Back-Illuminated Sensor Manufacturing via Through-Hole Embedding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in manufacturing a back-illuminated solid-state imaging device that balances thinness for enhanced light-receiving sensitivity with mechanical strength, while also simplifying the electrical connection process to improve yield and reduce technical difficulty in forming through holes in the support substrate.
Innovation Solution
The method involves preparing an imaging element with a photoelectric converter and a support substrate with through holes, aligning and joining them, and embedding a conductive member in the through holes to secure electrical connection, using a flattening film to enhance the joint security and employing solder balls for easy embedding, which reduces the risk of bubbles and improves the connection process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the sensor is made thinner to enhance light-receiving sensitivity, then light-receiving sensitivity is improved, but mechanical strength deteriorates
Solution Approach 1:
The sensor structure is segmented into a thin light-receiving region and a separate support structure. The support substrate with through-holes provides mechanical strength while the thin sensor region maintains high light-receiving sensitivity. This segmentation allows different parts to serve different functions optimally.
Solution Approach 2:
The invention uses a composite structure combining the sensor element with a support substrate. The support substrate acts as a mechanical reinforcement while allowing optical signals to pass through, creating a composite system that achieves both structural integrity and optical performance.
2Reliability
If through holes are formed in the support substrate after joining the sensor to enhance electrical connection, then electrical connection is improved, but manufacturing difficulty and yield deterioration occur
Solution Approach 1:
The through-holes are formed in the support substrate before the sensor is joined to it. This preliminary action allows for easier and more precise hole formation without the risk of damaging the already-joined sensor, thereby improving manufacturing yield while achieving reliable electrical connections.
Solution Approach 2:
Instead of forming through-holes after joining (conventional approach), the invention inverts the sequence by forming through-holes before joining. This reversal of the manufacturing sequence simplifies the process and reduces technical difficulty.
3Strength
If the outer edge parts are made thicker to secure mechanical strength, then mechanical strength is improved, but light-receiving efficiency per unit area deteriorates
Solution Approach 1:
The sensor is segmented into a thin active light-receiving area and a separate support structure for mechanical strength. This allows the light-receiving region to be maximally thin for high efficiency while the support substrate provides the necessary mechanical strength without reducing the light-receiving area.
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 approach facilitates easier manufacturing of solid-state imaging devices with improved yield and secure electrical connections, maintaining mechanical strength while enhancing light-receiving efficiency by embedding conductive members in the through holes of the support substrate.
Implementation Method 1
the surface of the imaging element is flattened by the flattening film, whereby the joint between the imaging element and the support substrate becomes more secure
Implementation Method 2
embedding a conductive member in the through hole and electrically connecting the conductive member to the electrode
Implementation Method 3
a photoelectric converter part for photoelectrically converting the incident energy line so as to generate a signal charge
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3
AI summary
A manufacturing method is provided for a solid-state imaging device which is easy to manufacture. A method for manufacturing a solid-state imaging device 1 comprises a first step of preparing an imaging element 10 including a first principal surface S1 for receiving an energy line incident thereon, a second principal surface S2 opposing the first principal surface S1 and having an electrode 14 arranged thereon, and a photoelectric converter part 11 for photoelectrically converting the incident energy line so as to generate a signal charge; a second step of preparing a support substrate 20, provided with at least one through hole 23 extending in a thickness direction thereof, having principal surfaces S3, S4 opposing each other; a third step of aligning the imaging element 10 and the support substrate 20 with each other so that the one electrode 14 is exposed out of the one through hole 23 while the principal surfaces S2, S3 oppose each other and joining the imaging element 10 and the support substrate 20 to each other; and a fourth step of embedding a conductive member 30 in the through hole 23 after the third step.