What a teardown reveals about their respective companies
Comparison Table summarizing the major differences between the AirTag and Tile Mate:
|Apple AirTag||Tile Mate (2020)|
|Cost||$29 or $99 for 4||$25 or $69 for 4|
|Design Complexity||High: 9 main components, double-sided PCBA with >10 ICs, soldered voice coil and magnet assembly||Low: 6 main components, singlesided PCBA with 2 ICs, adhered Piezo speaker|
|Connectivity||Bluetooth, UWB, NFC||Bluetooth|
|Replaceable Battery||Yes: CR 2032 but a little difficult to remove||Yes: CR 1632|
|Size/Volume||Diameter: 31.9mm, height: 8mm, volume: 6400 mm^3||Length: 35mm, Width: 35mm, Height: 6mm, Volume: 7350 mm^3|
|Key Ring Hole||No – accessory required||Yes|
Tile was one of the first companies to mass-produce a high-quality tracking device launching a crowdfunding campaign in mid-2013. However, after years of dominating this market segment and creating different form factors for their products, Tile is facing its first real competition as Apple has recently introduced their own product, the AirTag, in April 2021. In this teardown blog, we dive deeper into how these products were designed and built and what we can learn about the companies that made them.
The Tile Mate
It is really hard to survive as a hardware startup. From development costs to tooling to inventory, it takes a lot to just stay afloat let alone thrive. Despite all these challenges, Tile has managed to not just survive but thrive in the hardware world first as a startup and now as one of the premier tracking devices and apps. Without multiple business lines that can support new development, the best way to get started is to build something quickly with as much profit margin as possible. As a smaller company, they would not have received the preferential pricing that established companies get on electrical components or injection molding. Tile needed to do all it could to reduce the number of parts and simplify their assemblies and they have followed this playbook to a tee. Their trackers are designed with the bare minimum of major components while still achieving a small, tidy package and expanding and improving their product line over time.
The Tile Mate is a thin rounded square with a simple 2 part plastic construction. A white front casing and a gray back case meet to create a uniform reveal midway up the sides. The keyring hole is made by bringing the gray plastic from the bottom housing to the front surface creating both a pleasing pop of color and reinforcement in the area that experiences the most wear and tear. The front also has the chromed name badge which doubles as a physical button. The back of the product sports the removable battery door, an etched QR serial number, and 3 small speaker holes. Using the product is pretty simple with bluetooth connectivity, the product is easy to connect and pair to the Tile App whether you use an Android or iOS phone.
While this version of the Tile Mate has a replaceable battery, earlier versions made use of a non-replaceable soldered battery. While that likely saved them money up front, it caused some headaches for customers who wanted to extend the life of their products and as customers requested refunds or trade-ins to newer models. To address this, they added the removable door which allows users to access and replace the CR1632 coin cell battery. While the door is held on securely with several plastic snaps, the molded grip lines make it easy and intuitive to remove. However, once the battery is removed, opening up the product further requires more destructive force.
Held together by a bead of glue around the perimeter, the main housings of the tracker can be pried apart with a small flat-head screwdriver. Continuous glue beads are a common source of challenges in development, and an area that Instrumental’s customers often need help. Once separated, the only major component sandwiched inside is the PCBA. Both housings are labeled as being made from a PC-ABS plastic blend. The white casing is a straight core-cavity design while the tooling for the gray part required some moving slides to hold the battery door hooks in place.
Aside from 4 springs soldered to the board (2 for the battery and 2 for the speaker), there is not much else to remark on. There are only 2 integrated circuits and a small number of passive components. One chip is the arm controller with integrated bluetooth processing and the other is the speaker driver. The antenna is designed into the PCB itself, and a lone dome switch is taped to the center of the back side.
The last component in this device is a small piezo speaker which is taped into place. Two springs drive a voltage differential on the two different metal materials sandwiching the piezo electric material which causes it to vibrate and produce the range of alert tones.
As one of the top consumer hardware brands, Apple approached the challenge of creating a tracking device from a different perspective. Putting top engineers on the project, they created one of the smallest Apple products ever, but one that packs in plenty of embedded technology.
With a relentless focus on Industrial Design, Apple is known for driving the size and shape to be as small as possible. In a call back to some of the earliest iPod designs, the result is a product that looks like a perfectly round polished white stone. The back is an elegantly formed stainless steel cap that also serves as its removable battery door. As many reviewers have pointed out, however, this battery door is quite challenging to remove because there are few places to grip on the round slippery surfaces.
