Patent ID: 12249806

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, modes for implementing the present technology (hereinafter referred to as embodiments) will be described. Description will be given according to the following order.1. Embodiment (Semiconductor Laser Drive Device)2. Application (Electronic Device)

1. Embodiment

Semiconductor Laser Drive Device

FIG.1is a view illustrating an example of a top view of a semiconductor laser drive device10according to an embodiment of the present technology.

The semiconductor laser drive device10is assumed to measure a distance by ToF. ToF has characteristics of high depth accuracy though not so much as structured light and of being operable without difficulty even in a dark environment. In addition, ToF has many advantages in terms of simplicity of a device configuration, cost, and the like, compared to other methods such as structured light and stereo camera.

In the semiconductor laser drive device10, a semiconductor laser300, a photodiode400, and a passive component500are electrically connected and mounted by wire bonding on a surface of a substrate100having a laser driver200built-in. A printed wiring board is assumed as the substrate100.

The semiconductor laser300is a semiconductor device that causes a current to flow through a PN junction of a compound semiconductor to emit laser light. Here, as the compound semiconductor to be used, aluminum gallium arsenide (AlGaAs), indium gallium arsenide phosphide (InGaAsP), aluminum gallium indium phosphide (AlGaInP), gallium nitride (GaN), or the like is assumed, for example.

The laser driver200is a driver integrated circuit (IC) for driving the semiconductor laser300. The laser driver200is built in the substrate100in a face-up state. Regarding the electrical connection with the semiconductor laser300, it is desirable to make a wiring length as short as possible because the wiring inductance needs to be reduced. A specific numerical value will be described below.

The photodiode400is a diode for detecting light. The photodiode400is used for automatic power control (APC control) for monitoring light intensity of the semiconductor laser300and keeping output of the semiconductor laser300constant.

The passive component500is a circuit component other than active elements such as capacitors and resistors. The passive component500includes a decoupling capacitor for driving the semiconductor laser300.

FIG.2is a view illustrating an example of a cross-sectional view of the semiconductor laser drive device10according to the embodiment of the present technology.

As described above, the substrate100has the laser driver200built-in, and the semiconductor laser300and the like are mounted on the surface of the substrate100. Connection between the semiconductor laser300and the laser driver200is performed via a connection via101. By using the connection via101, the wiring length can be shortened. Note that the connection via101is an example of connection wiring described in the claims.

Furthermore, the substrate100includes a thermal via102for heat dissipation. Each component mounted on the substrate100is a heat source. By using the thermal via102, heat generated in each component can be radiated from a back surface of the substrate100.

The semiconductor laser300, the photodiode400, and the passive component500mounted on the surface of the substrate100are surrounded by a side wall600. As the material of the side wall600, a plastic material or a metal is assumed, for example.

An upper surface surrounded by the side wall600is covered with a diffusion plate700. The diffusion plate700is an optical element for diffusing laser light from the semiconductor laser300and is also called a diffuser.

FIG.3is views illustrating a definition of an overlap amount between the laser driver200and the semiconductor laser300according to the embodiment of the present technology.

As described above, since the connection between the semiconductor laser300and the laser driver200is assumed to be performed via the connection via101, the semiconductor laser300and the laser driver200are arranged to overlap when viewed from the upper surface. Meanwhile, it is desirable to provide the thermal via102in a lower surface of the semiconductor laser300, and a region therefor needs to be secured. Therefore, to clarify the positional relationship between the laser driver200and the semiconductor laser300, the overlap amount between the laser driver200and the semiconductor laser300is defined as follows.

In the arrangement illustrated in a inFIG.3, no overlapping region is present between the semiconductor laser300and the laser driver200when viewed from the upper surface. The overlap amount in this case is defined as 0%. Meanwhile, in the arrangement illustrated in c inFIG.3, the entire semiconductor laser300overlaps with the laser driver200when viewed from the upper surface. The overlap amount in this case is defined as 100%.

Then, in the arrangement illustrated in b inFIG.3, a half region of the semiconductor laser300overlaps with the laser driver200when viewed from the upper surface. The overlap amount in this case is defined as 50%.

