Backside Sensor Mounting in Camera Modules for Slimmer Optics

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Solution Overview

Problem

Current camera modules in portable electronic devices face issues such as increased size and protrusion due to dual lens configurations, leading to aesthetic and functional problems like damage from touch and reduced focal length and zoom range, as well as contamination and oxidation-related issues.

Innovation Solution

A camera module design where the photosensitive element is attached to the substrate's back surface, with a protective element and filler to prevent contamination, and electronic components are strategically placed to reduce size and enhance reliability, allowing for a thinner form factor while maintaining or improving focal length and zoom range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If passive components, photosensitive element and bearing are attached to the same side of the circuit board, then the layout is simplified, but safety distances must be reserved causing increased horizontal and height sizes

Engineering Contradiction:
Improvecomponent layout complexityVSAvoidcamera module size
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent applies dimensional change by moving passive components from the front surface to the back surface of the circuit board, transforming a two-dimensional layout problem into a three-dimensional spatial solution. This allows the photosensitive element and bearing to be positioned on the front surface without requiring horizontal safety distances from passive components, thereby reducing the overall camera module size while maintaining necessary electrical clearances.

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

2Reliability

If safety distance is reserved between passive component and gold wire, then electrical properties are ensured, but length and width sizes increase

Engineering Contradiction:
Improveelectrical propertiesVSAvoidcamera module footprint
Core Design Contradiction:
ReliabilityVSArea of moving object

Solution Approach 1:

The patent resolves this contradiction by relocating passive components to the back surface of the circuit board, creating vertical separation from the gold wires on the front surface. This three-dimensional arrangement eliminates the need for horizontal safety distances between passive components and gold wires, reducing the camera module's length and width while maintaining reliable electrical connections through the circuit board substrate.

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

3Volume of stationary object

If passive components and photosensitive element are located in the same space, then space utilization is improved, but oxidation shedding causes stain spots on photosensitive area

Engineering Contradiction:
Improvecomponent placement densityVSAvoidcontamination of photosensitive area
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies segmentation by spatially separating passive components from the photosensitive element into different regions of the circuit board - passive components on the back surface and the photosensitive element on the front surface. This physical segmentation prevents oxidation shedding from passive components from contaminating the photosensitive area, eliminating stain spots while maintaining high space utilization through vertical integration of the board structure.

Inventive Principle:
Principle #1Segmentation

4Strength

If adhesive is applied on circuit board to attach bearing, then bearing is securely fixed, but fluid state adhesive flows to photosensitive area causing contamination

Engineering Contradiction:
Improvebearing attachment strengthVSAvoidphotosensitive area contamination
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent resolves this contradiction by positioning the bearing and its adhesive application area on the front surface of the circuit board, away from the photosensitive element's active area. The adhesive is applied in a controlled manner within the bearing's mounting region, and the front-surface location prevents adhesive overflow from reaching the photosensitive area, thereby maintaining secure bearing attachment without contamination risk.

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

5Ease of manufacture

If photosensitive element is attached to the surface of the substrate, then assembly is simplified, but distance between photosensitive element and optical lens is limited reducing focal length and zoom range

Engineering Contradiction:
Improveassembly simplicityVSAvoidfocal length
Core Design Contradiction:
Ease of manufactureVSLength of moving object

Solution Approach 1:

The patent applies segmentation by separating the photosensitive element's mounting location from the optical lens position. The photosensitive element is attached to the front surface of the circuit board in a position that allows greater axial distance from the optical lens, enabling increased focal length and zoom range. This spatial segmentation maintains assembly simplicity while achieving the desired optical performance parameters.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4072120B1Camera module and molded circuit board assembly thereof, array camera module and electronic device
Publication Date: 2025.03.26 NINGBO SUNNY OPOTECH CO LTD
  • EP4072120B1 patent drawingFigure 1
  • EP4072120B1 patent drawingFigure 2A~2B
  • EP4072120B1 patent drawingFigure 3~4

AI summary

A camera module and a molded circuit board assembly thereof, a semi-finished product of the molded circuit board assembly, and an array camera module and a molded circuit board assembly thereof, as well as a manufacturing method and an electronic device, wherein the camera module comprises at least one optical lens, at least one back surface molded portion, at least one photosensitive element and a circuit board. The circuit board comprises at least one substrate and at least one electronic component that is conductively connected to the substrate; a part of the non-photosensitive area of the photosensitive element is attached to the substrate back surface of the substrate, and the photosensitive area and another part of the non-photosensitive area of the photosensitive element correspond to a substrate channel of the substrate; the back surface molded portion is integrally bonded to at least one part of the area of the substrate back surface of the substrate; and the optical lens is held in the photosensitive path of the photosensitive element.