Multi-stage beam contacts for backplane signal integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electrical connectors face issues with signal integrity due to the creation of antennas/stubs during high-frequency operations, leading to increased cross-talk and electromagnetic interference, as traditional contact systems require a minimum 2.0 mm to 3.0 mm contact over-travel which resonates and negatively impacts signal capability.
Innovation Solution
The design incorporates a wafer pair with beam contacts and a contact divider that compresses inwardly and outwardly to form reliable connections with a backplane connector, minimizing stub length and maintaining low initial insertion force while ensuring high normal force when fully mated, thereby reducing antenna behavior and cross-talk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional contact systems use 2.0 mm to 3.0 mm contact over-travel to accommodate system tolerances, then reliable mechanical connection is achieved, but antenna/stub resonance occurs at 20-30 GHz that negatively impacts signal capability
Solution Approach 1:
The contact structure is divided into multiple segments: a fixed contact portion and a movable contact portion with independent degrees of freedom. This segmentation allows the movable portion to compensate for tolerances through its range of motion while the fixed portion maintains a short, non-resonant stub length, thereby resolving the contradiction between connection reliability and signal integrity.
Solution Approach 2:
The contact system transitions from a static fixed contact to a dynamic movable contact that can move within a defined range. This dynamic capability enables the contact to adapt to tolerance variations during mating while maintaining optimal electrical contact geometry, eliminating the need for excessive over-travel that would create resonant stubs.
2Object-affected harmful factors
If contact over-travel is reduced to minimize stub length, then antenna effects are reduced, but system tolerances for design, manufacture and assembly become difficult to accommodate
Solution Approach 1:
By segmenting the contact into fixed and movable portions, the system separates the functions of tolerance accommodation (handled by the movable portion's range of motion) and electrical connection (handled by the fixed portion with minimal stub length). This resolves the contradiction between reducing antenna effects and accommodating manufacturing tolerances.
Solution Approach 2:
The movable contact portion acts as an intermediary element that absorbs tolerance variations through its mechanical range of motion, allowing the fixed contact portion to maintain a short, non-resonant stub length. This intermediary mechanism enables both reduced antenna effects and tolerance accommodation.
3Productivity
If high frequency signals are transmitted, then data bandwidth is increased, but electrical noise such as reflections, cross-talk, and electromagnetic radiation increases
Solution Approach 1:
The segmented contact structure with fixed and movable portions creates a more controlled impedance transition, reducing signal reflections. The movable portion's ability to maintain optimal contact geometry minimizes cross-talk between adjacent contacts, thereby enabling high bandwidth transmission with reduced electrical noise.
Solution Approach 2:
The invention changes the geometric parameters of the contact stubs by using a movable contact that can adjust its position, effectively varying the electrical length of the stub to minimize resonance effects at high frequencies. This parameter adjustment reduces electromagnetic radiation and allows higher bandwidth operation with less noise.
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 minimizes stub length, reduces antenna effects, and maintains reliable electrical contact with low initial insertion force and high normal force, effectively addressing signal integrity issues at high frequencies.
Implementation Method 1
The contact sections of the daughtercard beam contacts are compressed toward the center of the channel when the daughtercard connector is initially inserted to connect with the backplane connector. The contact sections of the backplane beam contacts are compressed away from the center of the channel when the wafer pair is initially inserted to connect with the backplane connector.
Data Source
AI summary
An electrical connector has a first wafer having a first housing with a first plurality of contact beams extending from the first housing in a first plane. A second wafer has a second housing with a second plurality of contact beams extending from said second housing in a second plane substantially parallel to the first plane. A dividing panel member extends from the insulative housing between the first plurality of contact beams and the second plurality of contact beams. Each of the contact beams extending from the wafer pair is configured to mate with a corresponding backplane contact in a backplane connector. The contact beams extending from the wafer pair and the backplane contacts are configured such that each pair of corresponding contacts includes a first contact point and a second contact point. When the wafer pair is fully received by the backplane connector, contact between the contact beam and the backplane contact is maintained at both the first and second contact points. Each of the contact beams includes a pivot member configured such that the electrical connector has a low initial insertion force, but a high normal force when fully mated with the backplane connector.