Memory of ultra slim mobile phones

Do you remember 3 kinds of Ultra Edition mobile phones that Samsung Electronics unveiled in 2006? At that time when cell-phones’ thickness was typically 20mm, very thin thickness of 6.9mm(X820), 9.9mm(D830) and 12.9mm(D900) and its attendant light weight gave a refreshing jolt to the mobile industry. It was refreshing to find that a mobile phone can be made light and thin enough not to feel its presence when keeping it in a hip pocket and rival companies started to make every effort to develop even thinner cell phones.  

Samsung Electronic’s Ultra Edition Mobile Phone

 
(Source: Samsung Electronics)

Ironically, the cellular phone market stopped competing for thickness and began another new competition after 1 year, or from 2007. That is because Apple unveiled iPhone which changed the rules of the game.  

Ahead of iPhone, or even before a smartphone became the mainstream in the mobile phone market, a feature phone was the mainstream with low demand for a big screen. At the time, the trend of the market was slim and light as shown in the fact the LCD size of the mainstream Windows Mobile 5.0 and 6.0 OS smartphone was 2.8 inch. It was the time for mobility to be considered important.   

Components getting smaller and disappearing, while another adding to bulk

When being launched, iphone was criticized for its reduced mobility resulting from the large size of 3.5 inches. However, smartphone’s LCD size has grown to 5 inches beyond 4 and along with it, demands for the performance of hardware and software are also rising day by day. Yet, given its mobility, since a smartphone cannot increase in size limitlessly, companies are exerting every effort in lightening of the components and development of substitutes to put more into the limited space.     

As a direct example, the release of Ultra Book led to the end of the ODD and HDD age and the opening of the SSD age. Furthermore, some products emerged with removing VGA Port, RJ45(internet) and RJ11(telephone) which had been considered essential. In addition, built-in battery models are emerging one after another. All of these are believed to be the process of selection and removal to make  thinner and lighter products.  

How about smartphones and tablet PC? SIM and memory cards have become smaller; connectors for recharging and exchanging data have been integrated with being separated and become smaller; analogue microphone and speaker have been replaced with MEMS components. Additionally, as a screen increases in size, the resolution also grows higher; AP(Application Processor), a central processing unit playing a role as a brain, is adopting a chip of Dual or Quad Core with a processing speed of GHz range, instead of Single Core with a processing speed of MHz range. The faster the processing speed, the higher the resolution of the camera: as a 5.0 megapixel camera is classified as low and middle priced products, the adoption of 8.0 or 10.0 megapixel cameras is increasing; short film clips can be shot at full 1080p HD-resolution. The rapid progress in terms of hardware deserves acclaim, but electricity consumption has increased as much as the development; and whether to optimize the power management is affecting real using time.

With adding LTE which has not yet completed construction of worldwide networks to this, communication mode of a smartphone is simultaneously supporting the 2nd-generation(GSM, GPRS and EDGE), 3rd-generation(WCDMA, HSDPA and HSPA) and 4th-generation LTE(Based on strict criteria, the current LTE is the 3.9th-generation one and the 4th-generation one is LTE Advanced. But, since it is not appropriate to discuss the communication standards here, call LTE the 4th-generation one according to the industry custom.); frequent network roaming causes the battery to run down more quickly.

The smartphone and tablet PC hardware is expected to be constantly upgraded afterwards, but there is a high chance that the battery cannot follow the speed of the performance improvement. While a feature phone is recharged once for 3 days, isn’t it usual to charge a smartphone 2 or 3 times for a day despite the increased battery capacity?  

For now, there seems to be no alternative except for increasing the battery capacity, as a way to extend and maintain the using time. Semiconductor increases in performance by two times every year and decreases in size, according to the Moore’s Law, while unfortunately, the battery increases in bulk almost in direct proportion to its capacity. Even when an efficient battery’s capacity doubles, it is known to increase in bulk by 1.7 times. As various electronic components are getting slim, the battery which even now takes up most of the space, is bulking up. As seen in the dismantlement picture of Apple iPad2 below, the battery occupies the largest space.

