JPH10123207A - Lsi handler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the alignment of an LSI and a probe accurately for accurate probing to a miniaturized LSI electrode such as an area bump in the electric inspection of the LSI by an LSI tester. SOLUTION: An LSI 13, which is picked up from a tray part, is carried to a positioning stage part 2 by a handler part 9 at first. After one-side contact correction is performed with the outer-shape reference of an LSI package, the LSI is carried to the upper part of a CCD camera 4 in an image processing part. The bump-electrode image obtained by the slant illumination of an LED illuminating part 3 is binarized. The average center-of-gravity coordinates of each bump are computed and compared with the probing position coordinates stored beforehand. Thus, the amount of position deviation is computed, and the correcting movement is performed. After the positioning of the LSI 1 and the probe is completed by this procedure, the handler part 9 carries the LSI 13 to a socket part 10, and probing is performed to the LSI electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an LSI handler, and more particularly to an LSI handler capable of accurately transporting an LSI in which a fine area bump is used for an electrode and probing the LSI electrode.

[0002]

2. Description of the Related Art When an LSI electrical test is performed using an LSI tester, it is necessary to accurately probe LSI electrodes. Therefore, it is necessary to accurately align the position of the LSI electrode and the probe.
In the handler, use a guide pin and guide bush to
After performing rough alignment between the SI and the LSI socket, the LSI
The package outline is inserted into an LSI socket and probed while being positioned by a device guide.

FIG. 8 is a diagram showing a contact mechanism of a conventional LSI handler disclosed in Japanese Patent Application Laid-Open No. Hei 7-263596.

In this conventional example, the lead 204 of the LSI under test 200 attracted to the head 206 is connected to the LSI socket 2
01, a guide pin 208 attached to the base plate 209 for positioning so as to be surely inserted into the contact portion 203, a guide bush 207 attached to the plate 210 corresponding to the guide pin 208, and the LSI under test 200
And an LSI socket 201 into which the LSI under test 200 is inserted while being positioned at the contact position by the device guide 202 based on the mold section 205.

The LSI under test adsorbed on the head 206
00 is conveyed to a predetermined coordinate point on the socket 201 together with the plate 210 and the like. Thereafter, the guide bush 207 and the head 206 are lowered by pressurization.
The guide bush 207 descends while being guided by the guide pin 208, and the head 206 inserts the LSI under test 200 into the LSI socket 201. LSI under test 200
Is the device guide 202 based on the mold portion 205.
To the LSI socket 20 while performing alignment.
Inserted into 1 and probed.

[0006]

The above prior art has the following problems.

[0007] The first problem is that an LSI tester
When electrical inspection of SI is performed, it is necessary to accurately probe the LSI electrode, and therefore, it is necessary to accurately align the position of the LSI and the probe. Fine area bumps have been used in place of leads, and sufficient positioning accuracy cannot be obtained by a method of performing positioning using a guide based on the outer shape of an LSI package.

[0008] The reason is that the use of fine area bump electrodes requires higher positioning accuracy than before, but the required accuracy exceeds the manufacturing accuracy of the LSI package.
This is due to the inability to accurately probe the I electrode.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an LSI handler which measures and positions the position of an LSI electrode by image processing and accurately probes the LSI electrode in an LSI in which a fine area bump is used for the electrode. And

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an LSI for performing an electrical inspection of an LSI.
In an LSI handler that aligns a probe with an electrode, a tray section on which an LSI is mounted, a positioning stage section that performs positioning based on the outer shape of the LSI package, and a CCD camera section that captures miniaturized bump electrodes of the LSI as images. And the bump electrode has an arbitrary light amount,
An LED illumination unit for irradiating at an angle, an image memory board unit for storing a bump electrode image captured by the CCD camera unit, and ON / OFF and an amount of light of the LED illumination unit controlled by a parameter stored in advance to perform the image processing. In addition to controlling the writing / reading of the image to / from the board unit, the bump electrode coordinates are obtained by a binarization process from the bump electrode image stored in the image memory board unit, and the positional deviation correction amount from the previously stored probing position coordinates Is calculated,
An image processing unit having a central processing unit for transmitting to the handler control unit; a socket unit composed of a probe and an LSI socket; , And move by a previously stored movement amount to
The SI is conveyed onto the image processing unit, then the image is taken into the image processing unit, an image processing execution command is sent, and the handler is corrected and moved according to the correction amount calculated by the image processing unit, and then stored in advance. And a handler unit that moves the moving amount and contacts the probe, and a handler unit that moves with high accuracy in the X, Y, and θ directions according to a movement command from the handler control unit. It is characterized in that the tray, the positioning stage, the image processing unit, and the socket are transported while correcting the displacement of the LSI in this order, and the probe is used to probe the bump electrodes.

