JP2876171B2 - Inspection methods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method.

[0003]

2. Description of the Related Art In the recent semiconductor field, a plurality of chips having different functions are mounted on a multilayer ceramic substrate provided with internal wiring in order to cope with an increase in the speed and complexity of arithmetic processing. The use of such modules as a chip array directly as a module is gradually increasing, and it is strongly desired that such a semiconductor module be used for a secondary inspection.

[0004] The secondary inspection of such a semiconductor module is carried out by inspecting the bonding state of each chip, the wiring state in the multilayer ceramic substrate, and the like. It is also necessary to inspect the basic performance of each chip having different standards and specifications (the number of electrode pads, electrode pad arrangement, etc.) and the operating characteristics in an intermediate process from input to output. In order to carry out such secondary inspection of semiconductor modules, probe pins are individually contacted with high precision to the electrode pads of each chip having different standards as described above, and the electrical contact with the tester side is made. Connection must be made. In response to such demands, conventional mounting board inspection equipment has not been able to say that probe pins are brought into contact with the electrode pads of individual chips with high accuracy. Inspection efficiency is expected to decrease by simply using the prober technology.

That is, in the current prober technology, the alignment between the electrode pads of each chip and the probe pins, that is, so-called fine alignment, is performed by visual observation or image recognition using a microscope. However, in the semiconductor module described above, since chips of different standards are mounted, fine alignment between the contact terminals corresponding to each chip and the chip must be performed, and the time required for alignment is long. This greatly increases the inspection efficiency.

[0006]

SUMMARY OF THE INVENTION As described above, a plurality of semiconductor modules having different standards are mounted on a substrate provided with internal wiring to enable operation as a module. In order to improve the inspection accuracy, it is inevitable that a probe pin should be brought into electrical contact with the electrode pad of the chip with high accuracy. In addition, in order to improve the inspection efficiency, it is necessary to accurately and quickly align a plurality of chips having different standards with the contact terminals corresponding to the respective chips. There is a strong demand for the development of semiconductor module inspection methods.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and eliminates the need for individual positioning of a plurality of test objects provided on a substrate having different standards, thereby achieving high accuracy in a short time. It is an object of the present invention to provide an inspection method capable of performing the above-described alignment and improving inspection efficiency while satisfying high inspection accuracy.

[Structure of the Invention]

[0009]

That is, according to the present invention, when a test terminal is brought into contact with electrode terminals of a plurality of test objects provided on a substrate and a predetermined test of the test object is performed, the test terminal is mounted on the substrate. A plurality of reference targets are provided in advance at predetermined positions of the substrate, and the reference targets of the substrate in an inspection standby state are provided.
Imaging the image and determining the position as a coordinate position on the substrate side; and correcting the correction mark provided on the inspection terminal side.
Image is taken and its position is calculated based on initial alignment.
Coordinate position on the inspection terminal side obtained as the distance from the reference point
And setting a position of the device under test provided on the substrate with obtaining coordinate information indicating based on the reference target, from the coordinate information and the coordinate position of the test terminal side, the obtaining step body and <br/> step of aligning said test terminal, the previous SL inspection terminal into contact with the electrode terminals of the obtaining step body, is characterized by a step of performing the inspection.

[0010]

A reference target indicating the position of the object to be inspected is previously provided on a substrate provided with a plurality of objects to be inspected.
The position of the get is obtained as a coordinate position on the inspection terminal side. The coordinate position of the measured reference target on the inspection terminal side,
By performing coordinate conversion on the coordinate position of the reference target on the substrate obtained as information, the position of the inspection object can be obtained as the coordinate position on the inspection terminal side. Therefore, by moving the inspection terminal based on the position of the inspection object based on the inspection terminal-side coordinates, the electrode terminals of each inspection object can be adjusted without performing detailed alignment of each inspection object by visual inspection or the like. Accurate alignment with the inspection terminal can be performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the inspection method of the present invention is applied to an inspection apparatus for semiconductor modules will be described below with reference to the drawings.

