JP2015090350A - Magnetic sensor, magnetic sensor device, and method of manufacturing magnetic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic sensor and a magnetic sensor device having an islandless structure and capable of being further downsized and thinned, and also to provide a method of manufacturing the magnetic sensor.SOLUTION: A magnetic sensor includes: a pellet 10 having electrode parts 13a to 13d; lead terminal 21 to 24 which are arranged around the pellet 10 and has a plating layer; thin metallic wires 31 to 34 which electrically connect the electrode parts 13a to 13d and the plating layer; an insulation layer 40 which covers at least a part of the rear surface of the pellet 10; and a mold resin 50 which covers the pellet 10, the lead terminals 21 to 24 and the thin metallic wires 31 to 34. At least a part of the rear surface of the lead terminals 21 to 24 and at least a part of the insulation layer 40 are exposed from the mold resin 50, respectively.

Description

  The present invention relates to a magnetic sensor, a magnetic sensor device, and a method for manufacturing the magnetic sensor.

  As a magnetic sensor using the Hall effect, for example, a Hall element that detects magnetism (magnetic field) and outputs an analog signal proportional to the magnitude, or a Hall IC that detects magnetism and outputs a digital signal is known. Yes. For example, Patent Document 1 discloses a magnetic sensor including a lead frame, a pellet (that is, a magnetic sensor chip), and a thin metal wire. In this magnetic sensor, the lead frame has terminals arranged at the four corners to obtain electrical connection with the outside, and the pellet is mounted on the island of the lead frame. And the electrode which a pellet has and each terminal which a lead frame has are connected with the metal fine wire.

JP 2007-95788 A

  By the way, in recent years, along with the downsizing of electronic devices, etc., the downsizing and thinning of magnetic sensors have also progressed. For example, the size of the magnetic sensor after packaging (that is, the package size) is 1.6 mm in length, 0.8 mm in width, and 0.38 mm in thickness. Further, the package size can be reduced to 0.30 mm by further thinning the pellet. In order to further advance the reduction in size and thickness of the magnetic sensor, a structure in which an island is omitted (that is, an islandless structure) is also conceivable.

  FIG. 12 is a conceptual diagram showing a configuration example of a magnetic sensor 400 according to a comparative embodiment of the present invention. As shown in FIG. 12, the magnetic sensor 400 has an islandless structure, and the pellet 310 is fixed with a mold resin 350. The electrode part of the pellet 310 is connected to lead terminal parts 325 and 327 made of a lead frame arranged around the pellet 310 via gold wires 331 and 332. Since the islandless structure can reduce the thickness by the absence of islands, the magnetic sensor can be made sufficiently small and thin.

However, when it is anticipated that electronic devices will be further miniaturized and that high-density mounting of components and the like in electronic devices will continue to progress in the future, magnetic sensors will be further reduced from the comparison form shown in FIG. Therefore, it is necessary to advance the thinning.
Therefore, the present invention has been made in view of such circumstances, and has an islandless structure, a magnetic sensor, a magnetic sensor device, and a method of manufacturing a magnetic sensor that can be further reduced in size and thickness. For the purpose of provision.

  In order to solve the above-described problem, a magnetic sensor according to one embodiment of the present invention includes a pellet having an electrode portion, a lead terminal having a plating layer disposed around the pellet, the electrode portion, and the plating layer. A conductive wire that electrically connects to each other; an insulating layer that covers at least a part of the surface of the pellet opposite to the surface having the electrode portion; and a resin member that covers the pellet, the lead terminal, and the conductive wire. And at least part of the surface of the lead terminal opposite to the surface connected to the conductor and at least part of the insulating layer are exposed from the resin member, respectively. In the present invention, the “plating layer” means a conductive layer formed by a plating method. Examples of the plating method include an electrolytic plating method, an electroless plating method, and a vapor deposition method. That is, in the present invention, the plating layer may be formed by an electrolytic plating method, an electroless plating method, a vapor deposition method, or a combination of these methods. Also good.

In the above magnetic sensor, the plating layer may contain nickel.
In the magnetic sensor, the plating layer includes a first plating layer containing gold or silver, and a third plating layer containing nickel formed above the first plating layer, At least a part of one plating layer may be exposed from the resin member.

