Laminated Circuit Substrate Self-Inspection Before Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor applications like photoelectric conversion apparatuses, the existing lamination configurations fail to effectively identify defects in substrates before lamination, leading to reduced yield due to the rejection of both defective and normal substrates, and increased costs associated with the separation process after lamination.
Innovation Solution
A circuit substrate with signal lines, input portions, signal processing circuits, and transistors connected to control lines, capable of supplying a predetermined voltage and performing AD conversion, allows for pre-lamination inspection of the substrate by comparing digital signals with expected values, thereby identifying defects before lamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a plurality of substrates is laminated without pre-lamination inspection, then the manufacturing process is simple and fast, but defective substrates cannot be identified before lamination leading to rejection of both defective and normal substrates
Solution Approach 1:
The patent applies preliminary action by implementing inspection circuits and test signal generation capabilities within the substrate itself before lamination occurs. The inspection circuit generates test signals that traverse through signal lines and are processed by signal processing circuits, allowing defects to be detected before the substrate is laminated with others, thereby preventing waste of normal substrates.
Solution Approach 2:
The substrate performs self-inspection through integrated inspection circuits that are part of the substrate structure. These circuits generate test signals internally and process them through the same signal processing paths that will be used during normal operation, allowing the substrate to self-diagnose defects without requiring external inspection equipment.
2Productivity
If inspection is conducted after lamination, then the manufacturing process is simple, but both defective and normal substrates must be rejected leading to yield loss
Solution Approach 1:
The patent implements preliminary defect detection before lamination by incorporating inspection circuits that can identify defective substrates in advance. This allows normal substrates to be selected for lamination while defective ones are discarded, eliminating the need for time-consuming separation processes after lamination and preventing loss of normal substrates.
Solution Approach 2:
The inspection system provides feedback about substrate quality before lamination occurs. The test signal processing circuits generate output signals that indicate whether substrates are defective or normal, allowing real-time selection and rejection decisions to be made, thus preventing waste and eliminating post-lamination separation needs.
3Reliability
If transistors supply predetermined voltage to signal lines without signals, then defects can be detected through AD conversion, but the circuit complexity increases
Solution Approach 1:
The patent applies universality by designing signal processing circuits that perform both normal signal processing functions and inspection functions. The same transistors, signal lines, and AD conversion circuits used during normal operation are also utilized for defect detection by supplying predetermined voltages and processing test signals, thereby enabling reliability improvement without proportionally increasing circuit complexity.
Solution Approach 2:
The inspection functionality is integrated into the existing circuit structure, allowing the circuit to self-diagnose defects using its own components. The transistors supply test voltages, the signal lines transmit them, and the AD conversion circuits process them, enabling defect detection without requiring entirely separate inspection circuitry.
Data Source
AI summary
A circuit substrate to be laminated on another substrate includes a plurality of signal lines, a plurality of input portions respectively connected to the plurality of signal lines, and each configured to receive a signal from an outside of the circuit substrate, a plurality of signal processing circuits respectively connected to the plurality of input portions via the plurality of signal lines, and a plurality of transistors configured to supply a predetermined voltage to the plurality of signal lines in a state where no signal is input to the plurality of input portions from the outside. A part of the plurality of transistors is connected to a first control line, and another part of the plurality of transistors is connected to a second control line different from the first control line.