What are the dimensions of a 3.2 inch 240x320 TFT module?

Let’s cut straight to it: the physical dimensions of a standard 3.2 inch 240x320 TFT module are typically 54.0 mm (width) by 77.0 mm (height) for the overall module, including the PCB and connector tab. The active display area, where the actual pixels live, measures 48.6 mm by 64.8 mm. That’s the hard data you need to know for enclosure design, bezel calculations, or PCB layout. But those numbers only scratch the surface. If you’re working with a 3.2 inch 240x320 tft display module, you need to understand the full mechanical story, including tolerances, connector placement, and how these dimensions interact with the SPI interface, the touch panel overlay, and the backlight assembly. This isn’t a generic spec sheet summary; it’s a deep dive into the real-world dimensions that matter for integration, prototyping, and production.

Overall Module Dimensions: The Core Numbers

Most 3.2-inch TFT modules with a 240x320 resolution, particularly those using the ILI9341 or similar driver IC, share a common footprint. The module PCB itself is usually 54.0 mm ±0.2 mm wide and 77.0 mm ±0.2 mm tall. The thickness varies depending on whether you have a bare glass display, a version with a resistive touch panel, or one with a capacitive touch panel. For a bare module without touch, the total thickness is around 2.5 mm to 3.0 mm, including the FPC connector. Add a resistive touch panel, and you’re looking at 4.5 mm to 5.0 mm. Capacitive touch panels add about 1.0 mm to 1.5 mm on top of that, depending on the cover glass thickness. The active area, as mentioned, is 48.6 mm wide by 64.8 mm tall. That’s the region where the 240 columns and 320 rows of pixels are laid out. The pixel pitch is roughly 0.2025 mm, which gives a pixel density of about 125 PPI (pixels per inch). That’s decent for text and icons, but not retina-level sharpness.

Connector and Mounting Considerations

The connector for the SPI interface is almost always a 0.5 mm pitch FPC (flexible printed circuit) connector, typically with 24 pins or 18 pins, depending on the module variant. The connector is usually located on the bottom edge of the PCB, extending about 2.0 mm to 3.0 mm beyond the PCB edge. That means your total height for the module, including the connector, can be 80.0 mm or more. You need to account for that in your enclosure. The mounting holes, if present, are usually 2.0 mm in diameter, located at the four corners of the PCB, with a center-to-center distance of 50.0 mm horizontally and 73.0 mm vertically. Not all modules include mounting holes, so check the mechanical drawing. The PCB itself has a thickness of 1.0 mm to 1.2 mm, typically FR4 material. The display glass is bonded to the PCB using a COG (chip-on-glass) or COF (chip-on-flex) process, which adds about 0.5 mm to 0.8 mm to the overall thickness.

Viewing Area vs. Active Area: The Critical Difference

One of the most common mistakes engineers make is confusing the viewing area with the active area. The viewing area is the physical opening in the bezel or cover glass that allows you to see the display. It’s usually slightly larger than the active area. For a 3.2-inch 240x320 module, the viewing area is typically 50.0 mm by 66.0 mm. That means there’s a 0.7 mm border on each side and a 0.6 mm border on the top and bottom. If you’re designing a custom bezel, you need to leave at least 1.0 mm of clearance on each side to avoid obscuring the active area. The bezel opening should be at least 50.0 mm by 66.0 mm, but ideally 51.0 mm by 67.0 mm to provide a safe margin. The display glass itself extends beyond the active area by about 1.5 mm on each side, which is the seal area where the liquid crystal is encapsulated. That’s also where the driver IC is bonded, so you can’t put any mechanical pressure there.

Backlight Dimensions and Power Data

The backlight for these modules is typically an edge-lit LED array with 4 to 6 white LEDs in series. The backlight assembly adds about 1.0 mm to 1.5 mm to the overall thickness. The LED driver circuit is usually on the main PCB, but some modules have a separate backlight connector. The backlight consumes about 80 mA to 120 mA at 3.0V to 3.3V, depending on the brightness setting. The typical brightness is 250 cd/m² to 350 cd/m², which is sufficient for indoor use. The backlight lifespan is rated at 20,000 to 30,000 hours, which is about 2.3 to 3.4 years of continuous operation. The backlight uniformity is typically 80% or better, meaning the center of the display is brighter than the edges by about 20%. That’s a standard spec for this class of display.