The magnetic sensor may further include a second plating layer containing palladium formed between the first plating layer and the third plating layer.
The magnetic sensor may further include a fourth plating layer containing palladium, gold, or silver formed on the third plating layer.
In the above magnetic sensor, the fourth plating layer and the electrode portion may be electrically connected by the conductive wire.

In the magnetic sensor, the back surface of the magnetic sensor is an exposed surface in which at least a part of the lead terminal and at least a part of the insulating layer are exposed from the resin member, respectively. The front surface and the side surface may be a non-exposed surface where the lead terminal and the insulating layer are not exposed from the resin member.
In the above magnetic sensor, the thickness of the plating layer may be 2 μm or more and 50 μm or less.

In the above magnetic sensor, the pellet may be a magnetoelectric conversion element.
A magnetic sensor device according to an aspect of the present invention includes the above magnetic sensor, a wiring board to which the magnetic sensor is attached, and solder that electrically connects the lead terminals of the magnetic sensor to a wiring pattern of the wiring board. It is characterized by providing.

  A method of manufacturing a magnetic sensor according to an aspect of the present invention includes a step of preparing a lead frame including a base material and a lead terminal formed of a plating layer formed on one surface of the base material; A step of placing the pellet via an insulating layer on one surface of the substrate and away from the lead terminal, and a step of connecting the lead terminal and the electrode portion of the pellet with a conductive wire Supplying a resin member onto one surface of the base material and covering the pellet, the lead terminal and the conductive wire with the resin member, and the base from the resin member, the lead terminal and the insulating layer. And a step of separating the material.

The magnetic sensor manufacturing method may further include a step of dicing the resin member into individual pieces after the step of separating the base material.
In the method for manufacturing a magnetic sensor, the base material may be removed by etching in the step of separating the base material.
In the method for manufacturing the magnetic sensor, the base material may be a copper plate.

In the method of manufacturing a magnetic sensor, the resin member may be diced in the step of dividing the resin member into pieces.
A magnetic sensor according to another aspect of the present invention electrically connects a pellet having an electrode part, a lead terminal including only a plating layer disposed around the pellet, and the electrode part and the plating layer. A lead wire, an insulating layer that covers at least a part of the surface of the pellet opposite to the surface having the electrode portion, and a resin member that covers the pellet, the lead terminal, and the lead wire, At least a part of a surface opposite to a surface connected to the conducting wire and at least a part of the insulating layer are respectively exposed from the resin member.

  According to one embodiment of the present invention, an islandless structure magnetic sensor can be further reduced in size and thickness.

The figure which shows the structural example of the magnetic sensor 100 which concerns on 1st Embodiment of this invention. The figure which shows the structural example of the lead terminal. FIG. 3 is a diagram illustrating a configuration example of a lead frame 120. The figure which shows the manufacturing method of the lead frame 120 in order of a process. The figure which shows the manufacturing process of the magnetic sensor 100. FIG. The figure which shows the manufacturing process of the magnetic sensor 100. FIG. The figure which shows the structural example of the magnetic sensor apparatus 200 which concerns on 1st Embodiment. The figure for demonstrating the effect (4) of 1st Embodiment. The figure which shows the structural example of 100 A of magnetic sensors which concern on the modification of 1st Embodiment. The figure which shows the structural example of the magnetic sensor 300 which concerns on 2nd Embodiment of this invention. The figure which shows the manufacturing process of the magnetic sensor 300. FIG. The figure which shows the structural example of the magnetic sensor 400 which concerns on the comparison form of this invention.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. Note that, in each drawing described below, parts having the same configuration are denoted by the same reference numerals, and repeated description thereof may be omitted.
<First Embodiment>
(Construction)
1A to 1E are a plan view showing a configuration example of the magnetic sensor 100 according to the first embodiment of the present invention, a side view seen from the short side, a side view seen from the long side, It is a back view and a perspective view. In FIGS. 1A to 1C, in order to easily understand the internal configuration of the magnetic sensor 100, a state where the mold resin is seen through is virtually shown.

