Graphene-Coated Metal Ball EMI Shield Sintered by Intensive Pulsed Light
Solution Overview
Problem
Conductive shielding layers for semiconductor devices require a time-consuming thermal process to sinter metal particles, which is inefficient and limits the manufacturing speed and effectiveness of electromagnetic interference (EMI) shielding.
Innovation Solution
A graphene-based shielding layer is formed using intensive pulsed light (IPL) irradiation, which sinters the metal balls with a graphene coating, creating a conductive path to dissipate EMI and RFI, and reduces the manufacturing time significantly compared to traditional thermal processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sprayed metal layer is used to form a shielding layer, then EMI shielding capability is achieved, but the thermal sintering process becomes time-consuming
Solution Approach 1:
The patent replaces the traditional thermal field sintering system with a light field system. Intensive pulsed light irradiation is used to sinter the metal particles instead of conventional thermal processes, dramatically reducing the time required while achieving the same bonding effect. The light energy is absorbed by the metal particles, converting to thermal energy locally and rapidly, enabling fast sintering without the need for prolonged thermal exposure.
Solution Approach 2:
The patent employs pulsed light irradiation instead of continuous heating. The intensive pulsed light delivers energy in short, high-intensity bursts, which is sufficient to sinter the metal particles quickly. This periodic action allows the material to be processed rapidly while maintaining control over the sintering process, reducing overall manufacturing time compared to continuous thermal sintering.
2Reliability
If a sprayed metal layer is used for shielding, then EMI protection is provided, but manufacturing efficiency is reduced
Solution Approach 1:
The patent substitutes the slow thermal sintering process with intensive pulsed light irradiation. The light field delivers energy much faster than thermal conduction or convection, enabling rapid sintering of metal particles. This increases manufacturing throughput and productivity while maintaining the EMI shielding function, as the same protective layer is formed in significantly less time.
Solution Approach 2:
The patent changes the energy delivery parameters from low-intensity continuous thermal heating to high-intensity pulsed light irradiation. By altering the intensity, duration, and delivery method of the energy input, the sintering process is accelerated dramatically. This parameter change enables faster production rates while achieving equivalent or superior sintering quality, thereby improving overall manufacturing efficiency.
3Strength
If traditional thermal sintering is used, then metal particles are bonded, but the process is slow and costly
Solution Approach 1:
The patent replaces the thermal sintering system with a light field sintering system. Intensive pulsed light irradiation directly energizes the metal particles, causing rapid heating and bonding. This substitution maintains the bonding strength achieved by thermal sintering but accomplishes it in a fraction of the time, as the light energy is absorbed and converted to thermal energy locally and instantaneously within the particle structure.
Solution Approach 2:
The patent applies intensive pulsed light irradiation to pre-heat and rapidly sinter the metal particles in place, eliminating the need for prolonged thermal exposure. The pulsed light delivers the necessary energy upfront, causing immediate sintering action. This preliminary energy input achieves the bonding effect quickly, reducing the overall process time while maintaining bond strength equivalent to traditional 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
The graphene-based shielding layer effectively reduces EMI and RFI interference while significantly reducing manufacturing time, increasing the number of units per hour and offering superior electrical conductivity, thus enhancing the manufacturing efficiency and cost-effectiveness.
Implementation Method 1
A graphene-based shielding layer is formed using intensive pulsed light (IPL) irradiation, which sinters the metal balls with a graphene coating
Implementation Method 2
intensive pulsed light (IPL) irradiation, which sinters the metal balls with a graphene coating
Implementation Method 3
creating a conductive path to dissipate EMI and RFI
Data Source
AI summary
A semiconductor device has a substrate and an electrical component disposed over the substrate. An encapsulant is deposited over the electrical component. A shielding layer is formed over the encapsulant. The shielding layer includes a plurality of graphene-coated metal balls in a matrix. The shielding layer is sintered using intensive pulsed light (IPL) radiation.