Concave Chip Pad Structure for Low-Impedance Circuit Bonding
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Solution Overview
Problem
Existing electronic devices face challenges in reducing impedance between metal pads and other conductive materials, leading to reliability issues due to damage and contact resistance, particularly during the manufacturing process.
Innovation Solution
The electronic device design incorporates a chip with a protective layer and encapsulation layer, featuring a concave pad surface treated using a combination of laser drilling and plasma etching processes to minimize residue and improve bonding, thereby reducing impedance and enhancing electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional manufacturing processes are used to form pads and conductive structures, then the manufacturing process is simple, but impedance between the pad and other conductive materials increases due to damage and contact resistance
Solution Approach 1:
The pad surface is pre-treated with laser drilling and plasma etching before bonding to remove contaminants and create a concave surface profile. This preliminary action ensures that when conductive materials are subsequently bonded to the pad, they achieve better mechanical interlocking and electrical contact, reducing impedance and improving connection reliability without complicating the overall manufacturing flow
Solution Approach 2:
Traditional mechanical or chemical etching methods are replaced with laser drilling followed by plasma etching. The laser provides precise, contactless material removal, while plasma cleaning eliminates the need for chemical baths and provides superior surface activation. This substitution reduces mechanical damage to the pad while achieving the desired surface morphology for low-impedance connections
2Reliability
If the pad surface is left flat and untreated, then the manufacturing process is simpler, but damage to the pad and impedance increase
Solution Approach 1:
Mechanical contact methods such as abrasion or chemical etching are replaced with laser drilling and plasma etching. The laser beam removes material without physical contact, eliminating mechanical stress and damage to the pad. Plasma etching then cleans and activates the surface without requiring chemical solutions. This substitution maintains pad integrity while achieving the concave surface profile needed for reliable electrical connections
Solution Approach 2:
The pad surface parameters are changed by controlling laser drilling parameters (power, pulse duration, scanning speed) and plasma etching conditions (gas composition, power, pressure) to create an optimal concave surface profile. By adjusting these parameters, the process achieves the desired surface morphology that reduces impedance and improves bonding without excessive material removal or damage to the pad structure
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 approach effectively reduces damage to the pads and impedance, improving the bonding ability with other conductive materials, resulting in enhanced electrical performance and reliability of the electronic device.
Implementation Method 1
at least one first surface treatment process is performed on the protective layer and the at least one pad to expose a portion of the at least one pad and form the concave surface of the at least one pad
Implementation Method 2
a combination of laser drilling and plasma etching processes to minimize residue and improve bonding
Data Source
AI summary
An electronic device is provided. The electronic device includes a chip, a protective layer, an encapsulation layer, and a circuit structure. The chip includes a base layer and at least one pad. The at least one pad is disposed on a first side of the base layer. The protective layer is disposed on the first side and has at least one opening. The at least one opening exposes a portion of the at least one pad. The encapsulation layer surrounds the chip and the protective layer. The circuit structure is disposed on the encapsulation layer and is electrically connected to the chip. The at least one pad has a concave surface. A portion of the circuit structure contacts the concave surface. A manufacturing method of the electronic device is also provided.