Despite rapid strides backed by incessant developments, the LED technology is still in its infancy, especially when it comes to challenges like heat management of LEDs wherein PCB is crucial.
As we all know like any electronic component, LEDs are sensitive to heat, therefore, heat management remains one of the most crucial considerations that the manufacturers of LED lights keep in mind. Technically, LEDs have very low external quantum efficiency (EQE) – and are able to convert only about 5% of the power input into light. The remaining 95% of the power is converted to heat which must be quickly removed to keep the LED junction below its maximum operating temperature. Failure to keep the LED die cool will at best shorten its life, and at worse cause it to fail catastrophically.
Gradually, LEDs are getting more powerful (the latest is 75mW), forcing the manufacturers to look at new/alternate ways to address the heat dissipation challenge. The question remains static as how to deal with the high thermal demands of the LEDs which with each passing day are getting more advanced. Amidst all this, they have to ensure that the components used in the final products remain cost effective, durable, machinable and resistant to wear.
All these are to be monitored keeping in view that LEDs are too small to radiate significant amount of heat from their surface. The only way, it can escape effectively, is through the back of the LED. In the normal process, heat is conducted from the LED chip, through the module PCB, before reaching the heatsink which releases it out to the atmosphere. This is where PCB automatically becomes an important factor when it comes to controlling or managing the heat.
Unlike the FR4 PCBs that are used in other electronics, the PCB on which the LED is to be mounted must have a high thermal conductivity, which for a visible light LED would usually be a metal-clad PCB (MCPCB). MCPCBs are manufactured from a sheet of metal (usually aluminium or copper) with the copper circuit layer attached with a dielectric layer of thermally conductive, but electrically insulating, epoxy.
Citing this change as an opportunity, quite a few PCB manufacturers in India have recently started transforming their facility encapsulating the infrastructure specifically needed to manufacture PCBs that are a must to cater to the needs of burgeoning LED lighting industry. However, as of now, this contributes only a meagre as major chunk of PCBs for lighting industry is still imported.
We, at LED World, after speaking to a few PCB players, found out that a wave of transformation has already started wherein quite a few indigenous manufacturers are either in process of adding or have already added specific machines or tooling equipment to their existing infrastructure in order serve the industry and make the most of the opportunities. A couple of such names are Ascent Circuits Pvt. Ltd. and Fine Trak Systems. Both the companies have just augmented their infrastructure to coin on the burgeoning opportunities floored on by the country’s ever brightening LED lighting industry.
“Three years back, we really started exploring the possibilities of PCB requirements in the LED lighting industry. It took us around a year and a half reaching to a conclusion to finally enter this stream to cater to the needs of the market. In fact, the PCB requirement in the lighting industry is different than what we have been manufacturing and supplying from decades for other industries,” said Girish Vaikar, Head-Business Development, Ascent Circuits Pvt. Ltd.
“We have recently added the needed infrastructure to manufacture a 4-feet PCB for LED lighting, the absence of which was restricting us to cater to the needs of the industry. We only wanted to supply quality products as we have an established brand carrying a legacy for so long. Unless, we invested in the LED lighting-specific machining and tooling equipment in our existing facility, we may not have been doing justice with our brand as well as with the industry,” elaborated Vaikar.
The story of Fine Trak is no different as the company has upgraded its existing facility only recently. “We have just upgraded our facility to cater to the varied needs of the country’s LED lighting industry,” stated Bhavik Gandhi, Director, Fine Trak Systems. Gandhi suggested that it needed entirely different setup because of the base material of the required PCBs. “Unlike traditional material FR4, the requirements of LED industry is metal core. Accordingly, some more machines and extra tooling equipment were needed to be installed,” he added.
Gandhi suggested that PCBs for LED lighting industry are to be manufactured according to the given specifications only. “We not only have setup infrastructure for metal core PCBs, but also got automated different departments like VAT process line, brushing line, CNC, heat score machines – all for metal core. With all this in place, we have become self-sufficient for all the steps involved in manufacturing PCBs for lighting industry. The unit is fully operational and commercial production has started,” he said.
Ascent Circuits Pvt. Ltd.
An integral part of a premier business group, with diverse commercial interests, Ascent Circuits is one of the leading manufacturers of Single side, Double Side and Multi Layer PCB’s in India. The company’s business philosophy is based on a judicious blend of innovative deployment of technology and exceptional customer service. With a distinct accent on quality, it delivers customised products without compromising on time-to-market. All thanks to the company’s promising engineering talent pool, spearheaded by the dynamic, young management.
