JPH0740578B2 - Wafer prober - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a wafer prober for conducting a probe test on a semiconductor wafer, and more particularly to a wafer prober suitable for automatically measuring a semiconductor wafer.

[Prior art]

In the manufacturing process of a semiconductor device, a large number of wafer chips of the semiconductor device are formed on one crystal wafer by using a photo-etching technique. When the wafer chip is completed on the wafer, an electrical characteristic inspection of the wafer chip called a probe test is performed. Then, this probe test is performed using an electric characteristic tester (tester) and a probe card. That is, the probe of the probe card is brought into contact with the electrode of the wafer chip, and the electrical characteristics of the wafer chip are inspected by the tester. At this time, a so-called wafer prober is used to fix the wafer with a chuck and bring the probe of the probe card into contact with all the wafer chips on the wafer by the wafer mounting table (stage) having an intermittent feeding mechanism. After the probe test is completed, the wafer is cut into individual semiconductor device wafer chips and then divided, and only the wafer chips that pass the inspection are mounted in the container. When the type of wafer to be inspected is different, it is necessary to replace it with a probe card according to the type, and conventionally, replacement was usually performed manually. Then, it is necessary that the probe card is mounted at a predetermined position on the X-axis and the Y-axis, and the pad of the wafer is at the correct position with respect to the probe card. In this case, the correction of the inclination angle θ of the position of the pad 11 of the wafer with respect to the probe card as shown in FIG. 9 has been performed by rotating the wafer chuck on the wafer mounting stage of the conventional wafer.

[Problems to be Solved by the Invention]

However, when the probe card is manually replaced, the test head is located above the probe card mounting portion, and the guide rails of the wafer stage are provided on the lower side, so the working space is narrow and Since the guard body of the card is attached to a ring structure called a replacement ring or the like, the card has a large weight, and there is a problem that the replacement work is troublesome. Further, in order to promote automation, it is very time consuming to correct the wafer tilt due to the inaccuracy of the probe card mounting position each time an individual wafer is inspected. It is required to correct the angle of the card as it is. SUMMARY OF THE INVENTION An object of the present invention is to provide a wafer prober which eliminates the above-mentioned conventional problems, allows easy replacement of the probe card, and can correct the angle of the probe card.

[Means for solving problems]

That is, the wafer prober of the present invention is a wafer prober for electrically measuring a wafer with a probe card provided below the test head, in which the probe card is fitted so as to detachably hold the probe card. A card chuck having an opening portion that has an inclined surface or a step of a lower pot at the opening edge of the opening portion, a stocker for storing a plurality of probe cards, and a probe held by the card chuck. A transfer mechanism for removing the card and exchanging it with the probe card in the stocker, and rotating the probe card held by the card chuck to align the θ rotation direction relative to the wafer mounting table. A rotation mechanism for performing the tilting of the card chuck on the outer peripheral portion of the probe card. An inclined surface or step corresponding to the inclined surface or step is formed, and when the probe card is fitted into the opening of the card chuck, the inclined surfaces or the steps are engaged with each other, so that the probe card is aligned with the card chuck. It is characterized by being performed.

[Action]

