JP4536525B2 - Semiconductor device test apparatus and test method - Google Patents

Description

  The present invention relates to a technical field for conducting an electrical test of an element having one or more terminals, and more particularly to a test apparatus and a test method for a semiconductor device.

  Each of the semiconductor elements formed on the semiconductor wafer is electrically inspected before being separated from the wafer, and the inspection is called a primary test or a probe test. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-2003) discloses a technique for attaching a plate spring to each probe pin for inspection and improving the electrical contact between the probe pin and the terminal of the element using the elasticity of the plate spring. 240801).

  In this type of technical field, as the number of semiconductor elements increases, the speed of the semiconductor elements increases, and the power consumption decreases, the signals flowing through the terminals arranged at a narrow pitch are increased in current and voltage. For this reason, an inspection using a vertical probe card having a simpler configuration than that of the inspection apparatus disclosed in Patent Document 1 is also performed.

  FIG. 1 shows a schematic view of an apparatus for inspecting semiconductor elements using such a vertical probe card. As illustrated, the inspection apparatus includes a card substrate 12, a needle holding unit 14, a large number of vertical probe pins (inspection needles) 16, a stage 20, and a camera 22. The vertical probe pin 16 is movable by a fixed distance in the vertical direction indicated by the z axis in the drawing. The vertical probe pin 16 has a straight portion and a curved portion, one end of the straight portion is coupled to the curved portion, and the other end has a shape on the sickle neck (after this shape, Such pins are also called cobra probes.) The curved portion can be elastically deformed when one end thereof contacts the terminal (contact pad) of the element. The end on the sickle neck has a size larger than the diameter of the hole surrounding the pin so that the pin does not fall further under its own weight (see enlarged view in circle).

When performing inspection, first, the semiconductor element 18 to be inspected is positioned below the vertical probe card. At this time, none of the vertical probe pins 16 are in contact with the electrode 13 of the card substrate 12. In order to perform the inspection, the semiconductor element 18 is brought close to the needle holding unit 14 so that the terminals 19 (contact pads) of the semiconductor element 18 are in contact with the vertical probe pins 16 respectively. The semiconductor element 18 is mounted on the stage 20 and can be moved in the z-axis direction and the direction perpendicular thereto (assuming that the vertical probe card is fixed). As the semiconductor element 18 approaches the needle holding unit 14, the vertical probe pin 16 comes into contact with the contact pad 19 of the semiconductor element 18 at one end thereof, and as the stage 20 moves in the positive direction of the z-axis, the curvature of the pin is increased. The bent portion is bent and the other end of the pin 16 in contact with the sickle neck contacts the electrode 13 of the card substrate 12. Thereafter, an appropriate voltage or current is applied to each of the contact pads and the desired electrical test is performed. When the test is completed, the semiconductor element 18 is pulled away from the vertical probe card. As a result, the large number of vertical probe pins 16 are lowered by their own weight in the negative direction of the z axis, and return to the state before the inspection. Thereafter, by repeating the same procedure, the semiconductor elements can be inspected one after another.
JP 2003-240801 A

  Since the vertical probe pin 16 is moved and deformed many times, it is expected that a defect such as breaking or inadvertent bending occurs. When such a failure is found, the vertical probe card is removed from the inspection apparatus and maintenance is performed, or it is replaced if necessary. The trouble of the vertical probe pin 16 is, for example, that several vertical probe pins are selected in advance as alignment pins, and the height (position in the z-axis direction) of the alignment pin is set, for example, in a state where the semiconductor element is not in contact. It is found by measuring using an optical camera 22 and detecting that the height difference measured for each pin is greater than a predetermined value. Although the height of all pins may be measured, the number of pins depends on the application, but there are, for example, several thousand pins. Therefore, it is not practical to measure the height of all pins. Accordingly, the height of the tip of the pin is measured only for a predetermined number of alignment pins.

