Assignment 8: Electronics Production
In this assignment, we learned about electronics production, including PCB milling and operating a PCB milling machine. We practiced soldering techniques to assemble components onto our PCB boards. Understanding the correct placement and orientation of components was crucial for a successful assembly. We also explored troubleshooting methods to check for soldering defects and ensure proper connections. Overall, this assignment helped us gain hands-on experience in fabricating and assembling electronic circuits.
Highlight Moments of the Week
PCB Fabrication
Etching for PCB Fabrication
Etching is a process used to remove unwanted copper from a PCB to create circuit traces. It involves transferring the PCB design onto a copper-clad board and then using a chemical solution like ferric chloride to dissolve the excess copper. Before etching, a protective layer (such as toner or UV-resistant ink) is applied to the desired traces to prevent them from being removed. The board is then submerged in the etching solution, and agitation helps speed up the process. Once the excess copper is removed, the board is cleaned, and holes are drilled for component placement. for More information
Material removal (engraving) for circuit board production
Material removal, also known as engraving, is a method used to create circuit paths on a copper-clad board. A high-speed cutting tool scrapes away unwanted copper, leaving only the required connections. This process is controlled by a programmed machine that follows precise coordinates to ensure accuracy. Unlike chemical etching, engraving does not involve harmful solutions, making it a cleaner alternative. The depth and width of the cuts depend on the tool size and material properties. Proper speed and feed rate settings are crucial to prevent damage to the board. After engraving, the board is cleaned to remove debris before component assembly. This method is widely used for rapid prototyping and custom PCB manufacturing. for More information
Material, Machine and Tools used in PCB Machining (Milling) for my Electronics Production:
Material:
- FR1-Phenolic paper is a type of insulating material used for making low-cost printed circuit boards. It is made from layers of cellulose paper soaked in phenolic resin, giving it good mechanical strength and electrical insulation. This material is easy to machine and drill, making it suitable for prototyping and simple electronics. Unlike fiberglass-based boards, FR1 is less durable but provides good heat resistance for basic applications. It is commonly used in single-layer PCBs due to its affordability and ease of processing.
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Machine:
The SRM-20 milling machine is a compact and precise desktop CNC used for PCB fabrication and prototyping. It operates by cutting away unwanted copper from a board using small milling bits. This machine follows G-code instructions to carve circuit traces with high accuracy. It supports different tool sizes, allowing for fine detail work and efficient material removal. The SRM-20 is user-friendly, making it suitable for beginners and experienced users alike. It requires careful speed and depth settings to avoid damaging the PCB. Regular maintenance, such as cleaning dust and checking tool alignment, ensures consistent performance. This milling machine is widely used for custom circuit board production and other precision machining tasks.
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Tools:
PCBs can be fabricated using conventional end mills. Flat end mills offer several benefits due to their straight profiles and uniform diameters, which help maintain consistent trace widths, even if the FR-1 PCB blank isn’t perfectly level. Additionally, flat end mills excel at removing large sections of material efficiently, with larger ones capable of rapid material removal.
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PCB assembly
PCB assembly is the process of soldering electronic components onto a printed circuit board (PCB) to create a functional electronic device. It involves placing and soldering components such as resistors, capacitors, ICs, and connectors onto the board. Read More,
Solder is a metal alloy used to join electronic components to a PCB by melting and bonding them securely. It creates a strong electrical connection between component leads and copper traces on the board. The most common types are lead-based and lead-free solder, each with different melting points and properties.
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Solder paste is a thick mixture of tiny solder particles and flux, used in PCB assembly to connect surface-mount components. It is applied to the board using a stencil before components are placed, and then melted during reflow soldering to form strong electrical connections. This process ensures precise and efficient soldering for modern electronics.
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Solder flux is a chemical cleaning agent that removes oxidation from metal surfaces before and during soldering. It helps solder flow smoothly, improves adhesion, and ensures a strong electrical connection. Without flux, solder joints may become weak or unreliable due to oxidation and impurities.
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Desoldering Vacuum Pump or Solder SuckerA desoldering vacuum pump, also known as a solder sucker, is a tool used to remove molten solder from circuit boards. It works by creating a quick suction force to pull away excess solder, making it easier to fix mistakes or replace components. This tool is essential for rework and repair in electronics.
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