©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)MCPC TR-023
Mobile Equipment
Safety Design Guideline
Version 2.00(E)September 1, 2017

Mobile Computing Promotion Consortium
Technical Committeei©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)Change history
Date

VersionSeptember 1, 2017

2.00(E)

Details
English translation version of TR-023 Ver2.00

NoticeThis Guideline is the translation from MCPC TR-023 only for the benefit of English readers. The
original version of MCPC TR-023 shall be the official specifications in its interpretation, construction
and understanding.

ii©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)Published and copyrights owned by:
Mobile Computing Promotion Consortium (MCPC)
Hasegawa Green Building,
5-12 Shiba-Koen 3-chome, Minato-ku, Tokyo, 105-0011 Japan
TEL： +81-3-5401-1935
FAX: +81-3-5401-1937
EMAIL: office@mcpc-jp.org
WEB SITE: http://www.mcpc-jp.org

Confidentiality
The MCPC Rules and the MCPC IPR Policy Shall Apply.

Disclaimer
This document is intended to provide standard specifications and recommended specifications, etc. on
mobile computing. Mobile Computing Promotion Consortium (hereafter MCPC) shall not be liable forany direct, indirect or consequential damages or infringements to patents or any other rights held by thethird parties arising out of using this Specifications. This document shall not be construed to grant (a)license(s) under any rights held by MCPC or the third parties.

How do we distinguish binary, decimal and hexadecimal numbers?
For binary numbers, we append small letter “b” (e.g. 10b)).
For binary numbers, we insert a space after every four bits. (e.g.：1000 0101 0010b).
For hexadecimal numbers, we append small letter “h” (e.g.：FFFFh and 80h).
All other numbers shall be considered to be written in decimal.

Key Words
 “May” means that something is recommended or optional at the free discretion of the vendor.
 “Should” means that although something is not essential, it is strongly recommended. When
implementing, the vendor shall take this requirement into consideration and determine whether this isessential or not.
 “Shall” means that something is an essential requirement. For connectivity and specification
compliance, the feature must be implemented, and is mandatory.

Trademark Notes
 Company names, product names, service names and the like described in this document are generally
trademarked or are registered trademarks of their respective owners.
 In general, the usage of ™ marks, © marks, and ® marks has been omitted in this document.
 In general Inc., Corporation, Co., Ltd., have been excluded from company names.

Application note
It is indicating as follows, when indicating a case of the operation on a document. :Application note :Case-of-the-operation entryiii

©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)Table of Contents
1.

Introduction ........................................................................................................... 1

2.

Safety Design of Smart Phones ........................................................................... 1

3.

Considerations in Designing ................................................................................ 1
3.1

Heat Considerations in Designing...................................................................................... 1

3.2

Designing Considerations for Sharp Edges on Devices ..................................................... 2

4.

Considerations for Temperature Measurement .................................................. 3

5.

Safety Standards ................................................................................................... 4
5.1

Standard for Low Temperature Burn .................................................................................. 4

5.2

Standard for Terminal Failure............................................................................................. 6

5.3

Standard for assumable harsh conditions .......................................................................... 6

5.4

Standard for Fire Prevention.............................................................................................. 7

5.5Standard for sharp edges of a device ................................................................................ 7

5.6

Standard for power leakage............................................................................................... 8

Appendix A: Design Considerations for Heat Generation and Temperature Rise
Property .............................................................................................................................. 9
Appendix B: Design Considerations at Other Safety Standards ................................... 9
Appendix C: Considerations in Test Procedure for Heat ............................................. 11
Appendix D: Reference Materials such as Standard Specifications (Normative) ...... 12iv

©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)

1. Introduction
This Guideline is intended to clarify the safety standard such as measures against terminal heat in newly
designing mobile devices.
The mobile devices in this Guideline mean mobile information terminals such as smart phones, featurephones and tablets (“Smart phones etc.”) that support voice communication and data communication
functionalities as standalone. They may be subject to change in case of future technological evolutions.

2. Safety Design of Smart Phones
As Smart Phones etc. are convenient enough to support not only conventional voice and othercommunications but also variety of software applications as PCs do, they have rapidly penetrated in themarket.
Along with the technological evolution of semiconductors, the computing processing power of a device aswell as the battery capacity has continued to be larger that has led to adopting high speed charging
technologies for higher convenience.
From the usage point of views, “safety in users contact” for Smart Phones etc. is an important element insafety designing. With an increasing heat as part of the energy that is consumed from the higher
functionalities and performances as stated above, measures against heat needs to be carefully observed indesigning safe contact. Furthermore, sharp edges of the devices that may derive from the miniaturizationand diversification of devices also need to be taken care of.

