Important Flex and Rigid Flex PCB Design Tip

, in just what will certainly be the initial of lots of rigid flex PCB ideas, we will certainly be reviewing optimum rigid flex PCB stackups and materials. One of our clients recently sent us a 6 layers stackup that needed a little tweaking. It’s outstanding just how a few modifications to your rigid flex PCB stackup design could make certain longevity and manufacturability on your rigid flex board.We talked it over with our designers and developed solutions and alternatives to all of the concerns

The Board:
– This was a six-layer rigid flex PCB with adapters calling for impedance control.
– The high-speed ports connected finger areas from the edge to the top side of the PCB board.

The Concerns:
– The board’s flex PCB layers were found on the outside of the stackup, which enhanced the possibility of manufacturing troubles
– Making sure the board met the impedance demands.

The Remedy:
When the flex layers are on the outdoors, panels are more difficult to deal with and more challenging to process. This made the board more sturdy and much easier to manufacture. It also allowed for much better impedance and better control around the flex finger location.
We embedded the flex PCBlayers in the center of the stackup. This safeguarded the layers throughout the PCB manufacturing process and ensured that the less-durable flex layers were not subjected to outer-layer plating. This is how most rigid flex PCB stackups are made.

Because the flex layer is a separate process, putting the flex layers inside enables flex PCB manufacturers the ability to etch far from the design while safeguarding the flex layers. The material used also played a huge component in making this rigid flex PCB instead of flex. Rigid PCB material was utilized, permitting better impedance and reliability. It was a better option than the original FR-4 material.

Putting the rigid PCB material on the outside likewise enables us to produce exactly what is basically a rigid panel. The flex PCB layers are also safeguarded by our surface area plating since it needs to weak the material.

iFastPCB rigid flex PCB manufacturing processes are as adhering to: first to process the flexible layer as a two layers flex PCB. Then to laminate the flex layers in between the rigid PCB layers. The ending action is milling the cover layers so the flex section becomes viewable.

Source from http://www.ifastpcb.com/blog/important-flex-and-rigid-flex-pcb-design-tip/

Flex PCB Is a Better Choice to Replace Cables

Flex PCB can give several apparent advantages over traditional ribbon cables in particular applications. As an example, a flex circuit can extend in between a board and an adapter on a bulkhead numerous inches away at a right angle in the same plane as the board. That’s not possible with a bow cable.

Flex connections have mechanical advantages over conventional bow cables in numerous applications however in some cases, they likewise have much better chemistry.

A flex circuit can be developed in complex shapes in 3 dimensions with branches to multiple connectors, which would certainly be difficult to accomplish with a ribbon cable. Additionally, flex circuits can be interfaced with rigid boards without the fairly tall and large connectors level cables require, or in the case of rigid flex PCB building and construction, they can be indispensable with the boards and remove external connectors entirely. Furthermore, the conductor thickness of flex PCB can much surpass that of bow cables.

Flex PCB’s Advantages

There are some refined benefits of flex PCB versus traditional ribbon cables past the many clear distinctions. Among the materials typically used for flex circuits, Kapton, has very reduced outgassing in ultra-high-vacuum atmospheres, such as room. Though Kapton-insulated bow cables are offered, they have a limited variety of conductors and could not be transmitted at angles in limited boundaries.

Ribbon cables shielded with Teflon and various other plastic materials outgas fluorine or reactive substances when subjected to high vacuum cleaners, which can attack electronic devices in sealed containers if treatment is not taken to completely duct the gases.

A Kapton Flex PCB

Sinclair Interplanetary integrates a Kapton Class 3 flex PCB made by iFastPCB in optical navigating gadgets the business produces for usage in small satellites. The nine-conductor flex PCB web links a D-type adapter, which secures to the tool unit, with pins on the rigid tool board that bring telemetry information, commands, and power.

The flex PCB in this situation is swaged to the pins on the six-layer rigid PCB board, which is about the size of a credit card. It brushes up the conductors upwards and at a best angle from the pins on course to the adapter and guarantees the port is mechanically isolated from the board.

