Component-on-Package Lead Insulation to Prevent Solder Wicking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Forming a reliable electrical connection between an externally attached component-on-package (CoP) and an underlying substrate is challenging due to issues with terminal configuration and interconnect reliability, particularly in high-power applications where current and thermal management are critical.
Innovation Solution
The solution involves an electronic device package with a substrate and a package body, where a component with insulated leads is mounted, featuring a conductive pad exposed through a hole in the package body. The leads include an insulated portion and a distal exposed portion, allowing for electrical connection via a conductive material like solder, with the insulating layer strategically positioned to prevent excessive solder wicking and ensure reliable contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If leads are fully exposed for electrical connection, then electrical connection reliability improves, but solder wicking and bead formation occur causing connection defects
Solution Approach 1:
The lead is designed with different surface properties at different locations: the distal portion remains exposed to enable reliable solder connection, while the intermediate portion is coated with an insulating layer to prevent harmful solder wicking. This local differentiation of surface quality allows the same lead to simultaneously achieve good electrical connection and prevent solder defects.
2Object-generated harmful factors
If insulating layer covers the entire lead, then solder wicking is prevented, but electrical connection reliability deteriorates
Solution Approach 1:
The insulating layer is applied selectively only to the intermediate portion of the lead, leaving the distal portion exposed. This localized insulation approach prevents solder wicking in the intermediate region while maintaining electrical connection capability at the distal region, resolving the contradiction between preventing harmful effects and ensuring reliable connection.
3Power
If component footprint is reduced for high-power applications, then power density increases, but electrical connection reliability becomes more critical and difficult to achieve
Solution Approach 1:
By applying insulation locally rather than uniformly, the design enables smaller component footprints while maintaining reliable electrical connections. The exposed distal portion ensures good solder joint formation in reduced space, while the insulated intermediate portion prevents solder defects that would compromise connection reliability in high-power density applications.
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 configuration enhances the reliability of electrical connections by preventing solder wicking and bead formation, thereby improving the mechanical, thermal, and electrical integrity of the connection between the component and the substrate, suitable for high-power applications with reduced footprint.
Implementation Method 1
the insulating layer strategically positioned to prevent excessive solder wicking
Data Source
AI summary
An electronic device and a method of forming such an electronic device are disclosed. The electronic device can include an integrated device package and a component. The integrated device package includes a substrate and a package body over the substrate, and a hole formed through the package body to expose a conductive pad of the substrate. The component is mounted over the package body, and includes a component body and a lead extending from the component body through the hole. The lead includes an insulated portion and a distal exposed portion, and the insulated portion includes a conductor and an insulating layer disposed about the conductor, wherein the distal exposed portion is uncovered by the insulating layer such that the conductor is exposed at the distal portion. The electronic device can also include a conductive material that electrically connects the distal exposed portion to the conductive pad of the substrate.