Today author from QiHe tvm802a mt pick and place machine sharing you with how to describe the characteristics of pcb circuit board solder resist ink
- viscous and thixotropic
During the fabrication of printed circuit boards,
Screen printing is one of the indispensable important processes.
To achieve pictorial fidelity,
It is required that the ink must have good viscosity and suitable thixotropy.
Viscosity is the internal friction of a liquid.
It shows that under the effect of external force,
slide one layer of liquid over another,
The frictional force exerted by the inner layer of liquid.
The thick liquid inner layer encounters greater mechanical resistance when sliding,
Thinner fluids have less resistance.
The unit of viscosity measurement is poise.
In particular, it should be pointed out that temperature has a significant effect on viscosity.
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Thixotropy is a physical property of liquids,
That is, its viscosity decreases under stirring conditions,
After standing still, it quickly restores its original viscosity characteristics.
After stirring, the thixotropic effect lasts for a long time,
Enough to make its internal structure from scratch.
To achieve high quality screen printing effect,
The thixotropy of the ink is very important.
Especially during the scraping process, the ink is agitated, thus making it liquefied.
This effect speeds up the speed of the ink passing through the mesh, and promotes the even integration of the ink that was originally separated by the mesh line.
Once the scraper stops moving and the ink returns to a static state,
Its viscosity just returns to original required data very quickly again.
Pigments and mineral fillers are generally solid,
After precision grinding,
Its particle size does not exceed 4/5 micron,
And form a homogeneous flow state in solid form.
Therefore, it is very important to require the ink to have precision.
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you can choose a reflow oven to meets your need like qfr630,qrf835,qrf1235
stencil printer model qh3040,qp3250,qfa5060
Also we have different kinds of smt pick and place machine like tvm802a,tvm802b,tvm802ax,tvm802bx,tvm925s,tvm926s,ql41,qm61,qm62,qm81,qm10
RF8835LS up8/down8 Zones Reflow Oven solder welding
QM10 SMT pick and place machine 10heads 80slots Fully Automatic Chip mounter SMT Assembly
QM81 SMT pick and place machine 8heads 80slots Fully Automatic Chip mounter SMT Assembly
QM61 SMT pick and place machine 6heads 63slots Fully Automatic Pick&place machine SMT Assembly chip mounter
QFA5060 automatic solder paste printer stencil printer machine screen printer machine
QP450+ automatic vision solder paste printer stencil printer machine screen printer machine
QRF1235 12 Zones SMT Reflow Oven solder welding with guide rail
QRF830 8 Zones SMT Reflow Oven solder welding with cabinet
QRF835 with rail 8 Zones SMT Reflow Oven solder welding
WHAT IS SMT pick and place machine？
SMT (Surface Mounted Technology) is a comprehensive system engineering technology, which covers substrates, design, equipment, components, assembly processes, production accessories and management. When it comes to SMT pick and place machines, the automatic SMT production line requires automatic loading and unloading machine, automatic solder paste printing machine, placement machine, reflow soldering machine, AOI inspection equipment, connecting table, etc. For these SMT assembly line equipment, Qihe SMT can offer you machines in prototype SMT line, small SMT production line, mass production SMT line at low SMT line cost. Contact us now if you are interested.
WHAT IS SMT ASSEMBLY LINE？
With the development of technology, future electronic products will be lighter, smaller and thinner. Traditional assembly technology can no longer meet the requirements of high-precision and high-density assembly. A new type of PCB assembly technology-SMT (Surface Mount Technology) has emerged. SMT Assembly is the use of automated machines to assemble electronic components on the surface of the circuit board. Its density, high speed, standardization and other characteristics occupies an absolute advantage in the field of circuit assembly technology. In addition, SMT assembly has a wide range of uses.
WHAT IS SMT PROCESS？
There are mainly three steps in SMT assembly line process flow： solder paste printing, components placement and reflow soldering.
- Solder Paste Printing
Its function in SMT line process is to print the solder-free paste on the pads of the PCB to prepare for the soldering of the components. The equipment used is a screen printing machine, located at the forefront of the SMT production line.
- Components Placement
Its function is to accurately install the surface mount components on the fixed position of the PCB. The equipment used is a placement machine, located behind the screen printing machine in the SMT production line.
- Reflow Soldering
Its function in SMT manufacturing line is to melt the solder paste so that the surface mount components and the PCB board are firmly bonded together. The equipment used is a reflow oven, located behind the placement machine in the fully automatic SMT production line.