  However, even when the difference in height of the tip position of the alignment pin is larger than a predetermined value, the pin does not always have the above-described problem. For example, as shown in FIG. 2, the vertical probe pin may not descend downward due to friction between the vertical probe pin 16 and the surrounding material. If the vertical probe pin 16 ′ caught in this way is selected as an alignment pin, there will be a difference in level with the alignment pin 16 that has descended normally. However, the height difference that occurs in this case does not reflect inconvenient deformation of the vertical probe pin. This is because the electrical test can be performed well even with the vertical probe pin 16 '. Therefore, conventionally, when the height difference of the tip position of a predetermined vertical probe pin exceeds a predetermined value, the vertical probe card is first removed from the apparatus, and whether or not there is a real defect is determined by the operator. For example, it is confirmed by inspection using a microscope. As a result, if the vertical probe pin is truly broken or the like, necessary maintenance inspection is performed. On the other hand, when it is confirmed that the state is as shown in FIG. 2, the vertical probe card is attached to the inspection device again (after properly returning the caught vertical probe pin) and used again for the inspection. Is done.

  However, it is convenient from the viewpoint of improving the inspection throughput that the operator intervenes and confirms the true / false of the defect each time the height difference of the tip position of the predetermined vertical probe pin exceeds a predetermined value. is not.

  On the other hand, as shown in FIG. 3, an attempt has been made to make the alignment pin longer than the other pins (16 ″) and prevent it from moving in the vertical direction. The above problem can be solved at least in part because the difference in height occurs only in the case of a malfunction. However, the provision of such a special vertical probe pin 16 " The card will be specially ordered, resulting in high costs. Furthermore, since the alignment pin is different in length and function from the other pins, the other pins cannot be substituted. Therefore, the alignment pin cannot be selected flexibly.

  If the above-mentioned problem can be partially solved by using special pins that do not move in the vertical direction as alignment pins, it may be considered that all the vertical probe pins are used as pins that do not move. However, taking into account the actual situation of this type of inspection device transaction, it is difficult to realize such a method in the first place, and even if it can be realized, the cost becomes high. Usually, the card substrate 12 and the needle holding unit 14 are made as separate bodies by different vendors, and both are combined when manufacturing the vertical probe card. Therefore, when connecting them, the tip portion of the pin 16 that is stationary in the vertical direction is processed at a low cost with high accuracy to such an extent that the tip portion on the sickle neck of the pin 16 always contacts the electrode 13 of the card substrate 12. It is difficult. Therefore, it is not a good idea to fix all pins. In the first place, in the vertical probe method, by making the pin 16 movable, it is guaranteed that the end on the sickle neck always contacts the electrode 13 during the electrical test, and the vertical probe card is made inexpensively (however, the above-mentioned Have such problems.)

  The present invention has been made in view of at least one of the above-mentioned problems, and its problem is that one or more terminals of an inspection target element are brought into contact with one or more probe pins constituting a vertical probe card. An object of the present invention is to provide a test apparatus and a test method for a semiconductor device that reliably determine the normality of one or more probe pins in an apparatus for performing a physical test.

According to one aspect of the disclosed invention,
In an apparatus for performing an electrical test by contacting one or more terminals of an element to be inspected with one or more vertical probe pins movable in the vertical direction constituting a vertical probe card ,
Means for aligning the tips of one or more vertical probe pins;
Means for measuring the position of the tip of one or more vertical probe pins ;
Means for determining the normality of the vertical probe pin ,
The means for aligning the position applies a force due to airflow to the vertical probe pin.
A device is used which is characterized by that.

  According to the present invention, in an apparatus for performing an electrical test by bringing one or more terminals of an inspection target element into contact with one or more probe pins constituting a vertical probe card, the normality of one or more probe pins is more reliably ensured. Can be determined.

  According to one aspect of the present invention, in an apparatus for performing an electrical test by bringing one or more terminals of an element to be inspected into contact with one or more vertical probe pins that constitute a vertical probe card and that are movable in the vertical direction, A force is applied to the one or more vertical probe pins so as to align the positions of the tips of the vertical probe pins. Then, the positions of the tips of the one or more vertical probe pins are measured, and the normality of the one or more vertical probe pins is determined according to the variation in the measured positions.

