JP4645174B2 - Solid-state image sensor inspection system - Google Patents

Description

  The present invention relates to a solid-state image sensor inspection system, and more particularly to a system with a high degree of freedom that can be easily changed according to the application.

  Patent Document 1 discloses a configuration of an apparatus capable of inspecting a color solid-state imaging device in a short time.

JP 2002-27506 A

  Solid-state imaging devices such as CCDs and CMOSs are used as imaging devices for digital cameras, for example, and higher integration is being promoted with the demand for higher display resolution. In particular, the CMOS solid-state imaging device has an advantage that a conventional CMOS manufacturing process can be diverted.

  FIG. 2 is a conceptual configuration diagram for explaining a solid-state imaging device and an inspection method for performing a quality inspection thereof. In the figure, the solid-state imaging device 1 is composed of a color filter 2 and a photoelectric conversion unit 3.

  The color filter 2 includes a plurality of G1 color filters, B color filters, R color filters, and G2 color filters. The G1 color filter and the G2 color filter transmit green light, but are distinguished because they have different characteristics. The B color filter and the R color filter transmit blue and red light, respectively.

The photoelectric conversion unit 3 is disposed to face the G1 color filter, the B color filter, the R color filter, and the G2 color filter, and is provided with a photoelectric conversion element PD _HV (H, V: integer). This photoelectric conversion element PD _HV becomes a sensor with color vision by the G1 color filter, the B color filter, the R color filter, and the G2 color filter.

  The light source 4 irradiates the solid-state imaging device 1 with uniform white light with a constant illuminance.

In such a configuration, when the light source 4 irradiates the solid-state imaging device 1 with uniform white light with constant illuminance over a certain period of time, the amount of charge accumulated in the photoelectric conversion element PD _HV of the photoelectric conversion unit 3 is not constant, The color filter 2 mounted on the photoelectric conversion element PD _HV is different for each color. This is because the spectral transmission characteristics of each color of the mounted color filter 2 are different, and the amount of charge converted by the photoelectric conversion element PD _HV is an amount depending on the spectral characteristics of the color filter 2.

Such a quality inspection of the solid-state imaging device 1 includes a method of performing separation for each color and a method of performing a gray image in which all colors are mixed. When a characteristic inspection separated for each color is necessary, as described in Patent Document 1, image data obtained from the solid-state imaging device 1 is sorted according to color, and the photoelectric conversion device PD corresponding to the color filter. Processing is performed for each _HV .

  On the other hand, in the case of handling as a gray image, all image data obtained from the solid-state imaging device 1 is subjected to image calculation processing without being sorted by color.

  FIG. 3 is a block diagram showing an example of such a conventional solid-state imaging device inspection apparatus. In FIG. 3, the solid-state imaging device 1 to be inspected is placed on a DUT board 5 and electrically connected.

  The CPU 6 comprehensively controls the operation of the entire solid-state imaging device inspection apparatus based on an inspection program corresponding to the specification standard of the solid-state imaging device 1 to be inspected set and input from the operation setting unit 7.

  The light source drive control unit 8 lights and drives the light source 4 based on a control signal corresponding to the specification standard of the solid-state imaging device 1 to be inspected input from the CPU 6.

  The element drive control unit 9 supplies a DC signal and a drive clock for driving the solid-state image sensor 1 based on a control signal corresponding to the specification standard of the solid-state image sensor 1 to be inspected input from the CPU 6. Image data is output from the solid-state image sensor 1 by irradiating the solid-state image sensor 1 with the output light of the light source 4 while the solid-state image sensor 1 is being driven.

  Image data output from the solid-state imaging device 1 is converted into digital data by the A / D converter 10. The digital data converted by the A / D converter 10 is stored in the data memory 11.

  The image data stored in the data memory 11 is transferred to the image processing memory 13 via a DMAC (direct memory access controller) 12.

  The DSP 14 performs predetermined image calculation processing on the image data transferred to the image processing memory 11 based on the control signal corresponding to the specification standard of the solid-state imaging device 1 to be inspected, which is input from the CPU 6, and the processing result Is output to the CPU 6.

  The CPU 6 determines pass / fail of the solid-state imaging device 1 to be inspected based on the processing result input from the DSP 14. Processing results and determination results of the solid-state imaging device 1 to be inspected are displayed on the display unit 15 via the CPU 6.