The AirTag comes packed with technology including clear sound, an accelerometer, ultra wideband and NFC support. Apple spent quite some time thinking about the feature set and use cases for their new tracker. The accelerometer allows Apple to determine if the device has been moved recently. If it hasn’t, the device can go into a low power mode until it is moved again. Adding in ultra wideband support improves the location accuracy over bluetooth by a few percentage points going the extra mile for their customers. In addition, Apple can take advantage of the vast network of iOS devices that support ultra wideband creating an instant network for locating lost devices. Using NFC to interact with the device also unlocks new ways of using the product such as triggering actions on your phone or other connected applications.
Twisting the cap in a counterclockwise manner reveals the CR2032 battery and underneath, the regulatory information. Three silver spring contacts poke through the plastic and touch off on the battery. The steel battery door looks to be made from 2 components – a polished machined steel cap and a thin leaf spring with the etched “+” symbol glued or welded in place.
To get a closer look at the insides, there are 3 snaps which hold the light gray plastic midframe to the polished white casing. It is almost impossible to get to the insides without breaking a snap because they are glued in place. This was likely done to prevent the parts from separating during a drop, squeeze, or twist event. Running a thin flat-head screwdriver or dental pick along the edge while gently squeezing the outer casing allows just enough room to pry the insides apart.
The main white plastic housing is a prime example of Apple’s design and manufacturing prowess. As a product designer, I am impressed by the lack of flash or witness lines of any kind on the plastic surface. The continuous curve which wraps around and under the product signifies a spare-no-expense post-processing step like machining or polishing to remove unwanted parting lines. Also, this part that is no more than an inch in diameter has undercut ribs along the entire circumference of the interior. This means that the tooling would have been quite complicated as the tiny lifters would need to move out of the way of each other as the part is ejected from the molding machine. No ejector pin or tooling markings indicate that the part was machined on the inside as well.
Once we get past the gray midframe, we find an annular printed circuit board with a lot of big components neatly stacked on the perimeter. These large components fit snugly in the recesses of the plastic midframe taking advantage of every last square millimeter of space. The battery contacts are revealed to be 3 small springs attached to a small plastic housing. Filling up the hole in the center of the board is a small magnet and copper coil with thin slivers of wire soldered to the ends of the board. Audio quality was clearly important for Apple because instead of a cheap and simple piezo, they have created their own speaker at the cost of making the assembly and disassembly process quite challenging.
The speaker magnet can be removed if it doesn’t automatically come attached to the plastic midframe, but to get the board out, the wires to the voice coil must be cut. It takes some force to extract the board and as we later see, this is because the dark gray plastic frame underneath is soldered directly to the board in several places.
The board itself has many different ICs including Apple’s own U1 chip for ultra wideband support, audio, bluetooth, NFC, and an accelerometer. Several other bloggers have done teardowns that do a deeper dive into the components and what they are used for. Many of these same parts are also used in their other products like iPhones and iPads allowing Apple to Take advantage of significant price discounts with volume pricing.
Getting a closer look at the antenna frame, there are 3 antennas which make use of the 3-D surfaces on the part. Using a process called LDS or Laser Direct Structuring, the plastic part is laser etched in the areas where metal traces will be created. The part is then plated in gold which allows the plastic itself to serve as 3 different antennas along with the contact points to the board. Apple is able to reduce interference by etching different antennas on different surfaces of the part. With a few plated holes on the underside, this frame can be soldered directly to the PCBA.
If I were to guess how this product was assembled, I would say the board and antenna frame are first soldered together. Then the speaker wire is soldered to the board and both the speaker and the board assembly are assembled to the gray midframe. A few drops of glue are added to the the cosmetic plastic part and the subassembly is pressed into place. Then the battery and pull tab are added before the steel cover is rotated into place.
Overall, these products reflect the approach their respective brands take to design and manufacturing. Tile, the plucky startup, saw a market opportunity to create a new category of tracking devices. Over time, they have refined their products and built up a loyal following that supports iOS and Android users. The product, though simple, is reliable and good at what it does. Apple has come a little late to the party but with a clear vision for what a tracker should be. They put the full weight of their engineering and supply chain expertise to bear cramming their device full of technology at a competitive price. Ultimately, consumers will decide whether to use Tile or AirTag but the fact that there is competition should only lead to newer and better products from both companies in the future.
On October 12th, 2021, Tile launched a refresh of all their product lines. They added water resistance at the expense of the replaceable battery. With QR codes prominently featured on the back, they are making it easier for anyone to identify a lost Tile without significantly increasing the BOM costs. Finally, they announced a new device, the Tile Ultra, which will be the first tracker with ultra wideband to be supported by both Android and iOS phones.
Chris Li is a former Amazon Product Design Engineering Manager and current teardown lead for Instrumental. He brought multiple generations of the Kindle to market and advised on the first Echo and Fire TV products. He also worked as the VP of Product Design at the health tech startup, PillDrill, which shipped an award-winning medication tracking system.