Custom Silicone Rubber Conductive Keypad For Pos Machine | Good Tactile Feedback

Manufacturing silicone keypads for POS machines involves several steps to ensure durability, functionality, and compliance with the machine's specifications. Here's a step-by-step guide to help you understand the process:

1.Design and Mold Creation

Sketch the layout: Define the key positions, shapes, sizes, and any special features like backlighting or symbols.

Software Design: Use CAD software to create a detailed design.

Mold Design & Fabrication: Based on the CAD design, create a mold, usually from metal. The mold design is critical for the shape and quality of the final product.

Liquid Silicone Rubber (LSR): Known for its strength, flexibility, and ability to mold intricate designs.

High Consistency Rubber (HCR): Used for more robust applications.

3. Silicone Preparation & Coloring

Mixing: Mix the base silicone with curing agents and other additives as required.

Coloring: Add color pigments as per the keypad design specifications.

4. Molding Process 

LSR Injection: The liquid silicone rubber is injected into the molds under high pressure.

Curing/Heating: The silicone is cured by heating inside the mold, usually between 120-150°C.

HCR Compression: Place pre-measured silicone rubber into the mold cavity and compress it.

Heating to Cure: Similar to injection molding, the silicone is then cured with heat.

Coating: Apply coatings for improved abrasion resistance or tactile feel.

Laser Etching: Laser etch the symbols and characters on the keys for clear visibility.

Protective Coatings: Apply protective layers to enhance durability and appearance.

Remove excess material (flash) from the keypads using mechanical or manual trimming.

6. Quality Control

Inspection: Check dimensions, tactile response, color consistency, and other specifications.

Functionality Testing: Ensure keys operate correctly and respond well to user interaction.

7. Assembly

Fit the silicone keypads into the POS machine housing.

Electrical Contacts: Ensure that the keypads provide proper tactile feedback and electrical signaling.

Packing: Pack the finished keypads according to industry standards to prevent damage.

Shipping: Arrange for distribution and delivery to POS machine manufacturers.

The snap ratio in rubber keypads refers to the relationship between the actuation force and the tactile force during the button-press action. Essentially, it determines how responsive and satisfying the button press feels to the user.

Here’s how it works:

Optimal Range: Ideally, a snap ratio between 40% and 60% provides a balanced experience. This range offers a good combination of a responsive snap action and a longer lifespan for the keypad.

Lower Snap Ratios: If the snap ratio drops below 40%, the tactile feedback diminishes. Users might notice that the button press feels less distinct, although this setting can actually prolong the switch's life.

Higher Snap Ratios: Conversely, snap ratios above 60% might improve the tactile feedback, making the button feel more immediate and crisp. However, this could potentially reduce the keypad’s durability over time.

Snap Ratio Definition: The relationship between the immediate response (snap action) and the force applied.

Optimal Snap Ratio: 40% to 60% for a balance of feel and durability.

Impact of Lower Ratios: Less tactile feedback but extended switch life.

Impact of Higher Ratios: Better tactile feedback but potentially shorter lifespan.

Understanding these dynamics helps in designing keypads that meet both user satisfaction and durability expectations.