Sinclair is among several iFastPCB clients that manufacture parts for small satellites or develop the total satellites. Tiny satellites– several of them bit larger than a shoebox– could do very complicated objectives matching those achieved by spacecraft costing loads of times extra.

Source from http://www.ifastpcb.com/blog/flex-pcb-is-a-better-choice-to-replace-cables/

iFastPCB Produces And Assembles PCBs In-House

Many global contract manufacturers accommodate huge firms seeking one-stop monitoring of their production needs. This can consist of every little thing from PCB fabrication to PCB assembly amongst product development and building and construction. These manufacturers specialize in comprehensive projects that generally involve long lead times and huge production amounts. The jobs those specialists take on is limited, and the revenue from each project is high. Most startups and medium-size companies could not afford those integrated PCB suppliers.

iFastPCB SPECIALIZES IN PCB MANUFACTURING AND ASSEMBLY AND RIGID FLEX PCB TECHNOLOGY. FROM PCB MANUFACTURING TO ASSEMBLY, iFastPCB HANDLES ALL ELEMENTS OF PCB PRODUCTION INTERNAL AT SHENZHEN CHINA.

There are contract PCB manufacturers who collaborate numerous elements of electronic devices development and fabrication for clients whose product quantities are tiny, or whose tasks are at the PCB prototype phase. Some of these service providers concentrate on PCB design in house yet partner with PCB manufacturers and, in turn, with PCB assemblers; others assemble PCBs but outsource PCB fabrication and may engage design solutions; still, others only manufacturing PCB boards and subcontract assembly.

Essentially, they coordinate services on their clients’ behalf as a solitary factor of get in touch with and responsibility. They earn the premium charged for that ease– if they supply high quality outcomes on schedule, which depends on whether their companions meet due dates and whether transshipments are postponed.

iFastPCB Is A One-Stop PCB Manufacturing Shop

iFastPCB fabricates and assembles PCBs of any kind of complexity completely in house on fast turn schedules, in quantities ranging from a solitary board to medium-scale production. All manufacturing is done on-site within our China Shenzhen centers. Our company design is tailored to structured PCB prototype growth and fabrication, as well as PCB manufacturing for high-value, low-volume systems for which reliability is important.

Benefits Include:

– Saving our clients time, money, and effort
– Providing our customers with extraordinary high quality, integrity, and a solitary factor of support
– Eliminating communication concerning project needs
– Guaranteeing limited quality assurance
– Getting rid of days of hold-ups, an unavoidable problem when utilizing multiple suppliers

Take into consideration, for instance, a start-up company cultivating a clinical analysis system that incorporates 40 various PCBs, which will certainly cost half a million dollars. Production quantity is anticipated to ramp to 100 units per year within two years, blog post advancement. A few of the boards are very complex, embedding high-speed DSP, optical-network monitoring, and data source analysis features. They otherwise include high-pin-count BGAs, stacked bundles, and gadgets in BGAs with a 0.4-mm sphere matrix. 2 have actually been significantly redesigned and wait for layout, while the second alteration to the layout of an additional nears conclusion. 3 designers within the company, two of which are founders, have architected every PCB board in the system. Time to market is vital, however the group does not have the transmission capacity to finish the designs prior to due date, and has actually had difficulty handling both PCB manufacturers and the PCB assembly store who developed the boards to this day.

Pleasing Clients Is Our First Goal

iFastPCB can help remove troubles like this. We remain in close collaboration with start-ups on delivery routines tighter than service providers who just integrate solutions could meet. Strategic relationships with key parts vendors allow us to expedite complete service in one smooth in-house operation: from the invoice of customer schematics, to layout, to PCB fabrication, to component purchase, to the delivery of assembled PCB boards.

We cater to the production demands of such companies that, when product development has actually been finished, could require just 10 collections of 40 various boards to fulfill preliminary client orders. And do so offering inexpensive costs.

Browse through iFast PCB to complete your free PCB fabrication or assembly quote.

