All About Flex: Flexible Circuits and Man-Made Satellites

The first satellite was launched by the USSR in 1957. The U.S. successfully launched its first satellite, Explorer 1, in 1958 while announcing the intention to “win” the race to outer space(1). Today satellites serve many vital purposes. They are used for telecommunications, weather observation, global navigation, climate analysis, space observation, land stewardship and military uses. There are currently over 1300 satellites in active orbit(2). About 80 satellites are launched into space every year and the technology race continues with new satellite suppliers aggressively competing for additional applications.

Flexible circuits have been used in satellites for several decades. They have been used in antennas, power bus bars, electronic interconnects, solar arrays, battery connections, and for thermal management. As space applications continue to proliferate, the utility offered by a lightweight, flexible and highly reliable electronic interconnection will also naturally grow. Oversized flexible circuits (>22 inches in length) are often adopted as the interconnection circuitry among a variety of satellite subsystems, replacing heavier and bulkier wire harnesses. Flex circuits more than 15 feet have been used in some satellites.

Satellites are generally classified in terms orbital altitude:

  • Low Earth Orbit (LEO) ranges from 100 miles to 1200 miles above the earth’s surface. Manned satellites such as the International Space Station (ISS), earth observation and spy satellites tend to be LEO because they allow a better view of the earth’s surface. Manned satellites stay at low altitudes because the radiation exposure at high altitudes would limit the time a human can remain at the station. Also, satellites requiring occasional servicing would be LEO so they are more accessible. LEO satellites will have a relatively short orbit life without occasional propulsion due to the drag caused by the relatively denser atmosphere. Most LEO satellites have some self-propulsion capabilities.
  • Medium Earth Orbits (MEO) range from 1200 miles to around 22,000 miles. Satellites used for wireless communication tend to be MEO. Their altitude is high enough to maximize communication coverage, yet low enough to allow relatively low powered transmitters.
  • High Earth Orbit (HEO) is 22,000 miles or more. The speed needed to maintain stable orbit depends on the altitude of the satellite. The higher the altitude the lower the velocity required. At 22,236 miles, a satellite will achieve geosynchronous orbit where the velocity matches the rotation of the earth. A satellite achieving geosynchronous orbit will appear to be stationary from the earth’s surface view point, as it maintains a static position relative to the earth. Satellites in geosynchronous orbit are frequently used for weather observation as a satellite can view the same area of the earth over long periods of time.

Many satellites are launched with the intention of lasting only a few years. A satellite in high earth orbit can theoretically stay in orbit forever as there is very little atmospheric drag to cause the orbit to decay. Satellites in medium and low earth orbit can stay in orbit for years without propulsion, but will eventually decay to the point of losing orbit. Many satellites break up in space due to wear and tear, equipment malfunction or collision with space debris. NASA is tracking over 17,000 artificial objects in orbit, which is just a fraction of the amount of debris that is estimated(3). The life of a satellite depends on the orbit altitude, the robustness of the materials and electronics, and its purpose. 

Physical demands on a satellite’s electronic systems vary through its journey as component parts must initially withstand an incredible launch stress. Intense shock and vibration place unusual reliability demands on interconnections. Highly reliable wiring systems are designed with flex circuits thereby eliminating connectors by integrating hard wired bundles and rigid circuit boards into a single flex circuit product design. Minimizing power consumption is another key product characteristic of an electronic interconnection in space. The ability to carry tremendous amounts of data with controlled impedance circuitry is an additional reason flex circuits are utilized in these high-performance applications.

The high vacuum environment required for space applications can cause outgassing to become an issue. Gases released in this vacuum may create problems as condensation occurs on sensitive components, most specifically camera lenses, and clouds the equipment’s visioning capability. ASTM International has developed a test standard ASTM E 595 as a method to evaluate outgassing(4). A variety of flex circuit material constructions are available in the marketplace with adhesiveless substrates being a favored material in space application environments.

Flexible circuits are ideal for many satellite applications because they allow lighter packages using less space. Flex circuits are also very reliable and have a long life expectancy. They can be designed with tight impedance control which is often a requirement for high frequency signals. Similar in construction, and also being a low weight advantage vs. competitive alternatives, flexible heater circuits are used to assist in the thermal controls needed to maintain the operation of system electronics.

References

  1. Explorer 1: The First U.S. Satellite
  2. New interactive chart shows just how many satellites are orbiting earth
  3. Space Debris and Human Spacecraft, NASA website.
  4. What is Outgassing and When Does It Matter?

Other Resources(P1)

Military space officials seek to more rapidly deploy newer satellites to meet threats, www.spacenews.com.

Construction of OneWeb’s new satellite factory is moving quickly, www.spacenews.com

Who owns outer space?, www.bbcnews.com

https://defensesystems.com/articles/2014/03/21/satellite-communications-future-options.aspx

 

Dave Becker is vice president of sales and marketing at All Flex Flexible Circuits LLC.

