PCBA Tech - Stm oil content tester and its multi-function features

STM oil content tester is a high-performance, one-box designSTM product, which has been widely used in the field of seed oil content testing. The product adopts a modular design concept and can be configured according to user needs to meet the actual needs of STM factories and scientific research. It has been widely used in food, agriculture, petrochemical, chemical fiber, energy, building materials and many other fields. It can not only meet the requirements of quality management and monitoring in the production process, but also can be used in research and development in related fields. This product not only has the characteristics of NMR without special sample preparation, non-destructive testing, and environmental protection, but also has excellent measurement accuracy and repeatability, fast analysis speed, simple and convenient operation, and is an ideal cost-effective instrument.

NMR has the significant advantages of non-destructive testing, multiple parameters in one machine, and the same number of parameters. When designing a magnet, first determine the type and size of the magnet based on experience, and then use the finite element method to calculate the exact size. The assembled magnet can achieve the required uniformity through passive shimming.

The principle of nuclear magnetic resonance analysis of the oil content tester:

In a static magnetic field, the magnetic nuclei have different energy levels. Electromagnetic waves of a specific frequency are used to irradiate the sample. When the energy of the electromagnetic waves is equal to the energy level difference, the nuclei absorb the electromagnetic waves and undergo energy level transitions, resulting in a resonance absorption signal. Nuclear magnetic resonance is in a static magnetic field. The physical phenomenon of atomic nuclei under the action of another alternating magnetic field, not all atomic nuclei can produce this phenomenon, atomic nucleus can produce nuclear magnetic resonance phenomenon because of nuclear spin. In NMR spectroscopy, spin-lattice relaxation time T1 and spin-spin relaxation time T2 can be used to describe the process of magnetization returning to an equilibrium state. The difference in NMR spectra can be seen from the difference in relaxation time. The NMR signal is a physical phenomenon of the emitted electromagnetic radiation, which is proportional to the density of the nucleus. NMR signals are used to reflect the chemical structure of the sample, the diffusion coefficient of molecules or atoms, the reaction rate, chemical changes and other properties.

Features of multi-function placement machine

Multi-function STM is also called high-precision STM or general-purpose machine. It can mount high-precision large and special-shaped components. Generally, it can also mount small chip components, which can cover almost all component ranges, so it is called multi-function placement machine. . Today, Kaiyang will talk about the basic features of the multi-function placement machine:

1. The structure of the functional placement machine mostly adopts the arch structure, which has the characteristics of high precision and good flexibility.

2. Most of the X and Y positioning systems are driven by full-closed-loop servo motors, and linear grating encoders are used for direct position feedback to avoid errors due to screw distortion. Some use dual motors and dual screw rods to drive on both sides of the platform in the y-axis, and use dual linear gratings for feedback, which can effectively reduce the waiting caused by the static placement of the head and reduce the asynchronous deformation of the beam. The error. There are more advanced linear magnetic levitation motors. In addition to the technical characteristics of dual drives, they also have the characteristics of direct drive, less wear on the mechanical structure, fast feedback, quiet, easy maintenance and high precision.

3. The multi-kinetic energy placement machine mostly adopts the fixed circuit board, and uses the movement of the placement head to achieve X and y positioning, and will not cause large or heavier components to shift due to inertia due to the movement of the table.

4. Can accept all material packaging methods, such as tape, tube, box and tray. In addition, when there are many materials in the tray, a multi-layer special tray feeder can be installed.

5. In addition to traditional vacuum suction nozzles, special suction nozzles can be used for special-shaped components that are difficult to suction. In addition, pneumatic grippers can be used for components that cannot be suctioned with vacuum suction nozzles.

6. When the components are calibrated, a top-view camera is generally used, which has the functions of front light, side light, backlight and online light, which can identify various components. If the size of the component is too large and exceeds one FOV of the camera, the top-view camera can also perform comprehensive analysis and correction after taking multiple videos. The placement head of some multifunctional placement machines is also equipped with a placement head moving camera, which can identify various smaller components.

7. In some products, some perforated plug-in (Pin h Paste) components also need to be mounted at the same time as other SMD components and processed by reflow soldering. The plug-in of such perforated plug-in components requires the machine to have high pressure placement. Ability. The placement head of some multifunctional placement machines has high-pressure placement capability, and the placement pressure can be controlled by a program, and the maximum can reach 5 kg.

8. Some multifunctional placement machines can be equipped with a flux dipping assembly system (Flux Dipping Assembly), which can carry out component stack packaging (Package on Package) and flip chip (Flip Chip) placement.

9. Some multifunctional STMs can also be equipped with a dispensing head for dispensing before mounting, tin patching or underfill for some STM components.

The multi-function placement machine can handle a variety of complex STM components and is an indispensable equipment in the production of complex electronic products. In some scientific research, testing, and trial production units, only one or more multifunctional placement machines are used for small batch production when they can accommodate the types of materials. However, the speed of the multi-function placement machine in processing small chip STM components is far from that of high-speed STM. Some high-speed STMs can mount small chip components at the same speed as the multi-function machine placement of the same components. 5 to 10 times the speed. Therefore, in medium and large-scale production, reasonable configuration is generally carried out according to the characteristics of the product, so that the efficiency of each equipment is close to the highest.