In the digital age, silicone keypad buttons have become the top choice for users, offering comfortable, durable, and high-performance operation. This article explores the manufacturing of silicone keypad buttons, detailing key steps and technologies involved. It explains everything you need to know, from materials and design to production, surface decoration, and application. By the end, you will have a better understanding of this crucial process and be able to make informed decisions.
What are silicone keypad buttons?
Silicone keypad buttons are keypads made from silicone material commonly found on television remote controls, air conditioner remotes, and instrument panel keypads. These buttons are characterized by soft elasticity, temperature resistance, and waterproof and dustproof performance. They provide a comfortable tactile experience, long-lasting durability, and adaptability to various environmental conditions.
Preparation of Silicone Raw Materials – Overview
High transparency
High-transparency silicone is a type of silicone material characterized by its excellent transparency and light transmission properties. Compared to regular silicone, high-transparency silicone exhibits lower transmission losses and higher levels of transparency within the visible light spectrum. Make a silicone keypad with better backlit characters.
Silicone hardness
The hardness range of silicone varies from 10 Shore A to 80 Shore A, where silicone with a Shore A hardness of 10 is the softest, while silicone with a Shore A hardness of 80 is relatively more rigid. As the hardness of silicone keypad buttons increases, the tactile feel improves; however, if the hardness is too high, it can negatively impact the product’s lifespan. On the other hand, lower hardness results in softer keypads with a poorer tactile feel and increased friction between the keypad buttons and the plastic housing, leading to potential issues with keypad button sticking. Therefore, a hardness of 50° or 60° is commonly recommended for silicone buttons.
high-temperature resistance and low-temperature resistance
Silicone rubber typically has a high-temperature resistance range of -50 °C to 200°C. This type of silicone can maintain its soft elasticity at lower temperatures and withstand long-term use under high-temperature conditions. Choosing silicone with high-temperature and low-temperature resistance properties is vital to prevent deformation in high-temperature environments and avoid hardening, becoming brittle, or losing elasticity in low-temperature environments.
Mold design and Fabrication
The design and manufacturing of molds are crucial in the manufacturing industry. It involves the process of transforming product design into actual components or products. Excellent mold design can enhance production efficiency and product quality. This article will examine the significance and essential elements of mold design and manufacturing for silicone keypad buttons.
Silicone keypad button basic structure
- Actuation Force: The amount of force required to press a button. Silicone keypad Buttons should have a moderate actuation force during use, ensuring they are not too light to cause accidental presses or too heavy to impact usability and comfort. Actuation force can be controlled by adjusting the hardness of the silicone material, as well as the shape and structure of the button.
- Travel: Refers to the distance or displacement from the original state to the fully pressed position of a silicone keypad button. The length of travel is typically determined based on user requirements and application scenarios. Extended travel can provide more noticeable tactile feedback, while shorter travel is more suitable for applications that require quick response.
- Position: Refers to the layout and placement of silicone keypad buttons. The positioning of silicone keypad buttons should adhere to ergonomics principles, making it easy for users to locate and operate them accurately. Proper silicone keypad button placement can provide a convenient user experience and help prevent accidental activations.
- Displacement: Refers to the distance or amount of movement that a silicone keypad button undergoes from its original position after being pressed. Displacement provides clear tactile feedback to users, enabling them to perceive if the silicone keypad button has been triggered. The magnitude of displacement can be adjusted based on user requirements and application scenarios.
Common silicone keypad button structures
keypad button mold design
The software commonly used for designing silicone keypad button molds includes UG, Pro/E, CAD, and Rhino. After creating the 3D drawings, they can be saved in STP format and sent to the factory for structural evaluation and quotation. If you have little experience in silicone keypad button design, you can rely on YueHouDZ engineers to provide design services.
These software applications are widely used in the design of silicone keypad button molds. Depending on the user’s needs and preferences, choosing the software that suits their requirements for silicone keypad button mold design is recommended.