Back

2017

All About Flex: Flexible Circuits and Man-Made Satellites

09-12-2017

The first satellite was launched by the USSR in 1957. The U.S. successfully launched its first satellite, Explorer 1, in 1958 while announcing the intention to “win” the race to outer space. Today satellites serve many vital purposes.

View Story

All About Flex: Using ZIF Connectors with Flexible Circuits

09-07-2017

Zero insertion force (ZIF) connectors are probably the most popular flexible circuitry connector because they allow the circuit to be inserted and removed multiple times with very little mechanical wear on the copper traces.

View Story

All About Flex: The Anatomy of a Flex Circuit Cutline

08-22-2017

Numerous methods are used to create the cutline of a flexible circuit. With the various tooling options, the methods, process steps, tooling and technology are different. These differences affect the actual physics of cutting, and create slight variations on the circuit material.

View Story

All About Flex: ITAR Registration

08-15-2017

Vendors building product for the defense industry often stipulate a supplier needs to be ITAR registered. ITAR stands for International Traffic in Arms Regulations and is a program run by the U.S. government to control the export of defense-related technology to foreign countries.

View Story

Successful Flex Circuit Assembly

08-02-2017

Many contract manufacturers are reluctant to mix rigid and flexible circuits on the same assembly line as the handling and fixturing requirements can be quite different. Characteristics allowing a flexible circuit to be flexible can often present learning curve challenges when component or mechanical assembly is required. This article details some of the common issues experienced when assembling flexible circuits, and strategies to ensure reliable assembly.

View Story

All About Flex: Button Plating on a Flexible Circuit

07-20-2017

Button plating describes a fabrication process widely used in the flex circuit industry to selectively electroplate copper to the vias and onto the pads capturing the vias. The rest of the copper traces do not have plating. Another industry term used to describe this feature is pads only plating. Producing a circuit with this processing methodology requires two photolithography steps.

View Story

All About Flex: Trends in the Medical Electronics Industry

07-17-2017

The U.S. medical electronics industry has been one of the fastest growing industries over the past decade. Similarly, to the rest of the electronics world, growth has been accompanied by the adoption of significant new product technology and innovation.

View Story

All About Flex: CAD for Flexible Circuits

07-12-2017

CAD engineers take a CAD file that defines a single part and panelize the data by creating a nested pattern repeated across the panel. Reverse nesting and off-angle part placement may optimize material utilization, which is a constant cost concern. But this optimization needs to be balanced by ease of stiffener placement and component assembly.

View Story

All About Flex: Flexible Circuit Component Assembly…and a Math Lesson

07-06-2017

The market for rigid PCBs is estimated to be about 10X the market size for flexible printed circuits (FPCs). As a result, the equipment infrastructure is driven primarily by the needs of the rigid board market. This is true of both equipment used to fabricate the circuitry (image, etch, copper plate, AOI, etc.) and equipment used for component assembly (wave solder and SMT assembly).

View Story

All About Flex: Etchback on Type 3 and Type 4 Flexible Circuits

06-22-2017

Through-hole etchback is a requirement that is sometimes specified on medical, military and aerospace procurement documents for multilayer flexible circuits and combination multilayer flex/rigid board circuits. It specifically relates to the copper plated through-holes and the relative dimensions between the dielectric layers and copper layers.

View Story
Back

2016

All About Flex: Customer Acquisition

12-22-2016

The “Customer Acquisition” process can be thought of as consisting of three major segments: collection, selection and execution. While these sub-divisions should be considered as intimately interrelated, examining them as separate disciplines can be enlightening.

View Story

All About Flex: Disruption in the Supply Chain

12-08-2016

Manufacturers need a highly dependable supply chain to successfully support their products. This is especially true of custom designed and built components, as many times, only one supplier is available for a component since tooling and development costs discourage dual sourcing.

View Story

All About Flex: Packaging Flexible Circuits and Assemblies

12-01-2016

Many facets are involved in delivering a flexible circuit. During the quote and design phase, requirements are reviewed. So assuming the relevant product documentation was gathered, the salesperson turned around the quote, and the customer placed an order and parts were built, it’s all over, right? Not quite. One critical aspect that does not get much discussion is packaging and shipping.

View Story

All About Flex: Non-Copper Flexible Circuit Applications

11-22-2016

While pure copper is the most common choice for flexible circuit fabrication, there are times a different metal is more suitable for an application. Copper is well known for its excellent electrical and thermal conductivity, but there are applications where the best thermal or electrical conductivity can be a disadvantage.

View Story

All About Flex: Flex Circuit Specifications for Commercial and Military Applications

10-27-2016

Applications across the various markets for printed circuit boards can have significantly different specifications and performance requirements. Circuits for toys and games logically have lower performance requirements than those used in medical devices. IPC-6013 is an industry-driven specification that defines the performance requirements and acceptance features for flexible printed circuit boards.