In the present embodiment, the overlap amount is desirably larger than 0% in order to provide a region for the above-described connection via101. Meanwhile, considering that a certain number of the thermal vias102are arranged immediately below the semiconductor laser300, the overlap amount is desirably 50% or less. Therefore, by setting the overlap amount to be larger than 0% and to be 50% or less, the wiring inductance can be made small and favorable heat dissipation characteristics can be obtained.

Wiring Inductance

As described above, in the connection between the semiconductor laser300and the laser driver200, the wiring inductance is the problem. All conductors have an inductive component, and even an inductance of a very short lead may be detrimental in a high-frequency region of such a ToF system. That is, at high-frequency operation, a drive waveform for driving the semiconductor laser300from the laser driver200may be distorted due to the influence of the wiring inductance, and the operation may become unstable.

Here, a theoretical formula for calculating the wiring inductance is examined. For example, an inductance IDC [μH] of a straight lead wire having a circular cross section with a length L [mm] and a radius R [mm] is expressed by the following expression in free space. Note that In represents a natural logarithm.
IDC=0.0002L·(ln(2L/R)−0.75)

Furthermore, for example, the inductance IDC [μH] of a strip line (substrate wiring pattern) having a length L [mm], a width W [mm], and a thickness H [mm] is expressed by the following expression in free space.
IDC=0.0002L·(ln(2L/(W+H))+0.2235((W+H)/L)+0.5)

FIGS.4and5are tables illustrating trial calculations of the wiring inductance [nH] between the laser driver built in the printed wiring board and the semiconductor laser electrically connected to an upper portion of the printed wiring board.

FIG.4is a diagram illustrating numerical value examples of the wiring inductance with respect to the wiring length L and the wiring width W in a case of forming a wiring pattern by an additive method. The additive method is a method of forming a pattern by depositing copper only on a necessary portion of an insulating resin surface.

FIG.5is a diagram illustrating numerical value examples of the wiring inductance with respect to the wiring length L and the wiring width W in a case of forming a wiring pattern by a subtractive method. The subtractive method is a method of forming a pattern by etching an unnecessary portion of a copper clad laminate.

In the case of the semiconductor laser drive device such as the ToF system, the wiring inductance is desirably 0.5 nH or less, and more favorably 0.3 nH or less, assuming that the semiconductor laser drive device is driven at several hundreds of megahertz. Therefore, considering the above-described trial calculation results, it is considered that the wiring length between the semiconductor laser300and the laser driver200is desirably 0.5 millimeters or less, and more favorably 0.3 millimeters or less.

Manufacturing Method

FIGS.6and7are views illustrating an example of steps of processing a copper land and a copper wiring layer (redistribution layer (RDL)) in the process of manufacturing the laser driver200according to the embodiment of the present technology.

First, as illustrated in a inFIG.6, an I/O pad210formed using, for example, aluminum is formed on a semiconductor wafer. Then, a protective insulating layer220such as SiN is formed on a surface, and a region of the I/O pad210is opened.

Next, as illustrated in b inFIG.6, a surface protective film230formed using polyimide (PI) or polybenzoxazole (PBO) is formed, and a region of the I/O pad210is opened.

Next, as illustrated in c inFIG.6, titanium tungsten (TiW) having a thickness of several tens to 100 nm and copper (Cu) having a thickness of 100 to 1000 nm are continuously sputtered to form an adhesion layer and a seed layer240. Here, as the adhesion layer, high melting point metal such as chromium (Cr), nickel (Ni), titanium (Ti), titanium copper (TiCu), or platinum (Pt) or its alloy may be applied, other than titanium tungsten (TiW). Furthermore, as the seed layer, nickel (Ni), silver (Ag), gold (Au), or its alloy may be applied, other than copper (Cu).

Next, as illustrated in d inFIG.7, a photoresist250is patterned in order to form a copper land and a copper wiring layer for electrical connection. Specifically, the photoresist250is formed by steps of surface cleaning, resist coating, drying, exposure, and development.

Next, as illustrated in e inFIG.7, a copper land and copper wiring layer (RDL)260for electrical connection is formed on the adhesion layer and the seed layer240by a plating method. Here, as the plating method, for example, an electrolytic copper plating method, an electrolytic nickel plating method, or other method can be used. Furthermore, the diameter of the copper land is desirably about 50 to 100 micrometers, the thickness of the copper wiring layer is desirably about 3 to 10 micrometers, and the minimum width of the copper wiring layer is desirably about 10 micrometers.

