JPH04355943A - Wafer prober - Google Patents

Abstract

PURPOSE:To facilitate an exchange work of a probe card and to make a stable probing test. CONSTITUTION:One pair of sliding guides 3a and 3b are provided on the lower surface of a probe card mount 1 installed on the side over a wafer chuck 2 in such a way that they are extended from a probing center to the end part of the mount 1. A card chuck 4 for holding detachably the probing center 5 is held by the sliding guides 3a and 3b via slide parts 41a and 41b and after the chuck 4 is moved from the probing center to the end part of the mount 1 along these sliding guides, the probe card 5 is exchanged. A positioning mechanism 7, which moves a lever 42 of said card chuck 4 for rotating the card 5 along with the mount 1, for example, is annexed to the chuck 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer prober for performing probe tests on semiconductor wafers.

0002

[Prior Art] In the manufacturing process of semiconductor devices,
After the IC chips are completed in the wafer, an electrical measurement test called a probe test is performed on each chip in the wafer by a wafer prober in order to eliminate defective chips before the assembly process.

The wafer prober includes a probe card equipped with a probe needle located above a wafer mounting stage, and a tester electrically connected to the probe card above the probe card by pogo pins or the like. For example, the wafer mounting stage is raised to bring the electrode pads of the chips inside the wafer into contact with the probe needles to perform electrical measurement and inspection, thereby determining the quality of the chips.

By the way, in this type of testing, it is necessary to replace the probe card with a probe card suitable for each type of IC chip, but in the probing center (the wafer measurement position), the test head is placed on the upper side. Further, since the wafer mounting stages are located on the lower side, the space for replacing the probe card is narrow, making automatic replacement difficult, and for this reason, conventionally, this has usually been done manually.

[0005] On the other hand, in order to improve work efficiency, efforts are being made to automate the work.
Publication No. 69341 discloses that a wafer chuck is shared for exchanging probe cards, the wafer chuck is moved in the X-Y direction by a mounting stage, and the probe card of the probing center is exchanged with another probe card in the storage device. The replacement technology is described.

[0006]

[Problem to be Solved by the Invention] However, when replacing the probe card manually as described above, the replacement work must be done in a narrow space between the test head and the wafer mounting stage, which is cumbersome. However, it also has the disadvantage of poor work efficiency.

[0007] Furthermore, in the method described in JP-A-62-169341, a protective plate is taken out from a storage device, carried to a probing center, a probe card is piled on the protective plate, and then transported to the storage device. Because of this, the wafer mounting stage must be moved back and forth twice for one exchange operation, and wafer exchange and probe card exchange cannot be performed at the same time, resulting in poor work efficiency. The structure is also complicated because a vacuum mechanism is required to attach and detach the probe card at the center.

Furthermore, as devices become more integrated, the number of electrode pads on the chip increases and their area becomes smaller, so the positional relationship between the probe card and the part where the probe card is mounted and fixed must be set very strictly. Even if the wafer stage side is precisely aligned in the X and Y directions, the contact position of the probe needle may not be appropriate for some of the electrode pad groups.

The present invention was made under these circumstances, and its purpose is to facilitate the work of replacing the probe card and to ensure that the probe needles and electrode pads are always in contact with each other. An object of the present invention is to provide a wafer prober that can perform stable probe tests.

0010

[Means for Solving the Problems] The present invention provides a wafer prober that performs electrical measurements on a wafer using a probe card attached to a probe card attachment section, in which a probe is inserted into the probe card attachment section laterally from a probing center. a holding guide mechanism provided to extend to a card attachment/detachment position; a card chuck for removably holding a probe card that is held and guided by the holding guide mechanism; A positioning mechanism that positions the probe card by rotating it around a central axis, and the probe card is replaced at the probe card attachment/detachment position.

[0011]

[Operation] When a probe test is completed on a certain wafer,
Next, when testing another type of chip, the card chuck located at the probing center is guided by the holding and guiding mechanism and moved to the probe card attachment/detachment position. Next, the probe card is removed from the card chuck manually by the operator or by a transfer mechanism installed separately and stored in the stocker, and then another probe card is taken out from the stocker and held in the probe card, and the holding guide mechanism to move the card chuck to the probing center. After that, for example, once the wafer and the probe needle are brought into contact with each other and the amount of positional deviation is checked from the needle trace, the card chuck is rotated by the positioning mechanism to position the probe card.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the entire embodiment of the present invention, FIG. 2 is a vertical side view showing a state in which a probe card is held on a card mount, and FIG. 3 is a plan view of the probe card. Reference numeral 1 denotes a probe card mount serving as a probe card mount, which is installed above the wafer chuck 2. The probing center of the probe card mount 1 has a probe needle of a probe card, which will be described later, and a probe inside the wafer. A viewing window 11 is formed for checking the positional relationship with the electrode pad using, for example, a TV camera. Further, the wafer chuck 2 is provided on a wafer mounting stage 21 that is movable in the X and Y directions, so as to be movable in the height direction and rotatable around a vertical axis.

