WO2021128076A1 - 无线充电背壳组件以及电子设备 - Google Patents

无线充电背壳组件以及电子设备 Download PDF

Info

Publication number
WO2021128076A1
WO2021128076A1 PCT/CN2019/128380 CN2019128380W WO2021128076A1 WO 2021128076 A1 WO2021128076 A1 WO 2021128076A1 CN 2019128380 W CN2019128380 W CN 2019128380W WO 2021128076 A1 WO2021128076 A1 WO 2021128076A1
Authority
WO
WIPO (PCT)
Prior art keywords
wireless charging
back shell
transmission line
coil
shell assembly
Prior art date
Application number
PCT/CN2019/128380
Other languages
English (en)
French (fr)
Inventor
刘泽南
汪宗
陈勇利
Original Assignee
瑞声声学科技(深圳)有限公司
瑞声科技(新加坡)有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 瑞声声学科技(深圳)有限公司, 瑞声科技(新加坡)有限公司 filed Critical 瑞声声学科技(深圳)有限公司
Priority to PCT/CN2019/128380 priority Critical patent/WO2021128076A1/zh
Publication of WO2021128076A1 publication Critical patent/WO2021128076A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F38/14—Inductive couplings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling

Definitions

  • the utility model relates to the technical field of wireless charging, in particular to a wireless charging back shell component and an electronic device adopting the wireless charging back shell component.
  • Wireless charging technology also known as non-contact inductive charging, is based on the principle of inductive coupling, in which energy is transferred from the power supply device to the electrical equipment, and the energy is used to charge the battery after the electrical equipment.
  • wireless charging technology mainly has the following three forms: magnetic induction, magnetic resonance and radio wave. From these technologies, there are three major wireless charging standard alliances, including Qi, A4WP and PMA, Qi and PMA. It is based on magnetic induction technology, and the A4WP protocol is based on magnetic resonance technology. At present, A4WP and PMA have merged into AirFuel Alliance (AFA) to promote a unified wireless charging standard.
  • AFA AirFuel Alliance
  • Wireless charging technology is widely used in electronic devices, such as mobile phones, tablet computers, etc. due to its convenient operation and low wear and tear.
  • the wireless charging function on some modern electronic devices is basically realized in the form of independent wireless charging modules.
  • the wireless charging module includes a PET layer, a wireless charging coil layer, a nanocrystalline layer, a graphite sheet layer and a glue layer.
  • One of the objectives of the present invention is to disclose a wireless charging back shell assembly with small thickness of the wireless charging module, good heat dissipation capacity and high flexibility in connection with the main board.
  • the second purpose of the present invention is to disclose an electronic device that uses the above-mentioned wireless charging back shell assembly.
  • a wireless charging back shell assembly includes a back shell, a wireless charging coil, a first pad, a second pad, a first FPC transmission line, and a second FPC transmission line.
  • the wireless charging coil is formed on the On the surface of the back shell, the wireless charging coil has an inner port located inside the coil and an outer port located outside the coil.
  • the inner port and the first pad are electrically connected through the first FPC transmission line, so The external port and the second pad are electrically connected through the second FPC transmission line.
  • the back shell is a ceramic glass back shell.
  • the wireless charging back shell assembly further includes a magnetic isolation layer that is pasted on the back shell and covers the wireless charging coil, the first pad, and the second solder Disk, the first FPC transmission line, and the second FPC transmission line.
  • the magnetic isolation layer is a ferrite layer or a nanocrystalline layer.
  • the wireless charging back shell assembly further includes a graphite sheet layer attached to a side of the magnetic isolation layer away from the wireless charging coil.
  • the wireless charging coil is formed on the surface of the back shell through a laser engraving process, and the heat generated by the wireless charging coil can be directly dissipated through the back shell, which improves the heat dissipation capacity; and Compared with the existing wireless charging module, this design method can remove the T EP protective film part to reduce the overall thickness of the wireless charging module; in addition, by setting the inner port of the wireless charging coil, the first FPC transmission line is connected to the first FPC transmission line. Pad connection, the external port of the wireless charging coil is connected to the second pad through the second transmission line. Compared with the existing method of directly laser engraving the transmission line and the pad on the back shell, the connection between the wireless charging coil and the motherboard can be improved. Flexibility.
