JP6608666B2 - Hall element, Hall sensor, lens module - Google Patents

Description

  The present invention relates to a hall element, a hall sensor, and a lens module.

Conventionally, magnetic sensors have been applied to many magnetic sensor products such as current detection devices and position detection devices. As a typical example of a magnetic sensor, there is a Hall element using the Hall effect.
The Hall element generally has a magnetic sensing part, a current electrode pair for passing a current through the magnetic sensing part, and an output electrode pair for detecting Hall electromotive force, and is detected from the output electrode pair. The magnitude and direction of the magnetism applied to the magnetic sensing part are detected from the Hall electromotive force.
Patent Document 1 discloses a Hall element including a semi-insulating GaAs substrate, an N-type operation layer, an N + contact layer, an ohmic junction metal film, a bonding metal film, and an insulating film. .

Patent Document 2 discloses a Hall element in which the four inner corner portions of a cross-shaped Hall element are formed by chamfering diagonally rather than at right angles.
Patent Document 3 discloses a pellet, a plurality of lead terminals arranged around the pellet, a plurality of electrode portions of the pellet, and a plurality of fine metal wires that electrically connect the lead terminals, respectively, and the back surface of the pellet Hall sensor in which at least a part of the insulating paste and at least a part of the back surface of each lead terminal are respectively exposed from the mold resin. Is disclosed.

  In Patent Document 4, in a Hall sensor using a Hall chip in which a cross-shaped magnetic sensing portion is formed on a substrate and an electrode is formed on each of the cross-shaped arms, the opposing portions between adjacent electrodes are parallel to each other. In addition, a Hall sensor is disclosed in which the parallel lengths of these facing portions are set to a dimension equal to or larger than the value obtained by subtracting the distance between the facing portions from 40 μm.

JP 60-175471 A JP-A-1-298354 International Publication No. 2014/091714 Pamphlet JP 2000-294853 A

In the prior art, noise reduction of the Hall element is not sufficient.
An object of the present invention is to provide a Hall element, a Hall sensor, and a lens module with low noise.

In order to solve the above-described problem, a Hall element according to an aspect of the present invention includes a substrate and a magnetic sensing portion formed on one surface side of the substrate, and the area of the substrate in plan view The ratio of the area of the effective region of the magnetosensitive portion is 20% or more and 100% or less.
A Hall element according to another aspect of the present invention includes a substrate and a magnetic sensing portion formed on one surface side of the substrate, and in a plan view, out of the outer periphery of the substrate and the magnetic sensing portion. The maximum distance between the outer periphery of the substrate and the adjacent part is greater than 0 μm and equal to or less than 100 μm.

  A Hall sensor according to an aspect of the present invention includes the Hall element, the first terminal portion, the second terminal portion, the third terminal portion, the fourth terminal portion, and the first electrode. And a first metal wire connecting the first terminal part, a second metal wire connecting the second electrode and the second terminal part, the third electrode and the third A third thin metal wire connecting the terminal portion of the first metal wire, a fourth thin metal wire connecting the fourth electrode and the fourth terminal portion, at least a part of the Hall element, the first to first wires. And a molding member for sealing the first to fourth fine metal wires.

  A lens module according to an aspect of the present invention includes the above-described Hall sensor, a lens holder to which a magnet is attached, and output signals from the first to fourth terminal portions of the Hall sensor. A drive coil to be moved.

  According to the present invention, the noise of the Hall element can be reduced.

It is a top view which shows the structural example of the Hall element 100 which concerns on 1st Embodiment of this invention. FIG. 2 is a cross-sectional view of the Hall element 100 shown in FIG. 1 cut along an A1-A′1 line and a B1-B′1 line. It is a figure which shows the structural example of the Hall sensor 600 which concerns on 1st Embodiment of this invention. FIG. 6 is a cross-sectional view illustrating a method for manufacturing the Hall element 100 in the order of steps. It is the top view and sectional view shown in order of a process which shows the manufacturing method of Hall sensor 600. It is the top view and sectional view shown in order of a process which shows the manufacturing method of Hall sensor 600. It is a top view which shows the structural example of the Hall element 200 which concerns on 2nd Embodiment of this invention. It is a top view which shows the structural example of the Hall element 300 which concerns on 3rd Embodiment of this invention. FIG. 9 is a cross-sectional view of the Hall element 300 shown in FIG. 8 cut along a line F8-F′8 and a line G8-G′8. It is a top view which shows the structural example of the Hall element 400 which concerns on 4th Embodiment of this invention. It is a top view which shows the structural example of the Hall element 500 which concerns on 5th Embodiment of this invention. It is a top view which shows the structural example of the Hall element 900 which concerns on a comparison form.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the same reference numerals are given to portions corresponding to each other in the drawings to be described below, and description of the overlapping portions will be omitted as appropriate. Further, the embodiment of the present invention exemplifies a configuration for embodying the technical idea of the present invention, and specifies the material, shape, structure, arrangement, dimensions, etc. of each part as follows. Not. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

<First Embodiment>
〔Constitution〕
(1) Hall element FIG. 1: is a top view which shows the structural example of the Hall element 100 which concerns on 1st Embodiment of this invention. 2A and 2B are cross-sectional views of the Hall element 100 shown in FIG. 1 cut along the lines A1-A′1 and B1-B′1.
As shown in FIGS. 1 to 2B, the Hall element 100 includes a substrate 10, a magnetosensitive portion 20 formed on one surface (for example, an upper surface) 10 a side of the substrate 10, and one of the substrates 10. 1st-4th electrodes 31-34 formed in the field side and electrically connected to magnetic sensing part 20 are provided. The first electrode 31 and the second electrode 32 are input electrodes of the Hall element 100, and the third electrode 33 and the fourth electrode 34 are output electrodes of the Hall element 100.