[0013] On the bottom surface of the probe card mounting base 1,
A pair of mutually opposing L-shaped slide guides 3a and 3b, which form a holding and guiding mechanism for a card chuck to be described later, are arranged so that they extend laterally from the probing center to the probe card attachment/detachment position, for example, the end of the probe card mount 1. It is set in.

A card chuck 4 is held in the slide guides 3a, 3b via a pair of inverted L-shaped slide parts 41a, 41b.
41b is provided with two pairs of pairs facing each other on the upper surface of the card chuck 4 in the horizontal direction. Here, in this example, the slide guides 3a, 3b and the card chuck 4
The slide parts 41a and 41b function as a stator and a rotor of a linear motor, respectively, and constitute a transport mechanism for accurately and quickly transporting the card chuck 4 between the probing center and the end of the probe card mount. It is something. Note that in the present invention, the card chuck 4 is manually moved to the slide guides 3a, 3 without using such a conveying mechanism.
It may be moved along b.

The card chuck 4 is formed in a circular shape and includes a lever 42 protruding from the side, and further has a stepped portion 43 (not shown in FIG. 1) on the inner circumferential surface in the center. An opening 44 is formed. The opening 44 of the card chuck 4 has a probe needle 51 on the bottom surface.
A probe card 5 equipped with a probe card 5 is detachably held via a replacement ring 6, and the replacement ring 6 has an inner surface and an outer surface that correspond to a step on the outer peripheral surface of the probe card 5 and a step in the opening 44, respectively. It has a shape that is engaged with the portion 43.

Also, the outer peripheral surface of the replacement ring 6 and the opening 4
4 have positioning pins 6 that engage with each other.
1 and a recess 45 are formed, and recesses and protrusions (not shown) that engage with each other for positioning are also formed on the inner circumferential surface of the replacement ring 6 and the outer circumferential surface of the probe card 5, respectively. By engaging these concave portions and convex portions with each other, and by engaging the pin 61 and the concave portion 45 with each other, the positioning of the probe card 5 in the rotational direction (direction around the vertical axis) with respect to the card chuck 4 is automatically performed. It is carried out according to

On the other hand, the lever 42 of the card chuck 4 is provided with a lever for rotating the probe card 5 around its central axis (center vertical axis) to position the probe card 5 when the probe card 5 is located at the probing center. A positioning mechanism 7 is provided in combination. As shown in FIG. 4, for example, the positioning mechanism 7 includes a long gear 72 provided in a housing 71, and a main body that meshes with the long gear 72 and moves in the length direction of the gear 72. diameter gear 7
3, a slide shaft 75 having one end attached to the gear 73 and having a screw threaded portion 74 formed on the outer periphery and sliding in the length direction while being screwed into the housing 71; and a slide shaft 75 that drives the long gear 72. A stepping motor M is attached to the housing 71 via a transmission mechanism 76 so as to do so.

The other end of the slide shaft 75 protrudes from the housing 71 so that, for example, the tip thereof is connected to the lever 42.
When the motor M is driven, the gears 72 and 73
It is designed to quickly deviate and extend or retract. As the slide shaft 75 extends and retracts, the lever 42 also moves forward and backward, and as a result, the card chuck 4 rotates together with, for example, the probe card mounting base 1.

In this case, the positioning mechanism 7 is configured to be fixed to the floor surface when the probe card 5 is located at the probing center, and the positioning mechanism 7 is configured such that it is fixed to the floor surface, for example, and a coiled spring is attached to the probe card mounting base 1. The lever 42 can be moved forward and backward by combining the above-mentioned elements so that the lever 42 always presses the tip of the slide shaft 75 by its restoring force. Alternatively, instead of having such a configuration, for example, a wide groove at the back is formed in the lever 42, and the tip of the slide shaft 75 is formed in a shape that fits the groove, so that the tip of the slide shaft 75 fits inside the groove. Alternatively, the lever 42 may be engaged so as to be rotatable and not detachable, and the lever 42 may be moved forward or backward in accordance with the extension or retraction of the slide shaft 75.

As for the structure in which the card chuck 4 rotates, for example, a fixed frame may be installed on the floor and the probe card mounting base 1 may be rotatably mounted on this fixed frame. It may be divided into upper and lower halves, and the lower side thereof may be rotated relative to the upper side.