  By the way, in the conventional solid-state image sensor inspection device, each functional block in the region 16 surrounded by the broken line in FIG. 3 is housed in a common housing (not shown) and configured as one solid-state image sensor inspection device.

  However, such a conventional configuration is specialized as an inspection apparatus dedicated to a solid-state imaging device. This means that when the demand for solid-state imaging devices becomes active and the production increase system is started, a new inspection facility must be invested.

  However, from the standpoint of a user who has already introduced a semiconductor inspection apparatus for inspecting other semiconductor devices other than the solid-state image sensor, if the existing semiconductor inspection apparatus can be easily diverted to the inspection of the solid-state image sensor, the factory The production plan can be made flexible, and the product production cost can be reduced to increase the market competitiveness.

  Also, in product development and improvement, failure factor analysis, and the like, image data and inspection data obtained by a solid-state image sensor inspection apparatus are often used by other apparatuses.

  However, in the conventional solid-state imaging device inspection apparatus, when image data or inspection data is to be used in another apparatus, a necessary interface must be prepared separately, and the degree of freedom is low.

  The present invention solves such a conventional problem, and an object of the present invention is to provide a solid-state imaging device inspection system with a high degree of design freedom that can easily cope with a change in the type of a product to be inspected. .

  Still another object is to make image data and inspection data available to other devices without using a special interface.

In order to achieve such a problem, the invention according to claim 1 of the present invention is:
A DUT board to which the solid-state imaging device to be inspected is electrically connected;
A light source for illuminating the solid-state image sensor to be inspected;
An inspection apparatus that drives the solid-state image sensor, the DUT board, and the light source with a predetermined inspection program;
An image processing apparatus connected to the inspection apparatus via a network and performing image processing for inspection on the image data of the inspection target solid-state imaging device output from the DUT board;
A test system server connected to the inspection apparatus and the image processing apparatus via a network, and supplying a predetermined inspection program corresponding to the inspection target solid-state imaging device to the inspection apparatus and the image processing apparatus;
Connected to these inspection device, image processing device, and test system server via a network, a monitor for displaying data of each part,
This is a solid-state imaging device inspection system.

The invention described in claim 2 is the solid-state imaging device inspection system according to claim 1,
The inspection target solid-state imaging device is a wafer on which a plurality of solid-state imaging device chips are formed.

The invention described in claim 3 is the solid-state imaging device inspection system according to claim 2,
The image processing device is mounted in a plurality of systems so that the image data of the plurality of solid-state imaging device chips is individually processed in parallel at the same time.

The invention described in claim 4 is the solid-state image sensor inspection system according to claim 3,
The plurality of image processing apparatuses are connected to each other via a dedicated network.

The invention described in claim 5 is the solid-state imaging device inspection system according to claim 1,
The DUT board includes an image data editing unit that edits and outputs image data of the plurality of solid-state imaging device chips for each chip.

The invention described in claim 6 is the solid-state imaging device inspection system according to claim 1,
A network connecting the inspection apparatus, the image processing apparatus, the test system server, and the monitor is a general-purpose network.

The invention described in claim 7 is the solid-state imaging device inspection system according to claim 6,
The general-purpose network is connected to a general-purpose personal computer that uses inspection results.

The invention described in claim 8 is the solid-state image sensor inspection system according to claim 7,
The general-purpose personal computer performs at least one of verification, evaluation, and development using an inspection result.

  According to the present invention, a predetermined inspection program may be supplied to each unit from the test system server in accordance with a model change of the inspection target solid-state imaging device, and a solid-state imaging device inspection system with a high degree of freedom can be realized.

  By connecting the entire system with a general-purpose network, the image data and inspection data in the solid-state imaging device inspection system can be used with the general-purpose personal computer simply by connecting the general-purpose personal computer to the general-purpose network.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, and the same reference numerals are given to portions common to FIG. In FIG. 1, the inspection device 17 includes a CPU 6, an operation setting unit 7, a light source drive control unit 8, and an element drive control unit 9. Here, when comparing the inspection device 17 with an existing LSI test device, the light source drive control unit 8 corresponds to a test pattern generation unit, and the element drive control unit 9 corresponds to a DUT drive control unit, By making a simple change, the existing LSI test apparatus can be used as the inspection apparatus 17.

