Embedded PCB Fuse Structure for Chip Short-Circuit Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In chip packaging, a short circuit during power-on can cause a large current, leading to high temperatures that carbonize the PCB and result in a fire, necessitating costly and space-consuming external fuses.
Innovation Solution
A package structure with an internal protection structure made of a hot-melt material, which blows at a lower melting point than the cabling layers to prevent excessive temperature rise and potential fire, using a via as part of the circuit board design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external fuses are added to protect against short-circuit currents, then the circuit board is protected from carbonization and fire, but the device complexity and space requirements increase
Solution Approach 1:
The protection structure is merged with the circuit board by embedding it within the dielectric layer, combining the protective function with the existing PCB structure rather than adding separate external components
Solution Approach 2:
The protection structure is nested inside the dielectric layer of the circuit board, with the hot-melt material positioned within the internal structure of the PCB to provide protection from within
2Reliability
If external fuses are added to protect against short-circuit currents, then the circuit board is protected from carbonization and fire, but the manufacturing cost increases
Solution Approach 1:
The protective function is merged into the circuit board manufacturing process itself, using the same lamination and curing steps to form both the dielectric layer and the embedded protection structure, eliminating the need for separate fuse component procurement and assembly
Solution Approach 2:
The circuit board structure itself provides the protection function through the embedded hot-melt material, making the system self-protecting without requiring additional protective components or assembly steps
3Reliability
If the protection structure uses a hot-melt material with lower melting point than the cabling layers, then the protection structure blows first to prevent fire, but the protection structure may be damaged under normal operating temperatures
Solution Approach 1:
The melting point parameter of the protection structure is specifically adjusted to be between the normal operating temperature range and the fire ignition temperature of the PCB materials, creating an optimal protection threshold that responds to dangerous conditions while remaining stable during normal operation
Solution Approach 2:
The hot-melt material utilizes phase transition (melting) as a protective mechanism, where the material transitions from solid to liquid state at a controlled temperature threshold to interrupt the electrical circuit and prevent fire, leveraging the predictable nature of phase change at specific temperatures
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
Prevents PCB carbonization and fire by effectively managing short-circuit currents without additional space or cost, enhancing layout efficiency and protection.
Implementation Method 1
The protection structure is made of a hot-melt material, and a melting point of the hot-melt material used by the protection structure is lower than melting points of the first cabling layer or the second cabling layer
Implementation Method 2
When the chip is short-circuited, currents at the protection structure, the first cabling layer or the second cabling layer, and the chip are increased. A temperature of a cable used to carry the current and a temperature of the protection structure rise due to the increase in the currents
Data Source
AI summary
A package structure includes a protection structure, a circuit board, and a chip. The circuit board includes a first cabling layer, a dielectric layer, and a second cabling layer that are laminated. The protection structure is disposed inside the dielectric layer. The protection structure is configured to electrically connect the first cabling layer to the second cabling layer, and the chip is electrically connected to the first cabling layer or the second cabling layer. When the chip is short-circuited, the protection structure blows first.