Circuit Board Insertion Hole Structure for Stable Wave Soldering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing circuit board design with circular insertion holes and terminal posts experiences issues with the protruding legs folding due to size limitations, leading to poor engagement and reduced yield during wave soldering, as liquid tin pushes the insert member upward, affecting bonding.
Innovation Solution
The circuit board features an insertion hole with an expansion hole portion and an insertion hole portion connected to each other, allowing a maximum width greater than the hole diameter of the insertion hole portion, enabling easier passage of protruding legs and stable positioning, and a conductive layer is formed to ensure electrical connection and secure soldering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a circular insertion hole with limited diameter is used, then the structural integrity of the circuit board is maintained, but the protruding legs of the insert member cannot pass through without folding, resulting in poor engagement
Solution Approach 1:
The insertion hole is divided into two distinct segments: an expansion hole portion with a larger diameter and an insertion hole portion with a smaller diameter. This segmentation allows the protruding legs to pass through the expansion portion without folding, while the insertion portion provides precise positioning and maintains structural integrity. The segmented design resolves the contradiction by enabling reliable engagement without requiring a uniformly large hole that would compromise the circuit board structure.
Solution Approach 2:
Different portions of the insertion hole are given different local qualities: the expansion hole portion has a larger diameter to facilitate easy passage of the protruding legs, while the insertion hole portion has a smaller diameter for precise positioning and structural support. This local differentiation allows each portion to perform its specific function optimally, resolving the contradiction between engagement reliability and structural integrity.
2Reliability
If the insertion hole diameter is increased to allow easy passage of protruding legs, then engagement effect improves, but the insert member becomes displaced by liquid tin during wave soldering, reducing manufacturing precision
Solution Approach 1:
The insertion hole is segmented into an expansion hole portion and an insertion hole portion, where the smaller insertion portion acts as a positioning constraint that prevents the insert member from being displaced by liquid tin during wave soldering. This segmentation allows the larger expansion portion to facilitate easy passage of protruding legs while the smaller insertion portion maintains positioning accuracy, thus resolving the contradiction between engagement reliability and manufacturing precision.
Solution Approach 2:
The insertion hole features local quality differentiation with a larger diameter expansion portion for easy leg passage and a smaller diameter insertion portion for precise positioning. This local variation allows the structure to simultaneously achieve reliable engagement through the expansion portion and maintain manufacturing precision through the constraint provided by the insertion portion, preventing tin-induced displacement.
3Manufacturing precision
If a uniformly small insertion hole is used, then manufacturing precision is maintained, but the protruding legs must fold during insertion, causing poor engagement and reduced reliability
Solution Approach 1:
The insertion hole is segmented into two portions with different diameters: the expansion hole portion provides sufficient space for protruding legs to pass through without folding, while the insertion hole portion maintains precise dimensional control. This segmentation resolves the contradiction by allowing the expansion portion to ensure reliable engagement while the insertion portion maintains manufacturing precision.
Solution Approach 2:
The insertion hole structure transitions from a two-dimensional circular cross-section to a three-dimensional tapered structure with varying diameter along its length. This dimensional change allows the expansion portion to accommodate the protruding legs without folding while the insertion portion maintains precise positioning, thus resolving the contradiction between engagement reliability and manufacturing precision.
4Ease of operation
If the protruding legs are made more resilient to enable folding during insertion, then ease of operation improves, but the legs cannot rebound and unfold properly after passing through, reducing engagement effectiveness
Solution Approach 1:
The insertion hole is segmented into an expansion portion that provides sufficient space for the protruding legs to pass through without folding, eliminating the need for high resilience. This segmentation allows the legs to maintain their structural integrity while still enabling easy insertion, as they can pass through the expansion portion straight without requiring significant flexibility or rebound capability.
Data Source
AI summary
A circuit board includes a substrate having opposite upper and lower surfaces, and an insertion hole extending through the upper and lower surfaces and having an expansion hole portion and an insertion hole portion connected to and communicating with each other. The insertion hole has a maximum width measured from one end of the insertion hole portion passing radially through the centers of the insertion hole portion and the expansion hole portion to one end of the expansion hole portion that is radially opposite to the one end of the insertion hole portion. The maximum width is greater than a hole diameter of the insertion hole portion, while the hole diameter of the insertion hole portion is greater than a hole diameter of the expansion hole portion. An electronic device having the circuit board and a method of manufacturing the same are also disclosed.