JP7190100B2 - Prober and wafer chuck - Google Patents

Description

The present invention relates to a prober and its wafer chuck for electrically testing a plurality of chips formed on a semiconductor wafer.

In recent years, FOWLP (Fan Out Wafer Level Package) has attracted attention as a new package manufacturing method. The substrate may be manufactured in a square shape in addition to the conventional circular shape. Also, as a feature of FOWLP, one side is molded with resin, so warping will inevitably occur. Conventional chucks have grooves dug concentrically, and vacuum lines are connected to the grooves for chucking.

JP 2015-115376 A

Conventional chucks cannot correct warped wafers in the FOWLP, making it difficult to chuck them. SUMMARY OF THE INVENTION It is an object of the present invention to provide a prober and a wafer chuck that correct a warped wafer and attach it to the chuck for probing.

The present invention is a prober comprising a wafer chuck having a wafer holding surface and a probe guard having a plurality of probes arranged on a surface facing the wafer holding surface, wherein the wafer holding surface has a wafer holding surface. At a position near the outer periphery of the holding area, a positive pressure port opens obliquely toward the outside of the wafer holding surface to supply positive pressure air, and a negative pressure port opens at the wafer holding surface to supply negative pressure air. and a pressure port.

In the above prober, the negative pressure port opens at the bottom of a groove formed concentrically on the wafer holding surface of the wafer chuck, and supplies negative pressure air. It is preferred to have holes.

Moreover, it is preferable that the partial area is a semicircular area obtained by dividing the wafer holding surface.

The above prober controls a positive pressure air supply unit that supplies positive pressure air to the positive pressure port, a negative pressure air supply unit that supplies negative pressure air to the negative pressure port, and a negative pressure air supply unit. a controller for controlling the positive pressure air supply to start and stop supplying positive pressure air to the positive pressure port while causing negative pressure air to be supplied to the pressure port.

Moreover, it is preferable that the negative pressure air supply unit is configured with a plurality of different paths.

The present invention relates to a wafer chuck having a wafer holding surface, in which the wafer holding surface is opened obliquely toward the outside of the wafer holding surface at a position near the outer peripheral portion of the wafer holding area of the wafer holding surface, and a positive pressure is applied to the wafer holding surface. and a negative pressure port that opens at a wafer holding surface and supplies negative pressure air.

According to the present invention, warped wafers in the FOWLP can be straightened, and the warped wafers can be straightened and chucked to the chuck.

Top view showing the configuration of the prober 1 Top perspective view of wafer chuck 20 Cross-sectional view of wafer chuck 20 A diagram showing the principle of adsorption of a warped wafer W. A diagram showing the flow of adsorption of a warped wafer W. A diagram showing an example of a combination of ON/OFF patterns for positive pressure and negative pressure supply

Preferred embodiments of the prober according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a top view showing the configuration of a prober 1 according to an embodiment of the invention.

[Configuration of Prober 1]
The prober 1 is composed of a prober body 2 and a loader 3. A wafer chuck 20 holds a wafer W, and a probe card 10 electrically inspects a die (not shown) formed on the surface of the wafer W. , a wafer transfer means 100 for transferring the wafer W to the wafer chuck 20, and a wafer cassette 30 for accommodating the wafer W. As shown in FIG.

The wafer chuck 20 is mounted on a known moving stage (not shown) and can move in the prober main body 2 in three-dimensional directions.

The probe card 10 electrically tests the die by connecting the die to a tester (not shown) via the probes 210 . The probe card 10 is fixed at a predetermined position within the prober main body 2. When probing the wafer W, the wafer chuck 20 moves below the probe card 10, and the wafer chuck 20 rises. By approaching the probe card 10, the probes 210 are pressed against the die.

The wafer transfer means 100 comprises a holding arm 110, and a load arm 120 and an unload arm 130 as load/unload arms.