Source from http://www.ifastpcb.com/blog/ifastpcb-produces-and-assembles-pcbs-in-house-2/

Rigid flex PCB designs can save costs during system assembly

A straight line is not constantly the shortest route between 2 factors in digital products: Thanks to rigid flex PCB style, circuits can be folded up onto themselves with 180º bends– laid over at minimum elevation– therefore diminishing item measurements. In addition, if a product has moving areas with electronics embedded, rigid flex PCB building is the ticket.

Credit rating rigid flex PCB architecture for the existence of smart devices and various other pocket-sized digital marvels. However, to realize the benefits of rigid flex PCB construction (including lightweight settings up) particular design restrictions apply particularly to the flex PCB layers in a stackup. Do not attempt your initial (or second, or 3rd) rigid flex PCB design prior to you consult your prototype PCB manufacturer.

Using Flex in Rigid Flex PCB Assembly

Unlike a traditional PCB stackup, foil building and construction could not be used for flex layers. The flex layers in a rigid flex PCB assembly are built from unreinforced base substrates normally containing polyimide dielectric film, outfitted with rolled stiff copper.

Consequently, the clothed base material is first pierced, openings are selectively plated, after that the traces and pads are engraved. Bondply, a layer of polyimide film with glue layer on both sides, isolates that conductor layer from the next, and so forth.

Flex PCB materials are flexible under all situations, including processing. During the last lamination of the rigid flex stack, they are much less dimensionally steady than the rigid core and prepreg materials that sandwich them. Vias should be farther from the side of the rigid area adjoining the flex bow than the minimum distance in rigid-only heaps, ideally at the very least 50 mils from the edge, but absolutely no less than 30 mils. This rule is the one most broken in rigid flex PCB designs.

Look for guidance to create your stackup and design guidelines. Differing coefficients of thermal expansion among the flex base material, adhesives, prepreg, and rigid cores needs an extremely careful equilibrium of thicknesses, specifically for impedance-controlled designs. There can be lots of layers of flex in a rigid flex design, depending upon the bend radius of the ribbon section and whether it will stay fixed after assembly. Flex layer count should be restricted in dynamic applications. Consult your PCB manufacturer. If more than four flex layers are required, bonding adhesive must be absent in the sections that are designed to bend. The bend radius will be no less than 12 times more than the circuit thickness.

Successfully Using Trace Routing

Trace routing in the ribbon location should be bent, not angled, to raise peel strength. This referral is other the transmitting technique for rigid PCB boards.

To increase ribbon versatility, airplanes ought to be cross-hatched; nevertheless, the cross-hatch makes complex impedance control. Once more, a cautious equilibrium is required. In some applications, a large, solid strip under critical traces suffices. Traces on various layers should be surprised vertically, not placed atop each other, to boost ribbon flexibility.

Annular rings should be as big as possible in flex-only regions to reduce the threat of peeling, and the change from the annular ring to the trace should be teardrop-shaped for the exact same factor. Including tabs or supports additionally helps to stop peeling.

The stiffeners can be laminated when the cover-coat is bonded and is the recommended approach to avoid tears. The most effective strategy is to avoid utilizing sharp corners in a flex PCB design.

An extremely basic checklist for rigid flex PCB designs consists of these routing factors to consider:
– Stagger flex traces up and down layer to layer
– Transforms should be progressive
– Vias needs to be no closer to the side of the rigid board compared to 30 mils at the flex shift
– Minimize flex PCB layers

Keep in mind, rigid flex PCB designs may be costly to produce, however they can conserve expenses during system assembly. Such design often is the only way to put the required product functions within the target package volume. It’s much better to get in touch with a rigid flex PCB manufacturer during the drawing board.

Source from http://www.ifastpcb.com/blog/rigid-flex-pcb-designs-can-save-costs-during-system-assembly/

Rigid Flex PCB Design Layout Demands

Rigid flex PCB are special with their incorporated building of both rigid PCB and flex PCB circuits innovations. Being unique includes a number of special needs that should be examined and carried out throughout the rigid flex PCB layout stage of the design process.