1 and 2 are diagrams schematically showing the configuration of an embodiment of an inspection apparatus to which the method of the present invention is applied. The apparatus main body 1 transports and transports a semiconductor module 2 to be inspected. An inspection unit 10 for performing a predetermined inspection in a non-conductive liquid on a work 3 in a testable state, and a semiconductor module 2 having a plurality of test objects, for example, semiconductor elements arranged on a substrate. A plurality of inspection contact terminals corresponding to a semiconductor element (hereinafter, referred to as a chip) are accommodated therein, and the inspection terminal supply unit 20 for exchanging and aligning the plurality of contact terminals is provided. The work 3 is loaded from the work set table 31 to the end of the
A walker section 30 for unloading the cassette table 31 is detachably provided. Further, on the apparatus body 1 and the walker section 30, a walker section 30, an inspection section 10, and an inspection terminal supply section 20 are provided, respectively.
A work transport mechanism 40 and an inspection terminal moving mechanism 50 that can move in the parallel direction (hereinafter, referred to as X direction) are mounted on the tower.

The work 3 is, for example, as shown in FIG. 3, a lower part of the semiconductor module 2 constituted by bonding a plurality of, for example, 36 chips 2a on a multilayer ceramic substrate 2b having internal wiring. In addition, a socket 4 and a socket board 5 which are in electrical contact with the respective input / output pins (not shown) of the semiconductor module 2 are arranged, and a pressing plate 6 and an O-ring are provided on the outer peripheral side of the semiconductor module 2. 7
Thus, a support board 8 serving as a clamp portion in which a liquid-tight seal is formed is arranged. Although not shown, a measurement electrode pad is provided around the chip 2a, an alignment target is provided at three corners on the upper surface of the multilayer ceramic substrate 2b, and a thermal expansion correction target is provided at two diagonal corners on the lower surface. The support board 8 is provided with positioning holes at four corners on the lower surface thereof.

The inspection unit 10 includes a base 1 a of the apparatus main body 1.
A square-shaped wire having a tank outer wall 11a and a tank inner wall 11b protruding from the upper surface side of the inspection unit base 11 installed thereon, and a seal portion formed of, for example, neoprene rubber or the like.
It has a liquid tank 13 formed by the work mounting table 12 and the work 3 itself, and the work 3 is formed with a clamp 14 so as to form a liquid-tight seal on the work mounting table 12. Is tightly fixed. Then, the work 3 is immersed in the non-conductive liquid injected into the liquid tank 13, and the inspection is performed in that state.

Below the opening of the work mounting table 12 in the shape of a square, a number of not shown illustrations for inserting and electrically connecting to the socket board 5 of the work 3 are provided. A work set base unit 15 having pins protruding therefrom and a lower alignment camera 16a, 16b provided in accordance with the formation position of a pair of thermal expansion correction targets provided on the lower surface of the ceramic substrate 2b of the work 3. Is arranged.

The inspection terminal supply unit 20 has a plurality of probe pins implanted in accordance with the shape and pitch of measurement electrode pads formed around the chip 2 mounted on the semiconductor module 2. A plurality of pin block changers 22 for individually holding the pin blocks 21 and a pin block for checking the holding state of the pin blocks 21 transferred to the inspection terminal moving mechanism 50 side and calculating the relative distance between the pin blocks 21 and an upper alignment camera described later. And a correction camera 23.

The pin block changer 22 includes a holding portion 24 for holding the pin block 21 and a holding portion 24.
Is raised to the inspection terminal moving mechanism 50 side, for example, and the cylinder mechanism 25. The used pin blocks 21 are individually raised according to the inspection program and supplied to the inspection terminal moving mechanism 50.

The work transport mechanism 40 includes a loader base 32.
The rails 32b and 1b provided on the upper surface of the base 1a of the apparatus main body 1 and connected in the X direction can be moved along the X direction. A holding unit 41 that can be transported between the printer unit 30 and the inspection unit 10.

