Electromagnetic Shielding for IC Modules Using Chemical-Resistant Tape
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Solution Overview
Problem
The challenge in manufacturing electromagnetic shields for integrated circuit modules is to effectively cover the sides of the modules without damaging input/output contacts and ensuring cost-effectiveness, while also preventing electromagnetic interference (EMI) and crosstalk.
Innovation Solution
A method involving a precursor package with IC modules on chemical-resistant tape, followed by a sweller and desmear process, and then applying a shielding structure using electroless and electrolytic plating processes to fully cover the top and side surfaces of individual IC modules, ensuring the ground plane is electrically coupled and protecting the bottom surface from chemical damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the shield fully covers the side of the circuit module, then electromagnetic shielding effectiveness is improved, but the I/O contacts located at the bottom of the IC module may be attacked by chemistries used in the shielding process
Solution Approach 1:
A chemical-resistant tape is introduced as an intermediary protective layer between the chemistry processes and the I/O contacts. The tape is applied to the bottom surface of the module substrate before the sweller and desmear processes, preventing chemical attack on the I/O contacts while allowing the shielding structure to fully cover the side surfaces of the module.
Solution Approach 2:
The chemical-resistant tape is applied in advance before the chemistry processes that form the shielding structure. This preliminary protective action ensures that when the shielding material is applied and chemistries are used, the I/O contacts are already protected, allowing full side coverage without contact damage.
2Object-affected harmful factors
If the shield only partially covers the side of the circuit module, then the I/O contacts are protected from chemical attack, but there are potential escape points for electromagnetic field resulting in decreased shield effectiveness
Solution Approach 1:
The chemical-resistant tape serves as a temporary intermediary that protects I/O contacts during processing but does not extend up the side surfaces. This allows the shielding structure to fully cover the side surfaces for maximum EMI protection while the tape provides contact protection only where needed during the chemistry processes.
3Reliability
If chemical processes are used to form the shielding structure, then comprehensive shielding coverage is achieved, but the I/O contacts may be damaged by the chemistry
Solution Approach 1:
The chemical-resistant tape acts as a mediator that allows chemistry processes to proceed for forming the shielding structure while protecting the I/O contacts from chemical damage. The tape is applied to the bottom surface before processing and removed after the shielding structure is formed, ensuring both comprehensive coverage and contact integrity.
4Ease of manufacture
If a traditional shielding process is used without protective measures, then the process is simple and cost-effective, but the I/O contacts are damaged by chemical attack
Solution Approach 1:
The chemical-resistant tape is a simple, low-cost intermediary that can be easily applied and removed. It protects I/O contacts during the chemistry processes without significantly complicating the manufacturing process, maintaining cost-effectiveness while ensuring contact integrity.
Solution Approach 2:
The tape application is a simple preliminary step that prevents chemical damage to I/O contacts. This straightforward protective measure integrates easily into existing manufacturing processes without requiring complex equipment or procedures, maintaining ease of manufacture while protecting contacts.
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 allows for comprehensive shielding of IC modules without compromising I/O contacts, enhancing EMC by fully covering the sides while maintaining the integrity of the modules and reducing EMI, and is cost-effective by using appropriate tape and plating processes.
Implementation Method 1
the first I/O contacts of each module substrate are sealed and against the chemical resistant tape
Implementation Method 2
the electromagnetic emissions are electrically shorted through the grounded conductive material, thereby reducing emissions
Implementation Method 3
applying a shielding structure is performed using an electroless plating process
Implementation Method 4
applying a shielding structure using electroless and electrolytic plating processes
Data Source
AI summary
The present disclosure provides electromagnetic shielding for integrated circuit (IC) modules. First, a precursor package with a number of IC modules is provided. The precursor package is then placed onto a chemical resistant tape. After a sweller process and a desmear process are performed, the chemical resistant tape is removed. Next, the precursor package is singulated to form a number of individual IC modules. The individual IC modules are placed onto a carrier tape, such that a bottom surface of each individual IC module is covered by the carrier tape, and a top surface and side surfaces of each individual IC module are exposed. A shielding structure is applied completely over the top surface and the side surfaces of each individual IC module. Herein, the shielding structure is electrically coupled to a ground plane within each individual IC module.