As shown in FIGS. 1A to 1E, the magnetic sensor 100 has an islandless structure, and includes a pellet 10, lead terminals 21 to 24 having a plating layer, a plurality of fine metal wires 31 to 34, and insulation. The layer 40 and the mold resin 50 are provided.
The pellet 10 is, for example, a magnetoelectric conversion element (Hall element). The pellet 10 is electrically connected to, for example, a semi-insulating gallium arsenide (GaAs) substrate 11, an active layer (that is, a sensing part) 12 made of a semiconductor thin film formed on the GaAs substrate 11, and the active layer 12. It has electrode parts 13a-13d to connect. The active layer 12 has, for example, a cross shape in plan view, and electrode portions 13a to 13d are provided on the four tip portions of the cross, respectively. A pair of electrode portions 13a and 13c facing each other in plan view are input terminals for flowing current to the Hall element, and another pair of electrode portions 13b facing in a direction orthogonal to the line connecting the electrode portions 13a and 13c in plan view, Reference numeral 13d denotes an output terminal for outputting a voltage from the Hall element. The shape of the pellet 10 in plan view (hereinafter referred to as a planar shape) is, for example, a square, and the length of one side is, for example, 0.12 mm or more and 0.3 mm or less. Moreover, the thickness of the pellet 10 is 0.09 mm, for example.

As shown in FIG. 1A, the lead terminals 21 to 24 are respectively arranged around the pellet 10 (for example, at positions near the four corners of the pellet 10 and away from the pellet 10). Here, as described above, each of the lead terminals 21 to 24 includes, for example, only a plating layer. The lead terminals 21 to 24 may have any planar shape.
FIG. 2 is a cross-sectional view illustrating a configuration example of the lead terminal 21. The lead terminal 21 consists only of a plating layer, for example. Moreover, as shown in FIG. 2, this plating layer has a laminated structure, for example. For example, the plating layer constituting the lead terminal 21 includes a first plating layer 26 containing gold or silver, a second plating layer 27 containing palladium formed on the first plating layer 26, and a second plating. It has the 3rd plating layer 28 containing nickel formed on the layer 27, and the 4th plating layer 29 containing palladium, gold | metal | money, or silver formed on the 3rd plating layer 28. And the 4th plating layer 29 and the electrode part 13a shown to Fig.1 (a) are electrically connected by the metal fine wire 31. FIG.

  In the magnetic sensor device, the first plating layer 26 and the second plating layer 27 have an effect of improving the wettability between the solder that is electrically connected to the wiring pattern of the wiring board to which the magnetic sensor is attached and the lead terminal of the magnetic sensor. There is. The second plating layer 27 is a layer that blocks diffusion of the third plating layer 28, and the presence of the second plating layer 27 also has an effect of making the first plating layer 26 thinner.

  The first plating layer 26, the second plating layer 27, and the third plating layer 28 are used when the substrate is removed by etching in the step of separating the substrate in the manufacturing process described later, that is, with an etching solution. When dissolving the base material, unlike the base material, it has an effect of separating from the base material without being damaged by the lead terminal by having the dissolution resistance. The third plating layer 28 is a relatively inexpensive material and has an effect of increasing the strength of the lead terminal itself. For the fourth plating layer 29, a material having good compatibility when thermocompression-bonded with a fine metal wire is selected.

  Further, at least a part of the first plating layer 26 is exposed from the mold resin 50. In FIG. 2, as an example of the first embodiment, all of the first plating layer 26 that is electrically connected by using solder to the wiring pattern of the wiring board to which the magnetic sensor is attached is disposed outside the mold resin 50. (That is, exposed from the mold resin 50), and the second plating layer 27, the third plating layer 28, and the fourth plating layer 28 are all disposed inside the mold resin 50 (that is, the mold resin). 50).

Further, FIG. 2 shows a case where the fourth plating layer 29 and the electrode portion 13a (see FIG. 1) are electrically connected by a metal thin wire 31 as an example of the first embodiment.
In the present embodiment, the lead terminal only needs to expose at least part of the surface (for example, the back surface) opposite to the surface (for example, the front surface) connected to the thin metal wire from the mold resin 50. It may be a form in which at least a part of the back surface protrudes from the surface, or a form in which at least a part of the back surface is exposed by being embedded in the mold resin 50.

  The magnetic sensor 100 uses a Ni film, which is a magnetic material, for the lead terminal 21, but the influence of magnetism on the pellet 10 is small. This is because the Ni plating film is used for the lead terminal 21, but the lead terminal 21 is located away from the pellet back surface, which is easily affected by magnetism, and is disposed at a lower position than the pellet sensing part. Because. Therefore, the pellet 10 is hardly affected by the magnetic influence from Ni which is a magnetic material.

