The autumn press conference of apple in 2020 brought a new growth hotspot. Apple once again pointed out a direction for the development of smart phones. In the following year, many manufacturers flocked to the market, and the wireless charging market was pushed to a high point. At present, all high-end mobile phones of mainstream brands such as apple, Samsung, Huawei and Xiaomi support wireless charging.
In addition to the mobile phone market, the application scenarios of wireless charging also include smart wear and electric vehicles, which will be further expanded to furniture, home appliances, motor vehicles and other fields in the future. According to the data released by China industry information research network, the wireless charging market will reach US $14billion in 2022.
Wireless charging is wireless charging technology. It does not need a wired connection. It uses electromagnetic wave induction principle or AC induction technology for charging. The Qi standard adopted by apple is the most mainstream electromagnetic induction technology. Its birth can be traced back to palm, a communications rookie in 2009.
Flash in the pan palm and touchstone
In 2009, Palm Pre plus with WebOS was officially released on CES in Las Vegas. It was a product beyond the imagination of all competitors and beyond the expectations of all users. At that time, iPhone4 was still in its infancy, and Palm Pre plus became an unparalleled favorite on CES that year with its jade like texture, cobblestone like innovative and practical appearance design, and magic full sliding interactive WebOS.
During Adam Kaufman's online communication activities, the mysterious accessories revealed were unveiled - a magnetic suction wireless charger with the same source as the "pebble" design, which was named touchstone and vividly called "touchstone" by Chinese users. As the first magnetic wireless charger applied to mobile phones, Touchstone has too many amazing colors, easily fits the desktop and can be removed without trace. The wedge-shaped slope design gives users a comfortable viewing angle, exquisite volume and exquisite appearance design while charging... However, due to the bold and advanced interaction concept of WebOS, a few mainstream applications cannot be adapted, After the press conference, palm could not get too much energy input from developers, which indirectly led to the uncontrollable decline of palm after it was acquired by HP. However, a number of wireless charging specifications inspired by touchstone have been established, which has also become the last wave aroused by it.
Apple's MagSafe and Android camp's Countermeasures
11 years later, at Apple's autumn press conference in 2020, an amazing "click" sound brought about the innovative charging method of the apple family. MagSafe magnetic attraction wireless charger earned enough attention. 10 months later, the first magnetic attraction wireless charger of Android camp was released by realme. This time, Apple has once again taken the lead in the Android camp in an innovative way, bringing more practical charging options to the iPhone with a strong ecosystem.
With one touch charging, 15W wireless charging power, shell recognition, and a wide range of cluster adaptation, MagSafe is not as expensive as 749 yuan
The sale price. Compared with the third-party magnetic absorption wireless charger, the price is much lower, from 69 yuan to 289 yuan, boasting a wide range of products with different performance parameters.
On August 3, 2021, realm became the first manufacturer in the Android field to launch magnetic attraction wireless charging products. The compact and extremely thin 15W wireless magnetic attraction flash charge is very similar to MagSafe, but it is lighter and thinner, with more stable power output and shorter full charge time. This time, realm took the initiative in the Android camp, played the role of a pioneer, and went further than apple.
In addition, realm has also released a 50W high-power wireless charger, which can be fully charged with a 4000 Ma battery in 54 minutes by using the flat desktop. The more radical scheme in terms of charging power has made it the focus of Android users. However, the user's enthusiasm for this product did not last long. The fan cooling mode made the volume of the high-power wireless charger much larger than that of MagSafe, and the appearance and portability were not as good as those of the 15W lightweight model. Moreover, in terms of the appearance design of the fan cooling method, sufficient cooling holes must be reserved to dissipate the heat supply, which leads to the decline of the overall protective performance of the equipment and the inability to play the role of waterproof and dustproof.