Further, as an LSI handler of the present invention,
Searching for the lower leftmost bump from the LSI bump electrode image transferred from the positioning stage to the image processing unit, and using this as the origin, searching for coordinates separated by the bump pitch in the X and Y axis directions, LSI transport correction means constituted by an automatic search algorithm for searching for bump electrode positions of image processing targets which are characteristically arranged, illuminating the LSI bump electrodes side-by-side using the LED illumination unit, and forming a plurality of bump electrodes , An average barycentric coordinate is calculated from each of the donut-shaped images obtained by performing the edge extraction, and the average barycentric coordinate is calculated at two specific locations with respect to one LSI. θ
A position shift correction means for calculating a position shift correction amount in the direction, and performing a correction movement in accordance with the direction, a teaching jig having a teaching hole having the same hole diameter at the same coordinate position as the LSI bump electrode on the metal plate at a normal probing position. Set and transported on the image processing unit by transporting the movement amount stored in advance by the handler unit in a direction opposite to the normal direction,
Outside of the LED illumination unit is coaxial epi-illumination.
Teaching means for performing image processing similar to the I-bump electrode image processing and storing the calculated coordinates as the probing position coordinates, and that the X-axis and Y-axis of the handler section and the socket section match each other. And the teaching jig is set on the socket section on the assumption that the X and Y axes of the handler section are orthogonal to each other. Then, the teaching jig is set on the image processing section by the handler section. Conveying, overlaying the camera coordinate axes on the image obtained from the CCD camera section,
The apparatus further comprises an axis aligning means for manually adjusting a camera position such that the camera coordinate axis in the image and the edge of the positioning pin hole of the teaching jig coincide with each other while slightly moving the handler section. It is.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an LSI handler according to the present invention.

The LSI handler of this embodiment is an LSI
A CCD camera unit 4 for capturing the miniaturized bump electrode 14 (FIG. 2) as an image, an LED illumination unit 3 for irradiating the bump electrode 14 with an arbitrary amount of light and an angle, and a bump electrode image captured by the CCD camera unit 4 The image memory board unit 5 for storing the image data 106 and the ON / OFF of the LED lighting unit 3 and the lighting parameters 105 which store the light amount are transmitted in advance, and the image is captured by the image control command 104 to the image processing board unit 5. / Read control and the image data 103 stored in the image memory board 5
, The bump electrode coordinates are obtained by binarization processing, and compared with the probing position coordinates stored in advance, the correction amount 102
An image processing unit 7 composed of a central processing unit 6 for calculating and transmitting the same to a handler control unit 8, a tray unit 1 on which an LSI 13 is mounted, a positioning stage unit 2 for performing positioning based on the LSI package outer shape, The LSI 13 picked up from the tray 1 is placed on the positioning stage 2
One-sided correction is performed based on the package outer shape, the LSI 13 is moved by a movement amount stored in advance, and is conveyed to the image processing unit 7.
1 and the correction amount 1 calculated by the image processor 7.
02, the handler unit 9 is corrected and moved, and then the previously stored movement amount is moved, and the handler control unit 8 that makes contact with the probe 11, the probe 11 and the LSI socket 1
2 and a handler unit 9 that moves in the X, Y, and θ directions with high accuracy in accordance with a control command 107 from the handler control unit 8.

The outline of the positioning operation of the LSI handler of the present invention will be described. FIG. 2 is a diagram showing how the LSI handler of the present invention is positioned.

The LSI 13 sucked from the tray unit 1 by the handler unit 9 and transported to the predetermined coordinates is lowered onto the positioning stage unit 2, and the edge of the positioning stage unit and the outer shape of the LSI 13 itself are drawn while being sucked. Use
One-sided correction is performed by pressing the LSI against the edge (see FIG. 2). After the completion of the rough positioning by the one-sided correction, the handler unit 9 rises while adsorbing the LSI 13 and the CCD camera unit 4
The LSI 13 is transported above. Of the LEDs arranged in the dome shape of the LED illumination unit 3, the edge of the LED is turned on, the LSI 13 is illuminated as side illumination, and the donut-shaped bump electrode image 106 is captured by extracting the edge of the bump electrode 14, which will be described later. Calculate the correction amount by image processing, X, Y, θ
Correction movement is performed in the direction. After that, the handler unit 9 conveys the determined movement amount, lowers the LSI 13 onto the socket unit 10, and makes the bump electrode 14 and the probe 11 contact.

