For our display screens, when customers mention waterproofing, it’s important for us to understand which specific parts they require to be waterproof.
- The product needs to be waterproof. This usually applies to products with touch screens, where the backside waterproofing of the display screen relies on the customer’s external casing to ensure. Our main considerations lie in sealing the cover plate and the customer’s casing, as well as sealing the interface between the touch screen and the display screen.
- The touch screen cover assembly onto the customer’s product needs to be waterproof. This requirement is quite common, and customers often have specific data requirements for sealing, such as an IP rating, which grades the resistance of an enclosure against the intrusion of dust or liquids. In this case, we only need to select the appropriate 3M double-sided adhesive to achieve the desired waterproofing.
- Waterproofing is required between the display screen and the touch screen. Although some of our touch screens are optically clear adhesive (OCA) bonded to the display screen, the sensor part remains exposed. Therefore, it is necessary to use RTV sealant to seal the periphery of the bond between the touch screen and TFT (thin-film transistor) display.
- Waterproofing for touch screen functionality:
In some cases, customers may use the touch screen in environments where water droplets are present. In such situations, the touch screen should be able to function normally even with water droplets present (ensuring normal touch functionality with water present and preventing accidental touches from falling water droplets). In this scenario, it’s necessary to select appropriate ICs for better water or salt water stability.
- Waterproofing for PCBs:
Sometimes, customers request waterproofing for PCBs. In such cases, the solution typically involves adding a layer of conformal coating (also known as three-proof paint) onto the PCB. This coating is a transparent polymer film applied to the PCB, maintaining the shape of the printed circuit board while protecting the electronic components from environmental damage. This process enhances and prolongs their usability.
IP Rating — IP XX
The two digits following “IP” indicate the device’s enclosure’s protection against solid foreign objects and water ingress. The first digit represents the degree of protection against dust and ingress of solid foreign objects, while the second digit represents the degree of protection against moisture and water ingress. A higher number indicates a higher level of protection.
For example, in the IP54 rating, “IP” is the designation letter, “5” is the first digit indicating protection against contact and ingress of solid foreign objects, and “4” is the second digit indicating protection against water ingress.
| 1st digit | Intrusion protection | 2nd digit | Moisture protection |
| 0 | No protection. | 0 | No protection. |
| 1 | Protected against solid objects over 50mm, e.g. accidental touch by hands. | 1 | Protected against vertically falling drops of water, e.g. condensation. |
| 2 | Protected against solid objects over 12mm, e.g. fingers. | 2 | Protected against direct sprays of water up to 15 degrees from the vertical. |
| 3 | Protected against solid objects over 2.5mm, e.g. tools & wires. | 3 | Protected against direct sprays of water up to 60 degrees from the vertical. |
| 4 | Protected against solid objects over 1mm, e.g. wires & nails. | 4 | Protected against water splashed from all directions, limited ingress permitted. |
| 5 | Protected against dust limited ingress, no harmful deposits. | 5 | Protected against low pressure jets of water from all directions, limited ingress permitted. |
| 6 | Totally protected against dust. | 6 | Protected against strong jets of water, e.g. on ships deck, limited ingress permitted. |
| / | / | 7 | Ability to withstand immersion in water under specified pressure for a set duration without allowing water ingress to a level that would cause harm. |
| / | / | 8 | Under conditions agreed upon by the manufacturer and user, the product should be able to be submerged in water without reaching a harmful level of water ingress. |
ISO 16750 Standard
ISO 16750 is an international standard that specifies environmental conditions and testing for electrical and electronic equipment in road vehicles. It covers various aspects such as mechanical loads, vibrations, temperature, and humidity, among others, to ensure the reliability and durability of automotive electronic components and systems.
1. Scope
Waterproof testing includes second characteristic digits ranging from 1 to 8, corresponding to protection level codes from IPX1 to IPX8.
2. Waterproof Test Content for Various Levels:
(1) IPX1
Test Method: Vertical Drip Test
Test Equipment: Drip test device and its test method
Sample Placement: The sample is placed in its normal operating position on a rotating sample table at 1 revolution per minute (1r/min), with the distance from the sample top to the drip nozzle not exceeding 200mm.
Test Conditions: Drip rate of 1.0 ± 0.5 mm/min; Test duration: 10 minutes
(2) IPX2
Test Method: 15° Tilt Drip Test
Test Equipment: Drip test device and its test method
Sample Placement: Tilt the sample at a 15° angle from the vertical, with the distance from the sample top to the drip nozzle not exceeding 200mm. After testing one side, rotate to another side, repeating this process four times.
Test Conditions: Drip rate of 3.0 ± 0.5 mm/min; Test duration: 4 cycles of 2.5 minutes each, totaling 10 minutes.
(3) IPX3
Test Method: Rainfall Test
a. Oscillating Tube Rain Test
Test Equipment: Oscillating tube rainfall test equipment
Sample Placement: Select an appropriate radius for the oscillating tube so that the height of the sample platform is at the diameter position of the oscillating tube. Place the sample on the platform, ensuring that the distance from the top of the sample to the water spray nozzle is not greater than 200mm. The sample platform does not rotate.
Test Conditions: The water flow rate is calculated based on the number of water spray holes in the oscillating tube, with each hole at 0.07 L/min. During rainfall, water sprays from the water spray holes within a 60° arc segment on each side of the midpoint of the oscillating tube, totaling 120°. The test sample is placed at the center of the oscillating tube’s semi-circle. The oscillating tube swings 60° on each side of the vertical line, totaling 120°. Each swing (2×120°) takes approximately 4 seconds.
