Selection of electric soldering iron for soldering circuit boards and soldering skills
The universal circuit board is a printed circuit board that is covered with pads according to the standard IC spacing (2.54mm), and can be inserted and connected with components and wiring according to one's own wishes, commonly known as "hole board". Compared with professional PCB plate making, perforated board has the following advantages: low threshold for use, low cost, easy to use, and flexible expansion. For example, in college students' electronic design competitions, the works usually need to be completed within a few days, so most of them use perforated boards.
Choice of pergboard
There are two main types of perforated boards currently on the market, one with independent pads, and the other with multiple pads connected together. Single-hole boards are divided into single-sided boards and double-sided boards. According to the author's experience, single-hole boards are more suitable for digital circuits and single-chip microcomputer circuits, while multi-hole boards are more suitable for analog circuits and discrete circuits. Because digital circuits and single-chip microcomputer circuits are mainly chips, the circuits are more regular; while analog circuits and discrete circuits are often more irregular. The pins of discrete components often need to be connected to multiple wires. At this time, it is more convenient if there are multiple pads connected together.
In addition, readers need to distinguish between two different materials of pergboard: copper plate and tin plate. The pad of the copper plate is bare copper, which is golden yellow. It should be wrapped in paper to prevent the pad from oxidizing. Clean with alcohol or wipe with an eraser. A layer of tin is plated on the surface of the pad, which is a tin plate, and the pad is silvery white. The substrate material of the tin plate is harder than the copper plate, and it is not easy to deform.
Preparation before welding
Before soldering the perforated board, it is necessary to prepare enough thin wires for wiring. Thin wires are divided into single-strand and multi-strand: single-strand hard wire can be bent into a fixed shape, and can be used as a jumper after peeling; multi-strand thin wire is soft and messy after welding.
The perforated board has the characteristics of tight pads, which requires our soldering iron tip to have higher precision. It is recommended to use a pointed soldering iron with a power of about 30W. Similarly, the solder wire should not be too thick, it is recommended to choose a wire diameter of 0.5~0.6mm.
Welding method of perforated plate
For the layout of components on the perforated board, most people are used to "follow the vines", that is, to focus on key components such as chips, and insert other components as needed. This method is planning while welding, order is reflected in disorder, and the efficiency is high. However, due to the lack of experience of beginners, this method is not suitable for use. Beginners can first make a preliminary layout on paper, and then use a pencil to draw on the front (component surface) of the perforated board, and then plan the wiring Come out to facilitate their own welding.
The welding method of the perforated board is generally to use the thin wire mentioned above to connect the flying wire. There is not much skill in connecting the flying wire, but the horizontal and vertical wiring should be done as much as possible, neat and clear. Now there is a popular method on the Internet called the tin connection method, as shown in Figure 6, the workmanship is good and the performance is stable, but it is a waste of tin. Pure tin wiring is more difficult and is affected by various aspects such as tin wire and personal welding process. If you pull a thin copper wire first, and then drag and weld with the thin copper wire, it is much simpler. The welding method of the perforated board is very flexible and varies from person to person, just find the method that suits you.
Perforated board welding skills
The boards soldered by many beginners are very unstable and prone to short circuits or open circuits. In addition to factors such as unreasonable layout and poor welders, lack of skills is one of the important reasons for these problems. Mastering some skills can greatly reduce the complexity of the circuit reflected to the physical hardware, reduce the number of flying wires, and make the circuit more stable. Let's talk about the welding skills of the perforated board based on the author's experience.
1. Initially determine the layout of the power supply and ground wires
The power supply runs through the circuit all the time, and a reasonable power supply layout plays a key role in simplifying the circuit. Some perfboard layouts have copper foil running through the entire board, which should be used as power and ground wires; if there is no such copper foil, you also need to have a preliminary plan for the layout of the power and ground wires.
2. Be good at using the pins of components
The soldering of the perforated board requires a lot of jumpers, jumpers, etc. Don't rush to cut off the extra pins of the components. Sometimes it will be more effective to jump directly to the pins of the surrounding components to be connected. In addition, for the purpose of saving materials, the cut component pins can be collected as jumper materials.
3. Good at setting jumpers
It is especially important to emphasize this point, multi-set jumpers can not only simplify the connection, but also look much more beautiful.
4. Be good at using pin headers
I like to use headers because they have so many flexible uses. For example, if two boards are connected, you can use pin headers and seat rows. The pin header not only plays the role of mechanical connection between the two boards, but also plays the role of electrical connection. This is borrowed from the board connection method of the computer.
5. Cut off the copper foil when needed
When using a perforated board, in order to make full use of the space, if necessary, a knife can be used to cut off a certain copper foil, so that more components can be placed in a limited space.
6. Make full use of double-sided panels
Double-panel is more expensive, since you choose it, you should make full use of it. Each pad of the double-sided board can be used as a via hole to flexibly realize the front and back electrical connections.
