JPH1126521A - Apparatus for evaluating solid state imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately evaluate the characteristics matching the light quantity distribution in an actual operating condition by increasing the quantity of light emitted from an optical source, oblique to a receiving plane of a solid state imaging element from the center to the periphery of this plane. SOLUTION: A wafer having solid state imaging elements to be evaluated is set on a prober, a measuring board 22 and prober card 21 are disposed above the wafer 10, light is emitted from an emitter 32 of an optical source 23, collimated through a lens 23b to provide a collimated beam of light which is radiated through an optical system 21b so that light components in directions approximately perpendicular to the receiving plane of a solid state imaging element are much at the center of the plane and those oblique to the plane increase toward the periphery. Electric signals from electrode pads of the imaging elements are sent to the measuring board 22 from the card 21 to evaluate the characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state imaging device evaluation apparatus for evaluating the light receiving characteristics of a solid-state imaging device.

[0002]

2. Description of the Related Art In recent years, as the optical size of a solid-state image sensor has been reduced, the distance between an optical lens for condensing light and the solid-state image sensor has been reduced. FIG. 3 is a schematic cross-sectional view illustrating a conventional solid-state imaging device evaluation device. That is, the evaluation device 1 ′ includes a lens 23b that converts light emitted from the light emitting source 23a into parallel light, a diffusion plate 23c that diffuses the parallel light, and an electrode pad of the wafer 10 on which the solid-state imaging device is formed. The probe card 21 includes a probe needle 21a that comes into contact with the probe card 21a, and a measurement substrate 22 including a circuit that performs a predetermined characteristic measurement based on an electric signal obtained from the probe card 21.

[0003] In this evaluation device 1 ', the diffusing plate 23
Light is generated in an oblique direction by c, so that the solid-state imaging device can be irradiated with light in an oblique direction.

In Japanese Patent Application Laid-Open Nos. Hei 3-190255 and Hei 8-227923, an optical path between a light source and a solid-state imaging device is divided into a plurality of optical paths, and a light-receiving portion of the solid-state imaging device corresponding to each optical path. There is disclosed a technique in which light is applied to each of the light sources and the incident angle of the light is limited to a small value.

[0005]

However, the distance between the optical lens and the solid-state imaging device has been reduced with the reduction in the optical size of the solid-state imaging device and the miniaturization of an imaging device incorporating the same. For this reason, in an actual solid-state imaging device, there are many parallel light components in the central portion of the light receiving surface,
In the peripheral part, the oblique light component is increased. That is,
In the evaluation apparatus for a solid-state imaging device as described above, there is a problem that accurate characteristics cannot be evaluated because the components of light generated by an actual optical system are not sufficiently handled.

[0006]

SUMMARY OF THE INVENTION The present invention is an apparatus for evaluating a solid-state image sensor which has been made to solve such a problem. That is, the present invention provides a probe card including a probe needle that contacts an electrode pad of a solid-state imaging device, a light source disposed to face a light receiving surface of the solid-state imaging device, and a light source and the solid-state imaging device. When the light is emitted from the light source and is incident on the solid-state imaging device, the amount of light in the oblique direction is smaller than the amount of light in the direction substantially perpendicular to the light-receiving surface as going from the central portion to the peripheral portion of the light-receiving surface of the solid-state imaging device. This is an evaluation device for a solid-state imaging device including an optical unit for strengthening.

In the present invention, the light emitted from the light source is passed through the optical means, so that the amount of light in the oblique direction is smaller than the amount of light in the direction substantially perpendicular to the light receiving surface from the central portion to the peripheral portion of the light receiving surface of the solid-state image sensor. I try to be stronger. This makes it possible to match the incident angle and the light amount of the light corresponding to the light receiving surface position in the actual use state with the light incident angle and the light amount corresponding to the light receiving surface position at the time of evaluation.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an apparatus for evaluating a solid-state image sensor according to the present invention.
FIG. 1 is a schematic cross-sectional view illustrating a main part of a solid-state imaging device evaluation apparatus according to the present invention. FIG. 2 is a diagram illustrating the overall configuration of the evaluation device.

As shown in FIG. 2, the evaluation device 1 includes:
The configuration is mainly a combination of the prober 2 and the measuring device 3. The prober 2 includes a probe card 21 disposed on the wafer 10 on which a solid-state imaging device (not shown) is formed, a measurement substrate 22 on which the probe card 21 is mounted, and a light source for irradiating the solid-state imaging device with light. 2
The measuring device 3 includes a control system for controlling the prober 2, the measurement substrate 22, and the light source 23.

