Board-to-Board Plug Connector Structure to Prevent Solder Wick
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Miniaturization of board-to-board connectors leads to reduced durability and instability in electrical connections due to deformation and solder wick issues during the surface mount technology process, especially when fitting nails are used for reinforcement.
Innovation Solution
A plug connector with an overlapping three-layered structure of fitting nails embedded in its sidewall, featuring central and lateral reinforcement portions, arm portions, and solder portions to enhance strength and prevent solder wick, ensuring stable electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the connector is miniaturized and has a low profile, then the connector size is reduced, but durability and strength of the connector body are degraded
Solution Approach 1:
The patent uses a composite structure combining a resin connector body with metal fitting nails embedded within it. This composite design allows the small connector to have enhanced strength and durability without increasing its overall size, as the metal fittings provide structural reinforcement while the resin body maintains the compact form factor.
Solution Approach 2:
The fitting nails are nested within the connector body, with metal reinforcement elements embedded inside the resin housing. This nested structure provides internal strengthening without adding external bulk, allowing the connector to maintain both small size and high strength simultaneously.
2Strength
If fitting nails are positioned at both ends of the connector to enhance strength, then connector durability is improved, but solder wick occurs during SMT process which degrades electrical connection stability
Solution Approach 1:
The patent extracts the harmful function of the fitting nail by separating its reinforcement function from its electrical connection function. The fitting nail is designed to provide mechanical strength without directly contacting the board, thereby preventing solder wick while maintaining structural integrity.
Solution Approach 2:
The connector body acts as an intermediary between the fitting nail and the board. The fitting nail is embedded in the connector body rather than directly soldered to the board, which prevents solder wick from occurring along the fitting nail while still providing the necessary mechanical reinforcement.
3Reliability
If fitting nails are directly connected to the board for electrical connection, then electrical connection is established, but solder wick moves toward the connector causing unstable electrical connection
Solution Approach 1:
The connector body serves as an intermediary that separates the electrical connection path from the solder wick migration path. Electrical connections are made through dedicated terminals within the connector body, while the fitting nails provide only mechanical support, preventing solder wick from traveling along reinforcement elements.
Data Source
AI summary
A plug connector for a board-to-board connector according to an embodiment includes: a connector main body which includes one pair of first sidewalls extended in a first direction and facing each other, and one pair of second sidewalls extended in a second direction perpendicular to the first direction, and facing each other; one pair of fitting nails which are over-molded in the plug connector; and a plurality of plug terminals which are over-molded on the one pair of second sidewalls, wherein each of the one pair of fitting nails includes: an upper surface contacting an upper end of the first sidewall; a central reinforcement portion which is curved downward from the upper surface to come into contact with at least a portion of an outer surface of the first sidewall; one pair of lateral reinforcement portions which are extended from the upper surface and are curved downward to come into contact with at least portions of respective outer surfaces of the one pair of second sidewalls; and one pair of arm portions which are curved from both left and right ends of the central reinforcement portion, are spaced toward an inside of the one pair of lateral reinforcement portions, and are extended in the second direction, wherein the central reinforcement portion includes a central solder portion which is extended downward from a lower end of the central reinforcement portion and encloses at least a portion of a lower surface of the first sidewall, wherein the one pair of arm portions include one pair of lateral solder portions which are extended downward from the arm portions and are curved to an outside to enclose at least a portion of a lower surface of the second sidewall.