Piezoelectric Element Bonding in Head Suspension Actuators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for attaching a piezoelectric element to an actuator in head suspensions are time-consuming and prone to adhesive flow into unintended gaps, affecting the rigidity, spring load, and dynamic characteristics of the head suspension.
Innovation Solution
A bonding tape is used to securely attach the piezoelectric element to the actuator attaching part, followed by a nonconductive adhesive to fix it in place, reducing the number of adhesive applying and hardening steps and preventing adhesive flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple adhesive applying and hardening steps are used to attach the piezoelectric element, then the fixation reliability is improved, but the manufacturing time increases and productivity deteriorates
Solution Approach 1:
The patent combines multiple adhesive applying and hardening steps into a single integrated process. The adhesive is applied once to the actuator attaching part, and the piezoelectric element is attached in one positioning operation, eliminating the need for separate applying and hardening cycles that were required in conventional methods.
Solution Approach 2:
The patent applies adhesive preliminarily to the actuator attaching part before the piezoelectric element is positioned. This preliminary adhesive application, combined with a positioning structure, ensures the element is securely fixed in the correct position during a single attachment operation, avoiding multiple subsequent adjustment and re-fixing steps.
2Strength
If adhesive is applied freely to attach the piezoelectric element, then the bonding strength is improved, but the adhesive flows into unintended gaps and affects the rigidity and dynamic characteristics
Solution Approach 1:
The patent applies adhesive locally to specific bonding surfaces of the actuator attaching part rather than freely across the entire assembly area. This localized adhesive application ensures strong bonding at the intended locations while preventing adhesive from flowing into unintended gaps that would compromise the rigidity and dynamic characteristics of the head suspension.
Solution Approach 2:
The patent introduces a positioning structure as an intermediary between the adhesive and the piezoelectric element. This positioning structure guides the adhesive to the correct location and prevents it from flowing into unintended gaps, while still allowing sufficient adhesive to be applied to achieve the required bonding strength.
3Manufacturing precision
If the piezoelectric element is attached with multiple adhesive steps, then the positioning accuracy is improved, but the number of process steps increases and manufacturing complexity increases
Solution Approach 1:
The patent incorporates a positioning structure that preliminarily determines the correct position of the piezoelectric element before adhesive bonding. This preliminary positioning action ensures high positioning accuracy is achieved in a single attachment step, eliminating the need for multiple positioning and repositioning operations that would increase process complexity.
Solution Approach 2:
The patent merges the positioning function and the bonding function into a single integrated attachment process. The positioning structure and adhesive application work together in one operation to achieve both accurate positioning and secure bonding, rather than requiring separate positioning and bonding steps as in conventional methods.
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 method stabilizes the rigidity, spring load, and dynamic characteristics of the head suspension by ensuring precise positioning and fixation of the piezoelectric element, improving productivity and preventing adhesive oozing into unintended gaps.
Implementation Method 1
a piezoelectric element fixed to the actuator attaching part and being deformable in response to a voltage applied thereto to move the head in the sway direction relative to the base
Implementation Method 2
a bonding tape bonding the piezoelectric element to the actuator attaching part
Implementation Method 3
an adhesive fixing the bonded piezoelectric element to the actuator attaching part
Data Source
AI summary
A head suspension includes a base to be attached to a carriage, a load beam having a rigid part and a resilient part that connects the rigid part to the base, the load beam applying load onto a read/write head, a flexure attached to the load beam and supporting the head, an actuator attaching part located between the base and the head, and a piezoelectric element being deformable in response to a voltage applied thereto to move the head in a sway direction relative to the base. For the head suspension, it bonds the piezoelectric element with a bonding tape to the actuator attaching part and applies an adhesive to fix the piezoelectric element to the actuator attaching part.