3. Considerations in Designing
3.1 Heat Considerations in Designing
The safety measures against the heat of Smart Phones etc. shall be designed to the following heatsources. Furthermore the other heat sources than the following list should be carefully observed in thermal
design and assessment in consideration not only of single functionality operation but also of probableconcurrent multiple functionality operations.
i.

Heat generation by CPU
Smart Phones etc. have capabilities to support higher load processing for video recording with a highresolution camera and high-definition game applications. In view of dynamic fluctuation of heatgeneration at CPUs in response to the load of tasks, they shall be required to secure their safety at the
maximum load condition.

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©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)ii.

Heat generation by Wireless Communication Circuits
A power amplifier that amplifies the signals of voice and other communications is a major heat source
at Smart Phones etc. An operation condition of a power amplifier varies in accordance with the distancefrom a base station and an instruction from a base station such as the speed of uplink data
communications. The safety shall be secured under the maximum load conditions as set out in a radio
standard.

iii.

Heat generation by Power Supply and Power Charging Circuit
Smart Phones etc. have different voltage and current specifications per functional block for which a
power supply IC that integrate multiple power circuits are used. Therefore, the electric current for a
power supply IC itself increases when multiple functional blocks are activated concurrently. As a battery
charging circuit is controlled its charging current in accordance with a battery charging status (voltage),heat generation conditions change accordingly.

3.2 Designing Considerations for Sharp Edges on Devices
For the Sharp Edges on Smart Phones etc., in addition to the normal user accessible areas, possible sharpedges that caused by manufacturing defects or minor user handling faults etc. shall also need to be taken
into consideration.

i.

Sharp edges at normally contactable areas

All contactable areas including but not limited to a case, a cover cap, a SIM slot, a SD card slot, a battery
pack and a battery lid shall be taken care of irrespective frequencies and purposes of a contact.

ii.

Sharp edges by manufacturing defects

Sharp edges that are caused by manufacturing faults include burrs by forming defects and roundmachining defects at a corner area. With an adhesive failure, the edges of a metal decoration panel that
normally do not expose may expose, too. The risks for sharp edge occurrences at manufacturing
processes shall be identified by FMEA etc. and fully addressed.

iii.

Sharp edges caused by minor user handling faults

The sharp edges that caused by damages by a fall, a mechanical shock or a compression stress etc.
shall require calling user’s attention with instruction manuals. Furthermore, cracks, scratches, dents,
ruptures and decoration panel detachments that that are expected by a stress for normal uses shall betaken into consideration in design that prevents an easy exposure of sharp edges.
2©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)Glasses that are generally used for a mobile equipment display can naturally expose sharp edges
caused by damages and breakages due to falls etc. The issues that cannot properly be addressed withdesign may alternatively be thoroughly warned by an instruction manual etc.

4. Considerations for Temperature Measurement
For temperature measurement, infrared thermometer (infrared thermography) based non-contact
temperature measurement and thermocouple based non-contact temperature measurement arerecommended. The temperature measurement by an infrared thermography for example is to detect infrared
energy from a target object and show an image of a surface temperature distribution. For an accurate
measurement however, use of a device that can correct a radiation rate to the target material property andcondition and adoption of surface treatment materials of which radiation rate is known shall be required.
In case of using a contact temperature measurement with a thermocouple, an enough care shall be taken
for an accurate measurement with a proper attention to the connection between a temperature measurement
point and a thermocouple and an effect of an wire.
Furthermore when measuring temperatures inside a thermostatic oven, the wind from convection and ablower may chill a target object that prevents an accurate temperature measurement. Proper measures suchas placing a surrounding shield shall be taken to protect a target object from wind.
Please note that the above descriptions are general aspects. For a real measurement, a measurement
environment and an accuracy and property of a measurement device shall be taken into consideration for a
precise measurement.

3©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)5. Safety Standards
This Guideline stipulates “essential standards” that must be fulfilled and “recommendable standards” thatare highly recommended to be fulfilled for higher safety.
5.1 Standard for Low Temperature Burn
5.2 Standard on Terminal Failure
5.3 Standard for Expected Harsh Conditions
5.4 Standard for Fire Prevention
5.5 Standard for Sharp Edges of a Device
5.6 Standard for Power Leakage

5.1 Standard for Low Temperature Burn
No.

Item

Specifications

1

Test environment
temperature

35 degree Celsius (°C)

2

Terminal state

Setting and operation of the max load conditions attemperature rise3

Measurement method

Measure the contact part temperature undercontinuous body contact with the max heat point.