The holding arm 110 is attached to the side wall 2a of the prober main body 2 so as to be expandable. As a result, the prober main body 2 can be installed in a space-saving manner. The holding arm 110 receives the wafer W before inspection taken out from the wafer cassette 30 by the load arm 120 and transfers it to the wafer chuck 20 . The holding arm 110 also receives the wafer W after inspection from the wafer chuck 20 and transfers it to the unload arm 130 .

The load arm 120 and the unload arm 130 are attached to the tip of a robot (not shown) arranged in the loader section 3, and move between the prober body section 2 and the loader section 3 according to the expansion and contraction of the robot. can do. Although the load arm 120 and the unload arm 130 according to this embodiment are provided independently of each other, they may be integrated. By providing the load arm 120 and the unload arm 130 independently of each other, the holding arm 110 smoothly exchanges the wafer W after inspection and the wafer W before inspection, so that the wafer W can be taken out and accommodated smoothly. It can be carried out.

The load arm 120 carries the wafer W to be inspected stored in the wafer cassette 30 to the holding arm 110 .

The unload arm 130 receives the wafer W after inspection from the holding arm 110 and transports it to the wafer cassette 30 .

[Configuration of Wafer Chuck 20]
FIG. 2 is a top perspective view of the wafer chuck 20. FIG. The wafer chuck 20 includes vacuum paths 23 including five vacuum paths 23a, 23b, 23c, 23d, and 23e, and supply port groups 40a, 40b, 40b, and 40b corresponding to the five vacuum paths 23a, 23b, 23c, 23d, and 23e, respectively. A supply port group 40 consisting of 40c, 40d and 40e, an adsorption groove 19, a 12-inch Bernoulli port 41, an 8-inch Bernoulli port 42, a 12-inch Bernoulli path 43, and an 8-inch Bernoulli path 44 are provided.

The supply port groups 40a, 40b, 40c, 40d, and 40e are arranged only in Y of the semicircular partial regions X and Y obtained by dividing the wafer W holding surface 18 of the wafer chuck 20 in half. The supply port groups 40a, 40b, 40c, 40d, and 40e are arranged at regular intervals along circumferences having different diameters. This is to secure a larger vacuum suction flow rate when the warped wafer W is sucked onto the holding surface 18 . A suction area for 12-inch wafers W is concentrically inside the supply port group 40e, and a suction area for 8-inch wafers W is concentrically inside the supply port group 40c.

The more the supply port group 40, the higher the flow rate. However, since many other members are also arranged around the wafer chuck 20, the above arrangement of the supply port group 40 is preferable.

The 12-inch Bernoulli port 41 and the 8-inch Bernoulli port 42 are holes for blowing positive-pressure air to the outside of the holding surface 18 to produce the Bernoulli effect.

FIG. 3 is a cross-sectional view of wafer chuck 20. As shown in FIG. As shown in part (a) of FIG. 3, the vacuum path 23b is connected to the bottom of the suction groove 19 concentrically formed in the holding surface 18 by making a hole through the wafer chuck 20 from the side. The positions of the upper and lower holes connecting the suction groove 19 to the vacuum path 23, the valve 24 and the vacuum source 25 are different for the vacuum paths 23a to 23e. This figure shows the case of the supply port group 40b. As an example, the width of the suction groove 19 can be about 0.8 mm.

Also, as shown in FIG. 3B, the 12-inch Bernoulli path 43 is connected to the oblique hole 41 extending from the inside to the outside of the holding surface 18 of the wafer chuck 20 . As an example, the diameter of the hole 41 can be about 0.6 mm, and the angle between the hole 41 and the holding surface 18 can be about 22.5°. The 12-inch Bernoulli path 43 is also connected to the valve 26 and the air supply source 27 . Although not shown, oblique holes connecting the 8-inch Bernoulli port 42, the 8-inch Bernoulli path 44, the valve 26, and the air supply source 27 are also formed in the wafer chuck 20 in the same manner. The supply of negative pressure by the vacuum source 25 and the supply of positive pressure by the air supply source 27 are controlled by the controller 28 .

