At present, many electronic devices are developing towards miniaturization and compactness, and the corresponding connectors should follow suit. Among them, FPC connector is an indispensable "artifact" in compact applications. This paper will analyze the application market, development direction and technical problems of FPC connector.

When the world's first computer came out in the 1940s, it was as big as a room. Today, computers can be the size of a palm. We have witnessed technological innovation making all kinds of electronic devices smaller and more compact. With the structure of electronic equipment becoming more and more integrated and modular, the corresponding connectors should develop synchronously towards the corresponding trend. Among them, FPC connector is one of the most demanding and important schemes in compact applications.

Wide application range and large demand

As one of the main functional accessories of flexible circuit board, FPC connector has become one of the main categories of flexible circuit board production, which is in line with the development trend of rapid miniaturization of electronic equipment. It can be said that the development of FPC connector is triggered by flexible circuit board, and has a greater and greater impact.

Because FPC connector is more flexible, saves more space and can effectively save cost, it is in great demand in compact applications“ The FPC connector has the advantages of small volume, light weight and thin thickness, which can effectively reduce the volume and weight of the product and increase the convenience of carrying. At the same time, FPC connector has the characteristics of flexibility, which can enhance the utilization of assembly in three-dimensional space. The spare assembly time can be saved. " Said Yang Wuxiao, business manager of Dongguan Kangrui Electronics Co., Ltd.

Based on the above characteristics, the downstream application field of FPC connector is constantly expanding. FPC connector can be found in various digital communication products, portable electronic products, household appliances, computer peripheral equipment, measuring instruments, automotive electronics, industrial control aerospace, LED lighting, medical treatment and other fields.

1. Consumer electronics is home

As a functional component of flexible circuit board, FPC connector is the main connection mode of flexible circuit to connect circuit board in consumer electronic equipment under the background of the rapid development of miniaturization of electronic equipment represented by smart phone. The most widely used downstream market of FPC connector is consumer electronics. Nowadays, the domestic consumer electronics market is developing very rapidly. Superimposed with the development trend of lightweight and folding of electronic products, consumer electronics accounts for more than 70% of FPC connector consumption.

The latest research report 2014-2024 global consumer electronics market forecast released by strategy analytics points out that in 2020, consumers' strong demand for home computers, tablets and game consoles will drive the revenue of consumer electronics trade to reach US $358.5 billion, an increase of 7% over 2019.

The report points out that because millions of consumers need new equipment to work and study, the shipment of home computers and tablets will increase by 11% to 396 million units in 2020; Revenue increased by 17% to $1990 billion. Meanwhile, due to the launch of new game consoles and the epidemic blockade, the revenue of game consoles increased by 18% to US $11.9 billion.

FPC connector is one of the most commonly used smart phones. FPC connector can be used for the connection of rear fingerprint identification module, main and auxiliary boards, mobile phone screen drive circuit (PCB), battery connection, etc. According to the latest report released by strategy analytics, global smartphone shipments will reach 1.38 billion in 2021. From the consumption of mobile phones, we can see that the application of FPC connector in consumer electronics is very huge.

At present, the demand for consumer electronic products is still increasing. According to the cbndata report, the scale of the global consumer electronics market continues to grow and is expected to exceed US $400 billion in 2021.

2. Wearable devices become a new driving force for growth

It is worth mentioning that smart wearable devices have become a new favorite in the consumer electronics market, leading the outbreak of a new round of consumer electronics.

In the consumer market of smart products in 2020, consumer spending on wearable devices reached US $69 billion, a year-on-year increase of 49%; It is expected to reach US $81.5 billion in 2021, with a year-on-year increase of 18%. At the same time, the global sales of wearable devices will exceed 2 billion by 2030, which will exceed the sales of smart phones. There is a huge growth space for wearable devices in the future.

FPC connector is thin and flexible, which is in line with the requirements of wearable devices. It is the preferred connecting device of wearable devices. Wearable devices have become a new growth pole of FPC connector.