The inspection terminal moving mechanism 50 is a rail 1
X stage 51 having a square shape mounted on b,
A rectangular Y stage 52 having a similar opening area disposed on the X stage, and a Z stage disposed in the openings of the X stage 51 and the Y stage 52. 5
3, the measuring head 54 fixed to the Z stage 53 is configured to be movable in the XYZ directions.

The measuring head 54 includes a pin block 2
1 and a top alignment camera 56 for obtaining the position of the chip 2a mounted on the semiconductor module 2 by imaging a reference target formed on the multilayer ceramic substrate 2b. ing. The chuck portion 55 is rotatable by a θ drive mechanism (not shown). Then, the pin block 21 held by the chuck portion 55 is moved down to the inside of the liquid tank 13 of the inspection section 10 by the Z stage 53 so that the pin block 21 contacts the work 3 immersed in the liquid tank 13. Done.

The measuring head 54 is provided with a non-conductive liquid introducing pipe 57 connected to a cooling mechanism (not shown) in the vicinity of the chuck section 55, and above the chuck section 55. Is provided with a pin plate 21 and a touch plate connected to a tester (not shown).
The electrical connection between the pin block 21 and the tester is made by this touch plate.

An inspection procedure in the semiconductor inspection apparatus having the above configuration will be described below. First, the work set table 31
The work 3 placed in the storage section of the
Is transported onto the work table 12 of the inspection unit 10. At this time, the inspection terminal moving mechanism 50 moves to the contact terminal supply unit 20 side.

Next, the work transfer pin 17 is lifted, and the tip of the work transfer pin 17 is inserted into a positioning hole formed at each of the four corners on the lower surface of the support board 8, and the work transfer pin 17 is inserted. The work 3 is mounted on the work mounting table 12 while positioning the work 3. The work 3 mounted on the work mounting table 12 is fixed in a liquid-tight manner by a clamp 14 and the work 3
Work set base on socket board 5 and inspection unit 10 side
The storage unit 15 is electrically connected. At this time, the lower alignment cameras 16a and 16b take an image of the thermal expansion correction target provided on the lower surface of the multilayer ceramic substrate 2b of the work 3, and recognize the initial position of the multilayer ceramic substrate 2b.

Around the setting of the work 3, the pin block 21 is mounted. At first, the pin block 21 is automatically mounted in accordance with the inspection program, and the pin block 21 corresponding to the chip 2a to be inspected first is automatically mounted.
The inspection terminal moving mechanism 50 is moved so that the chuck portion 55 is located above, and a predetermined pin block 21 is held.

Next, the holding state of the pin block 21 is checked (pin block alignment), and the work 3 held by the inspection unit 10 is aligned with the pin block 21 (work piece alignment).
Alignment) is performed in order. Each of these alignments will be described with reference to FIGS.

First, initial alignment is performed prior to pin block alignment. In this initial alignment, an initial target (not shown) projecting from the apparatus main body 1 onto the pin block correction camera 23 is fixed to a pin block correction camera 23 fixed at a predetermined position and an upper alignment camera. 56, the reference position of the upper alignment camera 56, for example, the image center is made coincident with the image center of the pin block correction camera 23 and focused, and the inspection terminal moving mechanism at the image center of the upper alignment camera 56 at that time X on the 50 side
-Store the position coordinates in the YZ stage coordinates (hereinafter referred to as measurement-side coordinates) as reference coordinates. Here, the Z coordinate can be obtained by, for example, the focal length.

Next, as shown in FIG.
The chuck unit 55 holding 1 is moved onto the pin block correction camera 23 to perform pin block alignment. This pin block alignment, as shown in FIG.
A correction mark 21b, such as a diameter, provided at a predetermined position of a corner, for example, a predetermined distance from each corner on a diagonal line
This is performed by taking an image of a hole of about 0.3 mm with the pin block correction camera 23 fixed at a predetermined position.

