PCB Busbar Layout for High-Current Power Tool Switches

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Traditional printed circuit boards (PCBs) in power tools face limitations due to thin metal traces that restrict the amount of power delivery to switches, necessitating larger trace widths that increase PCB size, which may not be feasible.

Innovation Solution

Incorporating busbars on the PCB surface to connect the power source directly to switches, increasing the cross-sectional area and improving current carrying capacity without significantly enlarging the PCB.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the width of metal traces is increased to deliver more power from the power source to the switches, then the power delivery capability is improved, but the size of the PCB increases

Engineering Contradiction:

Improvepower delivery capabilityVSAvoidPCB size

Core Design Contradiction:

PowerVSArea of stationary object

Solution Approach 1:

The patent transitions from two-dimensional metal traces on the PCB surface to three-dimensional busbars that extend vertically from the PCB surface. The busbars have a substantial thickness dimension (e.g., 0.0625 inches) that provides increased cross-sectional area for current carrying capacity without increasing the PCB's planar footprint. This dimensional change allows high-power current delivery while maintaining a compact PCB size.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The busbars are constructed from highly conductive materials such as copper or copper alloys, which provide superior electrical conductivity compared to standard PCB trace materials. This material selection enables the busbars to deliver high power through their increased cross-sectional area, resolving the contradiction between power delivery capability and PCB size by using materials with optimized electrical properties.

Inventive Principle:

Principle #40Composite materials

2Power

If the cross-sectional area of conductors is increased to improve current carrying capacity, then the electrical current transmission is improved, but the overall device size increases

Engineering Contradiction:

Improvecurrent carrying capacityVSAvoiddevice size

Core Design Contradiction:

PowerVSVolume of moving object

Solution Approach 1:

The busbars utilize the vertical dimension (thickness) to increase cross-sectional area for current carrying capacity. By extending conductors vertically from the PCB surface with substantial thickness (e.g., 0.0625 inches or greater), the patent achieves high current carrying capacity without increasing the device's planar footprint or overall volume, as the busbars are integrated within the existing PCB structure.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Enhances power delivery to motor switches, allowing for greater electrical current transmission and heat dissipation while maintaining a compact PCB design.

Implementation Method 1

The busbar electrically connects the power source to the switch for delivering an electrical current from the power source to the switch

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

allowing for greater electrical current transmission and heat dissipation

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS20250358934A1Power tool printed circuit board including busbars

Publication Date: 2025.11.20 MILWAUKEE ELECTRIC TOOL CORP

AI summary

A power tool including a motor, a power source that supplies power to the motor, and a printed circuit board (“PCB”) electrically connected to the motor and the power source. The PCB includes a switch and a busbar arranged on a surface of the PCB. The busbar electrically connects the power source to the switch for delivering an electrical current from the power source to the switch.