According to the global wearable device market report for the fourth quarter of 2020 released by IDC, the overall shipment in 2020 was 444.7 million, a year-on-year increase of 28.4%. Among them, in 2020, China's wearable market shipped nearly 110 million units, a year-on-year increase of 7.5%. It is understood that one FPC connector will be used for a single intelligent Bluetooth headset and watch. It is estimated that the market scale of FPC connectors can reach hundreds of millions.

Among them, TWS Bluetooth headset and smart watch / ring are the main driving forces for the growth of wearable devices. Ville ukonaho, deputy director of strategy analytics, said: "in 2020, headphones and bracelets / watches together accounted for 98% of global wearable device sales. TWS Bluetooth headset and smart watches such as Apple's airpods or Xiaomi Mi watch are the two major segments that drive the growth of wearable devices. "

3. Increment brought by automobile electronization

Electronic equipment accounts for only about 25% of the cost in traditional vehicles. With the increase of the application of sensor technology and the gradual penetration of the Internet into vehicles, the electronic trend of vehicles is becoming more and more obvious. In the future, with the deepening trend of automotive automation, networking and electrification, the proportion of automotive electronics in the cost of the whole vehicle is expected to exceed 50%.

In the future, with the intelligent and electric vehicles, the adoption ratio of circuit board FPC connectors inside the equipment will be greatly increased due to the demand for lightweight. With the progress of intelligent vehicles in ADAS, lighting, entertainment, navigation and safety systems, FPC connectors are widely used in radio devices, GPS devices, LCD displays and entertainment devices. At the same time, FPC connector can also meet the temperature conditions, double contacts and other requirements of on-board requirements, with high reliability.

In addition, due to its light weight, high integration, high wiring density and high reliability, FPC connector can also be used in military, aerospace and industrial fields. These fields require more stringent and flexible wiring in the machine, which drives the new development of FPC connector. In terms of medical equipment, FPC connector can help realize the miniaturization required by handheld equipment, including monitor equipment, etc.

Development direction of FPC connector

FPC connector is mainly used in various digital communication products, portable electronic products, computer peripheral equipment, measuring instruments, automotive electronics and other fields. It has become an indispensable part in most electronic equipment. Its advantages are also very obvious, high density, small volume and light weight, which can reduce space occupation, weight and cost. In order to adapt to the development of electronic products, the technology of FPC connector is constantly updated and iterated. High speed micro will be the general trend.

1. Miniaturization and precision

The increasing miniaturization of electronic equipment is promoting the development of flexible connectors to the direction of smaller spacing and thinner thickness. FPC connectors with small pitch, low height and multiple P in numbers are the main development direction in the future.

It is understood that the international minimum spacing can be 0.175mm; The minimum spacing of domestic FPC connectors can be 0.2mm.

Zhou Kunhua, associate manager of Canda Electronic Industry Co., Ltd., said: "the smaller, more precise and more pin pins of FPC connector will not occupy the limited space on PCB board, so as to achieve the effect of high integration." As an FPC connector previously deployed by Canda electronics in the consumer field, the overall height of 0.5mm pitch is 0.9mm, and the overall size can be smaller than that with a spacing of 0.3mm.

2. High frequency and high speed

In addition to miniaturization and precision, high frequency and high speed are also the development direction of connectors, which will be widely used in the field of automotive electronics and medium and high-end intelligent electronic equipment.

Taking LCD TV as an example, HD TV is marching from 2K to 8K and developing towards high frame rate and high definition, which also puts forward new requirements for connector transmission. The traditional flat cable technology such as signal transmission line, shielded line and LVDS line is costly and complex. FPC connector can well replace the traditional flat cable for connection, and not only the technology is constantly improving, It can also reduce costs.

Yang Wuxiao of Kangrui electronics said that the FPC connector can form the impedance of the line by adding the wiring layer and elastic structure design to form a high-speed transmission circuit to meet the special requirements of high-frequency and high-speed transmission.

With the continuous progress of FPC connector technology, it can also realize high-speed transmission in the case of tight internal space, so it will be widely used.

