Refrigerator Shelf Custom LED Lighting Solution

custom refrigerator LED solutions

Refrigerator Shelf Custom LED Lighting Solution

Part Number: Refrigerator Shelf Custom LED Lighting Solution

Overview

End-User – Major Residential Refrigerator Manufacturer
Partner – Major Glass Supplier to Refrigerator Industry
Application – Shelf-Light for Refrigerator

Project Summary – OEM glass supplier reached out to ILT for a new, improved solution for their integrated LED shelf light. Improved illumination and reduced power are the primary drivers as well as accomplishing this at a competitive price. OEM looking for a turn-key product that will easily mount to their shelves in a high-volume, manufacturing environment. Volumes greater than 100K per year!


Incumbent Technology – Current shelf fixtures have older LED technology embedded in a lens with low transmission. General configuration needed to be maintained to match mounting and assembly of existing assembly.
Problem – Creating a lens/LED assembly configuration to meet the light output and distribution requirements while maintaining a very low cost.

Design Approach – Basic assumptions were made at the beginning of this project as follows:

  • Optical design – To achieve improved light distribution, the LEDs needed to be angled inside the lens and the lens material must have a high degree of light transmission.
  • Circuit design – Circuit consists of small, low-power LEDs, diodes to enable reverse polarity, ESD protection and a mechanical design to enable twist of the circuit to change the angle of LEDs within the lens.
  • Thermal Management – Because of the low-power nature of this assembly and the refrigerated application, heavy copper on the circuit would suffice for thermal management.
  • Production Assembly – Handling and packaging must be thought through to provide the most effective method for both packaging the LED assembly, but also unpackaging during OEM shelf production. We chose to work with an adhesive tape the OEM is familiar with for attachment to the assembly within the OEM manufacturing process.
  • Cost – An injection molded lens, flex circuit and cost-effective LED achieved the cost objectives for this product.

 

Challenges 

Making a prototype that will simulate production parts!
The circuit was easy enough to prototype. The lens was more challenging. We use a 3D printing process for creating small quantity prototypes. The material is close, but not exact. Additional processes were needed to get closer to the final, injection molded design.

 

Solution

  • Optical design – Design provides about 10% more light in the desired target area at nearly 50% less power consumption.
  • LED strip design – We achieved the desired ESD protection while maintaining the reverse polarity requirement. Osram E3 LEDs were selected and provide excellent light output and efficiency.