing the relationship between the presence or absence of the supply of an antioxidant gas (nitrogen) and the contact resistance. FIG. 6 is a graph showing the relationship between the flow rate of the antioxidant gas (nitrogen) and the contact resistance.

  The horizontal axis of the graph shown in FIG. 5 is the number of contacts between the probe needle 3 and the electrode pad, and the vertical axis is the contact resistance. However, this contact resistance is obtained by calculating an average value every time the number of contacts reaches 20, and further normalizing the average value of the contact resistance obtained by the first 1 to 20 contacts to 1. In FIG. 5, a thin solid line indicates a graph when the antioxidant gas is not supplied to the probe needle 3, and a thick solid line indicates a case where 10 L / Min of nitrogen is supplied to the probe needle 3. The graph is shown.

  As shown in FIG. 5, when the antioxidant gas is not supplied to the probe needle 3, as the number of contacts increases, the contact resistance increases as a whole and the deflection width increases. That is, when the antioxidant gas is not supplied to the probe needle 3, the probe needle 3 is oxidized as the inspection is continued, and the inspection accuracy is lowered.

  On the other hand, when the antioxidant gas (nitrogen) is supplied to the probe needle 3, even if the number of contacts increases, the contact resistance does not increase so much and the fluctuation width remains small. That is, if an antioxidant gas (nitrogen) is supplied to the probe needle 3, it is possible to suppress the oxidation of the probe needle 3 and suppress a decrease in inspection accuracy even if the inspection is continued.

  In addition, the horizontal axis of the graph shown in FIG. 6 is the number of contacts between the probe needle 3 and the electrode pad, and the vertical axis is the contact resistance. In FIG. 6, a thin solid broken line indicates a graph when 0.2 L / Min of nitrogen is supplied to the probe needle 3, and a solid broken line with an intermediate thickness is 0. A graph when nitrogen of 5 L / Min is supplied is shown, and a thick broken line indicates a graph when 1.5 L / Min of nitrogen is supplied to the probe needle 3.

  As shown in FIG. 6, as the flow rate of the antioxidant gas (nitrogen) is increased, the contact resistance can be reduced as a whole and the fluctuation width can be reduced. That is, if the flow rate of the antioxidant gas (nitrogen) with respect to the probe needle 3 is increased, the oxidation of the probe needle 3 can be more effectively suppressed, and the decrease in inspection accuracy can be more effectively suppressed.

  Therefore, as shown in FIG. 5 and FIG. 6, when the filter device 30 is provided in the gas supply line 7, an antioxidant gas during the inspection is used to suppress the oxidation of the probe needle 3 and maintain high inspection accuracy. It is preferable to prevent the flow rate from decreasing and maintain the flow rate at a high level.

  The control apparatus 50 acquires the detection result of the flow sensor 40a with which the downstream flow meter 40 is provided at least, and determines whether it corresponds to an abnormal state. For example, the control device 50 stores a threshold value for the detection result of each sensor in advance, and determines that the state is abnormal if any one (or a plurality of) detection results exceed the threshold value. When the control device 50 determines that it is in an abnormal state, the control device 50 controls the pressure controller 42b, for example, to eliminate the abnormal state.

  Specifically, for example, when the control device 50 confirms that the flow rate of the antioxidant gas on the downstream side of the filter device 30 is insufficient based on the detection result of the flow sensor 40a of the downstream flow meter 40, the control device 50 determines that the state is abnormal. To do. Then, the control device 50 increases the pressure set in the pressure controller 42b in order to increase the flow rate of the antioxidant gas downstream of the filter device 30 and suppress the oxidation of the probe needle 3.

  Thereby, even if the flow rate of the antioxidant gas on the downstream side is reduced due to the clogging of the filter device 30, the flow rate of the antioxidant gas on the downstream side is recovered by increasing the pressure of the antioxidant gas on the upstream side. Is possible.

  Further, when the control device 50 confirms the abnormal state as described above, the control device 50 controls the notification device 51 to notify the user of the abnormal state. At this time, it is preferable that the control device 50 controls the notification device 51 when the abnormal state is still not resolved even when the pressure controller 42b is controlled. In this case, the notification device 51 notifies the user of the timing for replacing the filter device 30.