  • Fig. 1 is an exploded schematic diagram of the wireless charging back shell assembly disclosed in an embodiment of the present invention.
  • an embodiment of the present invention discloses a wireless charging back shell assembly 100, including a back shell 10, a wireless charging coil 20, a first pad 30, a second pad 40, a first FPC transmission line 50 and a Two FPC transmission line 60.
  • the wireless charging coil 20 is formed on the surface of the back shell 10 by a laser engraving process.
  • the wireless charging coil 20 has an inner port 21 located inside the coil and an outer port 22 located outside the coil.
  • the inner port 21 is welded to the first
  • the disks 30 are electrically connected through a first FPC transmission line 50, and the external port 22 and the second pad 40 are electrically connected through a second FPC transmission line 60.
  • the wireless charging coil 20 is formed on the surface of the back shell 10 through a laser engraving process, and the heat generated by the wireless charging coil 20 during operation can be directly dissipated through the back shell 10, which improves the heat dissipation capacity; moreover, this design method Compared with the existing wireless charging module, the TEP protective film can be removed to reduce the overall thickness of the wireless charging module; in addition, by setting the inner port 21 of the wireless charging coil 20 through the first FPC transmission line 50 and the first pad 30 is connected, the external port 22 of the wireless charging coil 20 is connected to the second pad 40 through the second FPC transmission line 60. Compared with the existing method of directly laser engraving the transmission line and the pad on the back shell, the wireless charging can be improved.
  • the back shell 10 is a ceramic glass back shell.
  • the back shell 10 is not limited to a ceramic glass back shell, but may also be a ceramic back shell or a glass back shell or some plastic back shell with better heat dissipation performance, such as an epoxy resin back shell, etc., which can be specifically based on actual conditions It depends on design needs.
  • the wireless charging back shell assembly 100 further includes a magnetic isolation layer 70, which is pasted on the back shell 20 and covers the wireless charging coil 20, the first pad 34, and the second pad 40. , The first FPC transmission line 50 and the second FPC transmission line 60.
  • the magnetic isolation layer 70 can be set to the size of the dashed frame M as shown in FIG. 1 to cover the above-mentioned components.
  • the magnetic isolation layer 70 is fixed to the back shell 10 by pasting, and the process is simple. The yield of the finished product is improved, and this fixing method facilitates the adjustment of the magnetic isolation layer 70.
  • the self-inductance value of the wireless charging coil 20 can be adjusted by adjusting the material of the magnetic isolation layer 70, instead of adjusting the wireless charging coil 20. The self-inductance value is adjusted to adjust the entire wireless charging back shell assembly 100.
  • the magnetic isolation layer 70 is a ferrite layer or a nanocrystalline layer.
  • the wireless charging back shell assembly 100 further includes a graphite sheet 80 attached to the side of the magnetic isolation layer away from the wireless charging coil.
  • the graphite sheet layer 80 is fixed to the back shell 10 by pasting, which is simple in process and improves the yield of the finished product.
  • this fixing method facilitates the adjustment of the graphite sheet layer 80, which can be adjusted in the later stage.
  • the layer 80 is used to adjust the heat dissipation of the wireless charging coil 20, which is convenient and simple.
  • the embodiment of the present invention also discloses an electronic device, and the electronic device adopts the wireless charging back shell assembly 100 described above.
  • the electronic device is a wireless charging base or a mobile phone or a tablet computer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Manufacturing & Machinery (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

本申请公开了无线充电背壳组件以及电子设备，其中，无线充电背壳组件包括背壳、无线充电线圈、第一焊盘、第二焊盘、第一FPC传输线以及第二FPC传输线，无线充电线圈通过激光镭雕工艺成形于背壳的表面，无线充电线圈具有位于线圈内侧的内端口和位于线圈外侧的外端口，内端口与第一焊盘之间通过第一FPC传输线电性连接，外端口与第二焊盘之间通过第二FPC传输线电性连接。本申请公开的无线充电背壳组件，无线充电线圈通过激光镭雕工艺成形于背壳的表面，散热效果好；而且，相对于现有的无线充电模组，可以去掉TEP保护膜部分，减小无线充电模组的整体厚度；此外，通过设置第一FPC传输线和第二FPC传输线可以提升无线充电线圈与主板连接的灵活性。

