Generally, cell phones and smartphones are not a subject we would cover here. Not only are they extensively covered elsewhere online, they are simply not very interesting, and they all share similar basic design principles. The CAT S22 Flip is a unique approach to a smartphone and is definitely worth featuring here. The S22 Flip is not actually manufactured by Caterpillar (CAT), but is actually manufactured by Phenix New Energy Co. LTD. in Shenzhen, China, for CAT. Most notably, it's a flip phone. It features a small display screen on the top casing which is visible when the phone is closed and serves the same purpose as the small notification screens included with traditional flip phones. It has two cameras, front and rear facing, and a lighted keypad with tactile buttons. It is IP68 water and dust resistant and can hold up to shocks and drops from up to 6 feet, according to the CAT phones website. The primarily LCD screen is a touchscreen, making it usable as a smart phone but not ideal for media consumption and video games due to the small screen size. That's a good thing though, as the intention of this phone is not really to be used as an entertainment device, instead as a cell phone with some additional capabilities. There is also a D-pad below the screen which can be used to navigate without using the touchscreen. CAT, being a manufacturer of heavy machinery for the construction industry, marketed this phone to construction workers and people in similar professions. It makes sense to have a phone that is easy to operate for individuals who may not be as experienced with or interested in high-tech cell phones. Also, the CAT S22 Flip can stand up to the harsh environment of a construction site or job site making it an ideal candidate for professionals in those industries.
The S22 Flip runs Android Go Edition, which is a special version of Android that has been slimmed down and optimized to run on less powerful hardware. It does not require a Google account to be signed in to function and may lack some of the advanced features included with the normal version of Android. We see this as a benefit since normal Android is pretty bloated and can be a privacy concern. The latest Android version that will run on the S22 Flip is version 11. The launcher is pretty lightweight and minimalist, and there are very few pre-installed applications or bloatware. Side-loading apps from APK files is very easy, just enable developer mode as you would with any Android phone. It's not incredibly fast, and definitely not thin or light. In fact, a belt clip is really the best way to carry this phone around. However, being an Android smartphone that is water and dust resistant, rugged and reliable, and has an exceptionally long battery life, it's really quite versatile. Combined with the lightweight operating system and low price on the used market, this is a strong option as a backup phone or something to take while camping or spending time outside. It can stand up to the elements and costs much less to replace than an expensive modern smartphone.
The battery, SIM card, and microSD card are all easily removable with only a coin or flat-blade screwdriver (for the back casing), which is a rarity in cell phones nowadays. For charging, it has a USB-C connection protected by a dust cover. It does not feature wireless charging or NFC. Another neat feature of the S22 Flip are the two circular contacts on the back case designed for a Pogo-pin charger. Oddly enough, CAT never released an official Pogo-pin charging base for this phone, but there after aftermarket options. We ended up buying a second S22 Flip after we inadvertently broke the first one while pushing it past its drop limits. This ended up being a great opportunity for a teardown to see how the phone is designed and constructed. Removing the back cover is easy, just loosen the captive screw with a screwdriver or coin and it pops off. There is a very high-quality gasket that firmly seals the cover to the rest of the housing. With the back cover removed, the battery is easily replaceable and just lifts out from the top.
With the battery removed, the SIM and microSD card slots are easily accessible. You can also see the back side of the USB-C port, battery contacts, and the contacts for the Pogo-pin charger.
Starting the actual disassembly, removing several very small Philips screws from the back side allows the inner plastic frame to lift out of the rear compartment (battery must be removed first). This reveals the rear side of the motherboard, USB-C port, several internal connections, and another red gasket that keeps the two pieces sealed together, preventing water and dust intrusion. Take note of the spring contacts for the antennas (top and bottom) and the small vibration motor (bottom) which also connects to the motherboard with spring contacts. This design has (so far) made the phone very easy to service. The side buttons are bonded to the casing and connect to the motherboard with their own individual connectors. Also note the long, rectangular flex connector towards the top which feeds the top half of the phone (both screens, flash, camera, speaker, etc) that passes through the gasket, creating a sealed, feed-through connection.
Removal of the motherboard is easy once all of the flat-flex connectors are popped off and a few more Philips screws are removed. With the system board out, we can see the back side of the keyboard matrix as well as the bottom speaker/microphone and USB-C port, which can be replaced as it's own module. This is impressive, the charging port is one of the most frequently damaged parts of a phone, yet essentially no phones allow replacement of the port alone. The modular design of the S22 Flip makes this possible, while sacrificing a thin and light design. At this point, you can't go much father without being destructive as the button matrix and side buttons are fused to the casing. Still, this is much better repairability than most modern smartphones.
The keyboard button assembly can be (destructively) removed after a small plastic frame is pried off first. Below it, you can see the keyboard matrix, buttons, and LEDs, which are located under the small squares of foil. This part is fused to the casing.
Taking a look at the motherboard of the CAT S22, we can see that it's powered by a Qualcomm QM215 Mobile Processor and features 16gb of internal storage. Several sets of spring contacts allow the motherboard to easily connect to the antennas, speakers, and vibration motor when the case is sandwiched together. Otherwise, it's pretty similar to a typical cell phone motherboard with the usual flex connectors, sensors, and a very small coax cable.
The top half of the phone is a clamshell design. The top cover is held on by snaps and is very difficult to separate. After it is removed, we can see an internal structure similar to the bottom side of the phone, where several screws hold on an internal plastic frame.
After the small Philips screws are removed, the internal plastic frame can be removed from the top casing of the phone. Several components are now visible including the front and rear facing cameras, flash LED, speaker, front microphone, and the small LCD notification screen. The top half of the phone contains its own circuit board which connects all of the top half components together and feeds the connection down to the motherboard on the bottom half of the phone. There is also another red gasket that seals the internal plastic frame to the top outer casing, providing a water and dust resistant seal just like the bottom half. The flat flex with gold contacts on the removed internal frame serves as a bridge to connect the inward-facing speaker using more spring contacts. It's worth noting that each of the screws used to secure the internal plastic frame have extremely small rubber washers which ensure a seal is made. There is a panel of glass glued to the casing that protects the notification screen.
With the circuit board removed, we are just left with the primary touchscreen and inward-facing speaker, both of which are fused to the plastic casing. There is also a small magnet in the corner, which is probably used in conjunction with a sensor to tell the phone when it's open or closed.
That's just about it. The CAT S22 Flip is an absolutely fascinating phone, and is impressively well designed and built. It's versatile, rugged, and despite not being very fast, it still has many uses as a backup phone or just something to bring to places that are rather unfriendly to electronic devices. Many compromises to the usual design philosophy of elegant, thin, and light smart phones were made to create a rugged and modular phone that is easy to repair.