Next, as illustrated in f inFIG.7, the photoresist250is removed, and the copper land and copper wiring layer (RDL)260of the semiconductor chip is masked and dry-etched. Here, for the dry etching, ion milling for emitting an argon ion beam can be used, for example. By the dry etching, the adhesion layer and the seed layer240in an unnecessary region can be selectively removed, and the copper land and the copper wiring layer are separated. Note that the unnecessary region can be removed by wet etching with aqua regia, or an aqueous solution of ceric ammonium nitrate, potassium hydroxide, or the like but dry etching is desirable considering side etching and thickness reduction of a metal layer constituting the copper land and the copper wiring layer.

FIGS.8to12are views illustrating an example of steps of manufacturing the substrate100according to the embodiment of the present technology.

First, as illustrated in a inFIG.8, a peelable copper foil130having a two-layer structure of an ultra-thin copper foil132and a carrier copper foil131is thermally bonded by roll laminating or laminating press on one side of a support plate110via an adhesive resin layer120.

As the support plate110, a substrate formed using an inorganic material, a metal material, a resin material, or the like can be used. For example, silicon (Si), glass, ceramic, copper, a copper alloy, aluminum, an aluminum alloy, stainless steel, a polyimide resin, or an epoxy resin can be used.

As the peelable copper foil130, a copper foil obtained by vacuum-bonding the carrier copper foil131having the thickness of 18 to 35 micrometers to the ultra-thin copper foil132having the thickness of 2 to 5 micrometers each other. As the peelable copper foil130, 3FD-P3/35 (manufactured by Furukawa Circuit Foil Co., Ltd.), MT-18S5DH (manufactured by Mitsui Mining & Smelting Co., Ltd.), or the like can be used, for example.

As the resin material of the adhesive resin layer120, an organic resin such as an epoxy resin, a polyimide resin, a PPE resin, a phenol resin, a PTFE resin, a silicon resin, a polybutadiene resin, a polyester resin, a melamine resin, a urea resin, a PPS resin, or a PPO resin, which contains glass fiber reinforcing material, can be used. Furthermore, as the reinforcing material, aramid non-woven fabric, aramid fiber, polyester fiber, or the like can be used other than glass fiber.

Next, as illustrated in b inFIG.8, a plating base conductive layer (not illustrated) having the thickness of 0.5 to 3 micrometers is formed on the surface of the ultra-thin copper foil132of the peelable copper foil130by electroless copper plating treatment. Note that the electroless copper plating treatment is to form a base conductive layer of electrolytic copper plating for forming a wiring pattern next. Note that the electroless copper plating treatment may be omitted, and an electrode for electrolytic copper plating may be directly brought in contact with the peelable copper foil130, and electrolytic copper plating treatment may be directly applied on the peelable copper foil130to form a wiring pattern.

Next, as illustrated in c inFIG.8, a photosensitive resist is attached to the surface of the support plate by roll laminating to form a resist pattern for the wiring pattern (solder resist140). As the photosensitive resist, for example, a dry film plating resist can be used.

Next, as illustrated in d inFIG.8, a wiring pattern150having the thickness of about 15 micrometers is formed by the electrolytic copper plating treatment.

Next, as illustrated by e inFIG.9, the plating resist is peeled off. Then, as pretreatment for forming an interlayer insulating resin, the surface of the wiring pattern is roughened to improve adhesiveness between the interlayer insulating resin and the wiring pattern. Note that the roughening treatment can be performed by blackening treatment by oxidation-reduction treatment or hydrogen peroxide-sulfuric acid-based soft etching treatment.

Next, as illustrated in f inFIG.9, an interlayer insulating resin161is thermally bonded by roll laminating or laminating press on the wiring pattern. For example, an epoxy resin having the thickness of 45 micrometers is rolled and laminated. In a case of using a glass epoxy resin, copper foils having an arbitrary thickness are laminated and thermally compressed by laminating press. As the resin material of the interlayer insulating resin161, an organic resin such as an epoxy resin, a polyimide resin, a PPE resin, a phenol resin, a PTFE resin, a silicon resin, a polybutadiene resin, a polyester resin, a melamine resin, a urea resin, a PPS resin, or a PPO resin can be used. Furthermore, each of these resins can be used alone, or a combination of resins by mixing a plurality of the resins or preparing a compound can also be used, for example. Moreover, an interlayer insulating resin obtained by including an inorganic filler in these materials or mixing a glass fiber reinforcing material can also be used.