(1.1) Substrate The substrate 10 is a compound semiconductor substrate, for example, and there is a GaAs substrate as an example. The resistivity of the GaAs substrate is 1.0 × 10 ⁷ Ω · cm or more. The upper limit of the resistivity of the GaAs substrate 10 is not particularly limited, but for example, it is 1.0 × 10 ⁹ Ω · cm or less. Moreover, the shape (henceforth planar shape) of the board | substrate 10 by planar view is a rectangular shape. Examples of the rectangular shape include a quadrangular shape, a rectangular shape, a rounded square shape, and a rounded rectangular shape. The plan view is a top view.
In the present embodiment, the area of the substrate is calculated as a substantially rectangular shape in plan view. For example, the side surface of the substrate has a cross section cut by dicing, and the substrate has an area approximating a substantially rectangular shape when viewed from above.

(1.2) Magnetic Sensitive Section The magnetic sensitive section 20 is formed on the upper surface 10a of the substrate 10, and its shape in cross-sectional view (hereinafter, cross-sectional shape) is a mesa shape. Alternatively, the magnetic sensitive part 20 may be formed inside the substrate 10. In the first embodiment of the present invention, the planar shape of the magnetic sensitive unit 20 is rectangular. In each embodiment of the present invention, the formation position of the magnetic sensitive part 20 is not limited to the upper surface 10 a of the substrate 10. A part or all of the magnetic sensitive part (active layer) 20 may be formed inside the upper surface 10 a of the substrate 10. The magnetic sensitive part 20 is preferably formed of GaAs from the viewpoint of temperature characteristics. However, the present embodiment is not limited to the configuration in which the magnetically sensitive portion 20 is formed using GaAs as a material, and for example, a compound semiconductor such as InSb or InAs can also be used.

The magnetic sensitive part 20 is a layer having a lower resistance than the substrate 10. For example, the magnetic sensitive unit 20 may be formed by implanting impurities such as Si, Sn, S, Se, Te, Ge, or C into the substrate 10 and performing activation by heating, or a compound semiconductor containing the above impurities by MOCVD (Metal It is formed by growing it on the substrate 10 by an epitaxial growth method by an organic chemical vapor deposition (metal organic vapor phase epitaxy) method, an MBE (molecular beam epitaxy) method, or the like.
For example, the magnetic sensitive part 20 has a conductive layer 21 and a surface layer 22 formed on the conductive layer 21. The conductive layer 21 is made of n-type GaAs formed on the substrate 10. The film thickness of the conductive layer 21 is not particularly limited, but is preferably 50 nm or more and 2000 nm or less, and more preferably 100 nm or more and 1000 nm or less from the viewpoint of manufacturability.

As the n-type impurity (that is, donor-type impurity) of n-type GaAs, a known one can be used, and for example, Si, Ge, Se, or the like can be used. The concentration of n-type impurities (effective carrier concentration) is not particularly limited, but the effective carrier concentration is 1.0 × 10 ¹⁵ [cm ⁻³ ] or more and 1.0 × 10 ¹⁷ from the viewpoint of the output and temperature characteristics of the Hall element. [Cm ⁻³ ] or less is preferable, and 1.0 × 10 ¹⁵ [cm ⁻³ ] or more and 1.0 × 10 ¹⁶ [cm ⁻³ ] or less is more preferable, and 1.0 × 10 ¹⁵ [cm ³ ] or less. More preferably, it is not less than cm ⁻³ ] and not more than 5.0 × 10 ¹⁵ [cm ⁻³ ]. If the effective carrier concentration is within the above range, it is preferable because the temperature dependency of the output is suppressed and the absolute value of the output can be easily obtained.

As a method for forming the conductive layer 21, there is a method in which an impurity is ion-implanted into the substrate 10 to form an n-type GaAs layer near or inside the surface of the substrate 10. As another method for forming the conductive layer 21, there is a method of epitaxially growing a GaAs thin film on the substrate 10 by MBE (molecular beam epitaxy) method or MOCVD (metal organic vapor phase epitaxy) method while doping impurity ions. Can be mentioned.
The surface layer 22 is a layer formed on the conductive layer 21 and made of a high-resistance crystal such as a GaAs layer having lower conductivity than the conductive layer 21 or AlGaAs or AlAs. The film thickness of the surface layer 22 is 150 nm or more, preferably 200 nm or more, and preferably 800 nm or less from the viewpoint of manufacturability in order to realize a Hall element in which variation in sheet resistance is suppressed. And more preferably 600 nm. Note that the surface layer may be omitted.

The method for forming the surface layer 22 is not particularly limited, and can be formed, for example, by ion implantation, or epitaxial growth using MBE or MOCVD. As a method for obtaining GaAs having a conductivity lower than that of the conductive layer 21 like the surface layer 22, a method of setting an impurity concentration lower than that of the conductive layer 21, a method of not intentionally doping impurities, and the like can be mentioned. Moreover, in order to directly ohmic-connect the conductive layer 21 and the 1st-4th electrodes 31-34, a part of surface layer 22 may be etched and thinned or removed.
In plan view, the center position of the rectangular magnetic sensing part 20 substantially coincides with the center position of the rectangular substrate 10. Further, in plan view, the first to fourth sides 26 to 29 on the outer periphery of the magnetic sensing unit 20 are respectively parallel to two of the first to fourth sides 11 to 14 on the outer periphery of the substrate 10. ing. That is, in plan view, the first to fourth sides 26 to 29 on the outer periphery of the magnetic sensing unit 20 are parallel or perpendicular to the first to fourth sides 11 to 14 on the outer periphery of the substrate 10.