KeyPad button mold fabrication
The manufacturing of silicone keypad molds is a complex and precise process, typically involving the following steps:
- Developing a mold manufacturing plan: Developing a mold manufacturing plan based on design requirements and production needs. Determining key parameters such as the type of mold, materials, dimensions, and manufacturing processes.
- Material preparation: Select appropriate mold materials, such as P20, 718, and S136, and ensure the quality and reliability of the materials, processing, and optimizing the materials through cutting, forging, heat treatment, and surface treatment processes.
- CNC machining: Utilizing CNC machine tools for precise mechanical processing, including milling, turning, drilling, and boring operations. Process and shape various mold parts according to design drawings and process requirements to manufacture the mold components.
- Precision grinding: Utilizing specialized grinding equipment with wheels to achieve the precise dimensions, shapes, and smoothness required for delicate parts. The grinding process requires high precision and patience to obtain high-quality mold components.
- Assembly and debugging: Assemble the various mold components, ensuring that the fit and clearances of each part meet the requirements. Conduct system testing and debugging of the mold to ensure its proper operation and compliance with product quality requirements.
- Surface treatment: Perform surface treatment on the mold as required, such as coating, polishing, plating, etc., to enhance the mold’s wear resistance, corrosion resistance, and aesthetic quality.
- Quality inspection: Conduct rigorous quality inspections on the manufactured molds, including dimensional measurements, material testing, and functional testing, to ensure that the quality and performance of the molds meet the design requirements and customer needs.
- Delivery and After-Sales Support: Deliver the completed silicone keypad molds to the customer and provide necessary after-sales support, including mold usage guidance, maintenance advice, and other relevant services.
Material preparation and compression molding
Material preparation and compression molding are critical components in mold manufacturing. Material preparation involves selecting and blending suitable raw materials, while compression molding involves solidifying and shaping the material through heating and applying pressure. This article will examine the significance of silicone material preparation and compression molding, as well as their applications in mold manufacturing.
Preparation of silicone raw materials
In addition to their superior performance characteristics, silicone products have a unique feature – they can change color. This makes silicone products more diverse and competitive. So, how are silicone products colored? Let YueHouDZ provide you with the answer.
Silicone Coloring Paste
Silicone coloring paste is formed by aggregating silicone raw materials, silicone oil, color pigments, and dispersants. It adds color to silicone, giving it the desired color effect. The reason for choosing to use Silicone Coloring Paste to create colors for silicone products is that it is stable in performance, has high dispersibility, is environmentally friendly, non-toxic, and non-polluting. Additionally, it does not expire after long-term storage, and many of its characteristics are similar to those of silicone raw materials. There are two main types of coloring paste: organic and inorganic.
Silicone Keypad Molding Process Flow
The molding of the silicone keypad is performed using the compression molding method. Here are the detailed steps regarding the molding process of the silicone keypad:
- Mold preparation: First, make a mold suitable for silicone buttons. The mold typically consists of two parts: the male mold and the female mold. The male mold has a button shape, and the female mold corresponds to the back of the button.
- Silicone preparation: Accurately weigh the silicone and curing agent materials according to the formula ratio and mix them thoroughly. Color and other additives can also be added during this process to achieve the desired effect.
- Silicone preparation: Accurately weigh the silicone and curing agent materials according to the formula ratio and mix them thoroughly. Color and other additives can also be added during this process to achieve the desired effect.
- Compression molding: Cut the prepared silicone into strips or blocks, place them into the female part of the mold, and then cover the male mold over the female mold to ensure a tight seal. Next, the silicone is filled into every mold space by applying pressure, allowing it to fill the entire essential shape.
- Curing: After silicone compression molding, the silicone in the mold needs to be cured under certain temperatures and time conditions. This method is suitable for making silicone products of various shapes and sizes.
- Demoulding: After the silicone keypad is completely cured, open the mold and remove the button from the mold. Thanks to the pre-applied release agent, the silicone keypad can be easily released from the mold.
