In the electronics industry, UV Dosimetry It is the process of using specialized equipment (such as Ushio UIT-250) To accurately determine the amount of ultraviolet light energy that components or materials receive in the production line.
Simply put, if we consider UV rays as the "heat" used to cook food, then photometric measurement is like using a "thermometer" to ensure the food (electronic components) is neither undercooked nor burnt.
In electronics manufacturing, the measuring instrument will provide two of the most important parameters:
Irradiance (mW/cm²): The intensity of the UV light at a given time helps check if the light is dimming or malfunctioning.
Light Dose/Stored Energy (mJ/cm²): The total amount of UV radiation that the components receive when passing through the drying oven is the most important indicator to ensure that chemical reactions (such as glue curing) occur completely.
Why is photometric measurement necessary in electronics?
The electronics industry demands extremely high precision, and measurement helps control three main issues:
UV Curing (Drying the glue and ink): Chip adhesives, barcode inks for PCBs, or protective coatings (conformal coatings) require a standard UV energy level to cure.
Too low: The thermal paste doesn't dry properly, causing components to detach or short circuits.
Too high: This can cause the adhesive to become brittle, the circuit board to yellow, or damage heat-sensitive components.
The process of photolithography: In printed circuit board (PCB) or semiconductor manufacturing, UV light is used to shape microscopic circuit traces. Photometric measurement helps ensure these traces are sharp and do not stick together.
Surface cleaning (UV Cleaning): Use short-wavelength UV light (such as 172nm measured by a probe). UVD-S172) to break organic bonds, cleaning the circuit board surface before soldering to increase adhesion.
The device of USHIO (Japan) It is the standard in high-precision industries such as semiconductor manufacturing, UV drying, and sterilization. For measuring photovoltaic (accumulated energy) and UV intensity, the two most common models are the UIT-250 and UIT-201
Popular device lines
Current UIT-250(Accumulated energy meter): Most versatile, allowing simultaneous measurement of intensity (mW/cm²) and stored energy (mJ/cm²The device can measure in 5 different wavelength ranges (172, 254, 313, 365, 405 nm) by changing the probe.
Current UIT-201 (Digital amperage meter): Specifically designed for measuring instantaneous intensity at common wavelength ranges such as 365nm and 405nm. Its compact design makes it suitable for rapid on-site testing.
UIT-700 series: The new generation features a touchscreen display and supports up to 6 wavelength ranges, including advanced UV LED lights.
Basic usage procedure: To obtain accurate results, you should follow these steps:
Install the sensor: Select a probe with a wavelength corresponding to the light source to be measured (for example, use a 365nm probe for a high-pressure mercury lamp).
Turn on the power and test: Press the power button and check the battery level. Ensure the device has been calibrated (Ushio recommends calibration every 6 months).
Perform the measurement:
Measure intensity: Place the probe directly under the light source. The value will be displayed in real time on the screen.
Measure accumulated energy: Press the “Start” button, pass the probe over the conveyor belt or under the UV lamp, then press “Stop”. The machine will calculate the total amount of light energy received by the surface.
Saving and Retrieving Data: Machine models such as UIT-250 It has internal memory (up to 4 minutes) and a PC connection port for plotting intensity distribution charts.
The combination of measuring instruments USHIO UIT-250 and probes UVD Series It is considered the gold standard in the UV industry (especially in the production of electronic and semiconductor components) thanks to the following outstanding advantages:
Flexible probe interchangeability (Plug & Play)The biggest advantage is its versatility. With just one UIT-250 unit, you can measure five different wavelength ranges by changing the interchangeable probes.
UVD-S254: Ultraviolet (UVC) range measurement, specifically for low-pressure mercury lamps (for germicidal purposes).
UVD-S313/S365/S405: Measures UVA/UVB levels, used with high-pressure mercury lamps or metal halide lamps (for drying glue, printing ink).
UVD-S172: Specifically for Excimer headlights (surface cleaning).
USHIO UIT-250 included UVD-S405 UV photometer probe (320 nm~470 nm)
Simultaneous measurement of Intensity and Accumulated EnergyThe device allows you to monitor two important parameters simultaneously on the screen:
Instantaneous intensity (mW/cm²): This helps check if the light output is stable.
Energy stored (mJ/cm²): The total amount of UV radiation that the product receives as it passes through the conveyor belt. This parameter determines the drying/adhesion level of the glue or ink.
Extremely heat-resistant design.The UIT-250 series and UVD probe are designed to withstand the harsh environment inside the drying oven.
The device body is capable of withstanding temperatures up to (for a short period of about 10 seconds). This allows you to place the device directly on a conveyor belt to run through the oven without damaging the internal electronic components.
Japanese Precision and Durability
Advanced optical sensors: UVD detectors offer extremely high sensitivity and very low error rates, helping to maintain product consistency in mass production lines.
Built-in memory: The device can continuously record measurement data. 4 minutesThis allows you to review the light intensity distribution graph after the machine has run through the drying oven.
Intelligent management features
Automatic power off: Helps save battery power when not in use.
Connect your PC: Data can be easily exported to a computer for quality management (QA/QC) reporting via a dedicated connection cable.
You can contact SEMIKI Company for advice on Ushio's UV photometers (such as the UIT-250 series and UVD Series probes).
SEMIKI is a reputable distributor and provider of calibration services for measuring equipment in Vietnam, specializing in Japanese-made instruments for the electronics industry.
Contact Semiki:
Website: You can find out more details and send a consultation request via Semiki.com.
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