Design guide to display integration

A display is rarely just a display. In an HMI solution, it needs to work with the front layer, keypad, touch function, sealing, mechanics and housing. This guide gives you a practical introduction to display integration — including stack-up considerations, construction principles and key questions to clarify before choosing a display.

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Display integration starts with the complete HMI

The right display choice depends on more than size, resolution and interface. It also depends on how the display will be built into the final product. Will it sit behind a foil or cover glass? Should it be combined with tactile keys or touch functions? Does the HMI need to be sealed, easy to clean, protected against impact or adapted to a specific housing? That is why display integration should be considered early in the design process. The display, front layer, input function, sealing and mechanical fixation all affect each other.

Display integration is a stack-up decision

A typical HMI stack-up can include:

Front layer: foil, cover glass or silicone
Sealing: adhesive, gasket or glue
Display
Input function: membrane keys, silicone keys, touch surfaces or touchscreen
Fixation to housing
Cable routing and connection to the PCB

Mekoprint HMI Design Guide Display Integration

Six examples to display integration

There is no single standard construction for display integration. The right principle depends on the application, user interaction, environment, design requirements and production setup.

A flat front foil with integrated membrane switch keypad and display area. Best suited for applications where the user needs clear function keys, but where the front should remain flat, sealed and cost-efficient to produce.
A front foil with protruding silicone keys around the display. Best suited for applications where the user needs clear tactile feedback, for example when operating with gloves or in low-visibility environments.
A cover glass display area combined with separate silicone rubber keys. Best suited for applications where display protection and tactile feedback are both important.
A silicone front cover with integrated tactile keys and a recessed display area. Best suited for applications where the HMI is exposed to impact, rough handling or demanding environments.
A touch display with fixed touch controls around the active display area. Best suited for applications where the user needs a dynamic touchscreen interface, but still benefits from fixed controls for key functions.
A standard display combined with a capacitive touch foil in the front construction. Best suited for applications where the display does not need to be touch-enabled, but where the HMI benefits from a flat front with integrated touch controls.

Questions to clarify

Before choosing a display for an HMI solution, it is useful to clarify both the display requirements and the construction around it. Consider questions such as:

What should the display show: text, numbers, icons, graphics or dynamic content?
Where will the display be used: indoors, outdoors or in changing light conditions?
Are there specific requirements for brightness, readability or viewing angle?
Which size, active area and outline dimensions are needed?
What resolution is required for the user interface?
How will the display be connected to the PCB?
Is touch needed, and should it work with gloves, wet hands or in dirty environments?
Will the HMI be exposed to moisture, dust, cleaning, vibration or impact?
Should the display be combined with membrane keys, silicone keys or separate touch buttons?

These questions help define whether the display requirements should be solved in the display itself, through semi-customisation or through the HMI construction around it.

Download the full guide

The full guide gives you a more detailed overview of display technologies, stack-up considerations and six practical construction examples for integrating displays into HMI solutions.

Download complete guide to display integration