(1.3) Electrode The first electrode 31 and the second electrode 32 face each other in the first direction. In addition, the third electrode 33 and the fourth electrode 34 face each other in a second direction that intersects (for example, is orthogonal to) the first direction in plan view.
When the separation distance between the first electrode 31 and the second electrode 32 in the first direction is D1, and the separation distance between the third electrode 33 and the fourth electrode 34 in the second direction is D2, D1 and D2 are 1 μm or more and 40 μm or less, respectively.

The shape and arrangement of the first to fourth electrodes 31 to 34 will be described with more specific examples.
The planar shapes of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are each rectangular.
As shown in FIG. 1, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are respectively disposed at four rectangular corners of the substrate 10. The outer sides of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are parallel to two of the four sides of the outer periphery of the substrate 10. It has become. That is, each side of the outer periphery of the first to fourth electrodes 34 is parallel or perpendicular to the first to fourth sides 11 to 14 of the outer periphery of the substrate 10 in plan view.

As shown in FIG. 2, the first to fourth electrodes 31 to 34 are respectively formed on the first metal film 131 that is electrically connected to the magnetic sensing unit 20 and on the first metal film 131. Second metal film 132 formed. That is, the first metal film 131 serves as a contact region for the magnetic sensitive part 20. Note that the first metal film 131 may not be provided, and the first to fourth electrodes 31 to 34 may be connected directly to the magnetic sensing portion from the opening (contact hole) of the insulating film 40.
An insulating film 40 is formed between the magnetic sensitive part 20 and the second metal film 132. The insulating film 40 is, for example, a silicon nitride film (Si ₃ N ₄ film), a silicon oxide film (SiO ₂ film), an inorganic film (Al ₂ O ₃ ), or a polyimide film, and is a multilayer film in which a plurality of these films are stacked. is there.

Note that the insulating film 40 may be formed on the first metal film 131 as shown in FIG. 2 or may not be formed on the first metal film 131. It may be formed in a part.
In the case where the insulating film 40 has a structure formed on the first metal film 131 (for example, in the case of the structure shown in FIG. 2), a contact hole 151 (see FIG. 1) is formed in the insulating film 40. The first metal film 131 and the second metal film 132 are electrically connected through the contact hole 151.

In the case where the insulating film 40 is partly inserted under the first metal film 131, a region of the first metal film 131 excluding the insulating film 40 is a contact region in plan view. That is, in the magnetic sensitive part, the area of the opening of the insulating film 40 becomes a contact area. The contact region is a region that is electrically connected to the electrode in the magnetic sensing portion. For example, the region occupied by the first metal film or the region of the opening of the insulating film 40 is in contact with the magnetic sensing portion. It becomes an area.
In the Hall element of this embodiment, it is preferable that the minimum distance between adjacent electrodes of the plurality of electrodes is 4 μm or more and 11 μm or less in plan view. This minimum distance is more preferably 4 μm or more and less than 10 μm, and further preferably 5 μm or more and 9 μm or less.
The minimum distance between adjacent electrodes is the minimum distance between all the electrodes.

(1.4) Wire Bonding Region As shown in FIG. 1, the first electrode 31 has a first wire bonding region 141 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the first electrode 31 serves as a contact region where the first electrode 31 is in contact with the magnetic sensing unit 20.
The second electrode 32 has a second wire bonding region 142 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the second electrode 32 serves as a contact region where the second electrode 32 is in contact with the magnetic sensing unit 20.
The third electrode 33 has a third wire bonding region 143 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the third electrode 33 becomes a contact region where the third electrode 33 is in contact with the magnetic sensitive part 20.

The fourth electrode 34 has a fourth wire bonding region 144 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the fourth electrode 34 becomes a contact region where the fourth electrode 34 is in contact with the magnetic sensing unit 20.
That is, the contact regions of the first to fourth electrodes 31 to 34 are located outside the center positions of the first to fourth wire bonding regions 141 to 144 as viewed from the center position of the magnetic sensing unit 20. To position.
As described above, since the first electrode 31 and the second electrode 32 are input electrodes of the Hall element 100, the Hall element is between the contact region of the first electrode 31 and the contact region of the second electrode 32. A signal input path 146 at 100 is formed. In addition, since the third electrode 33 and the fourth electrode 34 are output electrodes of the Hall element 100, a signal between the contact region of the third electrode 33 and the contact region of the fourth electrode 34 is a signal in the Hall element 100. The output path 145 becomes.

(2) Hall Sensor FIGS. 3A to 3D are a cross-sectional view, a plan view, a bottom view, and an external view showing a configuration example of the Hall sensor 600 according to the first embodiment of the present invention. FIG. 3A shows a cross section obtained by cutting FIG. 3B along a broken line E3-E′3. Further, in FIG. 3B, the mold member is omitted in order to avoid complication of the drawing.
As shown in FIGS. 3A to 3D, the Hall sensor 600 includes a Hall element 100, a lead terminal 520, first to fourth thin metal wires (conductive connection members) 531 to 534, and a protective layer. 540, a mold member 550, and an exterior plating layer 560. Further, the lead terminal 520 has first to fourth terminal portions 521 to 524.
The hall sensor 600 has, for example, an islandless structure and includes a plurality of terminal portions 521 to 524 for obtaining an electrical connection with the outside. As shown in FIG. 3B, the first to fourth terminal portions 521 to 524 are arranged around the Hall element 100.