Next, as illustrated in g inFIG.9, a via hole for interlayer electrical connection is formed by a laser method or a photoetching method. In the case where the interlayer insulating resin161is a thermosetting resin, the via hole is formed by the laser method. As laser light, an ultraviolet laser such as a harmonic YAG laser or an excimer laser, or an infrared laser such as a carbon dioxide gas laser can be used. Note that, in the case of forming the via hole using the laser light, a thin resin film may remain on a bottom of the via hole, so desmear treatment is performed. In the desmear treatment, the resin is swollen with a strong alkali, and the resin is decomposed and removed by using an oxidizing agent such as a chromic acid or a permanganate aqueous solution. Furthermore, the resin may be removed by plasma treatment or sandblast treatment with an abrasive. In the case where the interlayer insulating resin161is a photosensitive resin, a via hole170is formed by a photoetching method. That is, the via hole170is formed by exposing the interlayer insulating resin161using ultraviolet rays through a mask and then performing development.

Next, after roughening treatment, electroless plating treatment is performed on a wall surface of the via hole170and a surface of the interlayer insulating resin161. Next, a photosensitive resist is attached by roll laminating to the surface of the interlayer insulating resin161to which the electroless plating treatment has been applied. As the photosensitive resist in this case, for example, a dry film photosensitive plating resist film can be used. This photosensitive plating resist film is exposed and then developed to form a plating resist pattern in which the via hole170and the wiring pattern are opened. Next, the electrolytic copper plating treatment with the thickness of 15 micrometers is applied to the opening in the plating resist pattern. Next, the plating resist is peeled off, and the electroless plating remaining on the interlayer insulating resin is removed by hydrogen peroxide-sulfuric acid-based flash etching or the like, whereby the via hole170filled with copper plating and the wiring pattern, as illustrated in h inFIG.9, are formed. Then, a similar step of roughening the wiring pattern and a similar step of forming an interlayer insulating resin162are repeatedly performed.

Next, as illustrated in i inFIG.10, the laser driver200obtained by attaching the copper land and the copper wiring layer thinned to the thickness of about 30 to 50 micrometers to a die attach film (DAF)290are mounted in a face-up state.

Next, as illustrated in j inFIG.10, an interlayer insulating resin163is thermally bonded by roll laminating or laminating press.

Next, as illustrated in k inFIG.10and in l inFIG.11, via hole treatment, desmear treatment, roughening treatment, electroless plating treatment, and electrolytic plating treatment similar to the above are performed. Note that processing for a shallow via hole171in the copper land of the laser driver200, processing for a deep via hole172in one lower level, the desmear treatment, and the roughening treatment are simultaneously performed.

Here, the shallow via hole171is a filled via filled with copper plating. The size and depth of each via are about 20 to 30 micrometers. Furthermore, the size of the land is about 60 to 80 micrometers in diameter.

Meanwhile, the deep via hole172is a so-called conformal via having copper plating applied only to an outside of the via. The size and depth of each via are about 80 to 150 micrometers. Furthermore, the size of the land is about 150 to 200 micrometers in diameter. Note that the deep via hole172is desirably arranged at a distance of about 100 micrometers from an outer shape of the laser driver200via an insulating resin.

Next, as illustrated in m inFIG.11, an interlayer insulating resin similar to the above is thermally bonded by roll laminating or laminating press. At this time, the inside of the conformal via is filled with the interlayer insulating resin. Next, via hole treatment, desmear treatment, roughening treatment, electroless plating treatment, and electrolytic plating treatment similar to the above are performed.

Next, as illustrated in n inFIG.11, the support plate110is separated by being peeled from an interface between the carrier copper foil131of the peelable copper foil130and the ultra-thin copper foil132.

Next, as illustrated in o inFIG.12, the ultra-thin copper foil132and the plating base conductive layer are removed using sulfuric acid-hydrogen peroxide-based soft etching, whereby a substrate having components built-in with an exposed wiring pattern can be obtained.