Ascent Circuits has the futuristic plant in India with state-of-the-art “Reverse Pulse Plating” Line that ensures high reliability in PTH, especially for high-end applications like telecom, military, Aero Space, microwave & RF applications, plasma etc., for PTFE, ROGERS, GETEK, TACONIC & NELCO materials.
“We, at Ascent Circuits, understand our customers. We know that the many hours spent on the plant shop floor have to translate into tangible quality for the client. We understand what it means to partner a client and accordingly we maintain the needed operational speed in order to deliver to our clients helping remain ahead of competition. That’s what made us notched up an impressive clientele that includes companies like Crompton Greaves, Bajaj, Wipro, Surya, etc.,” asserted Vaikar adding that the real test of technology is the creation of products that plug seamlessly into customers’ critical equipment, which is the forte at Ascent Circuits.
All the products are manufactured and tested using controlled and documented procedures, guaranteeing complete traceability and batch uniformity. The company conforms to A-600D, IS-7405, JSS-52300, JSS-52301, UL-796 standards and welcomes independent audit by its customers. At Ascent Circuits, the pursuit of excellence in quality is a passion that has driven the business to the position it enjoys today.
Fine Trak Systems
A professionally managed organisation, Fine Trak Systems is proficiently engaged in manufacturing, components assembling and exporting of precision engineered printed circuitry boards. Incorporated in the year 1989, we have an excellent track record in PCB fabrication as well as servicing. We have consistently justified our reputation under the guidance of Bhavik Gandhi for offering top quality PCBs.
“In order to deliver competitive PCBs, we perform qualitative finishing on them. The layout designing efforts put by our engineers are backed by state-of the-art surface mounting technology. We are consistently striving to reach height of excellence, and are therefore, tapping the leading advances in the industry to bring out the best PCBs that are durable and have no discontinuities in tracks,” said Gandhi.
We offer a wide assortment of electronic circuit boards such as printed circuit boards that are used in different industries to produce varied items. These PCB’s are manufactured with acute precision by using qualitative laminates like Glass Epoxy, CEM1, CEM3, FR, FR4, XPC, Polyimide RT, Duroid PTFE and Metal Clade.
Gandhi assured that to ensure quality in our PCB’s, the company procures raw material from well established and trusted vendors across the world. “Our encompassing range of equipment includes single-sided PCB, double-sided PCB, computer PCB assembly, inverter PCB assembly, printed PCB assembly, etc. All these products are appreciated for their salient features such as: excellent surface finishing, durability, no current leakage, resistance against short circuit, rugged construction and corrosion-resistant,” he informed.
PCB for LEDs – The Thermal Manager
According to a recently published article by John Cafferkey of Cambridge Nanotherm, MCPCBs based on epoxy dielectrics are useful in visible light applications but advanced LEDs especially UV degrades organic substances such as epoxy, significantly reducing the lifespan of MCPCBs used in UV applications. Keeping in view such attributes of this tiny lighting wonder, the industry experts believe that the only viable alternative is to use electronics-grade ceramics.
Of these, Aluminium Nitride (AIN) features excellent thermal conductivity (140W/mK-170W/mK), but it is also expensive. Aluminium Oxide (Al2O3) is a more cost-effective alternative but doesn’t offer the thermal conductivity needed for advanced LEDs (20W/mK-30W/mK). Both are brittle and can damage easily, which means they cannot easily be screw-mounted and are not suitable for more rugged applications.
The alternative is nano-ceramic with a sputtered circuit layer that facilitates a more than adequate thermal conductivity of 150W/mK, well within the thermal range required. Using a patented electro-chemical oxidation (ECO) process, Cambridge Nanotherm used this approach to transform the surface of an Aluminium board into an incredibly thin layer of alumina (Al2O3) ceramic measuring just tens of microns thick.
This layer acts as the dielectric between the circuit above and the Aluminium below. As the layer produced by the ECO process is extraordinarily thin, heat can easily pass through, giving the substrate its exceptional thermal conductivity. Thin-film processing, or sputtering, follows the ECO process, which directly attaches the copper circuit layer to the nano-ceramic dielectric to further improve the thermal efficiency of the stack. At no stage is organic epoxy used, so there is nothing for UV to degrade.
