Light Diffusing Transmitter for Backside Irradiation Inspection
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Solution Overview
Problem
Existing inspection apparatuses for semiconductor devices, particularly backside irradiation type imaging devices, face challenges in efficiently inspecting multiple devices on a wafer due to limited probe needle formation and non-uniform light intensity distribution, which prolongs inspection time and prevents effective inspection of backside irradiation type imaging devices.
Innovation Solution
An inspection apparatus featuring a stage with a transmitter made of light-transmitting material that diffuses light from a light emitter, allowing for uniform in-plane light intensity distribution and enabling inspection of backside irradiation type imaging devices without the need for probe card openings, thus increasing the number of probes and reducing inspection time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If openings are formed in the probe card to irradiate the solid state imaging sensor with light, then the imaging device can be inspected, but the number of probe needles is limited and inspection time increases
Solution Approach 1:
The probe card is divided into two separate functional components: a probe card for electrical connection and a stage with transmitter for light irradiation. This segmentation allows the probe card to have probe needles in all necessary positions without openings, while the transmitter provides light only where needed for imaging sensor inspection, thereby increasing the number of inspectable devices and reducing inspection time.
Solution Approach 2:
A transmitter made of light-transmitting material is introduced as an intermediary component between the light source and the imaging sensor. The transmitter diffuses light uniformly across the inspection area, enabling simultaneous illumination of multiple imaging sensors without requiring openings in the probe card, thus improving inspection efficiency.
2Ease of manufacture
If probe needles are limited in number due to openings in probe card, then manufacturing is simplified, but inspection speed decreases
Solution Approach 1:
By separating the probing function (probe card) from the lighting function (transmitter on stage), the probe card can be manufactured with a dense array of probe needles without openings, maximizing inspection throughput. The transmitter is separately manufactured and integrated, maintaining manufacturing simplicity while enabling high-speed inspection.
3Device complexity
If light is emitted from above the probe card, then the structure is simplified, but the light intensity distribution becomes non-uniform
Solution Approach 1:
The transmitter acts as an optical intermediary that diffuses light uniformly across the inspection area. Placed on the stage beneath the imaging sensors, it provides uniform upward illumination through the transparent substrate, ensuring consistent light intensity across all imaging sensors without complex optical structures above the probe card.
Solution Approach 2:
The transmitter changes the physical parameters of light transmission by diffusing point-source or concentrated light into a uniform distributed illumination. This parameter transformation from concentrated to distributed light achieves uniform intensity distribution across the inspection area while maintaining structural simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables rapid inspection of backside irradiation type imaging devices with uniform light distribution, allowing for efficient batch inspection of multiple devices on a wafer without limiting the number of probes and maintaining light intensity uniformity.
Implementation Method 1
a transmitter including a flat plate formed of a light transmitting material, and configured to mount the inspection object on the transmitter; and a light emitter disposed at a location facing the inspection object with the transmitter interposed between the light emitter and the inspection object, and configured to emit light toward the transmitter, and wherein the transmitter transmits the light from the light emitter while diffusing the light
Data Source
AI summary
An inspection apparatus for inspecting a backside irradiation type imaging device formed on an inspection object includes: a stage on which the inspection object is mounted such that the stage faces a rear surface of the backside irradiation type imaging device, wherein the stage includes: a transmitter including a flat plate formed of a light transmitting material, and configured to mount the inspection object on the transmitter; and a light emitter disposed at a location facing the inspection object with the transmitter interposed between the light emitter and the inspection object, and configured to emit light toward the transmitter, and wherein the transmitter transmits the light from the light emitter while diffusing the light.