When certain types of wafers have been inspected and different types of wafers have been inspected, the transfer mechanism removes the probe card from the card chuck and returns it to the stocker, and then takes out a new probe card from the stocker and removes the card chuck. Fit into the opening. At this time, the inclined surface (or step) of the opening and the inclined surface (or step) of the probe card engage with each other, whereby the position of the central axis of the probe card with respect to the card chuck is automatically adjusted. Then, for example, the probe needle of the probe card and the wafer are brought into contact with each other, and the probe card is rotated based on the observation result of the trace of the needle to perform alignment in the θ rotation direction.
Therefore, the probe card can be automatically replaced, which is convenient, and the operation efficiency of the device is improved. If the central axis of the probe card with respect to the card chuck is automatically aligned with the inclined surface or the step, X and Y between the probe card and the wafer can be obtained when the wafer mounting table is at a predetermined position.
Since the relative positions in the directions match, the subsequent relative alignment between the probe card and the wafer becomes easier. For example, when observing a probe trace of a probe needle on a wafer with a camera or the like, it is possible to prevent the trace of the probe from falling within the visual field or recognizing a pad adjacent to a specific pad as a specific pad.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the wafer prober of the present invention. That is, 21 is a wafer chuck to which a wafer 23 is detachably attached.
Are mounted on a wafer mounting stage 25 that moves in the X-axis-Y-axis or θ-axis directions. This wafer stage 25
In the above, a probe card mount 27 is installed on the wafer 23 mounted on the wafer chuck 21, and a pair of card chucks 29 for sandwiching the probe card 31 from the side direction are attached to the probe card mount 27. ing. The pair of card chucks 29 are formed in an arc shape and advance and retreat in a direction in which they are opposed to each other at their opening portions. The probe card 31 having the probe needle 33 attached to the wafer 23 in a contactable manner is detachably attached to the card chuck 29. In the wafer prober as described above, the stocker 35 for the probe card 31 is provided in the wafer mounting stage 25. This stocker 35 is provided with a robot hand (not shown) that forms a transfer mechanism that can be swung or lifted up and down. The probe card 31 is extracted from the stocker 35 by a swiveling operation and lifted by a lifting operation to lift the probe card mounting base 27. It is designed to be attached from the bottom of the. As shown in the figure, the card chuck 29 is formed so that it can be pulled in on both sides to form an opening through which the probe card 31 can pass, and the opening surface has an inclined surface 37 that is a bottom jar. Further, the probe card 31 is also formed with an inclined surface 39 of a lower cavity corresponding to the inclined surface 37 around the probe card 31, and rises from the opening portion of the card chuck 29 to abut the probe card mounting base 27, In this state, the card chuck 29 advances to clamp the probe card 31. Reference numeral 41 is a replacement ring attached around the probe card 31.
The inclined surface 39 is formed on the replacement ring 41. The card chuck 29 is provided with a rotation mechanism for the probe card 31 including a worm gear 43. The worm gear 43 is driven by a stepping motor M or the like, and meshes with a gear 45 formed on the side surface of the replacement ring 41 to rotate the probe card 31 to a predetermined position. Next, FIGS. 5 to 8 show another embodiment of the wafer prober of the present invention. That is, 21 is the wafer 23
Is a detachably mounted wafer chuck, and the wafer chuck 21 is mounted on a wafer mounting stage 25 that moves in the X-axis-Y-axis or θ-axis directions. On the wafer mounting stage 25, a probe card mounting base 27 is installed on the wafer 23 mounted on the wafer chuck 21, and a card chuck 29 accommodating a probe card 31 can be slid on the probe card mounting base 27. Held in.
Reference numeral 30 is a slide guide that is clamped from both sides of the card chuck 29 and slides the card chuck 29. The pair of slide guides 30 are formed so as to face each other, and the slide portions 32 of the card chuck 29 are engaged with each other at their opening portions to move back and forth. The probe card 31 having the probe needle 33 attached to the wafer 23 in a contactable manner is detachably attached to the card chuck 29. In the wafer prober as described above, the stocker 35 of the probe card 31 is attached to the wafer prober.
The stocker 35 is provided with a robot hand 34 that can be swung or lifted up and down, and the probe card 31 is extracted from the stocker 35 by a swiveling operation, and the probe card 31 is moved up and down by moving along the support column 36 to lift it from the probe card mount 27 portion. The card chuck 29 is pulled out and mounted on the card chuck 29 from its upper surface. As shown, the card chuck 29 has an opening 38 into which the probe card 31 can be fitted, and the opening 38 has a step 37. Further, the probe card 31 is also formed with a step 39 of a lower bulge corresponding to the step 37 around the probe card 31, and the probe card 31 is fitted into the opening of the card chuck 29 and aligned by the guide pin 40, It can be moved to the probing center of the card mount 27. Reference numeral 41 is a replacement ring attached around the probe card 31. The step 39 is formed around the replacement ring 41. The probe card 31 mounted on the probing center of the probe card mount 27 is θ-corrected by the advancing / retreating mechanism 51 shown in FIG. 8 to perform predetermined probing. The advancing / retreating mechanism 51 is composed of a slide shaft 55 housed in a housing 53 provided with a stepping motor M, a long gear 57, and a transmission mechanism for transmitting the driving force of the motor M. The slide shaft 55 has a screw thread portion 61 formed on the periphery thereof and has a large-diameter gear 63 at the rear end. On the other hand, its tip projects from the housing 53 and contacts a lever 65 provided on the card chuck 29. Large diameter gear 63 is a long gear
It engages 57 and rotates while decelerating, and the slide shaft 55 advances and retracts in response to this rotation. A transmission mechanism for transmitting the driving force of the motor M is a timing belt 67 in the figure. Next, the operation of the wafer prober of the present invention will be described. In the first embodiment, when the predetermined inspection is completed, the type of the wafer to be inspected next is different from the types that have been used up to now, so it is necessary to replace the probe card 31 with the type. It was At this time, the corresponding probe card 31 is extracted from the stocker 35 of the probe card 31 by the robot hand or the like by the turning operation. Then, the robot hand is moved up and down to pass through the opening of the card chuck 29 in which an opening through which the probe card 31 can be passed is formed, and the probe card 31 is mounted on the probe card mounting base 27 from its lower surface. . After that, the card chuck 29 is moved forward to sandwich the probe card 31. Then, the motor M is operated to drive the worm gear 43 to rotate the probe card 31 to a predetermined position. Further, in the second embodiment, the corresponding probe card 31 is extracted from the stocker 35 of the probe card 31 by the robot hand 34 by the turning operation of 90 °. Then, by raising and lowering the robot hand, the probe card is moved in advance.
The probe card 31 is stored in the opening 38 of the card chuck 29 in which an opening 38 capable of storing 31 is formed, and the lower surface of the probe card 31 is slid on the probe card mounting base 27 and moved to the probing center for mounting. Next, the advancing / retreating mechanism 51 is driven, the θ of the probe card 31 is corrected, and then the probing is performed. After replacing the probe card 31 in this way,
According to the procedure shown in the figure, the probe card 31 and the wafer 23
Is relatively moved, for example, a position stored in advance by the wafer mounting stage 25, for example, X and Y amounts are moved, and after this movement, the probe needle 33 and the wafer 23 are relatively moved, for example, the probe needle 33 is moved. To contact the wafer 23 to form the needle marks A and B on the wafer 23 and confirm (positioning). Then, using the TV camera after the needle, the deviation from the predetermined position is calculated by the pattern recognition technique, and the probe card 31 and the wafer 23 are relatively moved so as to cancel the deviation, for example, the rotating mechanism. Then, the probe card 31 is rotated, and after correcting the predetermined angle θ, it is recognized that the deviation is eliminated and probing is performed. In the above embodiment, the chucking means of the probe card 31 is sandwiched from both sides, or is structured to be fitted into the opening portion, but of course the invention is not limited to such means, and other means may be used. You can also chuck.