That is, the correction marks 21b provided at the four corners are imaged by the pin block correction camera 23, and their positions are distances in the X, Y, and Z directions from the reference coordinates obtained by the above initial alignment. Asking.
Next, the center of the pin block 21 is calculated from the position information of these four correction marks 21b, and the coordinates of the center of the pin block 21 and the image center of the upper alignment camera 56 obtained by the initial alignment are measured. The relative positional relationship above is determined, and the pin block 21
Is determined in the θ direction.

After the pin block alignment is completed,
The inspection terminal moving mechanism 50 moves to the upper side of the inspection unit 10, and the work alignment is performed. In this work alignment, first, as shown in FIG. 4, the alignment targets 2c provided at the three corners of the multilayer ceramic substrate 2b are respectively imaged by the upper alignment camera 56, and alignment images are obtained from these images. The position of the target 2c is detected as position coordinates on the measurement side coordinates.

Here, each chip 2a is mounted on the multilayer ceramic substrate 2b based on the positions of the three alignment targets 2c, and is placed around the chip 2a on the ceramic substrate 2b. The position of the formed measurement electrode pad 2d is determined by three alignment targets.
For example, position coordinates on the manufacturing apparatus side based on the position of the get 2c are previously input to a control unit (not shown) of the semiconductor module inspection apparatus.

The position of the alignment target 2c input in advance and the position coordinates of the alignment target 2c detected by the upper alignment camera 56 in the measurement side coordinates are coordinate-converted, and the coordinates in the measurement side coordinates are converted. The position of the measurement electrode pad 2d is calculated. Next, the probe position of the pin block 21 is determined based on the relative distance between the upper alignment camera 56 and the pin block 21 obtained by the pin block alignment according to the position coordinates of the measurement electrode pad 2d of the chip 2a, and X The stage 51, the Y stage 52, and the θ stage 55a are driven to drive a probe electrode 2d formed around the chip 2a and a probe implanted in the pin block 21.
The bupin 21a is aligned.

After the completion of the work alignment, for example, a fluorine-based inert liquid is supplied into the liquid tank 13 from the non-conductive liquid introducing pipe 57, and the work 3 is immersed in the non-conductive liquid. State.

Thereafter, the non-conductive liquid is applied to the chip 2 to be measured.
The Z-stage 53 is driven and the measuring head 54 is lowered by driving the Z stage 53 so that the probe pin 21a of the pin block 21 is immersed in the non-conductive liquid while the measuring electrode pad is being supplied. Contact 2d. Then, a test voltage is supplied to the semiconductor module 2 to inspect the chip 2a.

With the above operation, the inspection for one chip 2a is completed. Next, when chips 2a of the same standard are present in the semiconductor module 2, first, the lower alignment cameras 16a and 16b confirm whether or not there is any deviation from the initial position of the multilayer ceramic substrate 2b due to thermal expansion or the like. After the contact position of the pin block 21 is corrected accordingly, the next chip 2a is similarly inspected.

After the completion of the chip of the same standard, if there is an untested chip 2a, the inspection terminal moving mechanism 5
0 is moved to a position above the inspection terminal supply unit 20, the pin block 21 is replaced, the pin block alignment step is performed according to the same procedure, and the chip 2a is inspected according to the position information obtained by the work alignment. carry out.

After the inspection of all the chips 2a is completed by repeating the above steps, the non-conductive inert liquid is discharged from the liquid tank 13, and after the liquid is discharged, the word moved to the upper part of the inspection section 10. Work transfer pin 17 to work transfer mechanism 40
The work 3 is transferred. Then, the work transport mechanism 40 is moved to the work loader section 30 to carry out the work 3, and a series of inspection steps is completed.

