As energy efficiency requirements continue to grow, lighting designers are always looking for ways to help them implement LED technology into their lighting applications easier and faster. Add chip-on-board (COB) LEDs into the mix and there are additional design challenges. One of the ways connector manufacturers are helping the LED lighting industry is by improving their solderless LED holder designs and systems. Typically, these holders focus on a few key areas of improvement for easy assembly, secure attachments, and lower cost.
Let’s look at TE Connectivity’s latest offering as a good example. TE developed a Zhaga-compliant LED holder that features solderless and snap-in features that make manufacturing and installation of LED-lighting applications much easier and faster. The LUMAWISE Type Z50 LED holder is the latest design to join the LUMAWISE family. The part conforms to the Zhaga Consortium specifications, established by a group of companies working together to enable the interchangeability of LED-light sources to simplify general LED-lighting applications.
The LUMAWISE LED holders are available for a variety of Bridgelux, Cree, Citizen, Everlight, Nichicon, OSRAM, Seoul Semiconductor, and Sharp COB LEDs. They also are available pre-assembled in either one- or two-piece configurations.
TE Connectivity provides five simple assembly steps to mount LED arrays and integrate the secondary optics: snap the COB into the Z50 base; apply the thermal interface material; poke the wires into the Z50 base; screw the assembly to the heatsink; and attach the secondary optics. The easy-to-use connector is designed to help reduce assembly costs, according to TE, along with providing a solderless power connection and secure mechanical attachment. “Snap-in LED retention simplifies installation by securing the LED to the holder before mounting, and poke-in wire connections to the LED eliminate the need for time-consuming soldering,” according to TE literature.
The LED holders are compatible with secondary optics, which gives engineers a variety of LED design options. The new Z50 holder series (Figure 1 shows the TE-Type Z50 LED holder with a TE optics retaining clip and a Sharp Mega ZENIGATA LED, LEDIL optics, and a generic heatsink) consists of products for Cree’s CXA Series, Nichicon COB, OSRAM’s Opto SOLARIQ array, and Philips LUMILEDS. These holders can be used for spotlights, downlights, stage lights, wall washers, and architectural lighting.
Figure 1: The TE Connectivity Type-Z LED holders provide a quick solderless connection to LED arrays and allow designers to develop Zhaga-compliant modules. (Courtesy of TE Connectivity)
The Type-Z50 holders are available with low profiles, as well as with or without optic attachments. The poke-in style provides contacts that support 18 AWG to 22 AWG solid, fused, and stranded wires. The holders offer an operating temperature range of -40°C to 105°C. They have a UL 300 V rating, and a flammability rating of UL94V-0.
Molex also continues to make strides in solid-state lighting (SSL) with the introduction of its plastic-substrate interconnect (PSI) for LED COB arrays. Like the TE Connectivity holder, these COB array holders are designed to deliver a speedier and more secure connection. The customizable interconnects also address space constraints often seen in lighting designs by featuring a low-profile harness interface that delivers power to the array via a simple connection to a holder, or plastic substrate.
The PSI offers a low overall package height of ~2.00 mm, which helps with space-constrained designs while reducing substrate costs. In addition to the low profile, the solution also allows the optics to be placed more closely to the LED. Using the Molex Pico-EZmate harness system, which integrates the electrical and mechanical features, eliminates the need for soldering by providing a solderless connection.
The PSI system targets high-density and high-light output applications such as downlighting (track, pendants, and linear) and area lighting (roadways, parking lots, and wall packs). Molex said it supports a variety of potential PSI designs including:
- Circular: 22.50 x 22.50 mm COB size; 36.00 mm outer diameter and 2.0 mm height profile
- Rectangular: 22.50 x 22.50 mm COB size; 36.50 x 28.50 mm outer dimension and 2.00 mm height profile
- Customizable shapes, sizes, mounting hole patterns, and interconnects
Molex also offers a variety of low-profile header and receptacle systems that can be integrated into a custom PSI.
Here’s how it works: The solderless Pico-EZmate harness (Figure 2) attaches to the LED array holder with no special processes or tools. This minimizes contact with the array to reduce the risk of damage. For greater reliability, the system features vertical snap-to-mate connection, positive-lock latching, and gold-plated contacts. The harnesses are available in three wire-gauge configurations and various lengths.
Figure 2: By using the Pico-EZmate harness system, the Molex PSI solution integrates the electrical and mechanical features with the LED array for a solderless connection, eliminating the risk of damage. (Courtesy of Molex)
If a designer is looking for a solderless solution for panel-mount LED indicators, VCC has developed solderless panel-mount LED holders that also are designed to speed up and simplify assembly. Like the other solutions, the CNX 440 and CNX 460 Series receptacles do not require tools for assembly, and provide easy threaded connections for a variety of panel lenses.
The CNX 440 Series 5 mm LED holder can be configured to support up to six leaded, RGB, undercover (UC), or infrared (IR) LEDs, while the CNX 460 10 mm LED holder targets high-flux and standard 10 mm LED packages (Figure 3). VCC said these receptacles work with all major LED brands. VCC recommends the CMC 441 and HMC 461 lens style with Fresnel ring for increased brightness for standard applications, and the CMS 442 and HMS 462 lens style for NEMA 4 applications requiring moisture-proof performance.
Figure 3: The VCC CNX 440 and CNX 460 LED holders for panel-mounted LEDs offer quick and solderless connections to a variety of panel lenses. They can be used in a number of applications, including automotive, aerospace, medical, industrial, military, mining, transportation, mining, and safety. (Courtesy of VCC)
The HMC 460 and HMS 462 lens series indicators fit a 0.5625 inch (14.29 mm) diameter mounting hole, while the CMC 441 and CMS 442 fit a 0.300 inch (7.62 mm) diameter mounting hole. The solution also offers quick assembly: slip the lens through the panel opening, slide the lock washer over the lens barrel, and the connector secures to the lens with a half turn.
Other features include interconnectors that provide additional stability for LED leads, as well as standard lead lengths and headers for connecting the LEDs to power sources. The receptacle can be used in custom cable assemblies or standalone assemblies with stripped-wire ends or a header connector for PCB connection, according to VCC.
In summary, while LED holders may be one of the last components that designers evaluate for their lighting designs, these parts can help lower overall system cost and reduce board space. Designers should look for solderless designs that help mitigate damage risk while speeding up assembly time. Also, they should start considering Zhaga-compliant products for general lighting applications that allow for the use of interchangeable LED light sources. Connector makers, including Molex and TE Connectivity, are members of the consortium that are a host of LED manufacturers.
For more information on the parts discussed in this article, use the links provided to access product information pages on the Hotenda website.