Panel-Molded Electronic Assemblies With Exposed Contacts and Heat Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing encapsulated electronic power converters face challenges in achieving high power density while minimizing mounting area and cost, particularly in efficiently managing heat and exposing magnetic core structures for effective thermal management.
Innovation Solution
A method involving a panel molding process where a printed circuit board with components is encapsulated between heat sink panels, allowing for the exposure of magnetic core structures and semiconductor devices, and subsequent singulation to form individual modules with exposed contacts, which are treated for oxidation protection and electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the printed circuit board is fully encapsulated with encapsulant, then thermal management is improved and components are protected, but magnetic core structures cannot be exposed for effective thermal management
Solution Approach 1:
The encapsulation is segmented to expose specific magnetic core structures while encapsulating other components. The mold panels are configured with openings that allow selective exposure of magnetic cores, creating a hybrid structure where some regions are encapsulated and others are exposed for thermal management.
Solution Approach 2:
Different regions of the printed circuit board receive different treatments: magnetic core structures are exposed in specific locations while other components are fully encapsulated. This local differentiation allows optimized thermal management at critical heat-generating points while maintaining protection elsewhere.
2Power
If power density is increased, then energy conversion capability is improved, but mounting area and cost increase
Solution Approach 1:
Multiple functions are merged into the encapsulant material: thermal management through exposed magnetic cores, mechanical protection of components, structural support, and electrical insulation. This consolidation allows high power density in a compact footprint without proportionally increasing mounting area.
Solution Approach 2:
The design transitions from planar mounting to three-dimensional vertical stacking with exposed cores extending upward. This dimensional change allows increased power handling capability without proportionally increasing the footprint area, as power conversion elements are arranged vertically rather than only horizontally.
3Reliability
If contacts are exposed after cutting, then electrical connectivity is enabled, but oxidation protection is required
Solution Approach 1:
The contacts are treated with oxidation protection before the module is put into service. The method includes applying conformal coating or other protective treatments to exposed contacts during the manufacturing process, preventing oxidation before it can occur during operation.
Solution Approach 2:
A conformal coating or protective layer is introduced as an intermediary between the exposed metal contacts and the oxidizing environment. This intermediate layer provides electrical insulation and oxidation protection while allowing the contacts to maintain their electrical connectivity function.
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 enhances thermal management, reduces material costs, and allows for higher power density by effectively distributing heat and optimizing module design, while maintaining electrical connectivity and mechanical integrity.
Implementation Method 1
Encapsulation in this manner may aid in conducting heat out of the over-molded components
Implementation Method 2
curing the encapsulant
Data Source
AI summary
A method of encapsulating a panel of electronic components such as power converters reduces wasted printed circuit board area. The panel, which may include a plurality of components, may be cut into one or more individual pieces after encapsulation with the mold forming part of the finished product, e.g. providing heat sink fins or a surface mount solderable surface. Interconnection features provided along boundaries of individual circuits are exposed during the singulation process providing electrical connections to the components without wasting valuable PCB surface area. The molds may include various internal features such as registration features accurately locating the circuit board within the mold cavity, interlocking contours for structural integrity of the singulated module, contours to match component shapes and sizes enhancing heat removal from internal components and reducing the required volume of encapsulant, clearance channels providing safety agency spacing and setbacks for the interconnects. Wide cuts may be made in the molds after encapsulation reducing thermal stresses and reducing the thickness of material to be cut during subsequent singulation. External mold features can include various fin configurations for heat sinks, flat surfaces for surface mounting or soldering, etc. Blank mold panels may be machined to provide some or all of the above features in an on-demand manufacturing system. Connection adapters may be provided to use the modules in vertical or horizontal mounting positions in connector, through-hole, surface-mount solder variations. The interconnects may be plated to provide a connectorized module that may be inserted into a mating connector.