From the viewpoint of linearity of the sensitivity (output) of the magnetoelectric conversion element, the total thickness T2 of the lead terminal 21 made of only the plating layer is, for example, 2 μm or more and 50 μm or less, and more preferably 5 μm or more and 35 μm or less.
Moreover, the thickness t2 of the part exposed from the mold resin 50 among the lead terminals 21 made of only the plating layer is, for example, 0 μm or more and 10 μm or less.

  FIG. 2 shows a form in which the thickness of the first plating layer 26 and the second plating layer 27 of the lead terminal 21 is exposed from the mold resin 50, but the plating layer is shown in cross section. Even if the thickness of the first plating layer 26 is exposed from the mold resin 50 (t2), the thickness of the first plating layer 26 is not exposed to the outside (t2 = 0). = Thickness of the first plating layer 26), a form in which the thickness of the plating layer protrudes outward from the mold resin 50 until a part of the third plating layer 28 is exposed (t2> the first plating layer 26 and Thickness of the second plating layer 27).

Moreover, the cross-sectional shape of the plating layer may be a rectangular shape, a parallelogram shape, a trapezoidal shape, a concave shape, or a convex shape.
Furthermore, among the first plating layer 26, the second plating layer 27, the third plating layer 28, and the fourth plating layer 29, the thickness of the third plating layer 28 containing nickel may be the largest. Thereby, the lead terminal 21 can be formed at low cost. Although not shown, the lead terminals 22 to 24 have the same structure and the same thickness as the lead terminal 21 shown in FIG.

  Returning to FIG. 1, the thin metal wires 31 to 34 are conductive wires that electrically connect the electrode portions 13 a to 13 d of the pellet 10 and the lead terminals 21 to 24, respectively, and are made of, for example, gold (Au). As shown in FIG. 1B, the fine metal wire 31 electrically connects the lead terminal 21 and the electrode portion 13a, and the fine metal wire 32 electrically connects the lead terminal 22 and the electrode portion 13b. Further, the fine metal wire 33 electrically connects the lead terminal 23 and the electrode portion 13c, and the fine metal wire 34 electrically connects the lead terminal 24 and the electrode portion 13d.

The insulating layer 40 covers at least a part, preferably the entire surface, of the surface (that is, the back surface) opposite to the surface (that is, the front surface) of the pellet 10 having the electrode portions 13a to 13d. FIG. 1D shows a case where the insulating layer 40 covers the entire back surface of the pellet 10 as an example of the first embodiment.
The insulating layer 40 includes, for example, an epoxy thermosetting resin, an ultraviolet (UV) curable resin, and a binder resin as its components. The thickness of the insulating layer 40 in the insulating layer 40 that covers the back surface of the pellet 10 is, for example, 2 μm or more and 50 μm or less, and preferably 5 μm or more and 20 μm or less.

  The mold resin 50 covers and protects the pellet 10 and at least the surface side (that is, the side connected to the metal thin wire) and the metal thin wires 31 to 34 of the lead terminals 21 to 24 made of only the plating layer (that is, resin-sealed). )doing. The mold resin 50 is made of, for example, an epoxy-based thermosetting resin, and can withstand high heat during reflow. On the back surface side of the magnetic sensor 100 (that is, the side mounted on the wiring board), at least a part of the back surfaces of the lead terminals 21 to 24 (the surface opposite to the surface connected to the thin metal wires) and at least the insulating layer 40 Part of each is exposed from the mold resin 50. FIG. 1D illustrates a case where the back surfaces of the lead terminals 21 to 24 and the back surface of the insulating layer 40 are exposed from the mold resin 50 as an example of the first embodiment.

  As shown in FIG.1 (e), the shape (namely, packaging shape) after resin sealing of the mold resin 50 is a rectangular parallelepiped, for example. As shown in FIGS. 1A to 1E, the length of the magnetic sensor 100 in the long side direction is L1, the length in the short side direction (that is, the width) is W1, and the thickness of the magnetic sensor 100 is T1. The length L1 is, for example, 0.6 mm or more and 1.6 mm or less, the width W1 is, for example, 0.3 mm or more and 0.8 mm or less, and the thickness T1 is, for example, 0.1 mm or more and 0.3 mm or less. In particular, the thickness T1 is 0.2 mm or less (actually smaller than 0.2 mm, 0.18 mm or less).

