Lead Pad Surface Layout for Resin Adhesion in Semiconductor Packages
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Solution Overview
Problem
Conventional plating films used to improve adhesion between resin parts and leads in semiconductor devices can have undesirable effects on the proper operation of the device.
Innovation Solution
A semiconductor device design featuring first and second leads with rough and smooth regions on their pad portions, along with conductor members and a resin part, where the rough regions have higher surface roughness to enhance adhesion without interfering with device operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If plating films are applied to lead surfaces to increase surface area and improve adhesion to resin part, then adhesion between lead and resin part is improved, but the plating films may have undesirable effects on the proper operation of the semiconductor device
Solution Approach 1:
The lead surface is divided into two distinct regions: a smooth region that contacts the semiconductor element and a rough region that contacts the resin part. This local differentiation allows the smooth region to maintain proper electrical and mechanical operation with the semiconductor element, while the rough region provides enhanced adhesion to the resin part through increased surface area and mechanical interlocking.
2Strength
If plating films are applied to improve adhesion, then adhesion is improved, but device complexity increases due to additional processing steps and material layers
Solution Approach 1:
Instead of applying additional plating film material layers, the invention changes the surface topology parameter of the lead by forming a rough region with increased surface area. This can be achieved through processes like laser treatment, chemical etching, or mechanical roughening, which modify the existing lead surface rather than adding complex multi-layer plating structures.
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
Improves adhesion between the resin part and leads, preventing unintentional detachment while maintaining the proper functioning of the semiconductor device.
Implementation Method 1
The first rough region has a higher surface roughness than the first smooth region... to enhance adhesion without interfering with device operation
Data Source
AI summary
A semiconductor device is provided, which is configured to improve the adhesion between the resin part and the leads without interfering with proper operation of the semiconductor device. The semiconductor device includes a semiconductor element 1, a first lead 2 including a first pad portion 21, a second lead 3 including a second pad portion 31, a conductor member 61, and a resin part 8. The first pad portion 21 has a first-pad obverse surface 21a including a first smooth region 211 to which an element reverse surface 1b is bonded, and a first rough region 212 spaced apart from the semiconductor element 1 as viewed in z direction and has a higher roughness than the first smooth region 211. The second pad portion 31 has a second-pad obverse surface 31a including a second smooth region 311 to which a second bonding portion 612 is bonded, and a second rough region 312 spaced apart from the second bonding portion 612 as viewed in z direction and has a higher roughness than the second smooth region 311.