Semiconductor Terminal Fillet for Visual Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in inspecting the connection state of downsized semiconductor devices, such as those used in IoT and mobile devices, after mounting is that existing methods are expensive, time-consuming, and have decreased accuracy due to the difficulty in visually confirming solder connections, especially when bonding pads are scaled down.
Innovation Solution
A semiconductor device design featuring a molded body with a semiconductor chip, terminal bodies, and a resin member, where the terminal bodies have exposed contact surfaces that form a fillet upon solder connection, allowing for easy visual inspection of connection quality without the need for expensive X-ray equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If semiconductor devices are downsized to chip size for IoT and mobile applications, then device portability and integration are improved, but inspection accuracy of solder connections deteriorates
Solution Approach 1:
The patent transitions the inspection problem from a two-dimensional surface inspection to a three-dimensional volumetric inspection by forming raised fillet structures that extend vertically from the mounting surface. This dimensional change allows standard visual inspection methods to effectively inspect downsized devices by observing the height and shape of fillets rather than attempting to resolve fine lateral details of miniaturized bonding pads.
Solution Approach 2:
The patent utilizes optical contrast enhancement by designing fillet structures with surfaces that reflect light differently from the mounting board and semiconductor chip surfaces. The raised fillet geometry creates visible optical differences that enhance detectability during visual inspection, effectively using optical property variations to improve measurement precision for downsized devices.
2Measurement precision
If traditional X-ray inspection methods are used for downsized devices, then inspection accuracy is maintained, but inspection cost and time increase
Solution Approach 1:
The patent replaces expensive, time-consuming X-ray inspection equipment with simple, inexpensive visual inspection methods. By creating fillet structures that are inherently visible through standard optical inspection, the system eliminates the need for costly specialized equipment while maintaining inspection effectiveness, thereby reducing both cost and time losses.
Solution Approach 2:
The fillet structures serve a dual function: they provide mechanical/electrical connection functionality and simultaneously serve as self-indicating inspection features. The raised fillet geometry automatically creates visible indicators of proper soldering, eliminating the need for separate complex inspection equipment and enabling rapid visual verification by inspection personnel.
3Volume of moving object
If bonding pads are scaled down to enable device downsizing, then device integration is improved, but visual confirmability of solder connections deteriorates
Solution Approach 1:
The patent compensates for the reduced lateral dimensions of scaled-down bonding pads by creating vertical dimensionality through raised fillet structures. Instead of relying on lateral resolution to detect small bonding pad connections, the inspection system observes the height and profile of fillets that extend upward, making connections visually detectable despite the miniaturization of underlying bonding pads.
Solution Approach 2:
The patent segments the connection structure into distinct functional components: the miniaturized bonding pad, the solder material forming the fillet, and the mounting board. By separating these components and allowing the solder to form a distinct raised structure, the inspection system can detect the solder connection independently of the bonding pad size, overcoming the visual detection difficulty caused by scaling.
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
Enables cost-effective, rapid, and high-accuracy inspection of solder connections by allowing direct visualization of fillets formed on the terminal bodies, simplifying the inspection process and improving accuracy compared to traditional methods.
Implementation Method 1
a connection member 205 connecting the terminal bodies 20 and connection pads 203 of the mounting substrate 210. The terminal body 20 includes... a metal layer 25 including a material having a wettability for a connection member 205, e.g., a solder material, that is higher than the wettability of the core member 23 for the connection member 205
Data Source
AI summary
A semiconductor device includes a molded body and an interconnection layer. The molded body includes a semiconductor chip, at least one terminal body disposed around the semiconductor chip and a resin member provided between the semiconductor chip and the terminal body. The molded body has a first surface, a second surface opposite to the first surface and a side surface connected to the first and second surfaces. The interconnection layer is provided on the first surface of the molded body. The interconnection layer includes an interconnect electrically connecting the semiconductor chip and the terminal body. The terminal body has first and second contact surfaces. The first contact surface is exposed at the first or second surface of the molded body. The second contact surface is connected to the first contact surface and exposed at the side surface of the molded body.