Description

无线充电背壳组件以及电子设备 技术领域
本实用新型涉及无线充电技术领域，尤其涉及一种无线充电背壳组件以及一种采用该无线充电背壳组件的电子设备。
背景技术
无线充电技术，又称非接触式感应充电，基于电感耦合原理，由供电设备将能量传输至用电设备，用电设备后将能量用于电池充电的技术。目前无线充电技术主要有以下三种形式：磁感应式、磁共振式和无线电波式，而从这几项技术衍生出来三大无线充电标准联盟，包含Qi、A4WP和PMA三大标准，Qi和PMA是基于磁感应式技术，A4WP协议则基于磁共振式技术。目前A4WP和PMA已经合并为AirFuel Alliance(AFA)，推动统一的无线充电标准。
无线充电技术由于操作方便、对设备磨损低等特点在电子设备，如手机、平板电脑等领域有着广泛的应用，现代有的电子设备上的无线充电功能基本以独立的无线充电模组形式得以实现，无线充电模组包括PET层、无线充电线圈层、纳米晶层、石墨片层以及胶层。
随着各电子设备厂商不断追求超薄化、轻量化，留给无线充电模组的空间越来越少，这使得传统的无线充电模组在整体尺寸上面临挑战。
发明概述
技术问题
本实用新型的目的之一在于公开一种无线充电模组厚度小、散热能力好以及与主板连接灵活性高的无线充电背壳组件。本实用新型的目的之二在于公开一种电子设备，该电子设备采用上述的无线充电背壳组件。
问题的解决方案
技术解决方案
本实用新型的目的之一采用如下技术方案实现：
一种无线充电背壳组件，包括背壳、无线充电线圈、第一焊盘、第二焊盘、第 一FPC传输线以及第二FPC传输线，所述无线充电线圈通过激光镭雕工艺成形于所述背壳的表面，所述无线充电线圈具有位于线圈内侧的内端口和位于线圈外侧的外端口，所述内端口与所述第一焊盘之间通过所述第一FPC传输线电性连接，所述外端口与所述第二焊盘之间通过所述第二FPC传输线电性连接。
作为一种改进方式，所述背壳为陶瓷玻璃背壳。
作为一种改进方式，所述无线充电背壳组件还包括磁隔离层，所述磁隔离层粘贴于所述背壳并覆盖所述无线充电线圈、所述第一焊盘、所述第二焊盘、所述第一FPC传输线以及所述第二FPC传输线。
作为一种改进方式，所述磁隔离层为铁氧体层或者纳米晶层。
作为一种改进方式，所述无线充电背壳组件还包括贴设于所述磁隔离层背离所述无线充电线圈一侧的石墨片层。
本实用新型的目的之二采用如下技术方案实现：
一种电子设备，所述电子设备采用上述的无线充电背壳组件。
发明的有益效果
有益效果
本实用新型实施方式相对于现有技术而言，无线充电线圈通过激光镭雕工艺成形于背壳的表面，无线充电线圈工作时产生的热量可以通过背壳直接散发出去，提高了散热能力；而且，该设计方式相对于现有的无线充电模组，可以去掉T EP保护膜部分，减小无线充电模组的整体厚度；此外，通过设置无线充电线圈的内端口通过第一FPC传输线与第一焊盘连接，无线充电线圈的外端口通过第二传输线与第二焊盘连接，相对于现有的将传输线和焊盘直接激光镭雕在背壳上的方式，可以提升无线充电线圈与主板连接的灵活性。
对附图的简要说明
附图说明
图1为本实用新型实施例公开的无线充电背壳组件的爆炸示意图。
发明实施例
具体实施方式
下面结合附图和实施方式对本实用新型作进一步说明。
需要说明的是，本实用新型实施例中所有方向性指示(诸如上、下、左、右、前、后、内、外、顶部、底部......)仅用于解释在某一特定姿态(如附图所示)下各部件之间的相对位置关系等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。
还需要说明的是，当元件被称为“固定于”或“设置于”另一个元件上时，该元件可以直接在另一个元件上或者可能同时存在居中元件。当一个元件被称为“连接”另一个元件，它可以是直接连接另一个元件或者可能同时存在居中元件。
请参阅图1，本实用新型的实施例公开一种无线充电背壳组件100，包括背壳10、无线充电线圈20、第一焊盘30、第二焊盘40、第一FPC传输线50以及第二FPC传输线60，无线充电线圈20通过激光镭雕工艺成形于背壳10的表面，无线充电线圈20具有位于线圈内侧的内端口21和位于线圈外侧的外端口22，内端口21与第一焊盘30之间通过第一FPC传输线50电性连接，外端口22与第二焊盘40之间通过第二FPC传输线60电性连接。
本实施例中，无线充电线圈20通过激光镭雕工艺成形于背壳10的表面，无线充电线圈20工作时产生的热量可以通过背壳10直接散发出去，提高了散热能力；而且，该设计方式相对于现有的无线充电模组，可以去掉TEP保护膜部分，减小无线充电模组的整体厚度；此外，通过设置无线充电线圈20的内端口21通过第一FPC传输线50与第一焊盘30连接，无线充电线圈20的外端口22通过第二FPC传输线60与第二焊盘40连接，相对于现有的将传输线和焊盘直接激光镭雕在背壳上的方式，可以提升无线充电线圈20与主板连接的灵活性，具体地，可以通过第一FPC传输线50和第二FPC传输线60的走线来匹配主板顶针(现有的一般采用主板上的顶针与无线充电线圈的焊盘连接)的位置，而无需调整无线充电线圈20的位置。
作为本实施例的一种改进方式，背壳10为陶瓷玻璃背壳。通过设置背壳10为陶瓷玻璃背壳，利用陶瓷玻璃散热较好的优点，可以进一步提高无线充电背壳组件100的散热效果。需要说明的是，背壳10不局限于为陶瓷玻璃背壳，也可以是陶瓷背壳或者玻璃背壳或者一些散热性能较好的塑料背壳，例如环氧树脂背壳 等，具体可以根据实际设计需要而定。
作为本实施例的一种改进方式，无线充电背壳组件100还包括磁隔离层70，磁隔离层70粘贴于背壳20并覆盖无线充电线圈20、第一焊盘34、第二焊盘40、第一FPC传输线50以及第二FPC传输线60。例如，磁隔离层70可以设置成如图1中所示的虚线框M的大小以覆盖上述部件，本实施例中，通过设置磁隔离层70采用粘贴的方式固定于背壳10，工艺简单，提高了成品的良率，而且，该固定方式便于磁隔离层70的调整，后期可以通过调整磁隔离层70的材料来实现无线充电线圈20自感值的调整，而不用为了调整无线充电线圈20的自感值而调整整个无线充电背壳组件100。
作为本实施例的一种改进方式，磁隔离层70为铁氧体层或者纳米晶层。
作为本实施例的一种改进方式，无线充电背壳组件100还包括贴设于磁隔离层背离无线充电线圈一侧的石墨片层80。本实施例中，通过设置石墨片层80采用粘贴的方式固定于背壳10，工艺简单，提高了成品的良率，而且，该固定方式便于石墨片层80的调整，后期可以通过调整石墨片层80来实现无线充电线圈20散热的调整，方便简单。
本实用新型的实施例还公开一种电子设备，电子设备采用上述的无线充电背壳组件100。
所述电子设备为无线充电底座或者手机或者平板电脑。
以上所述的仅是本实用新型的实施方式，在此应当指出，对于本领域的普通技术人员来说，在不脱离本实用新型创造构思的前提下，还可以做出改进，但这些均属于本实用新型的保护范围。