  As shown in FIG. 1D, the back surface of the magnetic sensor 100 is an exposed surface where the back surfaces of the lead terminals 21 to 24 and the back surface of the insulating layer 40 are exposed from the mold resin 50. Further, the surface and side surfaces of the magnetic sensor 100 are non-exposed surfaces where the lead terminals 21 to 24 and the insulating layer 40 are not exposed from the mold resin 50.

(Operation)
In the case of detecting magnetism (magnetic field) using the magnetic sensor 100, for example, the lead terminal 21 is connected to the power supply potential (+), the lead terminal 23 is connected to the ground potential (GND), and the lead terminal is connected. A current is passed from 21 to the lead terminal 23. Then, the potential difference V1−V2 (= Hall output voltage VH) between the lead terminals 22 and 24 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.

(Production method)
Next, a method for manufacturing the magnetic sensor 100 described above will be described.
(1) Lead Frame Preparation Step First, a lead frame 120 on which lead terminals 21 to 24 made only of a plating layer are formed is prepared.
FIG. 3 is a plan view illustrating a configuration example of the lead frame 120. As shown in FIG. 3, the lead frame 120 includes, for example, a copper plate 121 as a base material and a plurality of lead terminals 21 to 24 formed on one surface (for example, a surface) 121 a of the copper plate 121. For example, a plurality of pellet placement areas are set on the surface 121a of the copper plate 121, and a set of lead terminals 21 to 24 are formed so as to surround each pellet placement area in plan view. That is, the lead terminals 21 to 24 are formed on the surface 121a of the copper plate 121 with multiple faces.

4A to 4E are cross-sectional views showing the method of manufacturing the lead frame 120 in the order of steps. 4A to 4E correspond to the cross section obtained by cutting the lead frame 120 shown in FIG. 3 along the line XX ′.
As a process of providing a plating layer on a substrate, the following processes can be used. For example, a step of preparing a copper plate 121 as a base material (FIG. 4A), a resist film 123 is formed on both sides of the copper plate 121, and the resist film 123 on the surface of the copper plate 121 is exposed and developed to lead terminals of the plating layer A step of forming a resist pattern 124 (FIG. 4B), a step of pretreating the copper plate 121 on which the resist pattern 124 is formed with an alkaline or acidic liquid (FIG. 4C), Au, Pd A step of forming a plating layer 21 by plating with Ni, Pd, etc. (FIG. 4D), a step of removing the resist film 123 and the resist pattern 124 from the copper plate 121 (FIG. 4E), and the like. . In order to improve the adhesion between the plating layer 21 and the sealing resin and the anchor effect, a rough surface or a columnar structure may be formed on the plating layer 21.

(2) Pellet Pickup Step After preparing the lead frame 120 as described above, the semiconductor wafer is diced to pick up the pellet in order to attach the pellet to the pellet placement region of the lead frame 120.
FIGS. 5A to 5C are schematic views showing a pellet pick-up process in the manufacturing process of the magnetic sensor 100. As shown in FIG. 5A, first, a die attach film 140 is prepared. The die attach film 140 includes a film substrate 135 and an adhesive insulating layer 40 disposed on one surface of the film substrate 135. The back surface of the semiconductor wafer 160 in which a plurality of pellets 10 are formed on the adhesive insulating layer 40 of the die attach film 140 (that is, the surface opposite to the surface having the active layer 12 and the electrode portions 13a to 13d). Are brought into contact with each other for adhesion (ie, wafer mounting is performed).

  In the first embodiment, a process for adjusting the adhesive force of the adhesive insulating layer 40 may be performed. The reason for this is that in the step of FIG. 5B described later, adhesion between the pellet 10 and the film substrate 135 by the adhesive insulating layer 40 is maintained, while in the step of FIG. This is because the layer 40 is easily peeled off from the film substrate 135. The process for adjusting the adhesive force is performed at the timing of wafer mounting or at the timing before and after.

  For example, when performing wafer mounting, the die attach film 140 is heated through a stage to increase the adhesive strength of the binder resin component, which is one of the components of the adhesive insulating layer 40, and adheres to the semiconductor wafer 160. You may adjust to the direction which adheres the insulating layer 40 with property more strongly. In addition, after wafer mounting, UV is irradiated toward the die attach film 140 from the side opposite to the surface having the adhesive insulating layer 40 of the die attach film 140 to thereby provide an adhesive insulating layer. The UV curable resin component, which is one of the 40 components, is cured and hardened so that dicing is facilitated, and the adhesive strength between the film base 135 and the adhesive insulating layer 40 is reduced during die bonding. You may adjust to the direction to do. As described above, by performing at least one of heating through the stage and / or UV irradiation, the adhesive strength of the adhesive insulating layer 40 is increased or slightly cured, and the adhesive strength is adjusted to be reduced. It is possible.

