5. Electronics production¶
Group assignment requirements¶
The group assignment for this week is the following:
- Characterize the design rules for your in-house PCB production process: document feeds, speeds, plunge rate, depth of cut (traces and outline) and tooling.
- Document the workflow for sending a PCB to a board house.
- Document your work to the group work page and reflect on your individual page what you learned
Fine Milling Machine Specs¶
Machine name: Roland SRM-20 Spindle Max speed in RPM: Adjustable 3,000 – 7,000 rpm Machine bed size (work area): 203.2 (X) x 152.4 (Y) x 60.5 (Z) mm Toolpath generation software used: Mods
Safety¶
Before using the machine, Murad, who works at the lab, provided us with guidance on the setup process and highlighted key safety procedures. This included familiarizing us with the integrated safety features of the Roland SRM-20 milling machine, such as the necessity for the front cover to be closed during operation, the presence of safety interlocks, and the location of the emergency stop button. Following these safety protocols is crucial for maintaining a safe working environment and preventing accidents.
PCB production process¶
Generating toolpath:¶
We used a program from ModsProject to make paths for the milling machine from a long picture. This picture helped create detailed routes for the machine to cut and trace the PCB design accurately onto the material. The program converted the design into clear instructions for the milling machine, making the production process smooth and precise.
We utilized Mods to create a toolpath for a test file, comprising both traces and an outline. The traces and outline images served as a basis for generating precise cutting and tracing instructions for the milling machine.
Settings¶
| Process | Feeds | Spindle Speed | Plunge Rate | Depth of Cut | Milling Bit Used |
|---|---|---|---|---|---|
| Trace Milling | 4 mm/s | 7000 | 4 mm/s | 0.15 mm | 1/64 in |
| Outline Cutting | 4 mm/s | 7000 | 4 mm/s | 0.6 mm | 1/32 in |
Machine setup¶
To set up the machine for milling, we carefully installed the milling bit using a lock screw mechanism to ensure it remained securely in place during operation. Due to the small size of the milling bit, it required delicate handling to prevent any damage.
After securing the milling bit, we attached the material to the machine bed using double-sided tape to ensure it remained stable during the milling process. This method provided a reliable hold while allowing for easy removal once the milling was complete.
As part of the setup process, we initiated the homing procedure, aligning the machine coordinates with the user-defined coordinates to establish the starting point for the milling operation. This ensured precise positioning and accurate execution of the milling tasks.
Results¶
After finishing the milling, we meticulously examined the results to assess the quality of the cuts. While overall, the cuts appeared clean and precise, upon closer inspection, we observed some rough edges along certain sections of the PCB outline.
Upon further investigation, we concluded that these rough edges were likely caused by small burrs, which resulted from the cutting bit nearing the end of its operational life and becoming slightly dull. To address this issue, we carefully removed the burrs using a metal edge.
Despite encountering this challenge, our test provided valuable insights into the intricacies of the milling process and highlighted the importance of monitoring tool condition and making necessary adjustments to optimize cutting performance.
In summary, while our setup and parameters yielded satisfactory results overall, this experience served as a learning opportunity, prompting us to explore ways to enhance the milling process for future projects and achieve consistently high-quality outcomes.
The workflow for sending a PCB to a board house¶
Ordering from JLCPCB¶
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Sign In/Register: If you don’t have an account, you need to sign up. If you already have an account, log in to your JLCPCB account.
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Upload Gerber Files: Once logged in, upload your Gerber files, which contain the design of your PCB. Make sure your Gerber files are correctly generated and contain all the necessary layers.
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Specify PCB Parameters: After uploading your files, you’ll be prompted to specify various parameters for your PCB, including the quantity, PCB thickness, copper weight, solder mask color, surface finish, and other options. Make sure to select the options that match your requirements.
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Review and Confirm Order: Review the details of your order, including the PCB specifications, quantity, and pricing. Make sure everything looks correct before proceeding.
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Add to Cart: If everything looks good, add your order to the cart.
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Checkout: Proceed to the checkout page, where you’ll need to provide your shipping address and select the shipping method.
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Payment: Choose your preferred payment method and complete the payment process. JLCPCB accepts various payment methods, including credit/debit cards, PayPal, and bank transfers.
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Wait for Manufacturing: Once your order is submitted and payment is confirmed, JLCPCB will begin manufacturing your PCBs. The manufacturing time depends on factors such as the complexity of your design and the chosen manufacturing options.
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Track Order: You can track the progress of your order through your JLCPCB account dashboard. JLCPCB provides updates on the manufacturing and shipping status of your PCBs.
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Receive PCBs: Once your PCBs are manufactured and shipped, you’ll receive them at the shipping address provided during checkout.
Ensure that your design complies with JLCPCB’s design rules and guidelines to avoid any issues during manufacturing. It’s also a good idea to review JLCPCB’s FAQs and support documentation for more information on ordering and manufacturing processes.