  After applying some force to the pin so that the tip positions of the vertical probe pins are aligned as much as possible, the tip position of the pin is measured. For this reason, when there is no problem in the pin itself, the possibility of an elevation difference (variation) exceeding a predetermined value is remarkably reduced, and the normality of the vertical probe pin can be further reliably determined.

  In one aspect of the invention, the vertical probe card is removed from the device when the variation is greater than a predetermined value. Thereby, maintenance inspection by the operator can be performed only when there is a high possibility that a problem is truly occurring, which can contribute to improvement of inspection throughput.

  According to one aspect of the present invention, the alignment pin and other pins have the same structure and function, and therefore the alignment pin can be arbitrarily set. Further, in one embodiment of the present invention, a special pin is not required, so that inspection can be performed at a low cost. Although it is necessary to newly provide a means for applying a force to the vertical probe pin, since the force to be applied may be a slight force, such means can be introduced at low cost.

  In one aspect of the invention, the vertical probe pin is subjected to a force from the airflow. As a result, the pin tip position can be aligned without any electromagnetic influence on the pin, and there is no fear of giving an extra electromagnetic characteristic to the pin.

  In one aspect of the present invention, the means for aligning the tip position has an end portion for ejecting or sucking air, and the end portion protrudes from one surface of the vertical probe card. Besiege. Thereby, a force can be easily and effectively applied to one or more vertical probe pins at once.

  In one aspect of the invention, the vertical probe pin is subjected to electrical or magnetic forces. Thereby, an apparatus can be simply comprised, without requiring a large-scale apparatus structure like the pump which ejects or attracts | sucks air.

  FIG. 4 shows a schematic diagram of an inspection apparatus according to an embodiment of the present invention. Also in this embodiment, a vertical probe card is used to inspect the semiconductor element. The inspection apparatus includes a needle holding unit 14 provided on a card substrate (not shown), a large number of vertical probe pins (inspection needles) 16, a stage 20, a camera 22, and an air unit 42. The needle holding unit 14 holds the vertical probe pin 16 so that the vertical probe pin 16 is movable by a certain distance in the vertical direction indicated by the z-axis in the drawing. As shown, each of the vertical probe pins 16 has a straight portion and a curved portion, and one end of the pin has a sickle shape, and can contact the electrode 13 on the card substrate side. Yes, the other end of the pin can contact the contact pad of the semiconductor element. The semiconductor element 18 to be measured is mounted on the stage 20 and is appropriately moved in the z-axis direction and the direction perpendicular thereto.

  An air unit 42 is also prepared in the inspection apparatus. The air unit portion 42 has a generally funnel-like shape, and has an end portion 42 that is wide enough to cover one or more vertical probe pins 16 and an end portion 46 that is connected to a pump that blows out or sucks air. Have The air unit 42 is appropriately moved in the z-axis direction and the direction perpendicular thereto. In this embodiment, the air unit 42 and the stage 20 are movable in any direction, but the vertical probe card including the needle holding unit 14 and the like is fixed.

  FIG. 5 shows a flowchart of a method according to an embodiment of the present invention. The flow starts from step 502. In this step, the positional relationship between the semiconductor element 18 and the vertical probe pins is appropriately adjusted by moving the stage 20 appropriately. More specifically, the stage 20 is moved so that the positions of the pin 16 and the contact pad 19 corresponding to the pin are matched based on the position information of the arbitrarily selected pin.

  In step 504, among the many vertical probe pins 16, the heights of the tips of a plurality of pins (alignment pins) preselected to measure the heights of the tips (positions in the z-axis direction) are actually measured. Is done. The measurement is performed, for example, by photographing the tip of the alignment pin with the optical camera 22.

  In step 506, the variation (height difference) between the plurality of measured values of height is compared with a predetermined threshold value. The threshold value is set to a value (for example, 30 μm) larger than the length variation (for example, 20 μm) of the vertical probe pins 16. If the height difference is smaller than the threshold value, the tips of the alignment pins are properly aligned. Accordingly, the flow proceeds to step 518 and an electrical test of the semiconductor element 18 is performed. On the other hand, if the height difference is greater than or equal to the threshold, the flow proceeds to step 508.

