Multilayer Flex PCB

In response to market requirements, Hemeixinpcb also offers production of its core HDI PCB technology in combination with flexible PCBs. To make this possible, Hemeixinpcb can offer rigid-flex and flexible PCBs and HDIs for high-reliability applications, with features down to 25 µm and flexible pcb dielectric core down to 25 µm. With the revolution in portable communications’ products over the last decade, flex PCB manufacturing has become a preferred design solution for both complex, three-dimensional product assembly and advanced component surface mounting demands.

What is Flex PCB?

Flexible printed circuits, also known as flex circuits, are sometimes regarded as a printed circuit board (PCB) that can bend, when in reality there are significant differences between PCB’s and flex circuits when it comes to design, fabrication and functionality. One common mistake that designers make is to design a flexible circuit using the same rules as a PCB. Flex circuits require a unique set-up and have their own set of design rules that the Hemeixin team has termed “flex-izing” and have worked hard to perfect over the last many years.

Flexible PCB, which also called Flex PCB, Flexible circuit board or flex circuit, it consists of PI base material, adhesive layer, copper layer, coverlay and sometimes with stiffeners. Flexible PCBs are now being used widely to replace traditional FR4 PCB in various different applications due to the benefits from flex PCB specially. Although more expensive than a normal rigid PCB, the right design in the right application could save weight and time in assembly, coupled with the reliability which makes flexible circuit board a worthwhile consideration.

A flexible printed circuit consists of a metallic layer of traces, usually copper, bonded to a dielectric layer, usually polyimide. Thickness of the metal layer can be very thin (<.0001″) to very thick (> .010″) and the dielectric thickness can vary from .0005″ to .010″. Often an adhesive is used to bond the metal to the substrate, but other types of bonding such as vapor deposition can be used to attach the metal.

How to calculate your flex pcb bend radius?

Because copper tends to readily oxidize, the exposed surfaces are often covered with a protective layer, gold or solder are the two most common materials because of their conductivity and environmental durability. For non-contact areas a dielectric material is used to protect the circuitry from oxidation or electrical shorting.

The number of material combinations that could go into a flexible printed circuit are nearly endless; current, capacitance, chemical and mechanical resistance, temperature extremes and type of flexing are just some of the criteria that impacts the material selections that best meet the functional needs. An experienced All Flex design engineer takes the critical requirements into consideration when designing a circuit to meet your needs.

Flexible printed circuit boards (FPC) has become a common component of electronic products due to its lightness and flexibility performance. It is widely used in smart terminal, wearable electronics, consumer, automotive, industrial and medical fields. The miniaturization and integrated function of electronics product development is driving FPC to fine line and multilayer design.

What is Multilayer flex PCB

This type of flexible printed wiring boards are multilayered (with three or more conductor layers) and require plated-through holes. We could use through vias, buried vias and blind vias.

A multi layer flex circuit combine several single-sided or double-sided circuits with complex interconnections, shielding and/or surface mounted technologies in a multi layer design. The multi layers may or may not be continuously laminated together throughout the production process. If your design needs require maximum flexibility, continuous lamination may not be appropriate. Multi layer circuits are an effective solution when confronted with design challenges such as: unavoidable crossovers, specific impedance requirements, elimination of crosstalk, additional shielding and high component density. You can also link here to learn more about flex pcb bending radius. 

Benefits to Flex PCB including:

• Assembly Error Reduction
• Decreased Assembly Time and Costs
• Design Freedom
• Flexibility during Installation
• High Density Applications
• Improved Airflow
• Increased Heat Dissipation
• Increased System Reliability
• Point-to-Point Wire Replacement
• Reliability and Durability
• Repeatable Routings
• Simplified Circuit Geometry
• Package Size and Weight Reduction

Flex PCB Static Application

An application where flexible circuits are flexed only to install the circuit and fit it into its application (also known as flex-to-fit or flex-to-install). A static application will typically be made using the less expensive Electro Deposited (ED) copper.