[0021] Also, the end of the probe card mount 1 (
A stocker 8 equipped with a multi-stage storage table 81 is installed in the vicinity of the probe card attachment/detachment position for storing a plurality of probe cards. A transfer mechanism 9 is provided for removing the probe card 5 and replacing it with the probe card 5 in the stocker 8. The transfer mechanism 9 includes a lifting platform 92 that is raised and lowered along a column 91 by a lifting mechanism (not shown), and a robot hand that is attached to the lifting table 92 and has the function of sucking and holding the upper surface of the probe card 5 and rotating it. 93
It consists of

Next, the operation of the above embodiment will be explained. When a different type of chip is subsequently tested after a probe test has been completed on a certain wafer, first the card chuck 4 is moved from the probing center along the slide guides 3a and 3b using the driving force of the linear motor as described above. At the same time, the elevating table 92 is raised to a predetermined height position by a lifting mechanism (not shown), and the tip of the robot hand 93 is positioned above the card chuck 4. Then, the robot hand 93 is lowered by the lifting mechanism to release the probe card 5 held in the card chuck 4.
together with the replacement ring 6 is suctioned and held on the robot hand 93 from its upper surface side. Thereafter, the robot hand 93 is raised to remove the probe card 5 and the replacement ring 6 from the opening 44 of the card chuck 4, and the robot hand 93 is rotated toward the stocker 8 and the probe card 5 and replacement ring 6 are placed in a predetermined storage table 81. After placing it, the suction holding effect is released.

Thereafter, the robot hand 93 sucks and holds a predetermined probe card 5 stored in another storage table 81 together with the replacement ring 6 from its upper surface side, and rotates and lifts the probe card 5 and the replacement ring 6. ring 6
the pin 61 into the opening 44 of the card chuck 4, and the pin 61 into the recess 4.
After the card chuck 4 is inserted and stored in a state in which it is engaged and positioned inside the card chuck 5, the card chuck 4 is conveyed along the slide guides 3a and 3b to the probing center by the driving force of the linear motor.

After replacing the probe card 5 in this way, connect the terminal section (not shown) of the probe card 5 to the electrical connection section (not shown) of the test head T, and then follow the procedure shown in FIG. 5, for example. The probe needles 51 of the probe card 5 and the wafer W are aligned. That is, after aligning the wafer W, it is held on the wafer chuck 2 of the wafer mounting stage 21, and then the wafer W is held on the wafer chuck 2 of the wafer mounting stage 21.
After moving the wafer by a pre-stored amount of X and Y (movement amount in the The deviation from a predetermined position captured by a TV camera is calculated, and the positioning mechanism 7 moves the lever 42 of the card chuck 4 forward and backward to offset this deviation, thereby moving the probe card 5 together with the probe card mounting base 1, for example. After rotating the wafer W by an angle of about 1 to 2 degrees and confirming that the positional deviation has been resolved by bringing the wafer W and the probe needles 51 into contact in the same manner, a probe test is performed, that is, the probe needles 51 and the electrode pads of the chips of the wafer W are brought into contact with each other. A predetermined electrical characteristic test is performed by contacting the

In the present invention, a groove is formed on the lower surface of the probe card mount 1, and an engaging portion that engages in this groove is attached to the card chuck 4 to hold and guide the card chuck 4. Various mechanisms can be adopted as the mechanism, and as for the structure in which the probe card 5 is held by the card chuck 4, the probe card 5 is fitted into the opening 44 of the card chuck 4 via the replacement ring 6. It is not limited to those that cause
Furthermore, the shape and structure of the probe card mount 1 can also be adapted to accommodate the surrounding space, the structure of the test head, and the like.

In the present invention, moving the probe card 5 between the probing center and the attachment/detachment position may be done manually or by moving the probe card 5 placed in the attachment/detachment position. The work of removing the probe card from the card chuck 4 and replacing it with another probe card may also be performed manually.

[0027]

As described above, according to the present invention, the probe card mounting base holds the probe card through the card chuck and moves laterally from the probing center to the attachment/detachment position, and at the attachment/detachment position, the Since the probe card is replaced, the mechanism required for replacement is much smaller than when replacing the probe card in the narrow space sandwiched between the test head and the wafer mounting stage.
The structure becomes simpler and the work becomes easier.

Since the probe card is rotated through the card chuck by the positioning mechanism, the position of the probe card in the rotational direction relative to the wafer can be finely adjusted, so that the probe needle is always aligned with the electrode pad of the chip. Proper contact can be made and stable measurements can be made.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a longitudinal side view showing a state in which a probe card is held on a probe card mounting base.

FIG. 3 is a plan view showing the probe card.

FIG. 4 is a sectional view showing a positioning mechanism.

FIG. 5 is a flow diagram showing the flow of positioning a wafer and a probe card.

[Explanation of symbols]

1 Probe card mounting base 2 Wafer chuck 3a, 3b Holding guide mechanism 4 Card chuck 41a, 41b Slide part 5 Probe card 6 Replacement ring 7 Positioning mechanism 8 Stocker 9 Transfer mechanism

Claims (1)

[Claims] 1. A wafer prober that performs electrical measurements on a wafer with a probe card attached to a probe card attachment part, the probe card attachment part including:
a holding guide mechanism provided to extend laterally from the probing center to a probe card attachment/detachment position; a card chuck guided by the holding guide mechanism to detachably hold the probe card; A wafer prober comprising: a positioning mechanism for positioning the probe card by rotating the card chuck around the central axis of the probe card, and replacing the probe card at the probe card attachment/detachment position.