  In step 508, an operation for aligning the heights of the alignment pins is performed. In this step, the semiconductor element to be measured is separated from the vertical probe card, and the air unit 42 is attached to the vertical probe card. The air unit 42 is moved so as to achieve such a positional relationship. FIG. 6 shows a state after the air unit 42 is attached to the vertical probe card. It should be noted that the air unit 42 shown in FIG. 6 is shown in the form of an end view, unlike FIG. As illustrated, the air unit portion 42 is attached to the needle holding unit 14 so as to include one or more vertical probe pins 16 protruding from one surface of the vertical probe card in the opening 44. Air sent from a pump (not shown) is ejected from the wide opening 44 through the end 46 of the air unit 42. The injected air gives a stimulus to the pin (force of airflow acts on the pin) and prompts the uneven pin 16 'to descend due to its own weight. Since the frictional force between the pin 16 ′ and the surrounding material is very small, if any force is applied to the pin 16 ′, the pin that has been caught falls appropriately downward due to its own weight. As a result, the tips of the alignment pins are properly aligned or at least more likely as long as it does not really cause a malfunction. The flow rate of the air jetted by the air unit 42 may be such that the irregular drop of the pin 16 ′ is motivated.

  In step 510, the air unit portion 42 is removed from the vertical probe card, and the positional relationship between the semiconductor element 18 and the pins is appropriately adjusted by appropriately moving the stage 20 as in step 502. Based on the position information of the arbitrarily selected pin (or the pin selected in step 502), the stage 20 is moved so that the positions of the pin 16 and the contact pad 19 corresponding to the pin match.

  In step 512, as in step 504, the heights of the tips of the plurality of alignment pins are measured.

  In step 514, as in step 506, the variation (height difference) between the plurality of height measurement values is compared with a predetermined threshold value. The threshold value is set to a value larger than the length variation (for example, 20 μm) of the vertical probe pin 16 and may be the same as or different from the threshold value used in step 506. If the elevation difference is less than the threshold, the flow proceeds to step 516 and the semiconductor device 18 is electrically tested.

  In the case of reaching step 516, although the height adjustment operation is performed in step 508, the difference in height is equal to or greater than the threshold value, so there is a high possibility that a problem has occurred. For this reason, in step 516, the vertical probe card is removed from the apparatus and serviced by the operator, and if necessary, the vertical probe card is replaced with another. As a result, the inspection apparatus is provided with a vertical probe card that does not have a defect.

  Thereafter, the flow proceeds to step 516, and an electrical test of the semiconductor element 18 is performed.

  The method shown in FIG. 5 is merely an example. For example, steps 502, 504, and 506 may be omitted, and only the steps after step 508 may be executed.

  In the present embodiment, the air unit portion 42 injects air to the vertical probe pin 16, but in other embodiments, air may be sucked in reverse. In any case, it is sufficient that some mechanical stimulus can be applied to the irregular pins. Regardless of whether the air is jetted or sucked, it is desirable to generate an airflow in the vicinity of the pin in order to effectively apply a force to the pin. From such a viewpoint, as shown in FIG. 7, it is desirable to provide one or more holes (flow holes) 72 for circulating air on the wall surface of the air unit portion 42. It should be noted that FIG. 7 shows the external shapes of the needle holding unit 14 and the air unit portion 42, unlike FIG. Furthermore, it is desirable that the position of the hole is close to the tip of the pin from the viewpoint of causing the airflow to act on the pin.

  Furthermore, from the viewpoint of applying some mechanical stimulus to the irregular pins, not only the force due to the airflow but also the force due to electricity or magnetism may be applied to the pins. However, from the viewpoint of having no influence on the electrical test performed in step 518, it may be preferable to apply air force. From the viewpoint of simplifying the configuration of the apparatus without providing a relatively large mechanism such as a pump for ejecting or discharging air, it is preferable to apply an electric or magnetic force to the pin.