For example, the first terminal portion 521 and the second terminal portion 522 are disposed so as to face each other with the Hall element 100 interposed therebetween, and the third terminal portion 523 and the fourth terminal portion 524 are formed as holes. They are arranged so as to face each other with the element 100 interposed therebetween. A straight line (virtual line) connecting the first terminal portion 521 and the second terminal portion 522 and a straight line (imaginary line) connecting the third terminal portion 523 and the fourth terminal portion 524 are viewed in plan view. Cross at. The lead terminal 520 (first to fourth terminal portions 521 to 524) is made of a metal such as copper (Cu), for example.
The first to fourth fine metal wires 531 to 534 are conductive wires that electrically connect the first to fourth electrodes 31 to 34 included in the Hall element 100 and the first to fourth terminal portions 521 to 524, respectively. For example, it is made of gold (Au). As shown in FIG. 3B, the first thin metal wire 531 connects the first terminal portion 521 and the first electrode 31. The second thin metal wire 532 connects the second terminal portion 522 and the second electrode 32. The third fine metal wire 533 connects the third terminal portion 523 and the third electrode 33. The fourth thin metal wire 534 connects the fourth terminal portion 524 and the fourth electrode 34.

The protective layer 540 covers the surface of the substrate 10 opposite to the surface on which the first to fourth electrodes 31 to 34 are provided. The protective layer 540 is not particularly limited as long as it can protect the substrate 10, and may include at least one of a conductor, an insulator, and a semiconductor. That is, the protective layer 540 may be a film made of any one of a conductor, an insulator, and a semiconductor, or may be a film including two or more of these. As the conductor, for example, a conductive resin such as silver paste can be considered. As the insulator, for example, an insulating paste containing epoxy thermosetting resin and silica (SiO ₂ ) as a filler, silicon nitride, silicon dioxide, and the like are conceivable. As the semiconductor, for example, bonding of a Si substrate or a Ge substrate can be considered. However, from the viewpoint of preventing leakage current, the protective layer 540 is preferably an insulator. The protective layer 540 may have a stacked structure.
The mold member 550 molds the Hall element 100, the first to fourth terminal portions 521 to 524, and the first to fourth metal thin wires 531 to 534. In other words, the mold member 550 includes the Hall element 100, at least the surface side of the first to fourth terminal portions 521 to 524 (that is, the surface connected to the metal thin wire), and the first to fourth metals. The thin wires 531 to 534 are covered and protected (that is, resin-sealed). The mold member 550 is made of, for example, an epoxy thermosetting resin and can withstand high heat during reflow.

As shown in FIGS. 3A and 3C, the first of the first to fourth terminal portions 521 to 524 is provided on the bottom surface side of the Hall sensor 600 (that is, the side mounted on the wiring board magnetic sensing portion 20). At least a part of the surface (for example, the back surface) and at least a part of the first surface (for example, the back surface) of the GaAs substrate 10 are respectively exposed from the same surface (for example, the back surface) of the mold member 550. Here, the 1st surface of the 1st-4th terminal parts 521-524 is the 1st-4th metal thin wire 531-among the several surfaces which the 1st-4th terminal parts 521-524 have, respectively. This is the surface opposite to the surface connected to 534. The first surface of the GaAs substrate 10 is a surface opposite to the surface on which the first to fourth electrodes 31 to 34 are provided among the plurality of surfaces of the GaAs substrate 10.
The exterior plating layer 560 is formed on the back surface of the terminal portions 521 to 524 exposed from the mold member 550. The exterior plating layer 560 is made of, for example, tin (Sn).

[Operation]
In the case of detecting magnetism (magnetic field) using the Hall sensor 600 described above, for example, the first terminal portion 521 is connected to the power supply potential (+) and the second terminal portion 522 is set to the ground potential (GND). By connecting, current flows from the first terminal portion 521 to the second terminal portion 522. Then, a potential difference V1−V2 (= Hall output voltage VH) between the third terminal portion 523 and the fourth terminal portion 524 is measured. The magnitude of the magnetic field is detected from the magnitude of the Hall output voltage VH, and the direction of the magnetic field is detected from the positive / negative of the Hall output voltage VH.
That is, the first terminal portion 521 is a power supply terminal portion that supplies a predetermined voltage to the Hall element 100. The second terminal portion 522 is a grounding terminal portion that supplies a ground potential to the Hall element 100. The third terminal portion 523 and the fourth terminal portion 524 are signal extraction terminal portions that extract the Hall electromotive force signal of the Hall element 100.

〔Production method〕
(1) Method for Manufacturing Hall Element FIGS. 4A to 4E are cross-sectional views showing a method for manufacturing the Hall element 100 in the order of steps. As shown in FIG. 4A, first, a substrate 10 is prepared. The substrate 10 is, for example, a GaAs substrate 10. Next, donor-type impurities are ion-implanted into a position at a preset depth from the surface of the substrate 10. Examples of the donor-type impurity include Si, Sn, S, Se, Te, Ge, and C. Next, the substrate 10 is heated to activate the impurities. Thereby, as shown in FIG. 4B, a conductive layer 21 having a lower resistance than that of the substrate 10 is formed in the substrate 10, and a surface layer 22 is formed on the conductive layer 21. Since the surface layer 22 has a lower impurity concentration than the conductive layer 21, it becomes a layer having a higher resistance than the conductive layer 21 (that is, a layer having low conductivity).

