Lead Frame Bending for Sensor Package Moulding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensor packages for automotive applications, such as ABS systems, face mould flow problems due to the volume mismatch between moulded portions after bending, leading to potential die cracks and yield loss, especially when space is limited.
Innovation Solution
A sensor package design featuring a lead frame with a first portion along a longitudinal axis and a second portion inclined to it, with a moulding body forming a one-piece body in a single moulding step, allowing precise orientation and fixation of components like the magneto resistive sensor and ferrite, and using fingers for electrical connections to facilitate easy bending and reduce mechanical stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lead frame is bent to achieve the required orientation of the sensor, then the sensor can be positioned correctly, but the mould volume becomes larger on one side creating L-shape cross section
Solution Approach 1:
The lead frame is pre-bent to the required orientation before the moulding process. This preliminary action ensures that the sensor is positioned correctly in the final product while avoiding the need for complex post-moulding adjustments or additional bending steps that would increase mould volume.
Solution Approach 2:
The lead frame is divided into multiple segments or sections that can be bent independently. This segmentation allows the lead frame to be configured into the required orientation without creating excessive L-shape cross sections, as each segment can be optimized for its specific bending requirements.
2Volume of stationary object
If the mould volume is reduced to avoid L-shape cross section, then mould flow problems are reduced, but the sensor orientation may be compromised
Solution Approach 1:
By pre-bending the lead frame before moulding, the required sensor orientation is achieved without needing to compensate for volume reductions in the mould design. This ensures that even with optimized mould volumes, the sensor maintains its correct orientation.
Solution Approach 2:
The lead frame design incorporates local variations in thickness or cross-section at critical bending points. This local quality adjustment allows the lead frame to be bent into the required orientation while minimizing the overall mould volume, preventing L-shape cross sections without compromising sensor positioning.
3Reliability
If the lead frame is bent after assembly, then the sensor and electronic parts are protected, but the bending process becomes more complex and time-consuming
Solution Approach 1:
The lead frame is bent to the required orientation before the sensor and electronic parts are assembled. This preliminary action simplifies the overall process by establishing the correct geometry early, allowing subsequent assembly steps to proceed without complex bending operations. The components are protected during assembly because the lead frame structure is already in its final configured state.
4Adaptability or versatility
If multiple moulding steps are used to achieve correct orientation, then the sensor package is more flexible, but the manufacturing process becomes more complex and time-consuming
Solution Approach 1:
The lead frame is pre-bent to the required orientation before moulding, establishing the correct geometry in advance. This single preliminary action replaces the need for multiple subsequent moulding steps or adjustments, simplifying the manufacturing process while maintaining orientation flexibility through the pre-configured lead frame design.
Solution Approach 2:
The lead frame design incorporates adjustable bending parameters such as bend radius, bend angle, and segment positioning. By optimizing these parameters during the design phase, the lead frame can be bent into various orientations without requiring multiple moulding steps, reducing manufacturing complexity while maintaining adaptability.
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 design enhances handling and reliability by maintaining the correct orientation of components, reducing the risk of die cracks, and optimizing the sensor package's size and performance, particularly in safety-critical systems like ABS systems.
Implementation Method 1
a magneto resistive sensor (40) and a ferrite (50), which are mounted to the second portion (20) and which magneto resistive sensor (40) is electrically connected to the application specific integrated circuit (30)
Implementation Method 2
magnetic detector having a magnetic resistance element for detecting a magnetic field
Data Source
AI summary
A sensor package includes a lead frame with a first portion extending and a second portion extending in a direction inclined with respect to the first potion. The sensor package also includes an application specific integrated circuit and a magneto resistive sensor and a ferrite provided with a molding body.