This whole approach helps create an MCPCB with a thermal performance that rivals Aluminium Nitride (AlN) but without any of the problems associated with poor manufacturability or brittleness.
State of Indian PCB Market for LEDs
According to Vaikar, both the metal core and FR4 are viable for LEDs. “Technically speaking, owing to high-thermal conductivity requirements, metal core is suggested for LED lighting. But due to cost concern, people shifted to FR4. It was then that cheap Chinese manufacturers found this as an opportunity and started dumping very low-quality metal core in India, which is even cheaper than FR4. This induces industry stakeholders to switching over to the metal core,” he said.
He divulged further that those are actually of worst quality material and are produced without following even a single norm (for instance, thermal conductivity, heat dissipation, high voltage adherence, etc.) prescribed for the same. People here found it handy and imported the same in bulk for these being cheaper without concerning the harmful impact not only to the industry but also to their repute. This was the reason why players like us took so much time to jump on to the bandwagon.
“Therefore, we kept ourselves isolated from the market to do away with this dirty business tactics. It’s hampering the business, undoubtedly! But we didn’t buy to play with our repute as it took us so many years, putting so many efforts to develop the brand. We do not want to spoil our name simply by getting in to it. When we are supplying to lighting industry, it must be meeting the standards following the specifications meant for lighting products,” averred Vaikar.
Gandhi, kind of agreeing to all this, suggested that for PCBs business, delivery is the most stringent thing that everybody is stressing these days. “Most of the PCB suppliers have a lead time of up to 40-50 days, which is very long duration especially for the corporate giants as they need much faster delivery – in 10-15 days – owing to their current market requirements following the ongoing LED drive,” he said.
Elaborating on the timeline, Gandhi further added, “There is a process to be followed. First, we need to do sampling, which if passed, is followed by trail batch production, which once approved, moved on to the scheduled production. Therefore, if we get tied up with any corporate customer, we need to strictly follow these three stages. And for all this, we are now ready with the needed infrastructure.”
Each of the steps requires special monitoring & training. “PCB fabrication is simple, but being a much specialised field. Developing design is very complex part of the process. Designing needs special expertise and eats a lot of time wherein we are not interested to invest, for now,” said Gandhi suggesting that there are professional sample manufacturers like PCB Power that facilitate only sampling. “Quite a few clients prefer to have the sampling done from players like them after which the process gets easier and faster than usual. Besides, this helps avoid many human errors and saves a lot of time.”
Gandhi insisted that as of now, the company doesn’t want to step in to the designing part and focus mainly on the production capabilities. “Still, we do have a small design team that develops new but simple designs based on the specifications provided by our clients. However, for critical designing, we outsource the jobs to professional designers, especially when we are overloaded with big projects,” he shared adding that 60% of the production goes to LED lighting industry, and any further increase in the share will be only from LEDs.
The Knowledge Barrier
The dearth of knowledge keeps hampering most of the industries and PCB faces the same barrier. Vaikar highlighted that the industry is lacking knowledge on this front. “Many of the stakeholders do not know what their requirements are and what norms should be followed. The need is to first create the awareness, at least, among the industry partners who bear greater responsibilities; the industry would automatically get upgraded.”
He further added, “At Ascent, whomsoever comes to us, we educate them about the difference in between the ones coming from China and those required for their products. We educate them on why they should not opt for those PCBs. We make them believe as how those cheap quality PCBs are not going to solve their purposes. In this way, we are trying our best to communicate them the reality of what is available in the market and what should they opt for,” he said.
LEDs – The Growth Drivers
PCB manufacturers in India are seemingly determined and are taking long strides to capture as much pie as they can. “We have our factory in Hosur, with a capacity to produce 45,000 sqm per month for one-sided PCBs, 12,000 sqm for double-sided PCBs, and 4,000 sqm for multi-layered ones. This is pretty good capacity to feed the current market needs contrary to the fact that our order surpasses the capacity. As far as lighting industry is concerned, we have yet to study the percentage contribution from LED business in our total business, but we are sure that we have a very prominent place in the industry. When it comes to market, for now, north and west are showing greater potentials due to the accumulation of lighting industry giants in these regions,” said Vaikar.
Fine Trak’s currently installed capacity is of 10,000 sqm, while it only utilises 20-25% of it. “We are strategising to double the sales soon. To achieve this, we are targeting to rope in more customers from street lighting segment. As you know, our main focus is on LEDs. The testimonial of this fact is that whatever expansion we have done lately, all went in the addition and installation of metal core PCB-manufacturing equipment, aimed at catering to the LED lighting sector,” asserted Gandhi.