  In addition, you may perform the process of activating this impurity after the patterning process of the board | substrate 10 shown in FIG.4 (c). Moreover, you may perform by combining with the other heating process after the process shown in FIG.4 (c). The formation of the conductive layer 21 is not limited to ion implantation. For example, the conductive layer 21 may be formed by epitaxially growing GaAs containing impurities at a high concentration on the substrate 10 by MOCVD. In this case, following the formation of the conductive layer 21, GaAs containing impurities at a low concentration (or not containing impurities) is epitaxially grown to form a surface layer having a higher resistance than the conductive layer 21 on the conductive layer 21. 22 can be formed.

Next, the substrate 10 is patterned by using a photolithography technique and an etching technique to form a magnetic sensitive part 20 having a mesa shape as viewed in cross section, as shown in FIG.
Next, as shown in FIG. 4D, a first metal film 131 is partially formed on the substrate 10 on which the magnetic sensitive portion 20 is formed. Here, for example, an AuGe film, a Ni film, and an Au film are stacked in this order as the first metal film 131. The first metal film 131 is formed by, for example, lift-off or mask vapor deposition. Lift-off is a method in which a metal film is deposited on a substrate on which a resist pattern is formed, and then the resist pattern is removed, so that the metal film is left only on a region not covered with the resist pattern on the substrate. Mask vapor deposition is a method of depositing a metal film only on a region immediately below the through hole of the substrate by depositing a metal film on the substrate through a plate in which the through hole is partially formed. After the first metal film 131 is formed, the substrate 10 is heated to alloy the interface between the substrate 10 and the first metal film 131.

  Next, as illustrated in FIG. 4E, the insulating film 40 is formed on the portion of the substrate 10 that is exposed from below the first metal film 131. The insulating film 40 is, for example, a silicon nitride film. The insulating film 40 is formed by forming an insulating film on the entire upper surface of the substrate 10 by, for example, a CVD (Chemical Vapor Deposition) method, and then using the photolithography technique and the etching technique to form the insulating film formed on the entire upper surface. It is formed by patterning. Note that the first metal film 131 may be formed after an insulating film is formed over the entire top surface of the substrate 10 and patterned to form the insulating film 40.

Next, as shown in FIG. 4E, a second metal film 132 is partially formed on the substrate 10 on which the insulating film 40 is formed. Here, for example, a Ti film and an Au film are stacked in this order as the second metal film 132. Further, the second metal film 132 is formed by, for example, lift-off or mask vapor deposition.
Thereafter, a protective film (not shown) or the like is formed on the substrate 10. Then, the substrate 10 is diced, and the substrate 10 is separated into pieces for each of the plurality of Hall elements 100. Through the above steps, the Hall element 100 shown in FIG. 1 and the like is completed.

(2) Manufacturing Method of Hall Sensor FIGS. 5A to 5E and FIGS. 6A to 6D are a plan view and a cross-sectional view illustrating the manufacturing method of the Hall sensor 600 in the order of steps. In FIGS. 5A to 5E, the dicing blade width (ie, the kerf width) is not shown.
As shown in FIG. 5A, first, a lead frame 620 is prepared. The lead frame 620 is a substrate in which a plurality of lead terminals 520 shown in FIG. 3B are connected in the vertical direction and the horizontal direction in plan view.

  Next, as shown in FIG. 5B, for example, one surface of the heat-resistant film 580 is pasted on the back side of the lead frame 620 as a base material. For example, an insulating adhesive layer is applied to one surface of the heat resistant film 580. The adhesive layer is based on, for example, a silicone resin as a component. This adhesive layer makes it easy to attach the lead frame 620 to the heat resistant film 580. By sticking the heat resistant film 580 to the back surface side of the lead frame 620, the penetration region through which the lead frame 620 penetrates is closed with the heat resistant film 580 from the back surface side.

Next, as shown in FIG.5 (c), the hole which has the protective layer 540 in the area | region enclosed by the 1st-4th terminal parts 521-524 among the surfaces which have the adhesion layer of the heat resistant film 580. The element 100 is placed (that is, die bonding is performed). Here, die bonding is performed with the first surface of the substrate 10 opposed to the surface having the adhesive layer of the heat resistant film 580.
Next, as shown in FIG.5 (d), the end of the 1st-4th metal fine wires 531-534 is connected to the 1st-4th terminal parts 521-524, respectively, and the 1st-4th metal The other ends of the thin wires 531 to 534 are respectively connected to the first to fourth electrodes 31 to 34 of the Hall element 100 (that is, wire bonding is performed).

The wire bonding may be forward bonding performed by extending a thin metal wire from each electrode of the Hall element 100 toward each terminal portion of the lead terminal 520, and conversely, from each terminal portion of the lead terminal 520 to the Hall element 100. Reverse bonding may be performed by extending a thin metal wire to each electrode. Reverse bonding can reduce the height of the loop after the thin metal wire is bonded as compared with the forward bonding, and thus can contribute to a reduction in the height of the Hall element.
Then, as shown in FIG. 5E, a mold member 550 is formed (that is, resin molding is performed). This resin mold is performed using, for example, a transfer mold technique.

  For example, as shown in FIG. 6A, a mold die 590 including a lower die 591 and an upper die 592 is prepared, and a lead frame 620 after wire bonding is disposed in the cavity of the mold die 590. . Next, the mold member 550 heated and melted is injected into the cavity and the side of the heat-resistant film 580 having the adhesive layer (that is, the surface bonded to the lead frame 620) and filled. Thus, the Hall element 100, the lead frame 620, and the fine metal wires 531 to 534 are molded. That is, the Hall element 100, at least the surface side of the lead frame 620, and the fine metal wires 531 to 534 are covered and protected by the mold member 550. When the mold member 550 is further heated and cured, the mold member 550 is removed from the mold.