Claims (6)

  1. 一种无线充电背壳组件，其特征在于，包括背壳、无线充电线圈、第一焊盘、第二焊盘、第一FPC传输线以及第二FPC传输线，所述无线充电线圈通过激光镭雕工艺成形于所述背壳的表面，所述无线充电线圈具有位于线圈内侧的内端口和位于线圈外侧的外端口，所述内端口与所述第一焊盘之间通过所述第一FPC传输线电性连接，所述外端口与所述第二焊盘之间通过所述第二FPC传输线电性连接。
  2. 根据权利要求1所述的无线充电背壳组件，其特征在于，所述背壳为陶瓷玻璃背壳。
  3. 根据权利要求1所述的无线充电背壳组件，其特征在于，所述无线充电背壳组件还包括磁隔离层，所述磁隔离层粘贴于所述背壳并覆盖所述无线充电线圈、所述第一焊盘、所述第二焊盘、所述第一FPC传输线以及所述第二FPC传输线。
  4. 根据权利要求3所述的无线充电背壳组件，其特征在于，所述磁隔离层为铁氧体层或者纳米晶层。
  5. 根据权利要求3所述的无线充电背壳组件，其特征在于，所述无线充电背壳组件还包括贴设于所述磁隔离层背离所述无线充电线圈一侧的石墨片层。
  6. 一种电子设备，其特征在于，所述电子设备采用权利要求1-5任一项所述的无线充电背壳组件。
PCT/CN2019/128380 2019-12-25 2019-12-25 无线充电背壳组件以及电子设备 WO2021128076A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/128380 WO2021128076A1 (zh) 2019-12-25 2019-12-25 无线充电背壳组件以及电子设备