  Hereinafter, the means taught by the present invention will be listed as an example.

(Appendix 1)
In an apparatus for performing an electrical test by contacting one or more terminals of an element to be inspected with one or more vertical probe pins movable in the vertical direction constituting a vertical probe card,
Means for aligning the tips of one or more vertical probe pins;
Means for measuring the position of the tip of one or more vertical probe pins;
Means for discriminating the normality of the vertical probe pins.

(Appendix 2)
The apparatus according to claim 1, wherein the means for aligning the position causes a force due to an air current to act on the vertical probe pin.

(Appendix 3)
The means for aligning has an end portion for ejecting or sucking air, and the end portion surrounds one or more vertical probe pins protruding from one surface of the vertical probe card. The apparatus according to 1.

(Appendix 4)
The apparatus according to claim 1, wherein the means for aligning the position applies an electric force to the vertical probe pin.
(Appendix 5)
The apparatus according to claim 1, wherein the aligning means applies a magnetic force to the vertical probe pin.

(Appendix 6)
In an apparatus for performing an electrical test by contacting one or more terminals of an element to be inspected with one or more vertical probe pins movable in the vertical direction constituting a vertical probe card, the normality of the one or more vertical probe pins is determined. A method,
A force is applied to the one or more vertical probe pins to align the tips of the one or more vertical probe pins;
Measure the position of the tip of one or more vertical probe pins,
A method for determining the normality of one or more vertical probe pins according to variations in measured positions.

(Appendix 7)
The method according to claim 6, wherein the force applied to the one or more vertical probe pins is an airflow, electricity, or magnetic force.

(Appendix 8)
The method according to claim 6, wherein the vertical probe card is removed from the apparatus when the variation is larger than a predetermined value.

1 shows a schematic diagram of an apparatus for inspecting semiconductor elements using a vertical probe card. It is a figure which shows a mode that the height difference has arisen in the front-end | tip position of a vertical probe pin. It is a figure which shows another example of the conventional which detects the malfunction of a vertical probe pin. 1 shows a schematic view of an inspection apparatus according to an embodiment of the present invention. 5 shows a flowchart of a method for determining normality of a vertical probe pin. It is a figure which shows a mode that the air unit part was mounted | worn. It is a figure which shows a mode that the air unit part which has a through-hole in a wall surface was mounted | worn.

Explanation of symbols

12 card board; 14 needle holding unit; 16, 16 ', 16 "vertical probe pin; 18 semiconductor element; 19 contact pad; 20 stage; 22 camera;
42 Air unit part; 44 Open end part; 46 End part; 72 holes

Claims (3)

In an apparatus for performing an electrical test by contacting one or more terminals of an element to be inspected with one or more vertical probe pins movable in the vertical direction constituting a vertical probe card,
Means for aligning the tips of one or more vertical probe pins;
Means for measuring the position of the tip of one or more vertical probe pins;
Means for determining the normality of the vertical probe pin ,
The means for aligning the position applies a force due to airflow to the vertical probe pin.
A device characterized by that . In an apparatus for performing an electrical test by contacting one or more terminals of an element to be inspected with one or more vertical probe pins movable in the vertical direction constituting a vertical probe card,
Means for aligning the tips of one or more vertical probe pins;
Means for measuring the position of the tip of one or more vertical probe pins;
Means for determining the normality of the vertical probe pin ,
The means for aligning has an end for blowing or sucking air, the end surrounding one or more vertical probe pins protruding from one side of the vertical probe card.
A device characterized by that . In an apparatus for performing an electrical test by contacting one or more terminals of an element to be inspected with one or more vertical probe pins movable in the vertical direction constituting a vertical probe card, the normality of the one or more vertical probe pins is determined. A method,
A force is applied to the one or more vertical probe pins to align the tips of the one or more vertical probe pins;
Measure the position of the tip of one or more vertical probe pins,
Determining the normality of one or more vertical probe pins according to variations in measured positions ;
A method characterized in that the force acting on one or more vertical probe pins is an airflow, electricity or magnetism force .

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