  
Dismantlement Picture of Apple iPad2

 (Source: Reverse Engineering Analysis [Apple Tablet PC iPad2 – MC979LL], Displaybank, July 2011)

Touch panel getting lighter and thinner 

A current capacitive touch panel can be structurally classified into 3 large groups and divided into products with a total of 9 structures. As of now, when analyzing strengths and weaknesses between products, they are frequently compared typically on the basis of optical character, productivity, production yield, difficulty level of technology and cost. In the future, to equip them with a larger capacity battery or make thinner and lighter smartphones and tablet PC, thickness, weight and bezel width are likely to emerge as an important factor. 

Excluding others among several specifications to compare touch panels, the importance of weight and thickness in smartphones and tablet PC will be discussed.

Classification System of Capacitive Touch Panel by Structure

 (Source: Touch Panel Market Outlook & Cost/Issue/Industry Analysis 2012, Displaybank, Feb. 2012)

Touch panels’ weight and thickness, really important?

It is necessary to think of again whether dozens of grams or some tenths mm is so important. It is easy to think that the part of a touch panel occupying in the weight or thickness of a smartphone and tablet PC may not be so great. As shown in the table below, it represents how much portion a touch panel accounts for in terms of the thickness and weight of a tablet PC which is currently being sold well in the market; it shows the touch panel occupies around 15~20% of the thickness and weight, respectively. In other words, making more effort in a touch panel allows producing lighter and thinner products with ease.  

Portion of Touch Panel in Thickness & Weight of Major Tablet PC Products

(Source: Displaybank, April 2012)

If a touch panel becomes a little thinner, it is thought that the battery capacity can be expanded a little more and accordingly, the increased thickness can be offset even a little bit.   

When it comes to thickness and weight, the thicker, the heavier: as two sides of the same coin. Also, they may be affected by quality of the material and structure. An external attached touch panel(GG, GG2, GFF, G1F, G2, G1 and GF2) is typically more disadvantageous than the integrated type of a touch panel and a display panel(On-Cell and In-Cell). Among them, GG and GG2 which use 2 sheets of glasses like cover and ITO sensor glass, etc. are the most disadvantageous. In particular, as the size is getting bigger, the disadvantage of GG and GG2 becomes more obvious. 

Correlation between Thickness and Weight of 10.1”Capacitive Touch Panel by General Structure

 (Source: Displaybank, April 2012)

As seen in the figure above, among the 10.1” tablet products, GG and GG2 with 1.2mm in thickness and 150g in weight are in the most unfavorable position. It they did not have high transmittance and low resistance which is considered a strength compared with other structures, GG and GG2 could not  become a major product taking the lead in the touch panel industry like this. 

In terms of comparing weight and thickness, G1 and G2 are now the most competitive structure in the external attached touch panels. Since they consist of only a sheet of cover glass and film structurally, the weight became lighter by 46.7%, or 70g and the thickness decreased by 41.7%, or 0.5mm compared to GG and GG2. Due to their simple structure, they are in the most advantageous position in the aspect of weight and thickness.   

It is interesting that since On-Cell and In-Cell should have protection film for the purpose of anti-shattering following damage to cover glass, they are same in terms of structure, after connecting the G1, G2, G1F, GF2 touch panels with the display panel. This is one of the reasons why touch panel businesses are exerting all-out efforts in developing G1 and G2 as a substitute for On-Cell and In-Cell; and recently, there is a trend of using PMMA complex material in cover lens, instead of glass.

This year, it seems that there will be fierce competition between the display integrated touch panel(On-Cell and In-Cell) and the external attached one(GG, GG2, GFF, GF2, G1F, G2 and G1). It is believed to need to make constant efforts in developing thinner and lighter products than the touch panel of rival companies or another structure; or find substitutes.