As described above, the semiconductor module of this embodiment is
In the inspection device, the upper alignment camera 56 is mounted on the measuring head 54 on which the pin block 21 is mounted,
A work alignment between the chip 2a mounted on the semiconductor module 2 and the pin block 21 is performed by using the upper alignment camera 56 which moves together with the pin block 21. That is, the position of the reference target 2c indicating the tower mounting position of the semiconductor element 2a is adjusted by the upper alignment camera 56 to the X-position of the stage on the inspection terminal moving mechanism 50 side.
Detected as YZ coordinates, the detailed alignment between the chip 2a and the pin block 21 is performed based on the position coordinates.

As a result, it is not necessary to individually align a plurality of chips having different specifications by microscopic observation or the like, and the position of the semiconductor module 2 fixed in one alignment step is obtained. Chip 2
The alignment with respect to a can be automatically performed, and the alignment time in the process can be greatly reduced. In this embodiment, since the thermal shrinkage of the ceramic substrate 2b is obtained for each chip and the position of the pin block 21 is corrected by this, a more accurate inspection can be expected.

In the semiconductor module inspection apparatus of this embodiment, a plurality of chips 2a having different standards are provided with corresponding pin blocks 21, and these are automatically exchanged for inspection. Improving efficiency. Therefore, it is necessary to grasp the mounting state of the pin blocks 21 for each pin block 21. In this embodiment, the correction mark 2 is provided for each pin block 21.
1b, the position of the correction mark 21b is imaged by the pin block correction camera 23, and the relative positional relationship with the upper alignment camera 56 is always determined. Deviation can be prevented, and highly accurate alignment can always be performed.

In the above embodiment, the probing is performed in a non-conductive liquid, but this is intended to absorb the operating heat of each chip 2a to increase the inspection accuracy and to assume the actual operating temperature. Yes, as needed.

[0041]

As described above, according to the inspection method of the present invention, it is possible to omit individual alignment between a plurality of test objects provided on a substrate and having different standards and test terminals corresponding thereto. Thus, it is possible to perform the overall alignment with high accuracy and in a short time. Therefore, it is possible to significantly improve the inspection efficiency and the inspection accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration example of a semiconductor module inspection apparatus to which the method of the present invention is applied.

FIG. 2 is a sectional view in the X direction of the inspection apparatus shown in FIG.

FIG. 3 is a cross-sectional view showing an example of a semiconductor module used as a device under test.

FIG. 4 is a view schematically showing an alignment step in the inspection apparatus shown in FIG.

FIG. 5 is a diagram schematically showing a pin block alignment in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body 2 ... Semiconductor module 2a ... Chip 2b ... Multilayer ceramic substrate 2c ... Alignment target 2d ... Measurement electrode pad 3 ... Work 10 ... Inspection part 16a 16b Bottom alignment camera 20 Inspection terminal supply section 21 Pin block 21a Probe pin 21b Mark for pin block correction 23 Camera for pin block correction 30 -Unit 40 Work transfer mechanism 50 Inspection terminal moving mechanism 51, 52, 53 Stage 54 Measurement head 55 Pin block chuck unit 56 Upper alignment camera

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masaki Narishima 2-3-1 Nishishinjuku, Shinjuku-ku, Tokyo Inside Tokyo Electron Limited (56) References JP-A-62-254279 (JP, A) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) H01L 21/66

Claims (1)

(57) [Claims] When a test terminal is brought into contact with electrode terminals of a plurality of test objects provided on a substrate and a predetermined test of the test object is performed, a plurality of reference targets are previously set at predetermined positions on the substrate. The reference target of the substrate provided and placed in an inspection standby state
Capturing the position as the coordinate position on the substrate side, and capturing the correction mark provided on the inspection terminal side,
From the reference point determined by the initial alignment
Set the coordinate position on the inspection terminal side as the distance
A step, the position of the device under test provided on the substrate with obtaining coordinate information indicating based on the reference target, from the coordinate information and the coordinate position of the test terminal side, the obtaining step body
Inspection method characterized by comprising the steps of: aligning said test terminal, the previous SL inspection terminal into contact with the electrode terminals of the obtaining step body, and performing the inspection.