Flex PCB Dynamic Flexing Applications

A situation where the flexible circuit itself is dynamically (repeatedly) flexed during the actual use of the final product. Common examples include flip-type cell phones, laptops, printer heads and robotic arms. A dynamic application will require the use of Rolled Annealed (RA) copper.

High Density Flex PCB Applications

Flexible circuits allow for minutely narrow lines giving way to high density device population. Denser device populations and lighter conductors can be designed into a product, freeing space for additional product features.

With a large number of investments on the facilities of flexible printed circuit board and continuously innovating the flexible circuit board manufacturing technology, Hemeixin is able to manufacture flexible PCBs with a great variety of technologies, from simple single sided flex PCB, double sided flex PCB to complex multilayer flexible PCB, Rigid flex pcb and support prototype FPC with laser cutting & flying probe test to mass production with toolings.

Multilayer flex PCB bookbinding

Circuit bookbinding is one of the best practices employed by Hemeixin engineers for creating stacked PCBs. For flex PCBs, we offered a 12 layer flex PCB board with bookbinding. An additional small length is added to the circuit, making it move in an outward direction from the bend radius. There are copper traces placed at right angles to the bend. This helps restrict the circuit bend in one direction.

The length to be added depends on total number of layers in the PCB, as well as the tightness of the bend. The advantage of circuit bookbinding is that it removes a great amount of tension from the various circuit layers during the bending process. The method also helps prevent buckling of the circuits at the exact bend radius.

The bookbinded PCBs can easily meet the tight tolerance requirements in comparison to bonded PCBs. This is why this 12 layer flex PCB is a perfect choice for applications where stricter tolerances are required. Its polyamide construction delivers immense strength and flexibility. This flexi PCB can easily perform 180° bends. Also, the construction helps prevent buckling of inner layers, which often occurs in a long term use. This flexibility also helps reduce stress on the internal components. This 12 layer flex PCB board has better shelf life than a 12 layer bonded circuit board. The immersion gold plating offers low contact resistance, good wetting, as well as excellent shelf life. We can provide the 12 layer flex PCB board with book binding in width 4/4 mil, with minimum finish thickness 0.15 mm flex and maximum 1.6 mm.

10 Layer Flex PCB Board Bonded Together

At Hemeixin, we build multilayered flex PCBs for various industrial clients. These circuit boards can be employed for various applications from simple to complex. A flexible circuit board comprises a comprehensive array of conductors, which are bonded together on a thin dielectric film. Among various multilayered flex PCBs, the 10 layers flex PCB boards are the most popular. These Flexible circuit boards are equipped with copper foils and prepeg glass cloth sheets on the outer level. These prepeg glass cloth sheets offer various benefits to the PCB. The PCB layers are created such that they interchange between prepeg, and pretreated cores.

Advantages of Prepeg in 10 Layers flex PCB Boards

The following advantages of prepeg in flex PCB boards contribute to their popularity:

• The prepeg contains 35% resin, which makes it ideal for curing.
• The prepeg requires less curing time. After the heat curing cycle is completed, the part is ready for a service. Unlike the general prepeg, one don’t have to wait for 48 hours to allow a complete curing.
• Prepreg glass cloths are generally handled at room temperature, which helps control the pace of resin set up easily.
• The prepeg cloth lends mechanical support, which protects the circuit film, and components from damage.
• The prepeg enables to keep certain areas of flexible circuit board stable and flat.
• Steps Involved in Bonding PCB Layers

The layers are bonded together using various high quality presses available at our facility.

• First, the 10 layer stack is placed under a press.
• The baseplates are pinned and stacked together.
• In the next step, the PCB is placed in a bonding press, which employs pressure and heat to bond the layers.
• The resin in the prepeg is cured by heat, and different layers are bonded by the pressure.