Eventually, the company expects increased share from the LED market. “We will continue meeting the needs of the regulator market by supplying a considerable chunk to regulator manufacturers in Mumbai. Apart from that, we do serve many other electronic industries needing PCBs,” said Gandhi adding that for Fine Trak, most of the businesses is located in Mumbai, Vasai, Daman and in the north India. “For south, we are not exploring the potentials due to some limitations especially on the part of communications and delivery.”
PCB players agree that a lot of variations and developments are going around PCBs. In most of the instances, PCBs are customised products and are produced based on clients’ specifications. However, there are customers in the market, who are trading in Chinese PCBs, which they import in bulk with standard specifications. This apart there are customers, who get PCBs designed with standard specifications for tube lights i.e. 4-feet PCB with 96 LEDs. They market it to their respective clients who are greatly involved in assembling business and require PCBs in bulk.
Notably, the recent entrant in the name of advancement in PCB is ‘flexible PCBs’ to be used in LED strip. These are rapidly making inroad and is an emerging market in the LED lighting industry, especially for their applications in panel lighting. As of now, no manufacturers have these PCBs in their product portfolio for an entirely different infrastructure requirement. However, few of them are planning to add to their strength soon as these have a certain future in the projected smart cities.
Stencil – The Core of PCBs
An important process among other stages of electronics hardware manufacturing is developing stencil and the stencil printing, which is the foremost stage and requires utmost attention and consideration. When it comes to designing PCB, stencils become an integral part. To develop a particular stencil, a lot of design engineering is required as it replaces hand soldering of surface mount devices, and eliminates the inconsistencies created by hand soldering. It allows for direct placement of solder paste to the surface to be soldered. As far as stencil thickness is concerned, it is determined by the smallest component land pattern depending on the applications of the PCB.
While exploring the potential, we met Kapil Arora of Stencil Point. He informed that stencils are designed in many customised sizes along with standard sizes as per client’s need using high grade raw material mainly imported stainless steel, which is procured from certified vendors. “Our stencils are widely used in engineering, LED lighting, automobile, and industrial applications,” he added showing quite a few unique samples of LED signage that his team has developed lately using latest techniques.
Stencil Point is a CE/ROHS & ISO-compliant company, and manufacture and export a wide range & types of stencils for electronic industry. With accuracy as the USP, stringent quality tests are done with each product to meet the top rank, industrial standards, efficiency and quality. “We want to be continually known for our competency, reliability and expertise in the successful delivery of comprehensive manufacturing process solutions to our customers,” said Arora.
Technically, stencil printing process has to be accurate to get the PCB assembled error-free. It is believed that 85% of the PCB defects accrue due to misjudgment of variables caused during stencil printing process. Adding to the pain is the newer, smaller electronics assembly with huge differences in sizes among components. The latest generations of ultra low-profile and highly miniaturised components, such as QFN ICs, LGA power devices, and 03015 (0.3mm x 0.15mm) chip resistors are continuously posing challenge for both stencil manufacturers as well as printers.
According to Arora, Stencil Point has one of the best pools of skilled staff who constantly upgrade their skill sets so as to meet the vibrant and dynamic technological challenges in the world of electronics manufacturing. “We listen to our customers’ requirements, explore technological alternatives and provide them with tailor-made solutions. We provide easy to use, manageable and scalable solutions with continuous support and development. Technology being the key to success, we practice the use of advanced techniques and device our solutions according to the customers’ needs,” he said.
PCB is the base where all the components stand united and render smooth functioning to the device. Although PCB is the basis of almost all electronic circuits today, still it hasn’t got the attention it deserves. Nevertheless, technology in this area of electronics is developing quite fast. Track sizes are decreasing, the number of layers in the boards is increasing to accommodate the increased connectivity required, and the design rules are being improved to ensure that smaller SMT devices can be handled and the soldering processes used in production can be adjusted.
We observed a big communication gap between and among the industry stakeholders. They don’t want to share their strengths or achievements. Remember, PCB is the heart of any electronic device; and the way all its parts function in sync with each-other, every level/part of the PCB industry must work in tandem. Just the way one component malfunctions, the whole circuit may be affected and ultimately the device. In similar fashion, the entire PCB industry must stay together ensuring that the balance of demand and supply is maintained so that everyone in the industry flourishes.