The LEDs were not the problem. The way they were assembled was.
Some older LED products can continue meeting their electrical and lighting requirements for years, yet their original manufacturing methods may no longer be economical.
NKT encountered this situation while supporting a long-term US customer in the marine and vehicle lighting industry.
Some of the customer's products were still assembled using individual LEDs connected by wires. Others used through-hole LEDs. Many already had established PCB designs that worked well and did not need to be changed.
The right decision was different for each product.
An existing OEM LED module is worth upgrading when a specific design or manufacturing change offers a practical benefit that justifies the development effort and preserves the product's required performance.
Keeping the Original Design Was Often the Right Decision
NKT began supporting this customer after its previous LED module supplier went out of business.
The customer needed to maintain production of existing lighting products. For many modules, the original PCB drawings and bills of materials were available.
NKT continued manufacturing these products according to the customer's specifications.
There was no reason to redesign every LED board simply because production had moved to a different supplier.
These were established products with existing mechanical, electrical and lighting requirements. Changing an LED package, PCB layout or circuit without a clear benefit could introduce unnecessary work.
However, not every older assembly was equally practical to manufacture.
That difference became the starting point for several targeted improvements.
First Improvement: Replacing Manual LED Wiring With a PCB
Some older products did not use a PCB at all.
Individual LEDs were positioned and electrically connected using wires. Manufacturing these assemblies required skilled workers to handle LED positioning, manual soldering and assembly.
The process was time-consuming and relied heavily on the experience of the soldering operators.
With less experienced workers, poor solder joints, including incomplete or unreliable connections, were a concern.
NKT identified an opportunity to improve this manufacturing process and proactively recommended developing PCB-based versions of certain assemblies.
The objective was not to change the lighting function.
LED quantities, positions and operating requirements remained largely unchanged. Instead, the PCB provided defined mounting positions and electrical connections, replacing much of the original point-to-point wiring.
This reduced manual wire-soldering operations, simplified LED positioning and shortened assembly time.
For these products, the change lowered manufacturing costs and improved production efficiency.
It also reduced dependence on workers skilled in manual wire soldering.
PCB assembly still requires soldering and appropriate production inspection. The improvement was not the elimination of all soldering risks, but the reduction of labor-intensive, operator-dependent assembly operations.
This was a manufacturing improvement achieved without substantially changing the original product requirements.
Second Improvement: Redesigning Through-Hole LED Products With SMD LEDs
Other established products offered a different opportunity.
They already used PCBs, but their original designs relied on through-hole LEDs.
Over time, NKT observed changes in component pricing and manufacturing availability within its sourcing network in Guangdong, China.
For many commonly used LED types, SMD options had become more cost-effective than the older through-hole components used in these projects.
SMT assembly equipment was also widely available among NKT's manufacturing partners. Automated through-hole insertion equipment was less common in that supplier network, making manual insertion an important cost consideration for some legacy products.
These conditions made SMD conversion worth evaluating.
But changing from through-hole to SMD LEDs was not a one-for-one component replacement.
The selected SMD LEDs had different characteristics, so NKT adjusted the LED quantities and redesigned the electrical circuits where necessary.
The goal was to keep the updated modules close to the original requirements for operating voltage, current, brightness and light color.
This distinction matters.
The customer did not necessarily need higher brightness or a new lighting function. The purpose was to adopt a more economical component and assembly approach while maintaining compatibility with an established product.
The cost advantage was project-specific. It does not mean SMD LEDs are always cheaper than through-hole LEDs, or that every through-hole design should be converted.
For some existing products, the original design remained the more practical option.
Our earlier article on why some truck and RV LED products still use through-hole LEDs discusses the importance of preserving established product compatibility.
The Internal Design Can Change While the Product Requirements Remain
The two improvements required different levels of engineering work.
In the wired-to-PCB conversion, the major change was the manufacturing method. The LED arrangement and operating requirements remained largely unchanged.
In the through-hole-to-SMD conversion, the change involved LED selection, LED quantity and circuit configuration.
Yet both improvements had to respect the customer's existing products.
For the SMD redesign, maintaining similar voltage and current was important because the updated module needed to operate within the intended electrical conditions.
Brightness and light color also needed to remain close to the established requirements.
Mechanical fit and LED positions had to remain suitable for the original product.
A new LED type may require a different number of LEDs or a different series-parallel arrangement to achieve the intended operating parameters. A similar-looking component is not necessarily electrically or optically interchangeable.
That is why an OEM upgrade should be evaluated against the finished product's requirements, not simply against the specifications of an individual replacement LED.
How Should an OEM Evaluate Whether the Upgrade Is Worth It?
An existing product should first be reviewed for the specific problem that an upgrade is expected to solve.
| Existing situation | Practical decision |
|---|---|
| The PCB, components and manufacturing method remain suitable | Continue producing the approved design |
| Manual wiring and LED positioning create excessive assembly work | Evaluate a PCB-based assembly |
| Older through-hole components and manual insertion increase manufacturing cost | Evaluate an SMD redesign, including any necessary circuit changes |
The next consideration is the cost of making the change.
An updated PCB may require design work, new manufacturing preparation, sample production and customer evaluation.
The potential savings should be considered alongside expected production quantities and the remaining life of the product.
A manufacturing improvement that makes sense for repeated OEM orders may not be economical for a product with limited future demand.
Just as importantly, the proposed change must not create unacceptable differences in the product's electrical, optical or mechanical behavior.
The goal is not to introduce a newer design at any cost.
It is to determine whether the expected manufacturing benefit is worth the engineering effort and the compatibility requirements.
How NKT and the Customer Verified the Updated Designs
For the through-hole-to-SMD redesigns, NKT developed prototype samples and checked relevant module-level electrical and optical parameters.
The evaluations included operating voltage, current, light output and color-related performance against the intended requirements.
The samples were then supplied to the customer, who installed them in the existing products for application-level verification.
Only after the customer confirmed the updated design did the revised modules move into production.
This sequence was important because module-level measurements alone could not establish every aspect of compatibility with the finished product.
The customer was responsible for confirming performance in the original assembly, including relevant system-level operating conditions.
The process is discussed in more detail in LED module prototype validation before mass production.
A Better Upgrade Starts With the Existing Manufacturing Problem
The experience from this long-term OEM relationship was not that older LED technology should always be replaced.
Most of the customer's established PCB designs could continue in production.
For some products, however, removing unnecessary manual wiring delivered a meaningful manufacturing improvement.
For others, adopting SMD LEDs required more extensive electrical redesign but offered a more practical route for component sourcing and assembly.
What mattered was identifying where the original design or manufacturing process created costs that could reasonably be reduced.
For OEM manufacturers, that is a useful starting point when reviewing a legacy LED product: identify what must remain unchanged, what is making the product expensive to manufacture, and whether a targeted redesign can improve the economics without compromising the required function.
NKT supports both existing-design manufacturing and custom OEM LED module development and production support.
Considering an Upgrade to an Existing OEM LED Assembly?
If your established product still uses manually wired LEDs, an older through-hole LED PCB or another manufacturing method you would like to review, NKT can evaluate the available design information and discuss possible improvements.
Share your existing drawings, BOM, samples or assembly details, along with the requirements that must remain unchanged and the production issues you want to address.