Flexible printed circuit boards comprise components and printed board circuitry made of flexible materials. These circuit boards are also referred to as flexible circuits, flexible PCBs, flex circuits, flex circuit boards, and flexible printed circuits. A flex circuit board comprises a metallic layer of traces that are bonded to a layer of dielectric. The metallic layers are normally made of copper, and their thickness may vary from 0.0001ʺ to 0.010 ʺ. The dielectric is normally made of polyester or polyimide, and their thickness may vary from 0.0005ʺ to .010ʺ. The metal is bonded to the substrate using an adhesive.

4 Layer Flex PCB

Flexible printed circuit boards are now prominently used in the electronics industry. Being one of the leading manufacturers of these circuit boards, Hemeixin provides 4 layer flex printed circuit boards. These circuit boards are being used in a variety of industrial applications, including power, medical devices, automobile components, and industrial control equipment.

These printed circuit boards have 4 conductive layers, and made from polyimide, rather than FR4. Being thermally stable material, polyimide allows it withstand extreme heat when used in high-temperature applications. The flexibility offered by polyimide makes surface mounting easier than hard boards, thereby helping in streamlining the design. This polyimide also helps in creating intricate designs, which are otherwise impossible with rigid printed circuit boards. Also, this material helps in reducing the overall weight of the PCB.

Hemeixin provides these 4 layer printed circuit boards in various specifications such as component spacing/width 4/3 MIL, finish thickness 0.2mm, and board thicknesses 0.5mm~3.0mm (0.02″~0.12″), and maximum board size 18″x24″. Although immersion gold is the most popular choice for the surface finishing, we also provide options such as HASL and OSP. All these surface finishes help in improving the performance of these boards under stressful conditions.

Copper thickness is one of the important aspects of the PCB design. The current carrying capacity of the PCB entirely depends on this thickness. This is why we provide a wide range of copper thicknesses to choose from. This 6 layer PCB can be availed in copper thicknesses ranging from 0.5 OZ, 1.0 OZ, 2.0 OZ, 3.0 OZ, up to 6 OZ. The outline processing is performed using V-cut, punching, and routing. The boards are available in popular solder mask colors including blue, green, white, and red. We can also provide the boards with a specialized photo-imageable solder resist – Taiyo PSR4000 white. The PCBs can be availed in any of these silkscreen colors – white and black.

Hemeixin has gained immense popularity in developing flexible circuit boards with thinnest substrates. These substrates have helped reduce the weight, as well as improved the heat dissipation capacity of these boards. Also, we can create PCBs with low interconnection points, which help reduce the chances of system failure, and improves its reliability. Our vast industry experience and accessibility to advanced equipment in our facility enables us to create complex circuit boards in shortest turnaround times, with extremely thin substrates. These thin substrates contribute to reduced package sizes and weights – which is a major advantage in the electronics industry.

6 Layer Flex PCB

Hemeixin is one of the leading manufacturers of lightweight, yet high performing flexible printed circuit boards in the China. We provide these circuit boards in different specifications. Our in-depth technical knowledge, and well-equipped facility enable us to assure shortest turnaround times on all types of printed circuit boards including 6 layer flexible printed circuit boards. These circuit boards have six conductive layers that are placed on an extremely flexible substrate.

The PCB is created using a polyimide, which is a thermally stable alternative to FR4 designs. It also helps increase its heat dissipation capability. We provide the PCB with immersion gold surface finishing, which helps increase its surface planarity. Other advantages of availing this surface finish include increased oxidation resistance, and improved usability for contact surfaces that are untreated. These PCBs can be provided with other surface finishing options, including HASL and OSP on request. All these surface finishes help improve the shelf life, as well as durability of these circuit boards.

We can provide these circuit boards with board thicknesses 0.5mm~3.0mm (0.02″~0.12″), and copper thicknesses up to 0.5 Oz, 1.0, 2.0, 3.0, 4.0, 5.0 and 6 Oz. The printed circuit board can be availed in maximum panel size 18″x24″, and in solder mask colors such as white, black, green, blue, red, and Taiyo PSR4000 white. The circuit boards can be availed in any of the two popular silkscreen colors – white and black. We employ any of these methods for outline processing – V-cut, punching, and routing.