FIG. 4 shows the principle of adsorption of the warped wafer W to the wafer chuck 20 . When positive pressure air is blown out from the Bernoulli port 41 or 42, the air flow under the wafer W becomes faster, the pressure under the wafer W becomes smaller than the pressure above, and the downward force on the wafer W is increased. occurs (Bernoulli effect). Thereby, the warpage of the wafer W is corrected toward the holding surface 18 .

FIG. 5 shows the suction flow of the warped wafer W to the wafer chuck 20 . First, as shown in part (a) of FIG. 5, the warped center of the warped wafer W is sucked by the negative pressure supplied from the vacuum path 23 to the sucking groove 19 (step 1). As an example, the negative pressure is about -90 kPa.

Next, as shown in part (b) of FIG. 5, the wafer W is sucked by the negative pressure supplied from the vacuum path 23 to the sucking groove 19 from the center of the warp toward the outside (step 2). However, if the warp is strong, not all the outer sides of the wafer W are attracted.

Next, as shown in part (c) of FIG. 5, depending on the size of the wafer W, a positive pressure of about 0.4 MPa is applied to the Bernoulli port 41 for 12 inches or the Bernoulli port 42 for 8 inches for a short period of time (several tens of pressures). msec), and the Bernoulli effect is generated outside the wafer W, thereby correcting the warp on the outside of the wafer W (step 3). Since the negative pressure is still supplied from the vacuum path 23 during this time, the wafer W is attracted to the holding surface 18 almost simultaneously with the correction.

Finally, as shown in parts (d) and (e) of FIG. (Step 4). Actually, since the Y area closer to the supply port group 40 has a stronger attraction force to the attraction groove 19, the attraction of the wafer W starts from the Y area first as shown in FIG. As shown in part (e) of FIG. 5, the wafer W is also sucked in the X area. In addition, when the supply port group 40 is evenly arranged over the entire holding surface 18, any position of the wafer W is sucked at the same time.

Depending on the size of the wafer W, the controller 28 controls which of the 12-inch Bernoulli port 41 and the 8-inch Bernoulli port 42 to supply the positive pressure. FIG. 6 shows the ON/OFF pattern of the positive pressure supply to the 12-inch Bernoulli port 41 or the 8-inch Bernoulli port 42 according to the size of the wafer W and the ON/OFF pattern of the negative pressure supply by the vacuum path 23 . An example of a combination of off patterns is shown. The size of the wafer W is previously input to the control unit 28 by the user by operating a button or the like.

As described above, according to the prober 1 and the wafer chuck 20 of the present embodiment, the outer side of the warped wafer W is corrected by the Bernoulli effect, and the warped wafer W can be attracted to the holding surface 18 .

Reference Signs List 1 Prober 19 Suction groove 20 Wafer chuck 23 Vacuum path 40 Supply port 41 Bernoulli port for 12 inches 42 Bernoulli port for 8 inches 43 Bernoulli path for 12 inches 44 Bernoulli path for 8 inch

Claims (2)

A prober comprising: a wafer chuck having a wafer holding surface; and a probe guard having a plurality of probes arranged on a surface facing the wafer holding surface,
a positive pressure port for supplying positive pressure air to the wafer holding surface;
a negative pressure port for supplying negative pressure air from a plurality of supply port groups opened in a semicircular region obtained by dividing the wafer holding surface and which is a partial region of the wafer holding surface;
with
The plurality of supply port groups are arranged on the circumference of the wafer holding surface centered on the center position of the wafer holding surface and having different diameters from each other, and are arranged at equal angular intervals along the circumferential direction of the circumference. prober . A wafer chuck having a wafer holding surface, comprising:
a positive pressure port for supplying positive pressure air to the wafer holding surface;
a negative pressure port for supplying negative pressure air from a plurality of supply port groups opened in a semicircular region obtained by dividing the wafer holding surface and which is a partial region of the wafer holding surface;
with
The plurality of supply port groups are arranged on the circumference of the wafer holding surface centered on the center position of the wafer holding surface and having different diameters from each other, and are arranged at equal angular intervals along the circumferential direction of the circumference. wafer chuck .

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