The first two requirements relate to minimum area demands, as measured to the Flex Transition Zone within the design, of plated through openings (PTH) and exterior layer copper features. The 2nd two handle the mechanical flexibility and integrity of the flex PCB locations when the components are bent into the required form.

The Flex To Rigid Transition Zones

The “Flex Transition Zone” is specified as the size of the rigid area outline at which the layer framework modifications from a rigid area to a flex PCB area only.

The Flex Change Area are produced by the need to expand the flex PCB location coverlays by a tiny range right into the rigid areas. This allows the flex coverlays to be caught by the lamination of the rigid location layers and make certain a gapless shift in between the flex PCB areas and the rigid locations. The flex coverlays do not expand throughout the rigid locations as called for by IPC 2223C design criterion for flexible PCB.

Layered With Opening to Flex Transition Area min. spacing = 0.050″

– Ensures layered with opening integrity by protecting against any PTH from being drilled via the flex coverlays as they involve and are captured by the Rigid location layer lamination.
– Coverlays are laminated to the flex PCB layers utilizing a flexible adhesive, either acrylic or epoxy based. These adhesives have a very high co-efficient of thermal growth.
– A plated via hole pierced with a coverlay will certainly undergo considerable Z-Axis growth and contraction anxiety during both the assembly re-flow process and possibly throughout the procedure of the finished product. This has actually been determined as a key source of broken opening layering resulting in either instant product failing or long-term latent failing integrity problems.
– This requirement is called out in IPC2223C Sec. 5.2.2.3.

Exterior Layer Copper feature to Flex Transition Zone min. spacing = 0.025″

– Makes sure enough spacing to allow for reliable outside layer imaging processing.
– Rigid layers, while in production panel arrangement and prior to final lamination process, are called for to have the flex PCB areas got rid of. This develops in inner sides, created by the height difference in between the rigid area and the flex location, which the exterior layer image transfer films need to transition.
– Min. spacing 025″ supplies enough area for film attachment and a dependable imaging process.

Flex PCB Location Via Holes

– Not suggested and should be stayed clear of if design permits.
– Includes substantial cost as a result of the extra drilling and layering processes.– Requires blind via manufacturing processes.
Possibly creates mechanical stress concentrators in flex PCB layers which may cause breakage if part is bent in the vicinity of these vias.
– If design does need flex area vias:
-Make certain vias lie away from the certain bend place(s) in flex areas.
-Have PCB supplier review design to assess and determine if any risk aspects exist.

Flex PCB Location Trace Layout

-Traces ought to be maintained directly and parallel, if design enables.
-If trace direction adjustments are required utilized curved corners and minimize as much as feasible.
-Aids get rid of possible mechanical tension concentrators which could bring about breakage when flex PCB area is curved right into placement.
-Stagger traces on surrounding layers, if design permits.
-Improves adaptability and integrity by reducing the “I-Beam” impact of traces placed straight above one another from layer to layer.

Source from http://www.ifastpcb.com/blog/rigid-flex-pcb-design-layout-demands/

iFastPCB Produces And Assembles PCBs In-House

Most worldwide contract manufacturers accommodate huge companies looking for one-stop monitoring of their production demands. This can consist of everything from PCB fabrication to assembly amongst product development and construction. These manufacturers specialize in extensive jobs that generally involve long lead times and large production amounts. The tasks those specialists take on is limited, and the revenue from each job is high. Most start-ups and medium-size business can not pay for those integrated PCB providers.

iFastPCB SPECIALIZES IN PCB MANUFACTURING AND ASSEMBLY AND RIGID FLEX PCB MODERN TECHNOLOGY. FROM PCB MANUFACTURING TO ASSEMBLY, iFastPCB DEALS WITH ALL ASPECTS OF PCB PRODUCTION INTERNAL AT SHENZHEN CHINA.

