How does PCB design lay out components

What is circuit board welding? Virtual welding is a common line fault, there are two kinds, one is in the process of circuit board production, due to improper production technology, when the unstable state; The other is that after long-term use of electrical appliances, some of the more serious heating parts, the welding spot at the welding foot is very easy to appear aging stripping phenomenon caused by. The following patch processing manufacturer to explain how to identify circuit board problems and PCB design how to layout components related knowledge.

1. How to layout components in PCB design

Layout is an important link in PCB design. The result of layout will directly affect the effect of wiring, so it can be considered that a reasonable layout is the first step of successful PCB design. Layout is divided into two ways, one is interactive layout, the other is automatic layout, is generally adjusted on the basis of automatic layout with interactive layout, in the layout can also be redistributed according to the situation of the line, the two gate circuit exchange, so that it becomes the best layout for easy wiring.

After the layout is completed, the design documents and relevant information can be returned and marked on the schematic diagram, so that the relevant information in the PCB board is consistent with the schematic diagram, so that the future file and change design can be synchronized, and the relevant information of the simulation can be updated, so that the electrical performance and function of the circuit can be verified at the board level. Consider the overall beauty of a product is successful or not, one is to pay attention to the internal quality, two is to take into account the overall beauty, both are more perfect in order to consider the product is successful. On a PCB board, the Layout of components is required to be balanced, dense and orderly, not top-heavy or heavy.

Inspection of layout

1. Is the size of the printed board consistent with the size of the machined drawing? Can it meet the requirements of PCB manufacturing process? Is there a location marker? 2. Are there any conflicts between components in two-dimensional and three-dimensional space? 3. Is the component layout dense and orderly? Is it all done? 4. Can the components that need to be replaced frequently be easily replaced? Is the plug-in board easy to plug into the device? 5. Is there a proper distance between the heat sensitive element and the heating element? 6. Is it convenient to adjust adjustable components? 7. Are there radiators installed where heat dissipation is needed? Is the air flow smooth? 8. Is the signal flow smooth and the interconnection shortest? 9. Does the plug, socket, etc. contradict the mechanical design? 10. Has the interference problem of the line been considered?

2. How to identify circuit board problems

What is circuit board welding? Virtual welding is a common line fault, there are two kinds, one is in the process of circuit board production, due to improper production technology, when the unstable state; The other is that after long-term use of electrical appliances, some of the more serious heating parts, the welding spot at the welding foot is very easy to appear aging stripping phenomenon caused by. So how to distinguish circuit board welding problem? Circuit board welding identification method:

1. In the welding between the component foot of the circuit board and the solder, we can use the driver to press the solder welding edge to highlight the component foot. If the component foot can move, it is virtual welding.

2. If there is virtual welding between the solder joint and the pad, in general, we can press down on the circuit board components, which will lead to the loosening of the circuit board components, that is virtual welding. In the circuit board, virtual welding is divided into two basic situations: the first situation: Faced with this situation, we need to use a multimeter to test whether it is conductive. It is not easy to find the problem. If there is the influence of vibration or external force, it is easy to find at this time because the welding surface is small and it is easy to de-weld. The second situation: the circuit board is completely not welded, simple understanding is that the solder and solder joint is not welded, just simple contact. In this case, the first thing we need to do is to see if the cleaning of the welding surface is enough. If the cleaning is good, the multimeter also shows the conduction. Cleaning is not good, if there are oxides on the surface may be impenetrable, at this time the multimeter can not be very accurate check out the welding.

Solution: First of all, we need to apply a certain external force to the components to be welded. If there is no loosening, it can be judged that there is no virtual welding. In addition, can directly observe the solder joint, virtual welding of the solder edge and welding surface is not very good fit, generally can be seen, two methods, basically can be found out, at the same time, for not easy to judge, can take the method of welding to avoid, welding a solder joint quickly. To avoid virtual welding, mainly to the welding surface cleaning and tin, cleaning is best not to use solder paste, because contains acid material, may corrosion element pin, resulting in virtual welding, after cleaning oxide, to solder surface first on tin, and then welding is easy, is not easy to produce virtual welding.