4Standard (Essential)

The temperatures and duration for human bodycontact shall be under the following range in eachmaterial;

Reference/Source
specifications/Remarks
Refer to Appendix C-1
for cautions in test
environment
temperature/
Refer to Appendix C-2
for cautions in the max
load conditions attemperature rise.
The ways to contact
humanbodiesareassumed as ones undernormal usages.
[ISO13732-1]■Metal・51°C for 1 minute, 48°C for 10 minutes, 43°C
for 8 hours■Glass and Ceramic
・56°C for 1 minute, 48°C for 10 minutes, 43°C
for 8 hours■Others (Resin etc.)

5Standard(Recommended)

・60°C for 1 minute, 48°C for 10 minutes, 43°C
for 8 hours
The temperatures and duration for human bodycontact shall be under the following range in each4−©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)material;■Materials independent
・51°C for 1 minute, 48°C for 10 minutes, 43°C
for 8 hours

5©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)

5.2 Standard for Terminal Failure
No.

Item

Specifications

Reference/Source
specifications/Remarks
Refer to Appendix C-1
for cautions in test
environment
temperature/−

1

Test environment
temperature

25°C

2

Terminal state3

Measurement method

In a power amplifier part and similarly large power
consuming parts and the main circuit for proper
control of these larger power consuming circuits,
the power supply operations on a open/short state
to the terminal circuit parts when power is on and abattery charger is connected.
Inspection of terminal state

4Standard (Essential)

No smoke, fire and melt.

−

5Standard(Recommended)

The temperature at the maximum heat generation
point of a terminal surface shall be measured andthe maximum temperature of a terminal surface
where a human body may contact shall not exceed
70°C.

−

−

5.3 Standard for assumable harsh conditions
No.

Item

Specifications

1

Test environment
temperature

35°C

2

Terminal state

Setting and operation of the max load conditions attemperature rise by wrapping a terminal in ablanket etc.

3

Measurement method

Inspection of terminal state

Reference/Source
specifications/Remarks
Refer to Appendix C-1
for cautions in test
environment
temperature/
Refer to Appendix C-2
for cautions in the max
load conditions attemperature rise.
−4Standard (Essential)

No terminal error−

5Standard(Recommended)

−

−

6

©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)

5.4 Standard for Fire Prevention
No.

Item

Specifications

1

Standard (Essential)

1.A device shall be designed and manufactured toprevent a fire expansion from the device.
2. There shall have no ignition in the parts of adevice.
3. The materials that are used for a product case
except for a detachable battery pack shall havethe flame resistance grade of HB equivalent ormore at the UL standard.

2Standard(Recommended)

Reference/Source
specifications/Remarks[UL94]

4. The materials that are used for a circuit board(i.e. a board with major parts such as a power
supply IC etc. and with a high electric current,
except for FPC) shall have the flame resistance
grade of V0 equivalent or more at the UL
standard.
5. The materials for a battery pack that can be
detached by a user shall support V2 equivalent ormore at the UL standard. The circuit board with alarge current except for FPC shall support a noninflammable grade with V0 equivalent or more at
the UL standard.
−−

5.5 Standard for sharp edges of a device
No.

Item

Specifications

1

Measurement method

2Standard (Essential)

3Standard(Recommended)

Test by a sharp edge tester*The specifications of a sharp edge tester and atest procedure shall be as set forth in the UL1439
standard.
A pierced cut on a 2 layer detection tape atexternal sharp edge testers shall not be produced.
A pierced cut on a 1 layer detection tape atexternal sharp edge testers shall not be produced.

7

Reference/Source
specifications/Remarks[UL1439][UL1439]−

©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)

5.6 Standard for power leakage
No.

Item

Specifications

1

Measurement method

2Standard (Essential)

3Standard(Recommended)

Test with the procedures and the text circuits underJ6950* A battery charger shall be a standard option
accessory and support the maximum rated
charging.
The maximum touch current (effective value): 0.25
mA
The maximum touch current (effective value): 0.10mA

8Reference/Source
specifications/Remarks[JISC6950-1][JISC6950-1]−

©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)Appendix A: Design Considerations for Heat Generation
and Temperature Rise Property
The standard items as set forth in the Section 5.1 - 5.4 show the product safety guidelines for a burnand fire risk arising from a thermal energy of Smart Phones etc. In order to reduce anxieties of a user
toward heat generation, the following points should also be well into consideration at a design phase.
A-1 Maximum temperature on a case surface
When a human body touches a heated part, the surface temperature decreases rapidly. If theconditions as provided for in 5-1 Item No.4 are fulfilled under such state, a risk for a low temperatureburn can be smaller. However if the moment to touch a heat part is high, a user will become a cause for“an anxiety for a burn” and “an anxiety for a terminal failure”. Therefore for heat measures including at ahigh load state, the maximum temperature under a non-contact state may be observed in designing
A-2 Time for temperature rise at a case surface
A sharp temperature rise at the surface of a case can be a case for “an anxiety for a burn” and “ananxiety for a terminal failure”. Therefore for heat measures including at a high load state, the duration
for a temperature rise may be observed in such a designing manner to prevent a sharp temperature riseat a case surface.
A-3 Partial temperature rise at a case surface
As a sharp temperature rise at partial area of a case surface especially for Smart Phones etc. that are
higher in density for parts can be a cause for “an anxiety for a burn” and “an anxiety for a terminal failure”,
a design to possibly prevent a local temperature rise may be necessary in heat measures.