Next, the calculation of the correction amount in the image processing section will be described with reference to the drawings.

FIG. 3 is a diagram showing an example of bump electrodes for image processing among bump electrodes of an LSI, and FIG. 4 is a diagram for explaining an automatic search algorithm for a target bump electrode in the image processing procedure. FIG. 5 is a diagram illustrating a correction amount calculated by the image processing unit.

The LSI 13 coarsely positioned by the positioning stage 2 is first processed by the handler 9 into the image processing area 1.
5 are transported so that the bump electrodes A to D to be subjected to image processing arranged diagonally to the LSI 13 enter. Thereafter, bump electrodes A to D to be subjected to image processing are searched from the bump electrodes (see FIG. 3) within the image processing range 15 in the following procedure. Here, since the positional relationship among the bump electrodes A to D to be subjected to image processing is known, if the position of the bump electrode A is obtained, the positions of the outer electrodes B to D can be easily obtained.

All the bump electrode images within the image processing range are binarized to determine the barycentric coordinates 19 of each bump electrode (see FIG. 4).

The lower left one is searched for among the coordinates of the center of gravity 19, and this is set as the origin 20.

A search area 16 corresponding to the size of one bump electrode is provided at a position shifted from the origin 20 by one grid of the bump electrode 14 in the Y direction, and the center of gravity coordinate 19 exists in the search area 16. judge. If it exists, it is further moved by one grid in the Y direction with reference to the barycentric coordinate 19, a search area 16 is provided, and the process of determining the presence or absence of the barycentric coordinate 19 in the search area 16 is repeated. The barycentric coordinates 19 are the bump electrodes A to be image-processed.

Based on the determined coordinates of the center of gravity of the bump electrode A, a search is performed in the X and Y directions based on a predetermined positional relationship among the bump electrodes A to D, and the bump electrodes B to D are searched.
Is searched for the barycentric coordinate 19 of.

After all the bump electrodes A to D have been searched, an average value 17 (average barycentric coordinate 1) of each barycentric coordinate is obtained.
Thereafter, the handler unit 9 holds the other bump electrodes E to H while sucking the LSI 13 (see FIG. 3).
Is moved so as to enter the image processing range, and the average value 18 of the barycentric coordinates (average barycentric coordinates 2) is obtained in the same procedure (see FIG. 5).

FIG. 5 shows the calculated average barycenter coordinates 17 and 18 and the LSI barycenter coordinates 2 and 3, which are the respective middle points, and the probing position coordinates 21 and 22, which will be described later, and the rotation center coordinate 24, which is the respective middle point. △ X, △ Y, and △ θ, which are the correction amounts 102, are calculated.

FIG. 6 is a diagram for explaining a procedure for obtaining the probing position coordinates 21 and 22 as a reference when obtaining the correction amount. FIG. 6 is a view showing the position of the socket section 10 in FIG.

A teaching hole 26 having the same diameter at the same coordinate position as the LSI bump electrodes A to H to be image-processed on the metal plate.
Open the teaching jig 25 with the positioning holes 28 and 29
And the positioning pin 27 are used to set the socket section 10 at a normal probing position, and the handler section 9 suctions the suction groove 30 where the center of the groove coincides with the center of gravity of the teaching jig. In the state where the coordinates of the center of gravity of the teaching jig 25 and the coordinates of the center of gravity of the teaching jig 25 coincide with each other, the moving amount stored in advance is transferred from the socket unit 10 toward the image processing unit 7 in a direction opposite to the normal direction. Except that the teaching hole 26 is projected in black by setting the LED illumination unit 3 to coaxial epi-illumination, image processing similar to the normal LSI bump electrode image processing is performed, and the calculated coordinates are stored as probing position coordinates 21 and 22. I do.