- Trimming and inspection: Perform trimming on the molded silicone keypad, such as removing flash edges and cutting off excess material. The buttons are then visually inspected, dimensionally measured, and functionally tested to ensure quality meets requirements. Coating, printing, or other treatment steps can be done if required.
The silicone keypad button molding process requires careful operation to ensure the design and manufacturing quality of the mold while strictly controlling the parameters of the silicone ingredients and molding process to obtain high-quality and consistent silicone keypad button products.
How to add a conductive function to silicone keypad buttons
Adding conductive functions to silicone keypad buttons is a technology developed to meet the needs of specific applications. Electrical signal transmission between the silicone keypad and electronic devices can be achieved by adding conductive materials or coatings to the buttons. The following are some of the more common conductive methods.
Conductive ink
Conductive ink is primarily composed of conductive particles, solvents, connecting materials, and other additives, which confer conductive properties. It is applied to the substrate surface via printing technology. During drying, the solvent evaporates, creating conductive connections between the conductive particles and firmly bonding to the substrate. In this way, the conductive ink can perform its conductive function.
Conductive Particles
Conductive particles are tiny particles made of conductive materials, such as carbon powder or metal powders (such as silver powder, copper powder, or nickel powder). This combination enables the flexible application of conductive black particles to meet various conductive needs, providing a stable conductivity function.
Metal Dome
When the silicone keypad button is pressed, the metal dome, part of the membrane switch, is flattened to make contact with the circuit board, thereby achieving the conduction function.
Silicone keypad button post-processing and surface decoration
Silicone keypad button post-processing improves appearance, wear resistance, texture, durability, and functionality. Surface decoration can achieve different patterns and text on the silicone keypad.
post-processing technique
- Edge removal: There are three methods of edge removal (manual edge removal, mechanical edge removal, and frozen edge removal). The primary purpose is to remove burrs or hole chips associated with the product when it is released from the mold and to minimize fit gaps during the assembly of silicone rubber products. Silicone keypad buttons are primarily used for sealing and waterproofing purposes. If the edges are irregular and the cape is relatively large, the effect of the silicone products will be directly affected.
- Cleaning: Clean the formed silicone keypad products to remove dust, impurities, and other debris from the surface.
surface decoration
 | Laser Engraved Backlit Keycaps |
 | Laser Engraved Translucent Color-Key Keycaps |
 | Silk-screen Printing |
 | Doming Dome Coating |
 | In-Mold Engraving |
 | Color-Molded Keycaps |
 | Multi-color Silk-screened Keycaps |
 | Spray Lacquer, Matte Finish, and Polyurethane Varnish |
Quality control and testing
Silicone keypad button quality control is a series of measures to ensure that critical products have stable performance, reliable trigger response, and durable service life. Here are some standard silicone keypad button quality control methods:
- Appearance inspection: Inspect the appearance of the silicone keypad buttons, including surface flatness, scratches, bubbles, and other issues, to ensure the silicone keypad’s appearance is flawless.
- Size measurement: Measure the dimensions of the silicone keypad buttons, including length, width, and thickness, to ensure they meet the design requirements and standard sizes.
- Functional testing: Utilize professional testing equipment or instruments to assess the triggering force, rebound force, stroke, and other parameters of the silicone keypad button, and verify whether the triggering response of the silicone keypad button meets the standard.
- Lifetime testing: This process involves simulating the continuous use of silicone keypad buttons using a mechanical arm or specialized equipment to assess the durability and reliability of the silicone keypad buttons.
- Environmental testing: Silicone keypad buttons are exposed to various environmental conditions, including high temperatures, low temperatures, and humidity, to assess their performance under different conditions.
- Reliability assessment: Through sampling inspections and statistical analysis, among other methods, the overall reliability level of button products is evaluated to determine whether they meet the required standards.
- Quality Management System: Establish a comprehensive quality management system, including ISO9001 certification, to ensure the effective implementation and continuous improvement of quality control and management throughout the button manufacturing process.
Through the above silicone keypad quality control methods, companies can effectively monitor and manage the quality of silicone keypad products, providing customers with high-quality, stable, and reliable products.