The high-power fast charging performance is not as good as the wired charger. The desktop vertical wireless charger released by Huawei, vivo and other brands has always maintained a power of about 50W, which is difficult to make a breakthrough. The product form is limited to the desktop vertical charger. In terms of fast charging, the Android camp has fierce competition and radical means. 120W high-power chargers have appeared frequently, resulting in an embarrassing situation for 50W chargers. At present, there is no trace of 50W version on realme official website. Therefore, this paper will focus on the research on the mainstream light and thin product structure and analyze the application scheme of adhesive in structural design.
Analysis of fixing and sealing of magnetic absorption wireless charger
The heating problem of high-power magnetic absorption wireless charger during charging is the focus of users' attention. The heat removal mode of chip and charging coil is a key factor that manufacturers need to consider at the beginning of product design.
AC and DC power is lost during conversion. Generally, the power factor of the charger is less than 0.7, and most of the rest energy is converted into heat energy. The greater the power, the more heat. While supporting 50W power charging, it is also necessary to ensure a small heating capacity. Most domestic manufacturers adopt the strategy of physical cooling, that is, fan cooling, and the chip part is covered with thermal conductive silica gel layer.
The light and thin 15W charger has a low heating capacity and mainly adopts the mode of material interface temperature conduction.
In the process of product development, ancham compared and analyzed the domestic lightweight 15W charger and MagSafe. During the process of removing the charger structure and parts one by one, it was found that the domestic charger structure and parts use more electronic adhesives for fixation and protection, while MagSafe is relatively less, but still uses adhesives as the main fixation method.
Next, we will analyze the adhesive application of the two magnetic suction wireless chargers one by one, and explain ancham's product selection scheme. (the left side of the combination drawing is the domestic model, and the right side is MagSafe)
1. Charger panel covering material
The surface of MagSafe's charging surface is covered with silica gel, which is similar to most domestic products in shape. It is made of wear-resistant material. The skin friendly feel has obvious advantages in the touch experience. The shell is made of aluminum alloy, which is light and easy to be integrated.
In terms of domestic products, we list the light and thin models of realm. Its particularity is that it uses glass panel material, which can represent another mainstream design style. The appearance is more exquisite, but long-term use will cause wear on the glass surface. The shell is also made of aluminum alloy.
For both chargers, the charging surface is fixed with adhesive and the internal frame. The adhesive plays a sealing role while bonding, so as to prevent the user from immersing water stains or damaging the use experience due to the dumping of tabletop objects such as water cups in the daily use environment.
Both glass and aluminum alloy are high surface energy materials. The printed coating on the back of the glass plate has a certain impact on the long-term stability after bonding. The aluminum alloy shell has been surface treated at the supply end, and the bonding ability has been improved.
PUR Hot-melt adhesive is selected for the glass panel scheme: the curing speed is fast, the process time is reduced, and the manufacturing efficiency is improved; The gap is fully filled and has high protection performance after curing, meeting the requirements of daily waterproof and dustproof applications.
Quick drying adhesive (cyanoacrylate adhesive) is selected for MagSafe silicon film scheme: medical grade non-toxic and tasteless, rapid curing at room temperature, and excellent bonding ability to silicon rubber and anodized aluminum.
2. Fixed mode of wireless charging module
The charging board is disassembled. The structure of the domestic wireless charging module is complex. The whole module is wrapped by a metal cover. The middle layer of the metal cover is a PCB board. The PCB board and the charging coil are separated by a shield. The same is that the charging modules of the two products are fixed to the bottom of the shell with glue.
The product type recommended by ancham here is quick drying adhesive (cyanoacrylate adhesive), which has excellent new bonding ability for different types of metal materials, fast curing speed, convenient construction, and easy removal of residual adhesive during heavy work.
3. fixation of wireless charging coil and magnetic ring
The induction coil is pasted on the domestic wireless charging coil, and the bonding method is glue fixation. A layer of metal shielding cover is separated between the coil module and the PCB. The shielding cover is fixed on the metal wrapping cover of the charging module by spot welding, and is bonded to the bonding pad by glue. The base plate and the metal shielding cover are bonded and fixed by glue.