Next, as illustrated in FIG. 6B, the heat resistant film 580 is peeled from the mold member 550. As a result, the substrate 10 of the Hall element 100 is exposed from the mold member 550. Then, as shown in FIG. 6C, exterior plating is applied to the surface exposed from the mold member 550 of the lead frame 620 (at least the back surface exposed from the mold member 550 of each terminal portion 522-25). Then, the exterior plating layer 560 is formed.
Next, as shown in FIG. 6D, a dicing tape 593 is attached to the upper surface of the mold member 550 (that is, the surface opposite to the surface having the exterior plating layer 560 of the Hall sensor 600). Then, for example, along the virtual two-dot chain line shown in FIG. 5E, the blade is moved relative to the lead frame 620 to cut the mold member 550 and the lead frame 620 (that is, dicing is performed). Do.) That is, the mold member 550 and the lead frame 620 are diced for each of the plurality of Hall elements 100 to be singulated. The Hall sensor 600 shown in FIG. 3 is completed through the above steps.

[Effects of First Embodiment]
The noise component N included in the output signal of the Hall element is proportional to the reciprocal of the root of the area A of the effective region excluding the contact portion of the magnetic sensing unit 20 (N∝1 / √A).
In the first embodiment of the present invention, since the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 is as high as 20% or more, the area on the substrate 10 is effectively used to reduce the noise component. It becomes possible to do. The ratio of the area of the effective region of the magnetic sensitive part 20 is preferably 40% or more and 100% or less, more preferably 50% or more and 100% or less, and further preferably 50% or more and 95% or less.

The area of the effective region of the magnetic sensing unit 20 is the first to fourth of the areas of the magnetic sensing unit 20 where the magnetic sensing unit 20 and the first to fourth electrodes 31 to 34 are connected in plan view. It is an area excluding the total area of the contact region. For example, when the first to fourth electrodes 31 to 34 and the magnetic sensing portion 20 are connected by contact electrodes in cross-sectional view, the total area of the contact electrodes is excluded from the area of the magnetic sensing portion 20 in plan view. This area is the effective area of the magnetic sensitive part 20. Note that a portion of the first metal layer 131 that contacts the magnetic sensitive portion 20 corresponds to a contact electrode.
Further, when the first to fourth electrodes 31 to 34 and the magnetic sensing part 20 are connected by a contact layer formed on the substrate 10, the total of the contact layers in the area of the magnetic sensing part 20 in a plan view. The area excluding the area is the effective area of the magnetic sensitive part.

Moreover, in 1st Embodiment, the ratio of the total area of the 1st-4th contact area | region with respect to the area of the effective area | region of the magnetosensitive part 20 is 0.1% or more and 10% or less by planar view. As a result, the effective area of the magnetic sensing unit 20 can be relatively increased, so that the noise component can be reduced. In addition, since the area of the contact region is smaller than the effective region of the magnetic sensing unit 20, the constant current sensitivity of the Hall element is improved, and the S / N is also improved.
In a thin Hall sensor, the thickness of the mold member on the Hall element is thin, so that electromagnetic waves including light incident on the magnetic sensing part of the Hall element fluctuate the local conductivity of the magnetic sensing part due to the photoelectric effect. I will let you. Also, this variation causes an offset voltage Vu in the Hall element.

In the first embodiment, the ratio of the area of the effective region under the first to fourth electrodes to the area of the effective region in the plan view is 40% or more and 99% or less, and the effective region is the first to fourth. Covered with electrodes.
Here, the metal which is an electrode member absorbs electromagnetic waves including light very well. Therefore, the 1st-4th electrode can shield the electromagnetic wave which injects into the effective area | region of the magnetic sensitive part of a Hall element, and can suppress the local conductivity fluctuation | variation in the effective area | region of a magnetic sensitive part. This has the effect of suppressing fluctuations in the offset voltage Vu. The ratio of the area of the effective region under the first to fourth electrodes to the area of the effective region is preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less.
In the case of the first embodiment shown in FIG. 1, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 in a plan view is 73%. Further, in a plan view, the ratio of the total area of the contact region (the area of the first metal film 131) to the area of the effective region of the magnetic sensing unit 20 is 2%.
Further, the ratio of the area of the effective region under the first to fourth electrodes 31 to 34 to the area of the effective region of the magnetic sensing unit 20 is 87%.

Second Embodiment
FIG. 7 is a plan view showing a configuration example of the Hall element 200 according to the second embodiment of the present invention.
The hall element 200 shown in FIG. 7 differs from the hall element 100 shown in FIG. 1 in the ratio of the area of the execution region of the magnetic sensing unit 20 to the area of the substrate 10 in plan view.
Specifically, in the case of the second embodiment shown in FIG. 7, the ratio of the area of the effective region of the magnetic sensitive part 20 to the area of the substrate 10 in a plan view is 66%. In plan view, the ratio of the total area of the contact region (area of the first metal film 131) to the area of the effective region of the magnetic sensing unit 20 is 3%.

According to the second embodiment of the present invention, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 is as high as 20% or more. For this reason, it is possible to reduce the noise component by effectively using the area on the substrate 10. Moreover, the ratio of the total area of the 1st-4th contact area | region with respect to the area of the effective area | region of the magnetic sensing part 20 is 0.1% or more and 10% or less in planar view. For this reason, it is possible to further reduce the noise component and improve the S / N.
Further, the ratio of the area of the effective region under the first to fourth electrodes 31 to 34 to the area of the effective region of the magnetic sensing unit 20 is 83%.