There are contract PCB manufacturers who coordinate various aspects of electronic devices development and fabrication for clients whose item volumes are tiny, or whose tasks are at the PCB prototype stage. Several of these contractors concentrate on PCB design in house however partner with PCB manufacturers and, in turn, with PCB assemblers; others assemble PCBs however contract out PCB fabrication and may engage design services; still, others only manufacturing PCB boards and subcontract assembly.

In essence, they manage solutions on their consumers’ behalf as a solitary factor of get in touch with and duty. They earn the costs charged for that convenience– if they deliver top quality results on time, which relies on whether their partners satisfy due dates and whether transshipments are postponed.

iFastPCB Is A One-Stop PCB Manufacturing Shop

iFastPCB fabricates and assembles PCBs of any type of complexity completely in house on fast turn schedules, in quantities varying from a solitary board to medium-scale production. All PCB manufacturing is done on-site within our China Shenzhen facility. Our organisation model is customized to structured PCB prototype development and fabrication, in addition to PCB manufacturing for high-value, low-volume systems for which integrity is important.

Benefits Include:

– Conserving our consumers time, cash, and initiative
– Supplying our consumers with unprecedented high quality, reliability, and a solitary factor of assistance
– Removing interaction concerning project demands
– Making sure limited quality assurance
– Removing days of hold-ups, an inescapable trouble when using numerous suppliers

Take into consideration, as an example, a startup company establishing a medical analysis system that integrates 40 various PCBs, which will certainly cost half a million dollars. Production quantity is expected to ramp to 100 units per year within two years, post development. Several of the boards are very intricate, embedding high-speed DSP, optical-network management, and database analysis functions. They otherwise include high-pin-count BGAs, stacked bundles, and devices in BGAs with a 0.4-mm round matrix. Two have actually been substantially upgraded and await layout, while the second alteration to the layout of an additional nears conclusion. Three engineers within the company, two of which are founders, have actually architected every PCB board in the system. Time to market is important, however the team lacks the bandwidth to finish the layouts prior to target date, and has actually had trouble managing the two PCB manufacturers and the PCB assembly store who constructed the boards to this day.

Satisfying Consumers Is Our Number One Goal

iFastPCB can help eliminate troubles such as this. We are in close collaboration with startups on shipment timetables tighter compared to contractors who just integrate solutions can meet. Strategic partnerships with crucial parts distributors allow us to expedite complete solution in one smooth in-house procedure: from the receipt of client schematics, to layout, to PCB fabrication, to part purchase, to the delivery of constructed PCB boards.

We deal with the production needs of such companies that, when product development has actually been completed, might call for only ten sets of 40 different boards to meet initial customer orders. And do so providing economical prices.

Check out iFast PCB to complete your free PCB fabrication or assembly quote.

Source from http://www.ifastpcb.com/blog/ifastpcb-produces-and-assembles-pcbs-in-house/

Rigid Flex PCB Design Guide for IoT/Wearable Product (1)

Today, innovation patterns are progressively towards flex circuits or a combination of rigid flex PCB for IoT/wearable PCB designs. You can claim those fads place us on a different ground, so to speak. For that reason, it’s important to obtain a manage on brand-new design terms and points that should be factored in as you relocate to this following degree of embedded design.

This includes the following:

– Low and high modulus boards
– Bend distance, proportion, and pressures
– Dielectric thickness
– Via placement
– Board layers and associated copper quantities
– Normal copper versus hardened copper
– Copper density

Board modulus describes its construct– a reduced modulus implies a softer structure, while high modulus refers to a harder board with stiffener. A stiffener that supplies rigidness to the flex circuit for stable soldering is revealed; components mounted on the contrary side of the stiffener. Stiffeners are a cost-effective means to rigidize certain locations on the rigid flex PCB boards, such as SMT areas, pin areas, or hole pattern places for element placing.

SMT areas do not always require stiffeners depending on the parts being set up at that location. Nevertheless, adding a stiffener is mosting likely to include hardly any price to the assembly. Stiffeners are utilized to enhance solder joints and are sometimes used to force bend lines in the chosen locations. Stiffeners can be made from FR4, polyimide, copper, or aluminum-based materials.