Next, as illustrated in p inFIG.12, a solder resist180having a pattern having an opening in a land portion of the wiring pattern is printed on the exposed wiring pattern. Note that the solder resist180can be formed by a roll coater using a film type. Next, electroless Ni plating is formed on the land portion of the opening of the solder resist180in the thickness of 3 micrometers or more, and electroless Au plating is formed on the electroless Ni plating in the thickness of 0.03 micrometers or more. The electroless Au plating may be formed in the thickness of 1 micrometer or more. Moreover, the electroless Au plating may be precoated with a solder. Alternatively, electrolytic Ni plating may be formed in the opening of the solder resist180in the thickness of 3 micrometers or more, and electrolytic Au plating may be formed on the electrolytic Ni plating in the thickness of 0.5 micrometers or more. Moreover, an organic rustproof film may be formed in the opening of the solder resist180, other than metal plating.

Alternatively, a cream solder may be applied and printed to mount a solder ball grid array (BGA) as a connection terminal on the land for external connection. Furthermore, as the connection terminal, a copper core ball, a copper pillar bump, a land grid array (LGA), or the like may be used.

The semiconductor laser300, the photodiode400, and the passive component500are mounted and the side wall600and the diffusion plate700are attached to the surface of the substrate100manufactured as described above, as illustrated in q inFIG.12. In general, after the manufacturing is performed as a collective substrate, an outer shape is processed by a dicer or the like to be separated into individual pieces.

Note that, in the above-described steps, an example of using the peelable copper foil130and the support plate110has been described. A copper clad laminate (CCL) can be used instead of the peelable copper foil130and the support plate110. Furthermore, as the manufacturing method incorporating the components into the substrate, a method of forming a cavity in the substrate and mounting the components may be used.

As described above, according to the embodiment of the present technology, the electrical connection between the semiconductor laser300and the laser driver200is performed via the connection via101, whereby the wiring inductance can be reduced. Specifically, the wiring length between the electrical connection between the semiconductor laser300and the laser driver200is set to 0.5 millimeters or less, whereby the wiring inductance can be set to 0.5 nanohenries or less. Furthermore, the overlap amount between the semiconductor laser300and the laser driver200is set to 50% or less, whereby a certain number of thermal vias102can be arranged immediately below the semiconductor laser300, and favorable heat dissipation characteristics can be obtained.

2. Application

Electronic Device

FIG.13is a diagram illustrating a system configuration example of an electronic device800as an application of the embodiment of the present technology.

The electronic device800is a mobile terminal equipped with the semiconductor laser drive device10according to the above-described embodiment. The electronic device800includes an imaging unit810, a semiconductor laser drive device820, a shutter button830, a power button840, a control unit850, a storage unit860, a wireless communication unit870, a display unit880, and a battery890.

The imaging unit810is an image sensor that captures an image of an object. The semiconductor laser drive device820is the semiconductor laser drive device10according to the above-described embodiment.

The shutter button830is a button for giving an instruction on imaging timing of the imaging unit810from an outside of the electronic device800. The power button840is a button for giving an instruction on on/off of power of the electronic device800from the outside of the electronic device800.

The control unit850is a processing unit that controls the entire electronic device800. The storage unit860is a memory that stores data and programs necessary for operation of the electronic device800. The wireless communication unit870performs wireless communication with the outside of the electronic device800. The display unit880is a display that displays images and the like. The battery890is a power supply source that supplies power to each unit of the electronic device800.

A specific phase (for example, rising timing) of a light emission control signal for controlling the imaging unit810and the semiconductor laser drive device820is set to 0 degrees, and a light receiving amount from 0 degrees to 180 degrees is detected as Q1, and the light receiving amount from 180 degrees to 360 degrees is detected as Q2. Furthermore, the imaging unit810detects the light receiving amount from 90 degrees to 270 degrees as Q3, and detects the light receiving amount from 270 degrees to 90 degrees as Q4. The control unit850calculates a distance d to the object from these light receiving amounts Q1 to Q4 by the following expression, and displays the distance d on the display unit880.
d=(c/4πf)×arctan{(Q3−Q4)/(Q1−Q2)}

In the above expression, the unit of the distance d is, for example, meter (m). c represents a light speed, and the unit of the light speed is, for example, meter per second (m/s). arctan is an inverse function of a tangent function. The value of “(Q3−Q4)/(Q1−Q2)” indicates a phase difference between irradiation light and reflected light. π represents pi. Furthermore, f represents a frequency of the irradiation light, and its unit is, for example, megahertz (MHz).