<Third Embodiment>
In the first and second embodiments described above, the case where the planar shape of the magnetic sensitive unit 20 is rectangular has been described. However, the present invention is not limited to this.
FIG. 8 is a plan view showing a configuration example of the Hall element 300 according to the third embodiment of the present invention. FIGS. 9A and 9B are cross-sectional views of the Hall element 300 shown in FIG. 8 taken along lines F8-F′8 and G8-G′8.
As shown in FIGS. 8 and 9, the magnetic sensing unit 20 includes a main magnetic sensing unit 120 having a rectangular planar shape, and first to fourth extending outward from the four corners of the main magnetic sensing unit 120. You may provide the extension parts 121-124. In plan view, the first extension portion 121 and the second extension portion 122 are located on the extension line of the first diagonal line of the main magnetic sensing portion 120, respectively. Further, the third extending portion 123 and the fourth extending portion 124 are respectively located on the extension line of the second diagonal line of the main magnetic sensing portion 120.

As shown in FIG. 8, the first extending portion 121 is electrically connected to the first electrode 31. The second extension part 122 is electrically connected to the second electrode 32. The third extension part 123 is electrically connected to the third electrode 33. The fourth extension portion 124 is electrically connected to the fourth electrode 34.
In the case of the third embodiment shown in FIG. 8, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 in a plan view is 43%. In plan view, the ratio of the total area of the contact region (area of the first metal film 131) to the area of the effective region of the magnetic sensing unit 20 is 6%.

According to the third embodiment of the present invention, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 is as high as 20% or more. For this reason, it is possible to reduce the noise component by effectively using the area on the substrate 10. Moreover, the ratio of the total area of the 1st-4th contact area | region with respect to the area of the effective area | region of the magnetic sensing part 20 is 0.1% or more and 10% or less in planar view. For this reason, it is possible to further reduce the noise component and improve the S / N.
Further, the ratio of the area of the effective region under the first to fourth electrodes 31 to 34 to the area of the effective region of the magnetic sensing unit 20 is 49%.

<Fourth embodiment>
In the first and second embodiments described above, the case where the planar shape of the magnetic sensitive unit 20 is rectangular has been described. In the third embodiment, the case where the main magnetic sensing part 120 is rectangular has been described. However, the present invention is not limited to this.
FIG. 10 is a plan view showing a configuration example of the Hall element 400 according to the fourth embodiment of the present invention.
As shown in FIG. 10, the planar shape of the magnetic sensitive unit 20 is a cross (that is, a cross) shape, and includes a central part 220, first to fourth peripheral parts 221 to 224 positioned around the central part 220, and Is provided.

In plan view, the first peripheral portion 221 is located on one side in the first direction in the periphery of the central portion 220. The second peripheral portion 222 is located on the other side in the first direction in the periphery of the central portion 220. The third peripheral part 223 is located on one side in the second direction orthogonal to the first direction in the periphery of the central part 220. The fourth peripheral portion 224 is located on the other side in the second direction in the periphery of the central portion 220.
Further, in plan view, a contact hole 151 and a first metal film 131 filling the contact hole 151 are disposed on the first to fourth peripheral portions 221 to 224, respectively. For example, the planar shape of the contact hole 151 and the planar shape of the first metal film 131 are the same, and the size of the first metal film 131 is larger than that of the contact hole. For example, the planar shape of the contact hole 151 is a triangle. The planar shape of the first metal film 131 is a slightly large triangle similar to the contact hole 151.

And the 1st-4th electrodes 31-34 are each arrange | positioned on the 1st metal film 131 on the 1st-4th peripheral parts 221-223. Accordingly, the first peripheral portion 221 is electrically connected to the first electrode 31, the second peripheral portion 222 is electrically connected to the second electrode 32, and the third peripheral portion 223 is the third electrode. The fourth peripheral portion 224 is electrically connected to the fourth electrode 34.
In the case of the fourth embodiment shown in FIG. 10, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 in a plan view is 29%. In plan view, the ratio of the total area of the contact region (the area of the first metal film 131) to the area of the effective region of the magnetic sensing unit 20 is 42%.
According to the fourth embodiment of the present invention, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 is as high as 20% or more. For this reason, it is possible to reduce the noise component by effectively using the area on the substrate 10.
In addition, the ratio of the area of the effective region under the first to fourth electrodes 31 to 34 to the area of the effective region of the magnetic sensing unit 20 is 59%.

<Fifth Embodiment>
FIG. 11 is a plan view showing a configuration example of the Hall element 500 according to the fifth embodiment of the present invention.
As shown in FIG. 11, the planar shape of the magnetic sensing unit 20 is a cross (that is, a cross) shape, and includes a central part 220, first to fourth peripheral parts 221 to 224 positioned around the central part 220, and Is provided. In the case of the fifth embodiment shown in FIG. 11, the first to fourth peripheral portions 221 to 224 have a portion wider than the central portion 220. In the fifth embodiment, in each of the first to fourth peripheral portions 221 to 224, the contact hole 151 and the first metal film 131 are closer to the end in the first direction or the second direction. Is arranged.

Specifically, in the first peripheral portion 221, the contact hole 151 and the first metal film 131 are disposed at one end portion in the first direction. In the second peripheral portion 222, the contact hole 152 and the first metal film 131 are disposed at the other end portion in the first direction. In the third peripheral portion 223, the contact hole 153 and the first metal film 131 are disposed at one end portion in the second direction. In the fourth peripheral portion 224, the contact hole 154 and the first metal film 131 are disposed at the other end portion in the second direction.
The first peripheral portion 221 is electrically connected to the first electrode 31, the second peripheral portion 222 is electrically connected to the second electrode 32, and the third peripheral portion 223 is the third electrode The fourth peripheral portion 224 is electrically connected to the fourth electrode 34 and is electrically connected to the electrode 33.

