JPH04256331A - Adjusting method of position of probe card - Google Patents

Abstract

PURPOSE:To prevent an IC on a wafer from becoming defective when a probe at a probe card is aligned with a wafer to be measured by a method wherein the thickness of a wafer for contact-checking use is compared with the thickness of the wafer to be measured, a stage is moved according to their difference and a contact point is corrected. CONSTITUTION:A fundamental parameter is keyed in; after that, a wafer for contact-checking use is loaded on a stage; the thickness of the wafer is read out by using a capacity sensor at a prober and is stored in a memory at the prober as a first data. Then, the wafer is unloaded to a prescribed place. Then, a wafer to be measured is loaded; the thickness of the wafer to be measured is read out and stored in the memory as a second data. The computation of (second data)-(first data) is executed. In the case of a negative value, the stage is raised up to the position of (second data) + (difference). In the case of a positive value, the stage is raised up to the position of (second data)-(difference). Thereby, a correct contact point is decided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting the position of a probe card.

0002

2. Description of the Related Art As shown in FIG. 3, a conventional method for adjusting the position of a probe card involves bringing a profiler 1 into direct contact with a portion of a wafer to be measured 3 placed on a stage 2. As shown in FIG. 4, a wafer 3a coated with aluminum and having the same thickness as the wafer to be measured is placed on the stage 2, a needle sensor 4 is brought into contact with the wafer 3a, and a current is detected. The detection unit 5 of the prober detects that
The main method used is to detect the wafer and determine the contact point using the test head 6 and the tester body 7, as shown in Fig. 5. The probe 9 of the probe card 8 is set above the wafer 3a on which the same aluminum is deposited, and the test start (T-START) signal is sent from the prober to the tester body 7 through the test head 6, and the contact check program is run on the tester body 7. In this state, a rise signal is sent to the stage 2 of the prober, the stage 2 is raised, the tester body 7 determines the signal that the probe 9 of the probe card 8 has contacted the wafer 3a, and a test complete (T-COMP) signal is sent to the prober. Methods for determining contact points are also being used.

[0003] Instead of using the above method, there is also a method in which an operator determines contact points on a wafer to be measured based on experience and intuition.

[0004] Furthermore, as shown in FIG. 6, a method for determining the contact point without using a wafer to be measured is to enter the first basic parameter using the keys in the setup mode, and then set the contact check wafer on the stage. , the capacitive sensor of the prober reads the wafer thickness, and the data is automatically stored in the prober's memory, but at this time, the stage height display on the display panel is checked, the height display is recorded, and the wafer is then take out,
Interrupt the setup sequence. Next, set the wafer to be measured, load the wafer to be measured again in setup mode, read the thickness of the wafer placed on the stage, store the data in the memory of the device, perform alignment, and perform the following operations after completion. The operator determines the thickness of the wafer, and if it is not the same thickness as the wafer to be measured, calculates the difference in thickness, manually raises the stage, and if it is the same thickness as the wafer to be measured, raises the stage to the contact point. to rise. When we do not know the thickness of the wafer for contact checking, we use experience and intuition to raise the stage and find the contact point. Once the contact points were determined, the probes on the probe card and the electrodes on the IC chip were aligned, a five-point check was performed to confirm that they were aligned, and the setup was complete.

[0005]

[Problems to be Solved by the Invention] In the conventional probe card position adjustment method using a profiler, it is possible to detect either a wafer to be measured or an aluminum-deposited wafer, but when a wafer to be measured is used, There is a drawback that the IC in the center may become defective, and methods using needle sensors and test heads are limited to the use of aluminum evaporated wafers, so it is necessary to use a wafer with the same thickness as the wafer being measured. Wafers of various thicknesses have to be used depending on the product, which has the disadvantage of causing operational errors, significantly deteriorating the expensive probe cards, and lowering yields.

Furthermore, when a setup operation is performed without using a wafer to be measured, the setup operation must be interrupted midway and the setup operation must be restarted from the beginning, which has the disadvantage that the number of work steps cannot be reduced.

[0007] Furthermore, regarding the bump of TAB-IC,
Since this was not taken into consideration at all, there was a drawback that it was not possible to set the desired contact pressure.