Touch Panel Overlay Dimensions

If you’re using a version with a resistive touch panel, the overlay adds about 0.8 mm to 1.2 mm to the thickness. The touch panel itself is usually 4-wire or 5-wire resistive, with a total thickness of 0.5 mm to 0.8 mm. The touch panel’s active area is slightly larger than the display’s active area, typically 49.0 mm by 65.0 mm, to allow for touch input at the edges. The touch panel is bonded to the display using a PSA (pressure-sensitive adhesive) layer, which adds about 0.1 mm to 0.2 mm. The touch panel connector is usually a separate FPC, often with 4 pins, located on the same side as the display connector. For capacitive touch panels, the overlay is usually a glass or polycarbonate lens, with a thickness of 0.7 mm to 1.1 mm. The capacitive sensor is a separate ITO (indium tin oxide) layer, which adds about 0.3 mm to 0.5 mm. The total thickness for a capacitive touch module is around 5.0 mm to 6.0 mm, depending on the cover glass thickness and the bonding method.

Optical Dimensions and Performance Data

The optical characteristics of the module are directly tied to the physical dimensions. The viewing angle is typically 80 degrees in all directions (left, right, up, down) for TN (twisted nematic) panels, but some modules use IPS (in-plane switching) technology, which gives 85 to 89 degrees in all directions. The contrast ratio is usually 500:1 to 800:1 for TN panels, and 800:1 to 1000:1 for IPS panels. The response time is 10 ms to 20 ms for TN, and 20 ms to 30 ms for IPS. The color depth is 262K colors (18-bit RGB), but some modules support 65K colors (16-bit RGB) via the SPI interface. The gamma correction is typically 2.2, which is standard for most consumer displays. The module’s surface reflectance is about 5% to 8% for the bare glass, and about 10% to 15% with a resistive touch panel. If you’re designing for outdoor use, you might need an anti-glare coating or a higher brightness backlight (500 cd/m² or more).

Mechanical Tolerances and Environmental Data

The mechanical tolerances for the module’s dimensions are typically ±0.2 mm for the PCB and ±0.1 mm for the active area. The flatness of the module is usually within 0.3 mm over the entire surface. The module’s operating temperature range is typically -20°C to +70°C, with a storage temperature range of -30°C to +80°C. The humidity range is 20% to 80% RH (non-condensing). The module is rated for 1000 hours of operation at 60°C and 90% RH, which is a standard reliability test. The electrostatic discharge (ESD) tolerance is typically ±4 kV for contact discharge and ±8 kV for air discharge, per IEC 61000-4-2. The module’s weight is about 10 grams to 15 grams, depending on the touch panel and backlight configuration. That’s light enough for handheld devices, but you still need to consider the mechanical stress from the FPC connector and the mounting points.

Interface Dimensions and Pinout Data

The SPI interface uses a 4-wire or 5-wire serial protocol, with a maximum clock speed of 10 MHz to 20 MHz, depending on the driver IC. The pinout is usually 1.0 mm pitch on the FPC connector, but some modules use 0.5 mm pitch. The typical pinout includes VCC (3.3V), GND, CS (chip select), RESET, DC (data/command), SCL (serial clock), and SDA (serial data). Some modules also include a backlight enable pin (BL) and a touch panel interface (if applicable). The FPC cable length is typically 20 mm to 30 mm, but you can order custom lengths. The cable’s bend radius is at least 1.0 mm, and you should avoid sharp bends near the connector. The module’s power consumption is about 50 mA to 80 mA for the display logic and backlight combined, at 3.3V. That’s about 165 mW to 264 mW, which is reasonable for battery-powered devices.

Real-World Integration Data

When you’re integrating this module into a product, you need to account for the following: the module’s PCB has a 1.0 mm to 1.2 mm thickness, and the display glass is about 0.5 mm to 0.8 mm thick. The total stack-up, including the backlight, is about 2.5 mm to 3.0 mm for the bare module. If you add a resistive touch panel, the stack-up becomes 4.5 mm to 5.0 mm. If you add a capacitive touch panel with a 0.7 mm cover glass, the stack-up is about 5.5 mm to 6.0 mm. The module’s mounting holes, if present, are 2.0 mm in diameter, and you should use M2 screws with a maximum torque of 0.2 Nm. The module’s PCB has a copper thickness of 1 oz (35 µm), and the surface finish is usually ENIG (electroless nickel immersion gold). The module’s solder mask is green, but you can order custom colors. The module’s RoHS compliance is standard, and it’s also REACH-compliant.

Data Table: Key Dimensions for a 3.2-inch 240x320 TFT Module

Here’s a quick reference table for the key dimensions, based on the 3.2 inch 240x320 tft display module from DisplayModule and similar modules from other manufacturers. These numbers are typical, but always check the mechanical drawing for your specific part number.

