Multi-Diameter PCB Component Hole for Single-Step Reflow Soldering
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Solution Overview
Problem
The existing PCB manufacturing process involves two separate soldering operations, which increase cycle time and expose components to higher temperatures, reducing reliability due to thermal stress.
Innovation Solution
A multi-diameter component hole design on the PCB, with a larger first section and smaller second section, allows for increased solder paste storage and flow, enabling a single reflow soldering process that forms a stronger solder joint with reduced thermal exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wave solder operation is used to solder through-hole electrical components, then the components are soldered to the PCB, but the cycle time increases and thermal exposure increases reducing reliability
Solution Approach 1:
The patent combines the solder paste application and storage function directly within the component hole structure itself. The multi-diameter component hole design allows solder paste to be stored in the enlarged first section, eliminating the need for separate solder paste application steps and enabling both SMD and through-hole components to be soldered in a single reflow operation, thereby reducing cycle time while maintaining reliability
Solution Approach 2:
The patent introduces a dimensional change by creating a multi-diameter component hole with different cross-sectional areas at different depths. The first section has a larger diameter than the second section, creating a stepped configuration that provides additional volume for solder paste storage within the same horizontal footprint, enabling improved solder joint formation without increasing overall component size
2Reliability
If a wave solder operation is used to solder through-hole electrical components, then the components are soldered to the PCB, but thermal exposure increases reducing reliability
Solution Approach 1:
The patent merges the solder paste application and storage function directly within the component hole structure itself. The multi-diameter component hole design allows solder paste to be stored in the enlarged first section, eliminating the need for separate solder paste application steps and enabling both SMD and through-hole components to be soldered in a single reflow operation, thereby reducing cycle time while maintaining reliability
Solution Approach 2:
The patent enables continuous useful action by allowing solder paste to be stored and applied continuously during the reflow soldering process. The solder paste stored in the first section of the component hole is continuously available to form solder joints with through-hole components as they are inserted, eliminating interruptions and reducing total process time and thermal exposure
3Strength
If conventional component holes are used, then manufacturing is simple, but solder paste storage capacity is insufficient for strong solder joints
Solution Approach 1:
The patent introduces a dimensional change by creating a multi-diameter component hole with different cross-sectional areas at different depths. The first section has a larger diameter than the second section, creating a stepped configuration that provides additional volume for solder paste storage within the same horizontal footprint, enabling improved solder joint formation without increasing overall component size
Solution Approach 2:
The patent applies local quality by creating a specific enlarged region (first section) within the component hole where solder paste storage is needed. The rest of the component hole (second section) maintains its original diameter to accommodate the component lead. This localized modification provides enhanced solder paste capacity only where needed, without unnecessarily complicating the entire hole 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 reduces manufacturing cycle time, enhances mechanical and electrical connectivity, and minimizes thermal stress by allowing a single soldering step with improved solder joint quality and reliability.
Implementation Method 1
the PCBs with the SMDs positioned thereon are subjected to a reflow soldering process. The reflow soldering process generally includes applying heat in a controlled manner to solder the SMDs to the pads of the PCB
Implementation Method 2
the PCB with the through-hole electrical components is then drawn over the surface of a pool of molten solder in which all of the through-hole electronics are soldered to the component holes of the PCB at once. Such a process is known as a wave solder
Data Source
AI summary
In at least one embodiment, a circuit board assembly that includes a printed circuit board is provided. The printed circuit board includes a top surface and a bottom surface for supporting at least one through-hole electrical component. The printed circuit board defines at least one component hole extending from the top surface to the bottom surface for receiving the at least one through-hole electrical component. The at least one component hole includes a first section having a first diameter and a second section having a second diameter. The first diameter is different from the second diameter. Each of the first and the second sections are configured to receive solder paste for forming a solder joint with the at least one through-hole electrical component.