[0008]

[Means for Solving the Problems] The probe card position adjustment method of the present invention involves transporting the wafer, placing the contact check wafer on a stage that can rotate and move up and down, and measuring the thickness of the wafer with a capacitive sensor. The first
data is stored in the control unit, the height (contact point) when the wafer is brought into contact with the probe card is stored in the control unit, the contact check wafer is replaced with the wafer to be measured, and the wafer thickness is measured. The apparatus includes means for storing second data obtained by measuring a contact point, comparing the first data and the second data, and correcting the contact point by moving the stage based on the difference.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a process diagram for explaining one embodiment of the present invention.

[0011] In the setup mode, first key input of basic parameters is performed, then a contact check wafer is loaded onto the stage from a specified location, the thickness of the wafer is read by the capacitance sensor of the prober, and the thickness is automatically stored in the memory of the prober. The first data is stored in the wafer, and then the contact check wafer is unloaded to a designated location.

Next, the set wafer to be measured is loaded, the thickness of the wafer placed on the stage is read, and second data is stored in the memory of the apparatus,
Perform alignment, compare the first data when using the contact check wafer and the second data on the measurement wafer, calculate (second data) - (first data), and calculate minus If so, the stage is raised to (second data) + (difference), and if it is positive, the stage is raised to (second data) - (difference) to determine the correct contact point. If the data are the same when compared, no calculations are performed and the stage is raised to the contact point, the electrode pads of the IC chip and the probes of the probe card are aligned, and a 5-point check is performed to confirm that they are aligned. , exit setup.

FIG. 2 is a process diagram for explaining a second embodiment of the present invention.

For TAB-ICs whose bumps protrude from the surface of the wafer, alignment can be performed by inputting the amount of protrusion into the basic parameters in order to determine the contact point that includes the bump height h. After that, determine whether the bump height data has been input as a parameter in advance, and if there is bump height data,
The wafer thicknesses of the second data and the first data are compared, and if they are the same, the stage is raised to (second data) -h, and if the thicknesses are different, (second data) - Calculate (first data) - h. If the result is negative, raise the stage to (second data) + (difference), and if positive, raise the stage to (second data) - (difference). After that, align the probes and bumps on the probe card, confirm that they are aligned using a 5-point check, and complete the setup operation. The presence or absence of bump data is determined, and if there is no bump data, the same steps as the flow after data comparison in the first embodiment are performed.

In the second embodiment, for devices such as TAB-ICs in which bumps protrude from the wafer surface, contact points including the bump height can be calculated by inputting the bump height as data in advance. There are advantages to being able to decide.

[0016]

Effects of the Invention As explained above, the present invention allows data on the thickness of a wafer for contact point checking to be handled in a series of flows, so alignment between the electrode pads of the IC and the probes of the probe card can be performed. When performing this process, there is an effect that ICs at the center of the wafer are not made defective.

[0017] Furthermore, since it has become possible to use wafers of any thickness for contact point checking, workability has improved and there is no need to significantly deteriorate the probe card or reduce yield. It also has the effect of eliminating

Furthermore, it is now possible to set the contact point including the bump height for items such as TAB-IC bumps that protrude from the wafer surface, making it possible to obtain the desired contact pressure. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a process diagram for explaining a first embodiment of the present invention.

FIG. 2 is a process diagram for explaining a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a first example of a prober.

FIG. 4 is a schematic diagram showing a second example of a prober.

FIG. 5 is a schematic diagram showing a third example of a prober.

FIG. 6 is a process diagram for explaining an example of a conventional probe card position adjustment method.

[Explanation of symbols]

1 Profiler 2 Stage 3, 3a Wafer 4 Needle sensor 5 Prober detection section 6 Test head 7 Tester 8 Probe card 9 Probe

Claims (1)

[Claims] 1. A contact checking wafer is placed on a stage that can transport the wafer and can rotate and move up and down, and a controller stores first data obtained by measuring the thickness of the wafer with a capacitive sensor, and the wafer is The control unit stores the height (contact point) when the contact check wafer is brought into contact with the probe card, stores second data obtained by measuring the thickness of the wafer by replacing the contact check wafer with the wafer to be measured; A probe card position adjustment method comprising comparing first data and second data and moving a stage based on the difference to correct a contact point.