FIG.14is a view illustrating an external configuration example of the electronic device800as an application of the embodiment of the present technology.

The electronic device800is housed in a housing801and includes the power button840on a side surface and the display unit880and the shutter button830on a surface. Furthermore, optical regions of the imaging unit810and the semiconductor laser drive device820are provided on a back surface.

As a result, the display unit880can display not only a normal captured image881but also a depth image882according to a distance measurement result using ToF.

Note that, in this application example, a mobile terminal such as a smartphone has been illustrated as the electronic device800, but the electronic device800is not limited to the example and may be a digital camera, a game machine, a wearable device, or the like, for example.

Note that the above-described embodiments describe an example for embodying the present technology, and the matters in the embodiments and the matters used to specify the invention in the claims have correspondence, respectively. Similarly, the matters used to specify the invention in the claims and the matters in the embodiment of the present technology given the same names have correspondence, respectively. However, the present technology is not limited to the embodiments, and can be embodied by application of various modifications to the embodiments without departing from the gist of the present technology.

Note that the effects described in the present specification are merely examples and are not limited, and other effects may be exhibited.

Note that the present technology can also have the following configurations.

(1) A semiconductor laser drive device including:a substrate having a laser driver built-in;a semiconductor laser mounted on one surface of the substrate; andconnection wiring configured to electrically connect the laser driver and the semiconductor laser by a wiring inductance of 0.5 nanohenries or less.

(2) The semiconductor laser drive device according to (1), in whichthe connection wiring has a length of 0.5 millimeters or less.

(3) The semiconductor laser drive device according to (1) or (2), in whichthe connection wiring is provided via a connection via provided in the substrate.

(4) The semiconductor laser drive device according to any one of (1) to (3), in whicha part of the semiconductor laser is arranged over the laser driver.

(5) The semiconductor laser drive device according to (4), in whicha part of the semiconductor laser, the part having an area of 50% or less of the semiconductor laser, is arranged over the laser driver.

(6) The semiconductor laser drive device according to any one of (1) to (5), in whichthe substrate includes a thermal via at a position where the semiconductor laser is mounted.

(7) The semiconductor laser drive device according to any one of (1) to (6), further including:an outer wall surrounding a region including the semiconductor laser in the one surface of the substrate; anda diffusion plate covering an upper region of the region surrounded by the outer wall.

(8) The semiconductor laser drive device according to any one of (1) to (7), further including:a photodiode mounted on the one surface of the substrate and configured to monitor light intensity of laser light emitted from the semiconductor laser.

(9) The semiconductor laser drive device according to any one of (1) to (8), further including:a connection terminal to be connected with an outside on an opposite surface of the one surface of the substrate.

(10) The semiconductor laser drive device according (9), in whichthe connection terminal is formed by at least one of a solder ball, a copper core ball, a copper pillar bump, or a land grid array.

(11) An electronic device including:a substrate having a laser driver built-in;a semiconductor laser mounted on one surface of the substrate; andconnection wiring configured to electrically connect the laser driver and the semiconductor laser by a wiring inductance of 0.5 nanohenries or less.

(12) A method of manufacturing a semiconductor laser drive device, the method including:a procedure of forming a laser driver on an upper surface of a support plate;a procedure of forming connection wiring of the laser driver to form a substrate having the laser driver built-in; anda procedure of mounting a semiconductor laser on one surface of the substrate and forming connection wiring that electrically connects the laser driver and the semiconductor laser by a wiring inductance of 0.5 nanohenries or less via the connection wiring.

REFERENCE SIGNS LIST

10,820Semiconductor laser drive device100Substrate101Connection via102Thermal via110Support plate120Adhesive resin layer130Peelable copper foil131Carrier copper foil132Ultra-thin copper foil140,180Solder resist150Wiring pattern161to163Interlayer insulating resin170to172Via hole200Laser driver210I/O pad220Protective insulating layer230Surface protective film240Adhesion layer/seed layer250Photoresist260Copper land and copper wiring layer (RDL)290Die attach film (DAF)300Semiconductor laser400Photodiode500Passive component600Side wall700Diffusion plate800Electronic device801Housing810Imaging unit830Shutter button840Power button850Control unit860Storage unit870Wireless communication unit880Display unit890Battery