Spindle Motor Base Plate Segmentation for Rigidity and Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spindle motors in storage disk drives face challenges with reduced thickness leading to decreased rigidity and potential sealing issues due to the use of flexible printed circuit boards, which can result in vibration and compromised sealing reliability.
Innovation Solution
The design incorporates a stator unit with a base portion featuring a through hole and a recessed area for the circuit board, where the circuit board's connection portion is accommodated within the recess, and a groove portion that suppresses capillary forces, allowing for a resin layer to seal the internal space effectively while maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the thickness of the base plate is reduced to achieve thinner disk drive apparatus, then the overall thickness is reduced, but the rigidity of the base plate decreases causing vibration
Solution Approach 1:
The base plate is segmented into multiple regions with different thicknesses: a first region with greater thickness for rigidity and a second region with smaller thickness for overall thinness. This segmentation allows the base plate to achieve both reduced overall thickness and maintained local rigidity where needed.
Solution Approach 2:
Different regions of the base plate are given different thickness qualities according to their functional requirements. The first region (with attachment holes) has greater thickness to provide rigidity and support mounting functions, while the second region has smaller thickness to reduce overall apparatus thickness, creating a non-uniform thickness distribution optimized for both strength and compactness.
2Adaptability or versatility
If a flexible printed circuit board is used to accommodate the stator connections, then the circuit board can flexibly adapt to the housing structure, but sealing reliability deteriorates due to time-dependent solder changes
Solution Approach 1:
A resin layer is introduced as an intermediary substance to seal the connection portion of the flexible printed circuit board within the housing. This resin layer compensates for the poor sealing properties of solder joints, preventing external air from entering the housing while still allowing the flexible circuit board to perform its electrical connection function.
3Reliability
If the connection portion of the circuit board is sealed with a resin layer, then sealing reliability is improved, but the resin may flow out to the external region through the recess portion
Solution Approach 1:
A protrusion is formed in advance at the bottom of the recess portion to act as a barrier against resin flow. This preliminary structural feature prevents the resin layer from flowing out to the external region while still allowing the resin to effectively seal the connection portion of the circuit board within the confined space.
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 rigidity of the spindle motor's base portion, prevents adhesive overflow, and ensures reliable sealing, thereby reducing vibrations and improving the overall performance and durability of the storage disk drive apparatus.
Implementation Method 1
a groove portion that suppresses capillary forces, allowing for a resin layer to seal the internal space effectively
Data Source
AI summary
A spindle motor includes a stator unit and a rotor unit supported to be rotatable with respect to the stator unit. The stator unit includes a stator, a base portion including a through hole, and a circuit board. The circuit board includes a connection portion to which a conductive wire from the stator is connected after passing through the through hole. A lower surface of the base portion includes a central region, a peripheral region, a recess portion, and a protrusion. A position of a distal portion of the protrusion is provided at a level higher than a level of a lowermost surface region of the central region and lower than a level of a bottom surface of the recess portion in a direction parallel or substantially parallel to a central axis.