In the case of the fifth embodiment shown in FIG. 11, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 is 26%. Further, the ratio of the total area of the contact region (area of the first metal film 131) to the area of the effective region of the magnetic sensitive part 20 is 3%.
According to the fifth embodiment of the present invention, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 is as high as 20% or more. For this reason, it is possible to reduce the noise component by effectively using the area on the substrate 10.
Further, the ratio of the area of the effective area under the first to fourth electrodes 31 to 34 to the area of the effective area of the magnetic sensing unit 20 is 70%.

<Sixth Embodiment>
The lens module according to the sixth embodiment of the present invention is based on a Hall electromotive force signal that is an output signal from an external terminal of the Hall sensor, a lens holder to which a magnet is attached, and a Hall sensor. And a drive coil for moving. In the Hall sensor of this embodiment, since the mold member can be thinned, the Hall sensor itself can be thinned, and offset fluctuation can be suppressed, so that magnetism can be accurately detected. Therefore, the lens module can be reduced in size, and accurate position detection can be performed. The magnetic field of the magnet attached to the lens holder is detected by the Hall sensor of the present embodiment, and based on the detected output signal, a driving current is passed through the driving coil to perform autofocus control and camera shake correction control with high accuracy. be able to. In addition, since the Hall sensor of the present embodiment is thin, the Hall element inside the Hall sensor and the magnet can be brought closer to each other, and more accurate magnetic detection is possible.

<Comparison form>
FIG. 12 is a plan view illustrating a configuration example of the Hall element 900 according to the comparative embodiment.
In the case of the comparative form shown in FIG. 12, the ratio of the area of the effective region of the magnetic sensing unit 20 to the area of the substrate 10 is 13%. Further, the ratio of the total area of the contact region (area of the first metal film) to the area of the effective region of the magnetic sensing unit 20 is 14%. In the case of the comparative example, the ratio of the area of the effective region under the first to fourth electrodes 31 to 34 to the area of the effective region of the magnetic sensing unit 20 is approximately 0%.
In each embodiment of the present invention, since the area of the effective region of the magnetic sensitive part 20 is about 2 to 3 times as large as that of the comparative example, the noise component is effectively reduced. Can be reduced.
In addition, the first to third embodiments of the present invention have a high S / N ratio because the ratio of the total area of the contact region to the effective region of the magnetic sensing unit 20 is smaller than that of the comparative example.

<Other aspects>
The technical idea of the present invention is not limited to the embodiments and examples described above. Based on the knowledge of those skilled in the art, each embodiment and each example of the present invention may be modified in design, etc., and each embodiment and each example of the present invention may be arbitrarily combined. A mode in which such changes are added is also included in the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 10 Substrate 10a Upper surface 20 Magnetosensitive part 21 Conductive layer 22 Surface layer 31 1st electrode 32 2nd electrode 33 3rd electrode 34 4th electrode 40 Insulating film 100, 200, 300, 400, 500 Hall element 120 Main Magnetic sensing part 121 First extension part 122 Second extension part 123 Third extension part 124 Fourth extension part 131 First metal film 132 Second metal film 141 First wire bonding region 142 Second wire bonding region 143 Third wire bonding region 144 Fourth wire bonding region 145 Signal output path 146 Signal input path 151 Contact hole 220 Central portion 221 First peripheral portion 222 Second peripheral portion 223 Third Peripheral portion 224 fourth peripheral portion 520 lead terminal 521 first terminal portion 522 second terminal portion 523 third terminal portion 524 4th terminal portion 531 1st metal wire 532 2nd metal wire 533 3rd metal wire 534 4th metal wire 540 Protective layer 550 Mold member 560 Exterior plating layer 580 Heat resistant film 590 Mold die 591 Lower mold Mold 592 Upper mold 593 Dicing tape 600 Hall sensor 620 Lead frame

Claims (4)

A substrate,
A magnetic sensitive part formed on one surface side of the substrate,
In plan view, to an area of the substrate, the ratio of the area of the effective area of the sensing section is state, and are 20% or more and 100% or less,
A first electrode and a second electrode formed on the one surface side and facing each other in a first direction;
A third electrode and a fourth electrode formed on the one surface side and facing each other in a second direction intersecting the first direction in plan view;
The area of the effective area is the total area of the first to fourth contact areas where the magnetic sensitive part and the first to fourth electrodes are connected in the area of the magnetic sensitive part in plan view. Is the excluded area,
In a plan view, the ratio of the total area of the first to fourth contact regions to the area of the effective region is 0.1% or more and 10% or less,
In a cross-sectional view, further comprising an insulating film formed between the first to fourth electrodes and the substrate,
The insulating film is a Hall element having first to fourth openings in each of the first to fourth contact regions . 2. The Hall element according to claim 1, wherein a ratio of an area of the effective region under the first to fourth electrodes to an area of the effective region in a plan view is 40% or more and 99% or less. The hall element according to claim 1 or 2 ,
A first terminal portion;
A second terminal portion;
A third terminal portion;
A fourth terminal portion;
A first thin metal wire connecting the first electrode and the first terminal portion;
A second fine metal wire connecting the second electrode and the second terminal portion;
A third fine metal wire connecting the third electrode and the third terminal portion;
A fourth thin metal wire connecting the fourth electrode and the fourth terminal portion;
A hall sensor comprising: at least a part of the hall element, at least a part of the first to fourth terminal portions, and a mold member for sealing the first to fourth metal thin wires. Hall sensor according to claim 3 ,
A lens holder with a magnet attached thereto;
A lens module comprising: a drive coil that moves the magnet based on output signals from the first to fourth terminal portions of the Hall sensor.

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