Next, as shown in FIG. 5B, the semiconductor wafer 160 is diced using, for example, a blade 170, and a plurality of pellets 10 formed in the semiconductor wafer 160 are separated into pieces. Here, not only the semiconductor wafer 160 but also the insulating layer 40 having adhesiveness is diced together.
Next, as shown in FIG. 5C, the back surface of the pellet 10 is pushed up by the needle-like push-up pins 180 and the surface of the pellet 10 is sucked up by the collet 190 (ie, picked up). In addition, as described above, the adhesive insulating layer 40 of the die attach film 140 is adjusted in advance in a direction in which the adhesive strength with the film substrate 135 is reduced by performing at least one of heating and UV irradiation, for example. Yes. For this reason, in the process of picking up the pellet 10, the adhesive insulating layer 40 is peeled off from the film substrate 135 while being adhered to the back surface of the pellet 10.

(3) Pellet Attachment to Dicing Step FIGS. 6A to 6E are cross-sectional views showing the steps from the pellet attachment to the dicing step in the magnetic sensor 100 manufacturing process. 6A to 6E correspond to the cross section obtained by cutting the lead frame 120 shown in FIG. 3 along the line XX ′.
As shown in FIG. 6A, first, the pellet 10 is placed on the pellet placement area surrounded by the lead terminals 21 to 24 on the surface 121a of the copper plate 121 (that is, die bonding is performed). .) Here, the back surface of the pellet 10 is placed on the pellet mounting region on the front surface 121a of the copper plate with a certain weight applied by the collet 190 through the adhesive insulating layer 40. After this placement, a heat treatment (cure) is performed to cure the adhesive insulating layer 40 component (for example, an epoxy resin thermal effect resin component), and the back surface of the pellet 10 and the copper plate 121a are sufficiently bonded. The insulating layer 40 bonded with a sufficient strength is obtained.

  Next, as shown in FIG. 6 (b), one end of the fine metal wires 31 to 34 is connected to the lead terminals 21 to 24, respectively, and the other end of the fine metal wires 31 to 34 is connected to the electrode portions 13a to 13d on the surface of the pellet 10. Each is connected (ie, wire bonding is performed). Then, as shown in FIG. 6C, a mold resin 50 is formed (that is, resin sealing is performed). This resin sealing is performed using, for example, a transfer mold technique.

For example, as shown in FIG. 6C, a mold die 90 including a lower die 91 in which the lead frame 120 is disposed and an upper die 92 that is filled with a mold resin and serves as a magnetic sensor body is prepared. The lead frame 120 after wire bonding is placed in the cavity of the mold 90.
On the other hand, the copper plate 121 itself may be used as a lead frame. In this case, the total cavity depth of the lower mold and the upper mold is the thickness of the magnetic sensor body. When filling the mold resin, the gate into which the resin is injected is formed in the upper mold, so if you want to reduce the thickness of the magnetic sensor body, the thickness of the gate is reduced by the depth of the lower mold. It will cause trouble. For example, when the lead frame thickness is 0.125 mm and the thickness of the magnetic sensor main body is 0.2 mm, the upper mold thickness is 0.075 mm, and the mold resin is less than 0.1 mm. 50 injection becomes difficult, and an unfilled portion of the mold resin is generated. In the first embodiment, since the cavity depth of the upper mold is the thickness of the magnetic sensor main body, a gate having a thickness of 0.1 mm or more can be formed, and the problem can be avoided.

  Next, the molten mold resin 50 is injected into the cavity 121 on the surface 121a of the copper plate 121 and filled. Thereby, the pellet 10, the lead terminals 21 to 24, and the fine metal wires 31 to 34 are resin-sealed. When the mold resin 50 is cured by cooling, the lead frame 120 molded with the mold resin 50 is taken out from the mold 90. The depth of the cavity of the upper mold 92 becomes the thickness of the mold resin 50 as it is, that is, the thickness T1 of the magnetic sensor 100 shown in FIG. In addition, you may mark a code | symbol etc. (not shown) on the surface of the mold resin 50 by arbitrary processes after resin sealing.