Here, the displacement correction amount obtained by the LSI handler for the displacement detection method by image processing is a numerical value on the camera coordinate axis, whereas the actual corrected movement amount is a numerical value on the robot coordinate axis. . Therefore, when the movement amount of the handler unit 9 is captured by the CCD camera unit 4, CC
It is necessary to make adjustments so that the reading on the D-camera becomes the moving amount of the handler unit 9 as it is.

FIG. 7 is a diagram showing an axis alignment procedure for simply matching the deviation Δθ between the CCD camera coordinate axis of the image processing section 7 and the robot coordinate axis of the handler section 9.

It is assumed that the horizontal (X) axis and the vertical (Y) axis of the handler section 9 and the socket section 10 match each other, and that the X and Y axes of the handler section 9 are arranged orthogonally. As a premise, the teaching jig 25 is set on the socket section 10, and then the teaching jig 25 is transported onto the image processing section 7 by the handler section 9, and the camera coordinate axis 31 is overlaid on the image obtained from the CCD camera section 4. First, the handler unit 9 is moved so that the camera coordinate axis 31 in the image matches the edge of the positioning hole 28 of the teaching jig 25. Thereafter, the handler unit 9 is moved in the X-axis direction.
Is moved little by little to project the camera coordinate axis 31 and the other positioning hole 29 of the teaching jig 25, and manually adjust the camera position so that the edges of both positioning holes 28, 29 coincide with the camera coordinate axis 31.

[0031]

The first effect is that the positioning is performed directly from the electrode to be probed, so that the positioning of the LSI electrode and the probe can be performed with higher accuracy than the conventional method without depending on the mechanical manufacturing accuracy of the LSI. Become.

The second effect is that positioning of the LSI is performed by binarizing only two specific portions of the LSI, and the image processing time is shorter than that of a positioning method based on pattern recognition performed by normal gray processing. Also, the scale of the image processing unit can be reduced.

The third effect is that the conventional LSI
Although the probe position image to be contacted with the image is individually captured, in the present invention, since the position to be aligned is previously stored with probing position data using a teaching jig, there is no need to capture the probe position image.
For this reason, it becomes possible to perform alignment only with the LSI image, and C
The number of image capturing systems such as a CD camera and LED lighting can be reduced to one, and the size and cost of the device can be reduced.

The fourth effect is that the LSI is not affected by variations in LSI storage positions in the tray. The reason is as follows.

For the method of positioning with a fine electrode image,
It is necessary to capture an image with a high-magnification lens, but since the field of view is narrowed, the allowable transport error range from the tray unit to the image processing unit is narrowed. Therefore, L
This is because the LSI can be conveyed within the allowable conveyance range by taking a procedure of conveying it to the image processing unit after performing one-sided correction based on the outer shape of the SI package and performing coarse positioning of the LSI.

The fifth effect is that the LSI is sucked and picked up from the tray portion by the handler portion, and after the LSI is picked up and picked up, the LSI is transported without reversing the LSI until it is stored in the storage tray until the LSI is stored in the storage tray. High-speed operation is possible, and the processing in the image processing unit is also fast,
Tact is short.

The sixth effect is that the image processing section is composed of a central processing section and an image capturing system, and the required space is small. Therefore, the image processing section can be easily incorporated into an existing handler. In addition, a small size and a low price can be realized in a short development period.

The seventh advantage is that the alignment of the image processing system and the handler system can be performed by a simple operation, so that maintenance is easy, and the image processing does not require the coordinate conversion processing of the image processing system and the handler system. Error factors are reduced, and calculation speed and processing speed can be improved.

The eighth effect is that an algorithm for automatically searching for bump electrodes to be image-processed when the LSI is transported within the allowable transport range in the fourth effect is incorporated. Accurate image processing can be performed without being affected by deviation and inclination within the range only by carrying.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an LSI handler of the present invention.

FIG. 2 is a diagram showing a state of positioning of an LSI in an LSI handler of the present invention.

FIG. 3 is a diagram showing an example of bump electrodes for image processing among bump electrodes of an LSI;

FIG. 4 is a diagram for explaining an automatic search algorithm for a target bump electrode in an image processing procedure;

FIG. 5 is a diagram illustrating a correction amount calculated by an image processing unit.

FIG. 6 is a diagram showing a procedure for registering a probing position serving as a reference for positioning.

FIG. 7 is a diagram showing a procedure for simply matching a camera coordinate axis with a robot coordinate axis of a handler unit.

