There are occasions when even the greatest soldering irons will not velocity up your soldering tempo. So what if the board soldered itself? That is the purpose of Carl Bugeja and this PCB that may solder itself after which different boards!
Bugeja’s strategy is described utilizing a pizza analogy: The PCB is the dough, the solder paste is the sauce, and the toppings are the circuit elements. Put all of this into the oven and you’ve got a ̶t̶a̶s̶t̶y̶ ̶p̶i̶z̶z̶a̶ a PCB able to go!
For these not acquainted with floor mount electronics, massive stencils are positioned over pre-fabricated PCBs. By way of the stencils, a layer of solder paste (suppose toothpaste, not typical solder), is utilized. A pick-and-place machine is then used to drop the elements onto the solder paste, after which the entire board goes right into a reflow over the place the elements are baked into place. If it’s good to make hundreds of boards, then that is the way in which.
Bugeja makes use of one of many many layers within the PCB as a method to transmit warmth. Relatively than one huge copper floor aircraft, Bugeja has reconfigured that layer right into a monitor that gives some resistance and heats up the board. This warmth causes the solder paste to reflow and the elements to be soldered into place.
Bugeja saved the resistor values low on goal. This enabled the boards to self-solder at 165 levels Celsius (328 levels Fahrenheit) utilizing simply 9 Volts. The magic 165°C is the temperature wanted to soften the low-temperature solder paste (Chip Quik TS391LT50 for these within the know). Bugeja selected a PCB building that was good as much as 170°C and since it is a one-shot, five-minute solder it supplied a sturdy medium for the board.
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The draw back of the method is that it is a one-shot course of, however Bugeja is ready for this and can use this layer as a floor (GND) aircraft by soldering a zero ohm resistor from the monitor to the GND connection. A chic answer, if we are saying so ourselves.
The circuit was designed utilizing Altium Designer and Bugeja used this as a bonus, routing the wavy self-soldering monitor round many vias that work between layers of the circuit. The enter for the soldering energy is by way of two extensions to the PCB. These extensions take the facility across the monitor and may be simply damaged off when the job is completed. How is that attainable? Utilizing “Mouse chew vias,” in different phrases tiny nibbles which can be fabricated instantly into the construction of the PCB. They are often simply damaged off and sanded down, leaving little or no hint of their existence.
The primary take a look at went nicely. Certain it wasn’t good, with a number of soldering blobs that wanted a bit rework, however the board got here out with no harm all it wanted was a bootloader, a number of part modifications, and a customized Arduino sketch to manage the following a part of the undertaking.
Initially, Bugeja manually managed the temperature by steadily rising the voltage, however Bugeja felt that a pc may do it higher! What expertise may precisely self-solder one other circuit utilizing the precise temperature profile of the solder paste? Nicely, that might be the PCB that Bugeja had simply self-soldered. Sure the freshly created board has an Atmel MEGA32U4 (nicely used within the Arduino world) and a temperature sensor (thermocouple). All of the person has to do is join their suitable board to the PCB, press a button and a PID controller will exactly prepare dinner your ̶p̶i̶z̶z̶a̶ PCB to order.
The second model (Bugeja referred to as this a “daughter”)of the board was linked to the unique (mom) utilizing two machine screws. The thermocouple was then taped to the underside of the board. Urgent the button began the Arduino sketch to run, controlling the temperature profile to 165°C the place the elements settled into their closing positions. The daughter board was successful, and Bugeja celebrated by creating one other board, the grand-daughter of the unique.
Bugeja’s undertaking is a superb strategy to floor mount soldering and one which we are able to see catching the attention of many electronics specialists eager to push the boundaries of what’s attainable within the topic. Proper now we both buy costly tools to reflow our floor mount builds, construct small initiatives utilizing MHP30 sizzling plates or go DIY with your individual reflow toaster oven.
You may learn extra about Bugeja’s undertaking and obtain the PCB recordsdata from their GitHub repository.