Solve difficult problems around technical problems

Due to the characteristics of FPC connector, it is smaller, thinner and flexible than ordinary connectors, so it will also face some technical problems.

Yang Wuxiao of Kangrui electronics said that compared with conventional connectors, FPC connectors have thinner and shorter element structure, and there are certain difficulties in injection molding and inserting pieces. For example, after injection molding, the plastic will easily deform when heated.

Chen Xinji, engineering director of Dongguan Dianwei Electronic Technology Co., Ltd., said: "when FPC connectors are smaller and thinner, the plastic is not easy to form and is prone to unstable mold filling. At the same time, it has higher requirements for product warpage and high processing accuracy of injection mold parts. Therefore, when designing these connectors, we should consider the materials Machine selection and a series of verification. "

The materials, molds and production equipment used in production will affect the production of a precision FPC connector.

"For the production of molds, the production of a product requires the development of a mold. There may be thousands of parts in the mold. If each part has a deviation of 0.001 mm and thousands of parts are assembled together, the deviation value will be large." Zhou Kunhua of Canda electronics said that production and reliability are the two most important problems of FPC connectors.

Reliability is the most important performance index of FPC connector. Therefore, whether from the plastic mold flow, terminal performance, positive force or the cover of FPC connector, designers are required to use various software for detailed and comprehensive analysis before mass production, so as to determine its strength and structure and ensure the quality and design reliability of the connector.

Chen Xinji of Dianwei electronics said: "for precision FPC connectors, hardware mold parts are small, weak in strength and high in machining accuracy. Therefore, in mold design, in addition to comprehensively considering the selection of materials, we also need to focus on the problem of structural reinforcement strength of parts; For plastics, choose materials with high fluidity, low warpage and high temperature resistance, and choose brand machines with efficient and stable performance for injection molding machines; At the same time, mold flow analysis shall be carried out for plastic parts during development. " At the same time, he added: "for mold parts with high machining accuracy, Dianwei electronics processes them by itself."

The degree of localization is high, but there is still a gap

In the consumer electronics field where FPC connectors are most widely used, domestic FPC connectors occupy most of the domestic market share, with the largest consumption and high degree of localization. At the same time, the application of FPC connector is mainly 0.5mm pitch, and 0.3mm pitch products have been widely used. As the technology of domestic FPC connector is gradually maturing, the mainstream models can be achieved in the domestic market.

At the same time, domestic FPC connectors have great advantages in delivery time and price.

"At present, most domestic complete machine manufacturers choose domestic FPC connectors, and domestic connector manufacturers have laid out FPC connectors for many years, and the technology has been very mature." Said LV Zhenyuan, general manager of Dongguan Lianda Precision Products Co., Ltd.

However, the application in the medium and high-end fields is still in the hands of large foreign manufacturers. Although the degree of localization in the field of consumer electronics is high, FPC connectors from well-known foreign connector manufacturers are still selected in military industry, medical treatment and medium and high-end electronic equipment.

At present, the minimum spacing in China can be 0.2mm pitch, and a few manufacturers can achieve 0.3mm spacing.

As mentioned above, at present, the minimum spacing of FPC connectors can be 0.175mm, and some foreign connector enterprises with strong strength have already developed and applied 0.2mm spacing.

"Don't look at the difference of 0.1mm in the middle, but this may be a gap." Zhou Kunhua of Canda electronics said that these difficulties may not be solved by a single manufacturer, because it involves many aspects, including molds, materials, production equipment, automatic assembly and other factors, which can only be solved through joint progress in these fields.

summary

To sum up, FPC connectors are developing towards miniaturization, high frequency, high speed and reliability. At the same time, the flexible characteristics of FPC connectors also have incomparable advantages. In the future, the more compact, lightweight and high-speed equipment will depend on FPC connectors. Although there is still a technical gap between domestic and foreign FPC connectors, the technology of domestic manufacturers for the mainstream FPC connectors in the market has been relatively mature, and relevant products are also widely used in the market. The application end market scale of superimposed FPC connector is still expanding, which determines that the future development potential of domestic FPC connector market is huge.