FIG. 8 is a side view (A) and a perspective view (B) showing an LSI contact mechanism of a conventional LSI handler.

[Explanation of symbols]

 Reference Signs List 1 tray section 2 positioning stage section 3 LED lighting section 4 CCD camera section 5 image memory board section 6 central processing section 7 image processing section 8 handler control section 9 handler section 10 socket section 11 probe 12 LSI socket 13 LSI under test 14 bump electrode 15 Image processing range 16 Search area 17, 18 Average barycenter coordinate 19 Barycenter coordinate 20 Origin 21, 22 Probing position coordinate 23 LSI barycenter coordinate 24 Rotation center coordinate 25 Teaching jig 26 Teaching hole 27 Positioning pin 28, 29 Positioning hole 30 Suction groove 31 Camera coordinate axes

Claims (5)

[Claims] An LSI handler for aligning a probe with a bump electrode of an LSI for performing an electrical inspection of the LSI, comprising: a tray unit on which the LSI is mounted; and a positioning stage unit for positioning based on the outer shape of the LSI package. A CCD camera unit that captures an image of an LSI miniaturized bump electrode as an image, an LED illumination unit that irradiates the bump electrode with an arbitrary amount of light and an angle, and an image memory that stores a bump electrode image captured by the CCD camera unit A board unit, ON / OFF and an amount of light of the LED lighting unit are controlled by parameters stored in advance to control writing / reading of an image to / from the image processing board unit, and to control a bump electrode image stored in the image memory board unit. The bump electrode coordinates are obtained by binarization processing from the An image processing unit having a central processing unit for calculating a positional deviation correction amount from the placement coordinates and transmitting the correction amount to the handler control unit; a socket unit including a probe and an LSI socket; and an LSI picked up from the tray unit. The positioning stage unit performs one-sided correction based on the outer shape of the LSI package, moves the LSI by a previously stored movement amount, conveys the LSI onto the image processing unit, and then captures an image into the image processing unit, and issues an image processing execution command. Along with sending, according to the correction amount calculated by the image processing unit, after correcting and moving the handler, a handler control unit that moves a previously stored movement amount and contacts the probe, and according to a movement command from the handler control unit X, Y,
a handler unit that moves with high accuracy in the θ direction, and the handler unit conveys and moves while correcting the displacement of the LSI in the order of the tray unit, the positioning stage unit, the image processing unit, and the socket unit. And probing the bump electrode with the probe.
I handler. 2. Searching for a lower leftmost bump from an LSI bump electrode image conveyed from the positioning stage unit onto the image processing unit, and using this as the origin, coordinates separated by a bump pitch in the X and Y axis directions. LS constituted by an automatic search algorithm for searching for the position of a bump electrode to be image-processed, which is arbitrarily characteristically arranged, while searching
2. The LSI handler according to claim 1, further comprising an I transport correction unit. 3. An average center-of-gravity coordinate is calculated from each donut-shaped image obtained by illuminating the LSI bump electrode sideways using the LED lighting unit and extracting edges of a plurality of bump electrodes. Is performed at two specific locations for one LSI, and is compared with the probing position coordinates,
3. The LSI handler according to claim 1, further comprising a displacement correcting unit that calculates a displacement correction amount in the X, Y, and θ directions and performs a correction movement in accordance with the calculated amount. 4. A teaching jig having a teaching hole having the same hole diameter at the same coordinate position as that of an LSI bump electrode on a metal plate is set at a normal probing position, and a movement amount stored in advance by the handler unit is set to a normal value. The LED is transported on the image processing unit by transporting in the opposite direction,
4. The teaching device according to claim 1, further comprising teaching means for performing image processing similar to ordinary LSI bump electrode image processing except for setting the illumination unit to coaxial incident illumination, and storing the calculated coordinates as the probing position coordinates. LSI handler. 5. The teaching assuming that the X-axis and Y-axis of the handler section and the socket section match each other, and that the X and Y axes of the handler section are arranged orthogonally. A jig is set in the socket section, and then the teaching jig is transported to the image processing section by the handler section, and a camera coordinate axis is overlaid on an image obtained from the CCD camera section, and the handler section is slightly moved. 5. The LSI according to claim 1, further comprising an axis aligning means for manually adjusting a camera position such that the camera coordinate axis in the image coincides with an edge of a positioning pin hole of the teaching jig while moving. handler.