  Next, as shown in FIG. 6D, the copper plate 121 is separated from the mold resin 50, the lead terminals 21 to 24, and the insulating layer 40. In the step of separating the copper plate 121, for example, the copper plate 121 is removed by etching from the back surface (that is, the surface opposite to the front surface 121a) 121b. Thereby, the copper plate 121 is separated from the mold resin 50, the lead terminals 21 to 24, and the insulating layer 40. For the etching of the copper plate 121, for example, an etching solution having etching resistance to the lead terminals 21 to 24, such as an etching solution containing cupric chloride or an etching solution containing ferric chloride, is used.

  Next, as shown in FIG. 6E, a dicing tape 93 is attached to the surface (that is, the surface) opposite to the surface having the lead terminals 21 to 24 of the mold resin 50. Then, the mold resin 50 is cut (that is, dicing is performed) by moving the blade relative to the mold resin 50 at a width shown as the kerf width in FIG. 3 corresponding to the thickness of the blade. In this dicing, a region corresponding to the kerf width of the mold resin 50 is removed by cutting with a blade and separated into individual magnetic sensor bodies. Through the above steps, the magnetic sensor 100 shown in FIGS. 1A to 1E is completed.

(4) Mounting Step on Wiring Board FIG. 7 is a cross-sectional view showing a configuration example of the magnetic sensor device 200 according to the first embodiment of the present invention. After the magnetic sensor 100 is completed, a wiring board 250 is prepared as shown in FIG. 7, for example, and the magnetic sensor 100 is mounted on one surface of the wiring board 250. In this mounting process, for example, the back surface exposed from the mold resin 50 among the lead terminals 21 to 24 is connected to the wiring pattern 251 of the wiring board 250 via the solder 70. This soldering can be performed by a reflow method, for example. In the reflow method, a solder paste is applied (that is, printed) on the wiring pattern 251, and the magnetic sensor 100 is placed on the wiring board 250 so that the lead terminals 21 to 24 overlap with each other. This is a method of melting solder by applying heat to the paste. Through the mounting process, as shown in FIG. 7, the magnetic sensor 100, the wiring board 250 to which the magnetic sensor 100 is attached, and the lead terminals 21 to 24 of the magnetic sensor 100 are electrically connected to the wiring pattern 251 of the wiring board 250. The magnetic sensor device 200 including the solder 70 to be connected is completed.
In the first embodiment, the thin metal wires 31 to 34 correspond to the “conductive wire” of the present invention, and the adhesive insulating layer 40 corresponds to the “insulating layer” of the present invention. The mold resin 50 corresponds to the “resin member” of the present invention.

(Effect of 1st Embodiment)
The first embodiment of the present invention has the following effects.
(1) Each lead terminal 21-24 consists only of a plating layer, for example. Thereby, the thickness of the lead terminals 21-24 can be made thin compared with a lead frame. For example, the lead frame made of a copper plate or the like has a thickness of several hundreds μm, whereas the plating layer can be formed to an extremely thin thickness of 2 to 50 μm.

  And the height difference of the surface of the pellet 10 and each lead terminal 21-24 can be enlarged. Thereby, the metal thin wires 31 to 34 can be made into a low loop (that is, the height of the metal thin wires 31 to 34 from the surface of the pellet 10) can be reduced, and the thickness of the mold resin 50 can be reduced. Therefore, the islandless structure magnetic sensor can be further reduced in size and thickness (that is, reduced in height).

(2) Further, since the metal thin wires 31 to 34 can be reduced in the loop, when forming the mold resin 50 using the mold 90, a margin can be easily formed between the upper surface of the cavity and the metal thin wires 31 to 34. Can be secured. Thereby, it becomes easy to introduce the molten mold resin into the cavity. Furthermore, since the lead terminals 21 to 24 are thin, the cavity depth of the upper mold becomes the thickness of the magnetic sensor body, so that a gate having a thickness of 0.1 mm or more can be formed and surrounded by the lead terminals 21 to 24. It becomes easy to inject the mold resin 50 around the pellets 10 without filling.