View Story

All About Flex: Five Characteristics of a Reliable Flexible Circuit Supplier

10-27-2016

Due diligence when selecting a source for a custom electronic product can be a critical sourcing procedure. Chains are only as good as the weakest link, and the electronic components assembled to create a marketable product need to combine into a robust solution.

View Story

All About Flex: Flexible Circuit Prototypes

10-13-2016

Most electronic projects begin with at least one build of prototype parts before moving into volume manufacturing. But the definition of a flex circuit prototype can vary considerably from one project to another. In many cases, a prototype build is only a few parts used to verify form, fit and function, with engineering trying to determine if something actually works.

View Story

Flex Circuit Specifications for Commercial and Military Applications

09-30-2016

Applications across the various markets for printed circuit boards can have significantly different specifications and performance requirements. Circuits for toys and games logically have lower performance requirements than those used in medical devices. IPC 6013 is an industry-driven specification that defines the performance requirements and acceptance features for flexible printed circuit boards.

View Story

All About Flex: Lead-Free Soldering Flexible Circuits

09-23-2016

Ever since the European community adopted the RoHS directive in 2006, the U.S. electronics industry has been steadily increasing its use of lead-free solder. Medical was the first U.S. industry to go totally lead-free. Today, a significant percentage of electronics soldering is done with lead-free solder.

View Story

All About Flex: FAQs on RoHS for Flex Circuits

09-02-2016

In 2003, the European Union (EU) adopted a standard called the Restriction of Hazardous Substances (RoHS), which restricts the use of certain materials in electronic products and electronic equipment. The intent is to reduce the environmental impact of known hazardous materials and has driven changes in manufacturing processes and materials used to manufacture a wide array of electronic products.

View Story
Back

2015

All About Flex: Embracing the Mess

12-03-2015

Marketing in the world of printed circuits is an important discipline, but I have learned it is better to be prepared with a nimble reaction than to expect the marketing department to consistently be successful in predicting the future. The path to the goal is often achieved much more quickly by making an early decision followed by a course correction rather than waiting for all the information.

View Story

All About Flex: Flexible PCB: What’s in a Name?

11-12-2015

Flexible PCB is a common term that is synonymous with flexible circuits. While the term “PCB” is generally used to describe rigid printed circuitry, “flexible PCB” is a little contradictory because “boards” aren’t really flexible. Some companies, like All Flex, design and manufactures flexible PCBs, but not rigid PCBs. There are many similarities between the two, but also significant differences.

View Story

Plated Through-holes in Flexible Circuits

10-29-2015

There is probably no more important feature than the plated through-hole (also called via or via hole) with regard to the reliability and integrity of a flexible circuit. The through-hole provides electrical connection between insulated layers and enables electrical functionality on double-sided and multilayer flexible circuits.

View Story

Testing Flexible Circuits, Part 3: The Completed Flex Circuit

10-15-2015

Most flex houses perform a variety of tests on completed flexible circuits. The type, frequency, and complexity of these tests vary with customer and application. Test requirements are generally defined by the customer, but input is often solicited from the supplier during the quote process.

View Story

Testing Flexible Circuits, Part I: Requirements and Procedures

09-17-2015

In this first of a three part series regarding tests for flexible circuits, I will examine overall requirements and procedures; the second installment will focus on raw materials, and the third and final part will focus on testing for bare flexible circuit and circuit assemblies.

View Story

Catching Up to Yesterday

09-02-2015

Recently, KPMG, an international consultancy that operates as a network of member firms offering audit, tax and advisory services, came out with their 6th annual survey of manufacturing executives focusing on global manufacturing trends.

View Story

The Butterfly Effect

08-20-2015

If a random initial disturbance from the wings of a butterfly can have a dramatic effect, just think what can be accomplished with intentional acts aimed at making sure our customers are receiving proactive attention.

View Story

Is Wearable Technology Just a Fad?

08-13-2015

Wearable technology is in its infancy. The industry needs to mature and go back to basic marketing—finding a need and filling it. Flexible circuits have been around since the mid-1960s and have been successfully filling needs. Flexible circuits are ideal for wearable technology because they are thin and lightweight. As the marketing matures, the applications will come and flexible circuits will be there to fill the technical needs.

View Story

Unique Single-Sided Flexible Circuits

08-06-2015

The number of iterations, sequences and combinations possible when manufacturing a flexible circuit can create unique product features to reduce hand assembly of wires, create switch contacts, or eliminate connectors. With minor alterations in basic processing steps, a flex circuit applications engineer can often imagine and configure a dramatically different flexible circuit.

View Story

Agricultural Drones and Flexible Circuits

07-28-2015

According to MIT Technology Review, one of theTop 10 breakthrough technologies last year was the agricultural drone. I focused on drones in one of my recent columns, Flexible Circuits and UAV Applications, which briefly mentioned agriculture as one of the uses for drones.

View Story
Copyright © 2017 I-Connect007. All rights reserved.