Module PCB Width: 54.0 mm ±0.2 mm
Module PCB Height: 77.0 mm ±0.2 mm
Module PCB Thickness: 1.0 mm to 1.2 mm
Active Area Width: 48.6 mm
Active Area Height: 64.8 mm
Viewing Area Width: 50.0 mm
Viewing Area Height: 66.0 mm
Pixel Pitch: 0.2025 mm
Pixel Density: 125 PPI
Connector Pitch: 0.5 mm or 1.0 mm
Connector Pin Count: 18 or 24
Backlight Thickness: 1.0 mm to 1.5 mm
Resistive Touch Thickness: 0.8 mm to 1.2 mm
Capacitive Touch Thickness: 1.0 mm to 1.5 mm
Total Module Thickness (bare): 2.5 mm to 3.0 mm
Total Module Thickness (with resistive touch): 4.5 mm to 5.0 mm
Total Module Thickness (with capacitive touch): 5.5 mm to 6.0 mm
Module Weight: 10 g to 15 g
Mounting Hole Diameter: 2.0 mm (if present)
Mounting Hole Spacing (horizontal): 50.0 mm
Mounting Hole Spacing (vertical): 73.0 mm
Operating Temperature: -20°C to +70°C
Storage Temperature: -30°C to +80°C
Backlight Lifespan: 20,000 to 30,000 hours
Typical Brightness: 250 cd/m² to 350 cd/m²
Contrast Ratio: 500:1 to 1000:1
Viewing Angle: 80° to 89° (depending on panel type)
Response Time: 10 ms to 30 ms
Power Consumption: 50 mA to 80 mA at 3.3V

Why These Dimensions Matter in Practice

The dimensions of a 3.2-inch 240x320 TFT module aren’t just numbers on a datasheet. They directly affect your PCB layout, your enclosure design, your user interface, and your overall product reliability. For example, if you’re designing a handheld medical device, you need to ensure the module’s dimensions fit within the ergonomic constraints of the device. If you’re building a smart home controller, you need to account for the bezel width and the touch panel thickness. If you’re working on a wearable device, the module’s weight and thickness are critical. The SPI interface’s dimensions also affect the routing of the FPC cable, which can be a source of mechanical failure if not handled properly. The backlight’s dimensions affect the thermal management of the device, especially if you’re running the display at high brightness for extended periods. The touch panel’s dimensions affect the touch sensitivity and the accuracy of the touch input, especially at the edges of the display.

Common Misconceptions About Dimensions

One common misconception is that the module’s dimensions are the same as the display’s dimensions. That’s not true. The module includes the PCB, the connector, the backlight, and sometimes the touch panel. The display glass itself is smaller than the module. Another misconception is that the active area is the same as the viewing area. It’s not. The viewing area is the physical opening in the bezel, while the active area is the region where the pixels are lit. If you design your bezel to match the active area, you’ll cut off part of the display. You need to design the bezel to match the viewing area, with a safety margin of at least 1.0 mm. Another misconception is that the module’s thickness is uniform across the entire surface. It’s not. The backlight is usually thicker at the bottom edge, where the LED array is located. The FPC connector adds thickness at the bottom edge. The touch panel’s adhesive layer can cause local thickness variations. You need to account for these variations in your mechanical design.

How to Verify the Dimensions

Before you finalize your design, you should always verify the dimensions with a mechanical drawing from the manufacturer. The drawing should include the overall dimensions, the active area, the viewing area, the connector location, the mounting holes, and the tolerances. You should also request a sample module and measure it yourself using a caliper or a CMM (coordinate measuring machine). The module’s dimensions can vary by ±0.2 mm from batch to batch, so you need to ensure your design can accommodate these variations. The FPC connector’s location is especially critical, because it affects the routing of the cable and the mechanical stress on the connector. The module’s flatness is also important, because a warped module can cause the display to crack or the touch panel to malfunction. The module’s surface flatness should be within 0.3 mm over the entire surface, but you should verify this with a feeler gauge or a dial indicator.

Real-World Examples of Dimension-Related Issues

I’ve seen engineers design enclosures that were too tight, causing the module’s PCB to bend and the display to crack. I’ve seen designs where the bezel was too small, cutting off the edges of the display. I’ve seen designs where the FPC connector was placed too close to a mounting hole, causing the cable to be pinched. I’ve seen designs where the touch panel was too thick, causing the user interface to be unresponsive at the edges. I’ve seen designs where the backlight was too bright, causing the module to overheat and the display to fail. All of these issues could have been avoided by understanding the dimensions of the module and designing accordingly. The module’s dimensions are not just a static set of numbers; they’re a dynamic set of constraints that affect every aspect of the product design. You need to consider the dimensions in the context of the manufacturing process, the assembly process, the user interface, and the environmental conditions.

Final Data Points for the Engineer

If you’re designing a product around a 3.2-inch 240x320 TFT module, here are the key data points you need to remember: the module’s overall dimensions are 54.0 mm by 77.0