Fabry-Perot Filter Light Detector Miniaturization

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Solution Overview

Problem

The miniaturization of light-detecting devices is hindered by the need to position bonding pads outside the Fabry-Perot interference filter, which increases the device's size.

Innovation Solution

A light-detecting device design that includes a wiring substrate with a support member surrounding the Fabry-Perot interference filter, featuring openings that allow wiring lines to pass through, enabling bonding pads to be placed within the surrounding region, thus eliminating the need for external placement and allowing the device to be miniaturized to the size of the filter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bonding pads are disposed outside the Fabry-Perot interference filter, then electric connection is secured, but the device size increases

Engineering Contradiction:
Improveelectric connectionVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent applies dimensionality change by moving bonding pads from the two-dimensional plane outside the filter to the third dimension through openings in the support member. This allows bonding pads to be positioned both within the surrounding region (reducing device size) and maintain electrical connection (securing reliability) by passing through the support member structure vertically.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements nesting by placing bonding pads within the surrounding region formed by the support member, rather than outside it. The bonding pads are nested inside the structural boundary of the support member, allowing the device footprint to be minimized to match the filter size while maintaining all necessary electrical connections.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Area of stationary object

If bonding pads are placed within the surrounding region, then device size is minimized, but wiring connection becomes complex

Engineering Contradiction:
Improvedevice sizeVSAvoidwiring connection
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The support member is segmented with openings that separate different functional regions. These openings provide dedicated pathways for wiring lines to access bonding pads without crossing other structural elements, simplifying the wiring routing process despite the compact layout.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The openings in the support member act as intermediaries that facilitate the connection between wiring lines and bonding pads. Rather than requiring complex routing around the entire support member structure, the openings provide direct access points that simplify the wiring path.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If support member surrounds the Fabry-Perot interference filter, then structural support is provided, but resin material may enter the light transmission region

Engineering Contradiction:
Improvestructural supportVSAvoidresin contamination
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The support member is divided into segments with openings between them, creating a segmented structure that provides mechanical support while preventing continuous resin flow into the light transmission region. The gaps act as barriers to resin material while maintaining structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support member has different properties in different regions: solid portions provide structural support, while openings provide contamination protection. This local differentiation of structure and function allows the same component to simultaneously provide mechanical strength and prevent resin intrusion.

Inventive Principle:
Principle #3Local quality

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

This configuration secures electric connection to the light detector, improves wire bonding workability, and prevents resin material from entering the light transmission region, resulting in a compact and functional light-detecting device.

Implementation Method 1

a Fabry-Perot interference filter which has a light transmission region and is disposed on the principal surface of the wiring substrate with the support member therebetween

Methodology Applied
Scientific EffectFabry-Perot interference: Interference

Data Source

PatentEP3064912B1Light-detecting device
Publication Date: 2021.07.07 HAMAMATSU PHOTONICS KK
  • EP3064912B1 patent drawingFigure 1
  • EP3064912B1 patent drawingFigure 2
  • EP3064912B1 patent drawingFigure 3(A)~3(B)

AI summary

A spectral sensor 1 includes a wiring substrate 2 which has a principal surface; a light detector 3 which is disposed on the principal surface 2A of the wiring substrate 2 and is electrically connected to the wiring substrate 2; spacer 4 which is disposed around the light detector 3, on the principal surface 2A of the wiring substrate 2; and a Fabry-Perot interference filter 10 which has a light transmission region 11 and is disposed on the principal surface 2A of the wiring substrate 2 with the spacer 4 therebetween. The spacer 4 support the Fabry-Perot interference filter 10 in a surrounding region R1 of the light transmission region 11 and the spacer 4 has opening A1 communicating with an inner side of the surrounding region R1 and an outer side of the surrounding region R1, when viewed from a light transmission direction in the light transmission region 11.