  On the DUT board 5, an image sensor chip wafer is mounted as the solid-state image sensor 1 to be inspected, and image data editing unit 18 that edits and outputs image data of a plurality of solid-state image sensor chips for each chip. Is provided.

Image data output from the image data editing unit 18 is input to a plurality of image processing units 21 _{1 to} 21 _n corresponding to each chip constituting the image processing unit 20 via an image signal line 19. The image processing unit 20 includes a plurality of image processing units 21 _{1 to} 21 _n , a control unit 22, and a switching hub 23. Each of the image processing units 21 _{1 to} 21 _n is mounted with an image processing program that can perform processing independently. The plurality of image processing units 21 _{1 to} 21 _n and the control unit 22 are connected to each other via a high-speed dedicated network 24 such as 1G1ASE Ethernet (registered trademark) and a switching hub 23.

  The inspection device 17 and the image processing unit 20 are connected to each other via a general-purpose network 25 such as 100BASE Ethernet (registered trademark). For example, this network 25 is used to construct a factory backbone network, and is connected to a test system server 26, a real-time monitor 27, a general-purpose personal computer 28, an external storage device 29, and the like.

  A system operation selection unit 30 is connected to the real time monitor 27.

  The general-purpose personal computer 28 is a man-machine interface suitable for each application according to the use form (product mass production mode, product verification evaluation mode, product development mode) of the solid-state imaging device inspection system selected and set by the system operation selection unit 30. Function as.

  The operation of the solid-state image sensor inspection system configured as described above will be described for each usage form of the solid-state image sensor inspection system.

<Product mass production mode>
In the product mass production mode, the type of the image sensor chip wafer to be inspected is selected and set from the system operation selection unit 30 to the real-time monitor 27. The real-time monitor 27 transmits the type information of the image pickup element chip wafer selected and set to the test system server 26 and the control unit 22 of the image processing unit 20.

  The test system server 26 downloads to the CPU 6 of the inspection apparatus 17 a test program corresponding to the type of image sensor chip wafer that has been selected and set. The CPU 6 of the inspection device 17 operates the light source drive control unit 8 and the element drive control unit 9 with a predetermined test pattern based on the downloaded test program, and internally sets an expected pattern for determining the quality of the inspection result. Also do.

The control unit 22 of the image processing unit 20 transmits the type information of the image pickup device chip wafer selected and set to each of the image processing units 21 _{1 to} 21 _n , and starts a predetermined image processing program corresponding to each type.

When a series of system setups are completed, a solid-state imaging device chip wafer to be inspected is placed on the DUT board 5 and product inspection is performed. If the wafer, for example, eight product chips are formed is the image data of eight systems are simultaneously outputted to the image processing unit 21 ₁ to 21 _n of the image processing unit 20, the image processing unit 21 ₁ to 21 _In parallel, _n performs predetermined image processing necessary for capturing and inspecting image data. A series of examination progress statuses in each of the image processing units 21 _{1 to} 21 _n is displayed on the screen of the real-time monitor 27 as a real-time image pattern or list screen, individually or simultaneously on each of the image processing units 21 _{1 to} 21 _n. All can be monitored sequentially.

When predetermined image processing in each of the image processing units 21 _{1 to} 21 _n is completed, the CPU 6 of the inspection device 17 performs pass / fail determination for each chip of the image sensor chip wafer, and the image data and inspection collected in these series of inspections. The result is stored in the external storage device 30 and the next wafer is inspected. At the time of debugging after the inspection is completed, various data stored in the external storage device 30 can be read and confirmed through the general-purpose personal computer 28 as necessary.

<Product verification evaluation mode>
Verification and evaluation of a product for which inspection has been completed is performed on a wafer or chip device basis using image data stored in the external storage device 30 from a general-purpose personal computer 28 connected to a general-purpose network 25.

  The verification evaluation can be performed on a wide variety of items such as white spots / black spots, white lines / black lines, spots, and pixel defects formed by each pixel without imposing a large load on the inspection apparatus 17 or the image processing unit 20. In addition, when the image data is converted to a file, lossless compression is performed using a PNG format file, and the number of stored images is controlled by designating the product lot and the number of wafers.

