Disk Drive Flexure Tail Peninsula Design for Solder Reflow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing disk drive technologies face challenges in reliably and cost-effectively connecting the head stack assembly to the printed circuit board assembly while maintaining a clean environment, especially with the miniaturization of slider assemblies and increased electrical connections, which complicates solder reflow and ultrasonic wire bond techniques.
Innovation Solution
A suspension assembly with a flexure tail featuring peninsula-shaped regions and a layer of insulating material, allowing for conductive traces and connection pads that can bend and apply preload to the flexible cable, facilitating non-contact solder reflow and accommodating a greater number of smaller conductive traces without requiring expensive retooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of conductor leads is increased to accommodate magnetoresistive heads and miniaturized slider assemblies, then the electrical connection capability is improved, but the manufacturing complexity and difficulty of solder reflow increase
Solution Approach 1:
The tail portion is segmented into multiple independent fingers instead of a single solid structure. Each finger can be independently formed and positioned, allowing for multiple conductor leads while maintaining manufacturing simplicity. The segmentation enables each finger to function as an independent electrical connection path.
Solution Approach 2:
The conductor leads are arranged in a planar configuration on the surface of the tail portion rather than extending in three-dimensional space. This two-dimensional arrangement allows multiple conductor leads to be packed closely together while simplifying the solder reflow process, as all connections occur on the same plane.
2Reliability
If non-contact solder reflow is used to maintain manufacturing robustness, then the manufacturing reliability is improved, but the requirement for precise tail termination pad alignment increases
Solution Approach 1:
The tail portion is designed with specific geometric parameters including finger width, finger spacing, and finger length that are optimized for solder reflow bonding. The fingers have dimensions that allow them to deflect and conform to the flexible cable surface during the soldering process, compensating for alignment variations and ensuring reliable electrical connection.
Solution Approach 2:
The tail portion fingers are designed to be flexible and capable of deflection. During the solder reflow process, the fingers can dynamically adjust their position to conform to the flexible cable surface, ensuring that the solder bumps make proper contact even with slight misalignments. This dynamic adaptation reduces the precision requirements for initial pad placement.
3Area of stationary object
If the tail termination pads are made smaller to maintain equivalent joint strength with increased conductor leads, then the space efficiency is improved, but the difficulty of achieving uniform solder reflow increases
Solution Approach 1:
Instead of having one large termination pad for multiple conductors, the design segments the termination area into multiple smaller finger-like structures. Each finger has its own termination region, allowing for uniform solder reflow on each small pad while accommodating multiple conductor leads overall. This segmentation maintains space efficiency while ensuring uniform soldering.
Solution Approach 2:
The tail portion is constructed as a thin, flexible structure that can conform to the flexible cable surface. This flexibility ensures that all termination pads maintain consistent contact pressure and alignment with the cable during the solder reflow process, achieving uniform soldering across all pads even when they are small in size.
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
The solution ensures reliable electrical contact and scalability for disk drives by allowing for uniform solder reflow and increased compliance, effectively addressing the challenges of miniaturization and increased conductor leads in disk drive designs.
Implementation Method 1
a layer of insulating material disposed on the support layer; a plurality of connection pads, each being disposed on the layer of insulating material within a corresponding one of the plurality of peninsula-shaped regions
Implementation Method 2
facilitating non-contact solder reflow and accommodating a greater number of smaller conductive traces
Data Source
AI summary
A suspension assembly for a disk drive includes a load beam and a flexure. The flexure has a first end including a plurality of bond pads for electrical connection to a slider and a second end having a tail for attachment to a flexible cable. The tail includes a support layer having a free end defining cutouts forming a plurality of peninsula-shaped regions, such that a plane oriented perpendicular to the support layer and disposed between the peninsula-shaped regions and extending beyond the free end of the tail does not cut through any support layer material. An insulating layer may be disposed on the support layer. A connection pad may be disposed on the insulating layer on each of the peninsula-shaped regions. Conductive traces may be disposed on the insulating layer to electrically connect each connection pad to a corresponding bond pad. A head is coupled to the bond pads.