Sintered Electronic Component Joints Using Surface Roughness Matching
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Solution Overview
Problem
Existing methods for connecting electronic components using metal sintering paste do not consistently achieve high connection strength, particularly in terms of mechanical stability and conductivity.
Innovation Solution
The method involves adjusting the arithmetic mean roughness (Ra) of the metal contact surfaces and using metal sinter compositions with specific particle size D90, maintaining a Ra/D90 ratio between 0.05 to 0.3, and applying a non-volatile metal sinter composition between the components, followed by sintering under controlled conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional metal sintering paste is used with standard particle sizes and surface roughness, then the joining process is simple, but the connection strength and mechanical stability are insufficient
Solution Approach 1:
The invention changes critical parameters of the sintering process: metal particle size D90 is optimized to 1-20 μm (particularly 3-10 μm), surface roughness Ra is controlled to achieve specific Ra/D90 ratios (0.05-0.3), and metal content is increased to 80-100 wt%. These parameter optimizations enable significantly higher connection strengths (up to 44.3 MPa shear strength) while maintaining a relatively simple sintering process workflow.
Solution Approach 2:
The invention applies preliminary surface treatment to the metal contact surfaces before sintering to achieve the required roughness characteristics. This preliminary preparation of the surface ensures optimal mechanical interlocking and bonding conditions, which directly contributes to the high connection strength achieved after sintering without requiring complex post-processing.
2Strength
If metal sintering paste with larger particle sizes is used, then the paste is easier to apply, but the connection strength and density decrease
Solution Approach 1:
The invention optimizes the metal particle size parameter to D90 = 1-20 μm (particularly 3-10 μm), which represents a fine particle size range that balances paste applicability with bonding performance. The fine particles provide large surface area for bonding while maintaining adequate flow characteristics for application, achieving both high bond strength (up to 44.3 MPa) and reasonable ease of manufacture.
Solution Approach 2:
The invention uses a composite paste composition consisting of 80-100 wt% metal particles (particularly silver) combined with organic vehicle materials. This composite structure allows the fine metal particles to be suspended and applied effectively in paste form, while the organic binder provides workability and adhesion during application, resolving the contradiction between particle size and ease of application.
3Strength
If the metal contact surfaces are made very smooth, then the surface quality is high, but the mechanical interlocking and connection strength are reduced
Solution Approach 1:
The invention changes the surface roughness parameter to achieve specific Ra values that optimize mechanical interlocking. By controlling the Ra/D90 ratio to 0.05-0.3, the surface provides adequate roughness for mechanical anchoring of the sintered metal particles while maintaining manufacturing feasibility. This results in superior mechanical stability with shear strengths reaching up to 44.3 MPa.
Solution Approach 2:
The invention applies local surface treatment to create the required roughness characteristics specifically at the metal contact surfaces where bonding occurs. This localized quality enhancement ensures optimal bonding conditions at the critical interface without requiring the entire component to have uniform roughness, balancing mechanical interlocking needs with manufacturing precision requirements.
4Reliability
If the metal sinter composition contains high proportion of volatile substances, then the paste is more fluid and easier to apply, but the porosity and connection quality deteriorate
Solution Approach 1:
The invention changes the composition parameter by increasing metal particle content to 80-100 wt% (particularly 82-85 wt% silver) and reducing volatile organic substance content to 15-30 wt%. This high metal content formulation maintains adequate paste fluidity for application while ensuring low porosity (particularly at the interface with metal contact surfaces) and high connection quality with shear strengths up to 44.3 MPa after sintering.
Solution Approach 2:
The invention uses a composite paste composition with optimized ratios of metal particles (80-100 wt%), organic vehicle (10-30 wt%), and optional additives (0-20 wt%). This composite structure provides sufficient fluidity during application through the organic vehicle while the high metal content ensures low porosity and high connection quality after sintering, resolving the contradiction between paste fluidity and connection quality.
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 results in a sintered connection with high bond strength and low porosity, ensuring both mechanical stability and effective electrical and thermal conductivity between the components.
Implementation Method 1
sintering the joining of electronic components is a common process... The sandwich configuration created using metal sintering paste is then subjected to a drying and sintering step, during which a mechanically strong, electrically and thermally conductive bond between the components is formed
Implementation Method 2
the sandwich configuration created using metal sintering paste is then subjected to a drying and sintering step
Data Source
AI summary
A method for connecting electronic components, comprising (1) a sandwich arrangement comprising two electronic components A and B, each having metal contact surfaces, and a metal sintering composition located between a metal contact surface A' of electronic component A and a metal contact surface B' of electronic component B, (2) optionally, drying the metal sintering composition, and (3) sintering the sandwich arrangement, wherein the metal sintering composition, based on its non-volatile fraction, comprises 80 to 100 wt.% metal particles (i) with a particle size D90 in the range of 1 to 20 µm, wherein the metal contact surface A' has an arithmetic mean roughness RaA and the metal contact surface B' has an arithmetic mean roughness RaB, and wherein at least one of the quotients RaA/D90 and RaB/D90 is in the range of 0.05 to 0.3.