  As described above, in the inspection device 1, the amount of the antioxidant gas on the downstream side of the filter device 30 that directly reflects the influence of the clogging of the filter device 30 is detected by the flow sensor 40 a of the downstream flow meter 40. To do. Therefore, it is possible to confirm whether the filter device 30 is clogged by referring to the detection result of the flow sensor 40a. Therefore, a sufficient amount of antioxidant gas can be supplied to the probe needle 3, and high inspection accuracy can be maintained.

  In particular, as described with reference to FIG. 6, there is a correlation between the oxidation of the probe needle 3 and the flow rate of the antioxidant gas supplied to the probe needle 3. Therefore, by referring to the detection result of the flow sensor 40a of the downstream flow meter 40, it is possible to quickly confirm the state in which the probe needle 3 can be oxidized.

  Further, by comparing the detection result of the flow sensor 40a of the downstream flow meter 40 with the detection result of the flow sensor 41a of the upstream flow meter 41, the flow rate sensor 40a of the downstream flow meter 40 detects the amount of antioxidant gas. When a supply failure is detected, whether it is caused by clogging of the filter device 30 or an abnormality upstream of the filter device 30 (for example, an antioxidant gas supply source). It becomes possible to confirm. Further, at this time, the flow rate of the antioxidant gas on each of the downstream side and the upstream side can be directly compared with the filter device 30 interposed therebetween, so that the clogging of the filter device 30 can be accurately confirmed. Therefore, it is preferable.

  In addition, when a user confirms the detection result of the flow sensor 40a of the downstream flowmeter 40 directly and operates the test | inspection apparatus 1, the control apparatus 50 and the alerting | reporting apparatus 51 do not need to be provided. However, it is preferable to provide the control device 50 because it is possible to automatically and continuously monitor whether or not it is an abnormal state. Furthermore, by providing the notification device 51, it is possible to notify the user of the timing for replacing the filter device 30 as described above. And it becomes possible to prevent the fall of a test | inspection precision by replacing | exchanging the filter apparatus 30 by the notified user.

<Deformation, etc.>
<1> Although the structure for supplying the antioxidant gas to the probe needle 3 of the inspection apparatus 1 has been mainly described, the inspection apparatus 1 may include an exhaust structure for exhausting the gas inside the housing 2. . For example, an exhaust port or a fan for exhaust may be provided below the housing 2.

  When the exhaust structure as described above is provided, the antioxidant gas supplied to the probe needle 3 is then exhausted by flowing in one direction (particularly downward) in the case 2. Dust (for example, generated by the movement of the movable stage 8 or generated by the contact between the probe needle 3 and the electrode pad) is lifted up to the wafer W, or the antioxidant gas is applied to the tip of the probe needle 3. It is possible to prevent the spraying from being hindered. In order to prevent dust in the housing 2 from scattering outside the housing 2, it is preferable to provide a filter device at the exhaust port.

  <2> The above-described inspection device 1 has a structure in which the antioxidant gas supplied from the nozzle 6 provided immediately above the tip of the probe needle 3 is blown against the tip of the probe needle 3 through the opening 4 a of the probe card 4. However, the structure for supplying the antioxidant gas to the tip of the probe needle 3 is not limited to this example, and any structure may be adopted.

  For example, the above-described inspection apparatus 1 has a structure in which the antioxidant gas is blown from the vertical direction with respect to the tip of the probe needle 3. However, the structure may be a structure in which the antioxidant gas is blown from the horizontal direction. The structure which sprays antioxidant gas from the direction between directions may be sufficient. When these structures are employed, one or a plurality of nozzles 6 may be provided at a position in the horizontal direction at the tip of the probe needle 3. Further, without providing the nozzle 6, for example, one or a plurality of antioxidant gas outlets may be provided in the card support 5 or the like.

  <3> The above-described inspection apparatus 1 has a structure in which the probe card 4 is attached to the top plate 2a of the housing 2 by the card support portion 5, but the probe card 4 is directly attached to the top plate 2a of the housing 2. It may be a structure to be attached. The above-described inspection apparatus 1 has a structure in which the probe card 4 is electrically connected to the test apparatus 11 via the pogo pin ring 3 and the test head 4, but without using the pogo pin ring 3 or the test head 4. The probe card 4 and the test apparatus 11 may be electrically connected.