The design of MagSafe is more brief. You can directly see the charging coil by removing the silica gel sheet. The charging coil is fixed to the base plate with glue. A black plastic ring is added around it to play the role of isolation and shielding. The plastic ring is fixed with glue to the detection coil, which has the same function as the induction coil in the domestic model. The plastic ring is bonded to the bonding pad floor with glue.
Both products are arranged with 16 magnets around the shell. The magnet type is boron cobalt alloy strong magnet, which is arranged in the form of 8+8 to form a magnetic ring.
For the coil bonding part, ancham recommends one component RTV silicone : good bonding performance, moderate hardness after curing; High and low temperature resistance, stable product performance within the temperature range of -60~200 ℃.
For the magnet bonding part, ancham recommends Acrylic UV adhesive: rapid curing, excellent bonding performance; The sizing process is simple, low odor and environmentally friendly.
4、Glue for USB plug and charger motherboard
Both products use polyurethane three proofing adhesive to coat the PCB inside the USB tepy-c wire head, which can effectively prevent short circuit caused by water vapor and dust or other damage to the circuit operation. The inside of apple MagSafe wire head shell is reinforced and protected by a steel sleeve. The PCB board is equipped with an alloy inductor for boosting voltage. The domestic product places this chip on the charger motherboard.
In terms of charger PCB motherboard, domestic products are more introduced. The connection between coil and PCB and the back of motherboard are coated with polyurethane three proofing adhesive to protect the solder joints. On this basis, MagSafe also has two metal shielding covers on the front of the motherboard, which are fixed with the motherboard by welding and glue.
According to the above analysis, the product recommended by ancham here is acrylic UV conformal coatings adhesive: it does not contain harmful substances such as benzene and butanone, and has low odor; High strength, acid and alkali corrosion resistance; Excellent electrical insulation performance, UV detection.
Conclusion: adhesive has changed the life of mechanical fixation in intelligent hardware
Through comparison and analysis, Ancham fully elaborated on the fixed mode of magnetic suction wireless charger, which is in the design trend of lightweight and precision intelligent equipment,. Ancham develops in the six directions of bonding, sealing, three prevention, potting, heat conduction and conductivity, and completely covers the adhesive demand of the consumer electronics industry. In the gradually updated and optimized product system, we can provide a perfect adhesive application scheme for the magnetic suction wireless charger. Adhesive has always been considered as the most effective bonding method since the development of new materials. This assertion that Yaskawa new materials adheres to will be verified in more intelligent products.
The situation of the same type of products in the two ecological environments is the same. Apple MagSafe relies on the perfect iPhone ecological chain and is irreplaceable in the global medium and high-end market. The steel sleeve inside the wire head is protected by spot welding, and the PCB shield and other details make the gap between domestic products clear at a glance.
The design of disc shape, aluminum alloy shell and charging plate with induction coil is unique to domestic products. The growing domestic brands still can not get rid of the footsteps of apple, which has been passed by predecessors. The all-round imitation from design to performance is still the point where domestic products need to be innovated.
Like jobs' treatment of products, the design of every apple product has been finely polished, and the invisible internal structure should also be as delicate as a work of art. The application of adhesive can realize the simplicity and regularity of intelligent devices from the inside to the outside, making it a lightweight and exquisite work of art.
This can not help but remind people of palm and touchstone 13 years ago. In that era when the design was a little extensive, palm, through such magical imagination and continuous trial design and development, made a product that perfectly combines ergonomics and natural aesthetics appear in the eyes of the world. WebOS with full sliding interaction and smooth operation under a single core CPU, The touchstone that has never been seen before... Perhaps because it is too perfect and advanced, it is not accepted by the times. The lack and lag of the ecological chain and the imitation of competitors have become the most talked about topic of palm. 13 years later, Android and apple, which have been continuously developed and improved, are like a layer of snow covering the autumn leaves. People will no longer miss the bleak autumn when spring is coming.