Test Pressure: 400 kPa; Test Duration: Continuous rainfall for 10 minutes; After 5 minutes of testing, rotate the sample 90°.
b. Nozzle Type Rain Test
Test Equipment: Handheld rainfall test equipment
Sample Placement: Position the sample so that the parallel distance from the top of the sample to the nozzle of the handheld spray is between 300mm and 500mm.
Test Conditions: During the test, a shield with balance weights should be installed. The water flow rate is set at 10 L/min.
Test Duration: The test duration is calculated based on the surface area of the test sample enclosure, with 1 minute per square meter (excluding the mounting area), and a minimum of 5 minutes.
(4) IPX4
Test Method: Water Splash Test
a. Oscillating Tube Water Splash Test
Test Equipment and Sample Placement: Select an appropriate radius for the oscillating tube so that the height of the sample platform is at the diameter position of the oscillating tube. Place the sample on the platform, ensuring that the distance from the top of the sample to the water spray nozzle is not greater than 200mm. The sample platform does not rotate.
Test Conditions: The water flow rate is calculated based on the number of water spray holes in the oscillating tube, with each hole at 0.07 L/min. Water is sprayed from the water spray holes within a 90° arc segment on each side of the midpoint of the oscillating tube, totaling 180°. The test sample is placed at the center of the oscillating tube’s semi-circle. The oscillating tube swings 180° on each side of the vertical line, totaling approximately 360°. Each swing (2×360°) takes about 12 seconds.
Test Duration: Same as the IPX3 test described in section (3) above (i.e., 10 minutes).
b. Nozzle Type Water Splash Test
Test Equipment: Handheld rainfall test equipment
Sample Placement: Remove the shield with balance weights from the equipment. Position the sample so that the parallel distance from the top of the sample to the nozzle of the handheld spray is between 300mm and 500mm.
Test Conditions: During the test, a shield with balance weights should be installed. The water flow rate is set at 10 L/min.
Test Duration: The test duration is calculated based on the surface area of the test sample enclosure, with 1 minute per square meter (excluding the mounting area), and a minimum of 5 minutes.
(5) IPX4K
Test Name: Pressurized Oscillating Tube Rain Test
Test Equipment: Oscillating tube rainfall test equipment.
Sample Placement: Select an appropriate radius for the oscillating tube so that the height of the sample platform is at the diameter position of the oscillating tube. Place the sample on the platform, ensuring that the distance from the top of the sample to the water spray nozzle is not greater than 200mm. The sample platform does not rotate.
Test Conditions: The water flow rate is calculated based on the number of water spray holes in the oscillating tube, with each hole at 0.6 ± 0.5 L/min. Water is sprayed from the water spray holes within a 90° arc segment on each side of the midpoint of the oscillating tube, totaling 180°. The test sample is placed at the center of the oscillating tube’s semi-circle. The oscillating tube swings 180° on each side of the vertical line, totaling approximately 360°. Each swing (2×360°) takes about 12 seconds.
Test Pressure: 400 kPa.
Test Duration: Rotate the sample 90° after 5 minutes of testing.
Note: The spray tube has 121 holes with a diameter of 0.5mm:
— 1 hole in the center
— 2 layers in the core area (12 holes per layer, distributed at 30-degree intervals)
— 4 circles in the outer ring (24 holes per circle, distributed at 15-degree intervals)
— Removable cover
The spray tube is made of brass (copper-zinc alloy).
(6) IPX5
Test Method: Water Jet Test
Test Equipment: Nozzle with an inner diameter of 6.3mm
Test Conditions: Position the test sample 2.5 to 3 meters away from the nozzle, with a water flow rate of 12.5 L/min (750 L/h).
Test Duration: The test duration is calculated based on the surface area of the test sample enclosure, with 1 minute per square meter (excluding the mounting area), and a minimum of 3 minutes.
(7) IPX6
Test Method: Powerful Water Jet Test
Test Equipment: Nozzle with an inner diameter of 12.5mm
Test Conditions: Position the test sample 2.5 to 3 meters away from the nozzle, with a water flow rate of 100 L/min (6000 L/h).
Test Duration: The test duration is calculated based on the surface area of the test sample enclosure, with 1 minute per square meter (excluding the mounting area), and a minimum of 3 minutes. Note: D=6.3mm for IPX5 and IPX6K; D=12.5mm for IPX6.
(8) IPX7
Test Method: Immersion Test
Test Equipment: Immersion tank.
Test Conditions: The dimensions of the tank should allow the test sample to be submerged with the distance from the bottom of the sample to the water surface being at least 1 meter. The distance from the top of the sample to the water surface should be at least 0.15 meters.
Test Duration: 30 minutes.
(9) IPX8
Test Method: Continuous Immersion Test
Test Equipment, Conditions, and Duration: To be agreed upon by both the supplier and the purchaser. The severity should be higher than IPX7.
(10) IPX9K
Test Method: High-Pressure Jetting Test
Test Equipment: Nozzle with an inner diameter of 12.5mm
Test Conditions:
Water jet angles: 0°, 30°, 60°, 90° (4 positions)
Number of water spray holes: 4
Sample platform rotation speed: 5 ±1 revolutions per minute (r.p.m)
Distance: 100 to 150mm from the nozzle
Duration: 30 seconds at each position
Water flow rate: 14 to 16 L/min
Water jet pressure: 8000 to 10000 kPa
Water temperature requirement: 80 ±5℃
Test Duration: 30 seconds at each position, totaling 120 seconds.
If you have any questions about Display and Touch Waterproofing Requirements, please contact Orient Display support engineers