As shown in FIG. 1, the light source 23 is provided with a light source 23a composed of a lamp and a lens 23b for converting light emitted from the light source 23a into parallel light. Further, the probe card 21 has a probe needle 21.
The probe needle 21a is brought into contact with an electrode pad (not shown) of the solid-state imaging device formed on the wafer 10 to be measured, and a signal is input / output.

The evaluation apparatus 1 according to the present embodiment receives the parallel light emitted from the light source 23 and
An optical system 21b is provided to increase the amount of light in the oblique direction from the amount of light in the direction substantially perpendicular to the light receiving surface as going from the central portion to the peripheral portion of the light receiving surface of the solid-state imaging device formed at 0.

As the optical system 21b, an optical system having the same or similar optical characteristics as a lens system incorporated in an imaging apparatus using an actual solid-state imaging device is used. Further, the optical system 21 b is provided with an angle 21
c and is replaceable.

That is, the angle 21c allows the optical system 21 to have an optical system having the same or similar optical characteristics as the lens system used in the solid-state image sensor to be evaluated.
b is detachably attached. The optical system 21
When exchanging b, it may be exchanged with the probe card 21.

In order to evaluate the characteristics of the solid-state imaging device by the evaluation apparatus 1 in this embodiment, first, the wafer 10 on which the solid-state imaging device to be evaluated is formed is set on the prober 2 shown in FIG. Measurement substrate 2 above 10
2 and the probe card 21 are arranged.

It is assumed that the optical system 21b (see FIG. 1) described above is attached to the probe card 21. Next, the probe card 21 and the wafer 10 are aligned, and the probe needle 21a is brought into contact with the electrode pad of the solid-state imaging device to be evaluated.

Next, in order to measure the characteristics, light is emitted from the light source 23a of the light source 23 shown in FIG.
, And emits parallel light. This parallel light is transmitted to the optical system 21b.
As a result, a light amount distribution similar to that used in an actual imaging device is emitted to the solid-state imaging device to be evaluated.

That is, due to the optical system 21b, the central part of the light receiving surface of the solid-state image pickup device has a large amount of light components in a direction substantially perpendicular to the light receiving surface, and the light components in the oblique direction with respect to the light receiving surface toward the peripheral portion. Irradiation is performed to increase the light component.

Next, an electric signal (signal obtained by photoelectric conversion) output from the electrode pad of the solid-state imaging device is brought into contact with the electrode pad in advance in a state where light is irradiated through the optical system 21b. The probe card 21 is taken in through the probe needle 21a, and the measurement substrate 22 is
Send to

The fetched electric signal is sent as a measured value from the measuring board 22 to the measuring device 3 shown in FIG. 2, where the characteristic is evaluated by a predetermined calculation.

To evaluate the characteristics of another solid-state imaging device, another wafer on which the solid-state imaging device to be evaluated is formed is set on the prober 2 shown in FIG. And
The measurement substrate 22 and the probe card 21 are arranged above the wafer. At this time, the probe card 2
An optical system 21b having the same or similar optical characteristics as the actual lens system applied to the solid-state imaging device to be evaluated is set to 1. Or such an optical system 2
The probe card 21 in which 1b is set in advance is arranged.

Thereafter, in the same manner as described above, light is emitted from the light source 23, and the light having the same light amount distribution as that used in the actual image pickup device is transmitted through the set optical system 21b to the solid-state image pickup device. Irradiation. Then, based on the electric signal output from the electrode pad of the solid-state imaging device, the characteristic is evaluated by the measuring device 3 (see FIG. 2).

[0022]

As described above, the present invention has the following effects. In other words, the amount of light emitted from the light source by the optical means is increased in an oblique direction with respect to the light receiving surface as it goes from the central part to the peripheral part of the light receiving surface of the solid-state imaging device. It can be adjusted to the distribution, and accurate characteristic evaluation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a main part of an evaluation device according to an embodiment.

FIG. 2 is a diagram illustrating an overall configuration of an evaluation device.

FIG. 3 is a schematic sectional view illustrating a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Evaluation apparatus, 2 ... Prober, 3 ... Measuring instrument, 21 ... Probe card, 21b ... Optical system, 22 ... Measurement board, 2
3. Light source

Claims (2)

[Claims] A probe card having a probe needle that contacts an electrode pad of the solid-state imaging device; a light source arranged to face a light-receiving surface of the solid-state imaging device; and a light source and the solid-state imaging device. When the light emitted from the light source is incident on the solid-state imaging device through the light emitted from the light source, the amount of light in a direction substantially perpendicular to the light-receiving surface of the solid-state imaging device from the central portion to the peripheral portion thereof An evaluation device for a solid-state imaging device, comprising: an optical unit for increasing the amount of light in an oblique direction. 2. The apparatus according to claim 1, wherein the optical unit is detachably attached to the probe card.