Appendix B: Design Considerations at Other Safety
Standards
B-1 Design considerations for sharp edges on devices
The safety standard as set out in Section 5.5 is the one to ensure no risk for an injury at a contact
under the certain condition (i.e. a pressure and the speed of touch and trace of an edge under the[UL1439]). In addition, the sharpness of an edge of a device may be designed with consideration toensure “no pain at contact” and “no anxiety for an injury”.
As the sense of touch varies on materials of a device case, a sensory evaluation may be applied tocheck the sense of touch. In case the surface gives pain or an anxiety, an improvement to the surface
treatment such as chamfering may be implemented.
In case the characteristics of a product is targeted a specific age group especially for a younger
generation that tends to have thinner skins and be weaker to physical stimulations, a special attention
shall be paid.
B-2 Design considerations for power leakage
Similarly to the safety standard for a sharp edge on a device, “no pain or numbness on touching”
9©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)regarding a leakage current may be observed.
The measures for an output and an electricity leakage on a charger are prevalent. However as thematerials, especially metals of a case can influence a sensory leakage power, a sensory evaluation may
be applied to check the sensory leakage power and see if it is low enough not to feel a pain andnumbness.
B-3 Design considerations for other safety standards
The mobile devices are lately used not only for the traditional voice calls and data communications
but also popularly used as a player for an audio and audiovisual content. Thus, safety considerations
toward an acoustic energy have become important.
The requirements for the acoustic properties of phone functions are set out in ITU-TP360 and IEEE
std.269 (2010), UL60950-1, CAN/CSA-C22.2No.60950-1-07 and the ones when connected with an ear
with a headset are in EN60950-1/A12:2011(2nd ed.), EN500332-1/02. In addition, unsafe acoustic levelthat could be produced by user’s erroneous or unintended operations may be avoided in design.

10©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)Appendix C: Considerations in Test Procedure for Heat
C-1 Test environment temperature
An ambient temperature at test is set as either 25 degrees Celsius as normal ambient temperature,or 35 degrees Celsius maximum that is as recommended to a user in the instruction manuals of a genericmobile device. In case an instruction manual sets out a higher range of an ambient temperature than
this Guideline, the design may have further safety considerations in observing the maximum ambient
temperature.
In describing in an instruction manual that continuous or temporary uses in a car under blazing sun orin other high temperature environments such as a bathroom are allowed, a safety check at the maximum
ambient temperature that is carried in the instruction manual and an alert for a low temperature burn etc.
at a higher temperature may be well observed.
C-2 Maximum load condition at temperature rise
As set forth in the chapter 3, the maximum load condition at temperature rise shall be carefully
observed in consideration of not only a single functionality operation condition but also of probableconcurrent multiple functionality operations in the main heat sources such as CPU, a radio circuit, apower supply and a battery charger.
Furthermore in view of the utmost attention to user safety, maximum load condition shall be “themaximum load condition for terminal specifications” rather than “the maximum load condition that is
expected in use cases”.
Concrete example;
In case of smart phones
Set the brightness of a display at maximum and make the display a power-on state always, measure
the temperature rise in operating all of the concurrent operable functionalities such as continuous
packet transmissions at the maximum transmission power (toward a simulator), Wi-Fi tethering, acamera function (such as video shooting), video viewing and battery charging etc.

11©Copyright 1997-2017 Mobile Computing Promotion Consortium (MCPC)MCPC TR-023 Mobile Equipment Safety Design Guideline Version 2.00(E)Appendix D: Reference Materials such as Standard
Specifications (Normative)[ISO13732-1][UL94][UL1439][JISC6950-1]

ISO13732-1：2006 Ergonomics of the thermal environment – Methods for theassessment of human responses to contact with surfaces Standard for Tests for Flammability of Plastic Materials for Parts in Devices andAppliances
UL Standard for Safety Tests for Sharpness of Edges on Equipment
JIS C6950-1:2012+Addendum1(2014) Information technology equipment – Safety Part 1: General requirements

12