Occurring the bend

Regardless of the application, a rigid flex PCB must be flexible and flexible, yet the question is: Just how pliable and flexible can it be? The court is still out on the accuracy of bendability (or “bendableness”). As of this writing, the IPC is being instead conservative with its call. So, basically, the precise interpretation or scale of bendability hasn’t already been pinned down and most likely will not be because of its nebulous nature. The very best recommendations provided is to rely upon a knowledgeable EMS Provider that has a number of wearable/IoT PCB designs under its belt and has a warehouse of crucial nuances associated with flex PCB bendability.

Having said this, it readies to recognize terms like bend span, bend ratio, and stress, all of which are totally intertwined. Bend span, as the name implies, is just how far you could flex that flex circuit before something breaks or incurs an unexposed fracture. It’s likewise required to understand that the measurement of the bend radius is performed from the bend’s underside surface area. Once more, it’s a good idea to companion with an intelligent EMS Supplier to evaluate and settle bend radius concerns and problems.

The 2nd term, bend ratio, thinks about the ratio of the bend radius to the density of the flex circuit. For instance, the bend proportion for a multi-layer flex circuit for a medical electronic devices wearable device is at the very least 20:1. Comparative, for the solitary and double-sided flex circuits the bend proportion must go to the very least 10:1. Tighter bends may create the danger of circuit damages. It’s always more effective to utilize more progressive angles as opposed to an appropriate angle bend with a sharp radius. Bend span is computed by gauging the range from the inside surface area of the bend to the facility of the distance.

It’s also vital to recognize there are two facets connected with flex PCB circuits flexing. One is static or one-time bending; the other is dynamic flex entailing numerous bending procedures. The bend span for fixed bending should be at least 10 times the thickness of the wiring and the strain on the critical layers will be 2.2% or less. On the other hand, the bend span for dynamic rigid flex PCB will be 25 times or less.

The bend span for vibrant rigid flex PCB, such as the example inhabited with µBGA bundles, ought to be less than 0.8% for 50,000 cycles, less than 0.6% for 100,000 cycles, less than 0.4% for as much as one million cycles, and less than 0.2% for a million cycles or more.

As was kept in mind over, the bend radius, bend ratio, and pressures created by the flexing activity of the boards are totally linked. In the case of stress, these are currently integrated in when the rigid flex PCB manufacturer creates the flex circuit. To puts it simply, stress is inherent in the various circuit layers and can be minimized with pressure relief devices such as stiffeners.

Dielectric thickness

Dielectric materials within the flex circuit could cause more stress relying on their density. Dielectrics differ in their proportion of stiffeners to density. Choosing a dielectric material inning accordance with the underlying application offers the completed flex circuit the quality it requires. In regards to impedance designs, the conductor sizes and dielectric densities can be adapted to fulfill the needed impedance results.

As previously noted, high modulus PCBs are difficult boards with stiffeners. Right here, bend radius is very essential and has to be factored in due to the fact that the estimation of bend ratio must also include the thickness of the stiffener, thereby raising the total density for the flex PCB. Maintaining the bend ratio little boosts the flex circuits’ dependability.

This suggests that it is essential to understand the pressure at different levels within rigid flex PCB layers. Consequently, this means understanding which layers utilize exactly what quantities of copper. Altering the quantities of copper has the most unfavorable result on stress difference.

As an example, take a rigid flex PCB with a Hoz of copper weight. This will flex with a certain stress quantity with a certain bend ratio. Nonetheless, if the amount of copper were to be increased to one ounce, the versatility would be considerably decreased, and the bend ratio would be restricted since the copper thickness has doubled, thereby creating a total thicker flex design. All of this suggests that you need to calculate the bend proportion very meticulously.

Moreover, you need to inspect copper density at various layers within the flex material. This is because the density influences the bend proportion and the stress variable. You can utilize certain sorts of flex material for certain applications, so it’s not a situation of “one-size-fits all.”

Source from http://www.ifastpcb.com/blog/rigid-flex-pcb-design-guide-for-iotwearable-product-1/