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/128380 WO2021128076A1 (zh) 2019-12-25 2019-12-25 无线充电背壳组件以及电子设备

Publications (1)

Publication Number Publication Date
WO2021128076A1 true WO2021128076A1 (zh) 2021-07-01

Family

ID=76575069

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/128380 WO2021128076A1 (zh) 2019-12-25 2019-12-25 无线充电背壳组件以及电子设备

Country Status (1)

Country Link
WO (1) WO2021128076A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4195888A4 (en) * 2021-10-28 2024-01-31 Honor Device Co Ltd ELECTRONIC DEVICE

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104409869A (zh) * 2014-11-29 2015-03-11 青岛歌尔声学科技有限公司 一种多合一天线及一种多功能通讯设备
CN204216621U (zh) * 2014-11-18 2015-03-18 东莞劲胜精密组件股份有限公司 一种无线充电结构以及可充电电子产品
CN108109827A (zh) * 2018-01-11 2018-06-01 信利光电股份有限公司 一种背面盖板的制作方法和背面盖板
CN207752865U (zh) * 2018-01-11 2018-08-21 信利光电股份有限公司 一种背面盖板和移动终端
WO2018152015A1 (en) * 2017-02-17 2018-08-23 Microsoft Technology Licensing, Llc Smart battery for ultrafast charging

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN204216621U (zh) * 2014-11-18 2015-03-18 东莞劲胜精密组件股份有限公司 一种无线充电结构以及可充电电子产品
CN104409869A (zh) * 2014-11-29 2015-03-11 青岛歌尔声学科技有限公司 一种多合一天线及一种多功能通讯设备
WO2018152015A1 (en) * 2017-02-17 2018-08-23 Microsoft Technology Licensing, Llc Smart battery for ultrafast charging
CN108109827A (zh) * 2018-01-11 2018-06-01 信利光电股份有限公司 一种背面盖板的制作方法和背面盖板
CN207752865U (zh) * 2018-01-11 2018-08-21 信利光电股份有限公司 一种背面盖板和移动终端

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4195888A4 (en) * 2021-10-28 2024-01-31 Honor Device Co Ltd ELECTRONIC DEVICE

Similar Documents

Publication Publication Date Title
JP7381027B2 (ja) ミドルフレーム、リヤカバー、および製造方法、ならびに電子デバイス
US10475750B2 (en) Systems, methods, and apparatuses for implementing an organic stiffener with an EMI shield for RF integration
US9667077B2 (en) Cordless charging apparatus
CN203103042U (zh) 用于无线充电或nfc近场感应的线圈装置
KR20150131923A (ko) Nfc 통신이 가능한 전자장치
WO2021120948A1 (zh) 扬声器模组和电子设备
WO2021128076A1 (zh) 无线充电背壳组件以及电子设备
WO2013029473A1 (zh) 无线终端
CN108695929B (zh) 一种无线充电模组用屏蔽片及无线充电模组
CN206332939U (zh) 移动终端
CN108541208A (zh) 无线充电用电磁屏蔽片的制备方法
KR20160001403U (ko) 전자 장치 열 관리 시스템
CN206124339U (zh) 一种包边型复合天线模组
CN211530856U (zh) 无线充电背壳组件以及电子设备
CN206293600U (zh) 一种改良型射频天线
WO2018102963A1 (zh) 电子设备及其集成式隔磁片
CN208423831U (zh) 一种无线充电模组用屏蔽片及无线充电模组
WO2022110364A1 (zh) 集成nfc天线的无线充电接收模组及移动终端
CN209708796U (zh) 一体成型组合电感器
JP3241982U (ja) 無線伝送モジュール
CN208480058U (zh) 一种手机摄像模组小型化pcb布局结构
CN202737051U (zh) 卷绕式软包装锂离子电芯
KR20220076083A (ko) 노이즈 유도 구조를 포함하는 전자 장치
KR20170073321A (ko) 안테나 일체형 모바일 기기 케이스의 제조 방법
CN218514379U (zh) 无线传输模块

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19957126

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19957126

Country of ref document: EP

Kind code of ref document: A1