Last Updated on November 3, 2022 by You Ling
Kindly note the Temperature, Time, and Ways.
This is the most frequent question about “How to Solder Piezo Ceramics”, whether you have the same doubt? As a piezo supplier, HE SHUAI company. The short answer is to contact us now. Cause finding the piezo expert for helping you for saving on more time and cost. Also, you will understand it well after reading this article.
What is welding(soldering)?
What are the welding methods？
What are the main welding methods of piezoelectric ceramics？
What tools are needed for welding piezoelectric ceramics？
HE SHUAI company experts share piezoelectric ceramic welding technology with you
HE SHUAI offer the Piezoelectric Ceramic Welding Case Sharing
1、What is welding(soldering)?
Soldering is the process of joining two or more electronic components or assemblies together using solder.
The choice of soldering technique depends on your needs, the materials used, and other specific factors such as high heat resistance or other requirements.
Before choosing the right welding process, you must know the meaning and precautions of each method.
Once the wrong soldering process is selected, it may directly burn out the electronic components or cause the finished product to fail.
2、What are the welding methods
There are more than 40 kinds of metal welding methods, mainly divided into three categories: fusion welding, pressure welding, and brazing.
Fusion welding is a method in which the workpiece interface is heated to a molten state during the welding process, and the welding is completed without pressure. During fusion welding, the heat source rapidly heats and melts the interface of the two workpieces to be welded to form a molten pool. The molten pool moves forward with the heat source, and after cooling, a continuous weld is formed to connect the two workpieces into one.
Pressure welding is to achieve atomic bonding between two workpieces in a solid state under pressure, also known as solid-state welding. The commonly used pressure welding process is resistance butt welding. When the current passes through the connecting end of the two workpieces, the temperature of the place rises due to the large resistance. When heated to a plastic state, the connection becomes one under the action of axial pressure.
Brazing is to use a metal material with a lower melting point than the workpiece as the solder, heat the workpiece and the solder to a temperature higher than the melting point of the solder and lower than the melting point of the workpiece, and use the liquid solder to wet the workpiece, fill the interface gap, and realize the connection with the workpiece. The interdiffusion of atoms to achieve the method of welding.
3、The welding methods mainly used for piezoelectric ceramics:
Soft Soldering is a popular soldering process in the PCBA assembly industry. Also the best choice for connecting smaller, compact, fragile components to printed circuit boards.
Specifically, what is soft soldering?
Soft Soldering is a type of connection method that uses solder with a melting point of not more than 450°C and is heated to a soldering temperature lower than the melting point of the base metal and higher than the melting point of the solder. The brazing filler metal spreads on the closely fitting joining surfaces by capillary action or on the workpiece surface by wetting.
Soldering material is a soldering material for soldering whose liquidus temperature (melting point) does not exceed 450°C. Solder filler metals are usually alloys that do not contain iron. A temperature of 450°C is the demarcation point between brazing and soldering. Most of the process parameters and influencing factors involved in brazing also apply to soldering. In fact, industry terms such as soldering, brazing, or silver soldering are also used to distinguish soldering from brazing.
Soft soldering is not as durable as other methods and does not form a strong joint, hence the “soft” designation.
Brazing or silver soldering
Hard soldering (also known as brazing, or silver soldering) produces stronger joints in your PCB than soft soldering.
Brazing heats the molten filler (solder) with a melting point lower than the workpiece to be connected to a temperature higher than the melting point, so that it has sufficient fluidity, and fully fills the space between the two workpieces by capillary action (called infiltration), and after it solidifies A method of joining the two together, traditionally called brazing (brazing) in the United States at temperatures above 427°C
Advantages of Brazing
Brazing has many advantages over other metal joining techniques such as welding. Because welding does not melt the joined base metal, it allows for tighter tolerances and produces clean joints without the need for secondary machining. In addition, it can weld different metallic and non-metallic materials (eg metalized ceramics). In general, brazing also produces less thermal deformation than welding due to uniform heating. Complex and multi-component workpieces can be welded. Another advantage is that brazing can coat or wrap the base metal for protective purposes. Finally, brazing is easily adaptable to mass production and can be automated because individual process parameters are not sensitive to changes.
Disadvantages of Brazing
The main disadvantage is that the joint strength is low. Due to the use of reflow fillers, the strength of the welded joint is likely to be lower than that of the base metal (which is much different from the strength of the general electric welded joint than the base metal), but greater than that of the filler metal. Another disadvantage is that solder joints can be damaged at high temperatures. In industrial production environments, the base metal of brazed joints requires a high degree of cleanliness. Some brazing needs to be controlled with a proper flux cleaner. The joint color is often different from the base metal, causing an aesthetic disadvantage.
Wave soldering is used for assembly in through-hole processes or surface mount technology (SMT). It is used for the mass assembly of printed circuit boards.
The PCB goes over a pan of molten solder that looks similar to a wave pool (that’s where the name comes from). When the board is in contact with the solder, the board components are attached together.
Components must be glued to the board prior to SMT wave soldering.
The SMT method has become more popular than through-hole, making wave soldering a less popular technology choice. Wave soldering was subsequently replaced by reflow soldering
The reflow soldering process involves the use of heated solder paste to attach components to a circuit board. The solder paste is heated and turned into a molten state, allowing the pads and pins to connect. Reflow soldering results in a permanent connection.
4、What tools are needed for welding piezoelectric ceramics
Manual welding using a welding torch, suitable for small batches, high-precision welding of piezoelectric ceramic samples
The automatic welding machine is suitable for welding large quantities and standardized piezoelectric ceramic products. It can ensure the consistency of welding.
5、He-shuai company experts share piezoelectric ceramic welding technology with you
There are 4 key points in piezoelectric ceramic welding
If the soldering time is too long, the piezoelectric ceramic may be desoldered
If the problem is too high, it will burn the piezoelectric ceramics
Choice of Solder
The component leads and pads are successfully heated immediately, knowing that you are ready to pay for the solder. What you do is place the tip of the solder on the pads and component leads, not the tip of the soldering iron.
Note that if they are all hot enough, the solder will flow freely all over the pads and leads. You will see how the flux melts and liquefies.
Continue adding solder to the joint until the pad is fully coated, and the solder forms a hillock with a concave side.
However, if it should start to pilling, you will have to use a lot of solders or if the pads placed on the board are not as hot as you think. Do not move the joint until the solder has solidified.
Check joints and clean
The next step is to check it. You should try to check the connector.
The next step is to trim the leads with a small set of side cutters, which you want to cut on top of the solder joints. After all the solder joints are made, you want to clean the board of any excess flux residue.
Some fluxes are hygroscopic and can absorb a lot of water, so they are very conductive. Most fluxes can be easily cleaned up by using methyl hydrate and a rag.
6、He-shuai’s Piezoelectric Ceramic Welding Case Sharing