【The invention's effect】

According to the present invention, a plurality of probe cards are stored in the stocker, and the probe card held by the card chuck is removed by the transfer mechanism and replaced with the probe card in the stocker. It is very convenient because the exchange work can be automated. Since the probe card rotation mechanism is provided, the probe card and the wafer can be aligned in the θ rotation direction, and the probe card can be engaged with the opening of the card chuck by the inclined surface or the stepped portion. Since the axes are automatically aligned, the subsequent alignment becomes easy as described in the section (action).

[Brief description of drawings]

FIG. 1 is a plan view of a probe chuck portion showing an embodiment of a wafer prober of the present invention, FIG. 2 is a sectional view thereof, FIG. 3 is a schematic sectional view of a wafer prober, and FIG. A flow chart, FIG. 5 is a perspective view showing another embodiment of the wafer prober of the present invention, FIG. 6 is a sectional view of essential parts, FIG. 7 is a plan view of the advancing / retreating mechanism, FIG. 8 is a sectional view of the advancing / retreating mechanism, Further, FIG. 9 is a plan view showing the inclination of the wafer. 21 ... Wafer chuck, 23 ... Wafer 25 ... Wafer mounting stage 27 ... Probe card mount 29 ... Card chuck, 30 ... Slide guide 31 ... Probe card, 32 ... Slide part 33 ... Probe needle, 34 ... Robot hand 35 ... Stocker , 36 ... Strut 41 ... Replacement ring, 43 ... Worm gear 45 ... Gear, M ... Motor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 61-4968 (JP, A) JP 62-298128 (JP, A) JP 63-244855 (JP, A) JP 63- 60542 (JP, A)

Claims (1)

[Claims] 1. A wafer prober for electrically measuring a wafer with a probe card provided on the lower side of a test head, wherein an opening portion into which the probe card is fitted so as to detachably hold the probe card. A card chuck having an inclined surface or a step of a lower cap formed on the opening edge of this opening, a stocker for storing a plurality of probe cards, and a probe card held by the card chuck. And a transfer mechanism for exchanging the probe card in the stocker, and a probe card held by the card chuck for rotating to perform relative position in the θ rotation direction with respect to the wafer mounting table. A rotation mechanism is provided, and an outer peripheral portion of the probe card corresponds to the inclined surface or the step of the card chuck. An inclined surface or a step is formed, and when the probe card is fitted into the opening of the card chuck, the inclined surfaces or the steps are engaged with each other, whereby the probe card is aligned with the card chuck. Wafer prober.