  <4> The above-described inspection apparatus 1 has a structure in which the gas supply line 7 includes the filter device 30. For example, unlike the case illustrated in FIG. 4, the gas supply line 7 may be provided without the filter device 30. If there is not much dust mixed in the antioxidant gas passing through the filter, the installation of the filter device 30 can be omitted. Further, when the installation of the filter device 30 is omitted, either the downstream flow meter 40 or the upstream flow meter 41 may not be provided.

  INDUSTRIAL APPLICABILITY The present invention can be used for an inspection apparatus that performs an electrical inspection of an object to be inspected in a wafer state using a probe card.

1: Inspection device 2: Case 2a: Top plate of case 3: Probe needle 4: Probe card 5: Card support part 6: Nozzle (gas supply part)
7: Gas supply line 8: Movable stage 9: Pogo pin ring 10: Test head 10a: Test head opening 11: Test device 12: Shield 20: Dust sensor (internal sensor)
21: Gas sensor (internal sensor)
21a: Antioxidant gas sensor 21b: Oxidizing gas sensor 30: Filter device 40: Downstream flow meter (supply control unit)
40a: Flow rate sensor (supply sensor)
40b: Flow controller (supply controller)
41: Upstream flow meter (supply control unit)
41a: Flow rate sensor (supply sensor)
41b: Flow controller (supply controller)
42: Pressure gauge (supply control unit)
42a: Pressure sensor (supply sensor)
42b: Pressure controller (supply controller)
50: Control device 51: Notification device

Claims (11)

An inspection apparatus for performing an electrical inspection of the inspection object by contacting an electrode pad formed on the surface of the inspection object in a wafer state and a tip of a probe needle attached to the probe card,
A housing in which the inspection is performed in an internal space;
A gas supply unit for supplying an antioxidant gas for preventing oxidation of the tip of the probe needle to the tip of the probe needle;
A gas supply line that receives the antioxidant gas and supplies the antioxidant gas to the gas supply unit, and
An internal sensor for detecting the amount of a predetermined substance contained in the gas inside the housing;
A supply sensor for detecting the amount of gas passing through the gas supply line;
An inspection apparatus comprising at least one of the sensors. As the internal sensor,
A gas sensor that detects at least one of a concentration of the antioxidant gas in the gas inside the housing and a concentration of an oxidizing gas that oxidizes the tip of the probe needle in the gas inside the housing;
The inspection apparatus according to claim 1, further comprising: As the internal sensor,
A dust sensor for detecting the concentration of dust in the gas inside the housing;
The inspection apparatus according to claim 1, further comprising: an inspection apparatus.   The inspection device according to any one of claims 1 to 3, wherein the internal sensors are respectively disposed at a plurality of different locations inside the housing. As the supply sensor,
A flow sensor for detecting a flow rate of the antioxidant gas passing through the gas supply line;
The inspection apparatus according to claim 1, wherein the inspection apparatus is provided. As the supply sensor,
A pressure sensor for detecting the pressure of the antioxidant gas passing through the gas supply line;
The inspection apparatus according to any one of claims 1 to 5, further comprising: A control device for determining whether or not an abnormal state is a state in which the inspection accuracy can be lowered based on a detection result of at least one of the internal sensor and the supply sensor.
The inspection apparatus according to claim 1, further comprising: A notification device for performing notification to the user;
8. The inspection apparatus according to claim 7, wherein when the control device determines that the abnormal state is present, the control device controls the notification device to notify the user of the abnormal state. A supply controller that adjusts the amount of the antioxidant gas passing through the gas supply line;
9. The inspection apparatus according to claim 7, wherein the control device controls the supply controller so that the abnormal state is resolved when the control device determines that the abnormal state is present. As the supply controller,
A flow rate controller for adjusting the flow rate of the antioxidant gas passing through the gas supply line;
The inspection apparatus according to claim 9, further comprising: As the supply controller,
A pressure controller for adjusting the pressure of the antioxidant gas passing through the gas supply line;
The inspection apparatus according to claim 9 or 10, further comprising:

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