More Details
Background & Customer Needs
This project was developed for a customer designing illuminated control buttons used in electronic and home appliance products.
Before committing to injection molding and final surface treatment, the customer needed small-batch prototypes to evaluate:
- Light transmission consistency
- Button appearance under backlight
- Surface color and texture
- Overall visual quality in real-use conditions
The prototypes needed to closely match final production appearance, not just basic shape.
Key Challenges
Prototyping translucent buttons presents several technical challenges:
- Light Control: Light must pass through evenly, without visible bright spots or shadows.
- Surface Uniformity: Coating thickness must be consistent, and color deviation is not acceptable.
- Production-Like Finish: The surface must resemble molded and coated parts, suitable for design review and user testing.
The customer required a rapid prototyping solution that could simulate mass-production surface effects.
Rapid Prototyping Solution
PC Base Material Selection
Polycarbonate (PC) was selected due to its:
- High light transmission
- Good impact resistance
- Dimensional stability
PC is commonly used for illuminated buttons and display-related components.
Vacuum Film Coating + Spray Painting
The surface process included two key steps:
Vacuum film coating
- Creates a uniform semi-transparent layer
- Helps control light diffusion and brightness
Spray painting
- Adjusts final color tone
- Improves surface appearance and durability
This combination allows precise tuning of light transmission and visual effect, making the prototypes suitable for real evaluation.
Key Features & Advantages
1️⃣Controlled Light Transmission
Vacuum film coating ensures even light diffusion without hotspots.
2️⃣Production-Like Appearance
Surface finish closely matches injection-molded and coated production parts.
3️⃣Small-Batch Flexibility
Ideal for design verification without high tooling costs.
4️⃣Fast Turnaround
7–10 day delivery supports tight development schedules.
Technical Specifications
| Parameter | Value |
|---|---|
| Base Material | Polycarbonate (PC) |
| Surface Process | Vacuum film coating + spray painting |
| Light Transmission | Customizable |
| Prototype Type | Appearance & functional prototype |
| Batch Size | Small batch |
| Lead Time | 7–10 days |
Application Scenarios
▶️Home appliance control panels
▶️Consumer electronics buttons
▶️Illuminated switches and indicators
▶️User interface design validation
This prototyping method is widely used for pre-tooling visual and functional verification.
Why This Case Matters
This case shows how surface processing is critical for illuminated components.
By validating vacuum film coating and painting at the prototype stage, customers can: Avoid costly color and light issues later | Speed up design approval | Reduce risk before tooling investment
Production Process & Quality Assurance
- DFM Review: Light path and surface requirements are reviewed before processing.
- Rapid Prototyping: Small-batch parts are produced for appearance and light testing.
- Visual & Light Inspection: Parts are checked under backlight for uniformity and color consistency.
- Quality Commitment: If surface defects caused by processing are found, rework support is provided.