  The verification result report can be analyzed in many ways using a parameter tuning support GUI tool. Specifically, the measurement values for each inspection are aggregated, the limit value change setting for each inspection is verified, the definition change setting for the feature amount used in the inspection determination, the relationship diagram of the feature amount and the determination value, etc. Are displayed on each screen for each item such as white spot / black spot, white line / black line, spot, pixel defect and the like. The ranking of each inspection is displayed as a list in units of wafers and chip devices.

  Furthermore, using the acquired inspection image data, the image processing unit 20 performs an inspection offline, and how the limit value change setting and the feature amount definition change setting for each inspection are applied to the inspection by the image processing unit 20. It can be specifically verified whether it is reflected in.

<Product development mode>
If necessary, the user edits the parameters used in the image processing unit 20 according to the developed product on a GUI basis, confirms the result in the verification step as described above, and then sends the test program to the test system server 26. Can be reflected in the mass production inspection process.

  By adopting such a configuration, a user who has already introduced a semiconductor inspection apparatus to inspect a semiconductor device other than the solid-state imaging element can easily use the existing semiconductor inspection apparatus for inspecting the solid-state imaging element. Can be diverted. A user newly introduced for inspecting the solid-state imaging device can be diverted to inspect other semiconductor devices as necessary.

  Further, according to the solid-state imaging device inspection system of the present invention, image data and inspection data obtained by inspection can be used in other devices without using a necessary interface, and product development and improvement, failure factors It can be used for analysis.

  As described above, according to the present invention, it is sufficient to supply a predetermined inspection program to each unit from the test system server in accordance with the model change of the inspection target solid-state imaging device, and a solid-state imaging device inspection system with a high degree of freedom is realized. it can.

It is a block diagram which shows one Example of this invention. It is a conceptual block diagram for demonstrating the inspection method which performs a solid-state image sensor and its quality inspection. It is a block diagram which shows an example of the conventional solid-state image sensor inspection apparatus.

Explanation of symbols

1 Solid-state image sensor 5 DUT board 6 CPU
7 Operation setting unit 8 Light source drive control unit 9 Element drive control unit 18 Image data editing unit 19 Image signal line 20 Image processing unit 21 Image processing unit 22 Control unit 23 Switching hub 24 High-speed dedicated network 25 General-purpose network 26 Test system server 27 Real time Monitor 28 General-purpose personal computer 29 External storage device 30 System operation selection unit

Claims (8)

A DUT board to which the solid-state imaging device to be inspected is electrically connected;
A light source for illuminating the solid-state image sensor to be inspected;
An inspection apparatus that drives the solid-state image sensor, the DUT board, and the light source with a predetermined inspection program;
An image processing apparatus connected to the inspection apparatus via a network and performing image processing for inspection on the image data of the inspection target solid-state imaging device output from the DUT board;
A test system server connected to the inspection apparatus and the image processing apparatus via a network, and supplying a predetermined inspection program corresponding to the inspection target solid-state imaging device to the inspection apparatus and the image processing apparatus;
A monitor that is connected to these inspection devices, image processing devices, and test system servers via a network, and displays data of each part,
A solid-state image sensor inspection system, comprising:   The solid-state image sensor inspection system according to claim 1, wherein the inspection target solid-state image sensor is a wafer on which a plurality of solid-state image sensor chips are formed.   3. The solid-state image sensor inspection system according to claim 2, wherein the image processing apparatus is mounted in a plurality of systems so that image data of the plurality of solid-state image sensor chips is simultaneously and individually processed.   4. The solid-state image sensor inspection system according to claim 3, wherein the plurality of image processing apparatuses are connected to each other via a dedicated network.   The solid-state image sensor inspection system according to claim 1, wherein the DUT board includes an image data editing unit that edits and outputs image data of the plurality of solid-state image sensor chips for each chip.   2. The solid-state image sensor inspection system according to claim 1, wherein a network connecting the inspection apparatus, the image processing apparatus, the test system server, and the monitor is a general-purpose network.   The solid-state imaging device inspection system according to claim 6, wherein a general-purpose personal computer that uses inspection results is connected to the general-purpose network. The solid-state imaging device inspection system according to claim 7, wherein at least one of verification, evaluation, and development is performed using the inspection result by the general-purpose personal computer.

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