Flip-Bonded Dual-Substrate Inductor With Nanoparticle Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flip-bonded dual-substrate inductors face challenges in achieving desired RF performance due to inconsistent spacing and uneven surface distribution between substrates, which affects mutual inductance and Q-factor, and the high temperatures required for solder bump reflow lead to unreliable bonding.
Innovation Solution
The method involves forming nanoparticle bumps using Ag, Cu, or Au nanoparticles to connect interconnection pads on separate substrates, allowing for flip bonding at lower temperatures (150° C - 300° C) and reducing substrate spacing, while ensuring consistent bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If solder bump reflow is used to bond substrates, then bonding strength is achieved, but substrate spacing becomes inconsistent and bonding reliability decreases
Solution Approach 1:
The patent changes the bonding parameters by using nanoparticle bumps with lower melting points (150-300°C) compared to traditional solder bumps, enabling bonding at reduced temperatures. This parameter change allows for more consistent substrate spacing and improved bonding reliability while maintaining adequate bonding strength through controlled nanoparticle sintering and diffusion.
Solution Approach 2:
The patent utilizes phase transitions of nanoparticles during the bonding process. The nanoparticle bumps undergo sintering and diffusion phase transitions at lower temperatures (150-300°C) to form reliable bonds between substrates. This phase transition approach enables consistent spacing control and improves bonding reliability compared to traditional high-temperature solder reflow.
2Strength
If traditional solder bump reflow is used, then bonding is achieved, but high temperatures cause inconsistent substrate spacing
Solution Approach 1:
The patent changes the temperature parameter from high-temperature solder reflow (>700°C) to low-temperature nanoparticle bonding (150-300°C). This parameter change prevents thermal expansion and warping issues that cause inconsistent substrate spacing, while still achieving adequate bonding strength through nanoparticle sintering and diffusion mechanisms.
3Volume of moving object
If substrate spacing is reduced for compact design, then miniaturization is achieved, but RF performance deteriorates due to uneven surface distribution
Solution Approach 1:
The patent changes the bonding temperature parameter to enable precise control of substrate spacing at low temperatures (150-300°C). This allows for consistent and uniform substrate spacing even at reduced distances, maintaining RF performance while achieving compact device design. The controlled nanoparticle bonding process ensures uniform spacing distribution.
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 enables precise control of substrate spacing, enhances RF performance, and provides a more reliable and consistent bonding process compared to traditional solder bump reflow, allowing for compact and high-performance inductor designs.
Implementation Method 1
attaching the base substrate surface to the cover substrate surface using a nanoparticle bonding material that electrically connects the first inductor body portion and the second inductor body portion
Implementation Method 2
The at least one nanoparticle bump preferably has a height in a range of about 10 μm to about 50 μm, for example. The step of attaching the base substrate surface to the cover substrate surface is preferably performed at a temperature between about 150° C. and 300° C., for example.
Data Source
AI summary
A flip-bonded dual-substrate inductor includes a base substrate, a first inductor body portion provided on a surface of the base substrate, a cover substrate, a second inductor body portion provided on a surface of a cover substrate, and a nanoparticle bonding material provided between the base substrate surface and the cover substrate surface to electrically connect the first inductor body portion and the second inductor body portion. A method for fabricating a flip-bonded dual-substrate inductor including forming a first inductor body portion on a surface of a base substrate, forming a second inductor body portion on a surface of a cover substrate, and attaching the base substrate surface to the cover substrate surface using a nanoparticle bonding material that electrically connects the first inductor body portion and the second inductor body portion.