Hemeixin utilizes thinnest substrates for manufacturing these PCBs. This helps us create narrow lines and streamlined designs. These streamlined designs enable denser device populations, and create complex circuit boards. Also, these circuit boards enable heat dissipation from both its sides. We can design the PCBs with minimal interconnections, which helps reduce the system failures, as well as improve its reliability. The printed circuit boards are vacuum packed, which protects them from shocks during the transportation. This helps us ensure that all our printed circuit boards are delivered in working condition.

8 Layer Flex PCB

Hemeixin provides high performance and high speed flex PCBs. These printed circuit boards help us meet the most complex design challenges, as well as eliminate errors that are associated with manually designed wire harnesses. The 8 layer flex PCB is one such high performance PCB. These PCBs are excellent replacement for FR4 designs, and are manufactured using a polyimide, which increases its thermal stability. Additionally, the surface treatment of immersion gold, OSP, and HASL helps improve the performance, shelf life, and durability of these boards in hostile conditions.

The boards can be availed in thicknesses ranging from 0.5mm~3.0mm (0.02″~0.12″), with the maximum panel size up to 18″ x 24″. We can provide the boards in thicknesses ranging from 0.2mm to 1.6mm. We can provide these boards in copper thicknesses ranging from 0.5 Oz, 1.0 Oz, and 2.0 Oz up to 6 Oz. The boards are available in all leading solder mask colors, such as white, blue, black, green, and red. In addition to this, we also provide a specialized liquid photo imageable solder resist – Taiyo PSR4000 white.

We can provide this 8 layer flex PCB in either of two silkscreen colors – black, and white. The circuit board of this type comprises thinner dielectric substrates, which enables a streamlined and lightweight design. This streamlined design also helps improve the heat dissipation of the circuit board. These 8 layer flexible circuit boards can flex up several million times, and are ideal for circuit boards with most moving parts. There is a high demand for lightweight, and high performance printed circuit boards, which makes these PCBs popular in the industry. Each PCB is vacuum packed to avoid damages during the transit.

12 Layer Flex Circuit Board with Book Binding

Circuit bookbinding is one of the best practices employed by Hemeixin engineers for creating stacked PCBs. For flex PCBs, we offer a 12 layer flex circuit board with bookbinding. An additional small length is added to the circuit, making it move in an outward direction from the bend radius. There are copper traces placed at right angles to the bend. This helps restrict the circuit bend in one direction.

The length to be added depends on total number of layers in the PCB, as well as the tightness of the bend. The advantage of circuit bookbinding is that it removes a great amount of tension from the various circuit layers during the bending process. The method also helps prevent buckling of the circuits at the exact bend radius.

The bookbinded PCBs can easily meet the tight tolerance requirements in comparison to bonded PCBs. This is why this 12 layer Flex PCB is a perfect choice for applications where stricter tolerances are required. Its polyamide construction delivers immense strength and flexibility. This flexi PCB can easily perform 180° bends. Also, the construction helps prevent buckling of inner layers, which often occurs in a long term use. This flexibility also helps reduce stress on the internal components. This 12 layer flex circuit board has better shelf life than a 12 layer bonded circuit board. The immersion gold plating offers low contact resistance, good wetting, as well as excellent shelf life. We can provide the 12 layer flex circuit board with book binding in width 4/4 mil, with minimum finish thickness 0.15 mm flex and maximum 1.6 mm.

Being one of the leading flex PCB manufacturers, we can provide you flexible circuits in a wide range of specifications and capabilities.

Being a trusted flexible printed circuit board manufacturer with a vast industry experience, we specialize in rigid and flexible circuit boards. We have a team of experienced professionals who have in-depth knowledge and understanding of various technologies and trends. They work with clients to understand their challenges and business requirements. The different types of flexible circuit boards that we provide are strong enough to survive unfavorable environments, and assure a high ROI. A well-equipped facility and a team of experienced professionals help us assure the quickest turnaround times in the industry. Do you wish to know more about flexible PCBs or other types of circuit boards that we manufacture? Please get in touch with our professionals today.