(3) In the step of separating the copper plate 121, the copper plate 121 is etched and separated from the mold resin 50, the lead terminals 21 to 24, and the insulating layer 40. That is, the copper plate 121 is not separated by applying a physical force but chemically separated. Thereby, when separating the copper plate 121, it is possible to prevent the insulating layer 40 from being peeled off from the back surface of the pellet 10 together with the copper plate 121, and the lead terminals 21 to 24 from being peeled off from the mold resin 50 together with the copper plate 121. Therefore, it can contribute to the improvement of the yield of the magnetic sensor.

(4) In the islandless magnetic sensor, at least a part of the back surface of the pellet 10 (more preferably, the entire back surface of the pellet 10) is covered with the insulating layer 40. Accordingly, when the magnetic sensor 100 is attached to the wiring board 250, as shown in FIG. 8, for example, even when the solder 70 protrudes from below the lead terminal 21 connected to the power source to below the pellet 10, the pellet 10 and the solder Insulating layer 40 is interposed between 70 and 70. For this reason, it is possible to prevent a Schottky junction from being formed between the pellet (semiconductor) and the solder (metal), and a current flows in the forward direction of the Schottky junction (ie, from the metal toward the semiconductor). It can be prevented from flowing. Therefore, even when the pellet is thinned in the islandless structure magnetic sensor, an increase in leakage current can be prevented.

(5) The first plating layer 26 electrically connected to the solder 70 or the like contains gold or silver. Furthermore, the 4th plating layer electrically connected with the metal fine wires 31-34 contains palladium, gold | metal | money, or silver. Thereby, the joining strength between the solder 70 and the lead terminals 21 to 24 and the joining strength between the lead terminals 21 to 24 and the metal thin wires 31 to 34 can be increased.
(6) In the wire bonding step, the pellet 10 to which one end of the fine metal wires 31 to 34 is joined and the lead terminals 21 to 24 to which the other ends of the fine metal wires 31 to 34 are joined are the surface 121a of the copper plate 121. Each is arranged above. Since the thin metal wires 31 to 34 are bonded to each other with the copper plate 121 as a base, it is possible to suppress the wire bonding force (load) and ultrasonic power from being dispersed, and to perform bonding stably.

(7) In the dicing process of cutting the mold resin 50 along the kerf width, only the mold resin 50 may be cut. That is, in the prior art, it was necessary to cut the mold resin and the lead frame tie bar together, but in the present invention, since the copper plate 121 has already been separated and removed during dicing, only the mold resin 50 is cut. That's fine. Therefore, in the present invention, the kerf width does not depend on the width of the tie bar (for example, 0.2 mm), and the kerf width can be set to a smaller value (for example, less than 0.2 mm) than before. Thereby, the cutting area in dicing can be reduced and the waste of mold resin can be reduced, so that the production efficiency of the magnetic sensor can be increased.
Moreover, in this invention, what is necessary is just to cut only mold resin at a dicing process. Since it is not necessary to cut the mold resin and the diver made of different materials in an overlapping state, the dicing process can be facilitated.

(Modification)
(1) In the first embodiment, the case where the copper plate is removed by etching in the copper plate separation step shown in FIG. 6D has been described. However, in the present invention, the copper plate separation method is not limited to etching. For example, the separation of the copper plate is not a chemical method such as etching, but may be a physical method such as peeling the copper plate from a mold resin or the like. Even with such a method, the magnetic sensor 100 shown in FIGS. 1A to 1E can be formed. In this case, a SUS plate or the like can be used in addition to the copper plate.

(2) Moreover, in said 1st Embodiment, as shown to Fig.1 (a) and (d), the case where the planar shape of the lead terminals 21-24 which consist only of a plating layer was a rectangle was demonstrated. However, in the present invention, the planar shape of the lead terminal is not limited to a rectangle. In the present invention, the planar shape of the lead terminal may be any shape such as a polygon other than a rectangle.

  9A to 9E are a plan view showing a configuration example of a magnetic sensor 100A according to a modification of the first embodiment, a side view seen from the short side, a side view seen from the long side, It is a back view and a perspective view. In FIGS. 9A to 9C, in order to easily understand the internal configuration of the magnetic sensor 100A, a state where the mold resin is seen through is virtually shown. As shown in FIGS. 9A and 9D, the planar shape of the lead terminals 21 to 24 made of only the plating layer may be, for example, a pentagon.

Moreover, when the planar shape of the pellet 10 is rectangular (that is, square or rectangular), the planar shape of each lead terminal 21 to 24 is one side parallel to the side facing the lead terminals 21 to 24 in the outer periphery of the pellet 10. It is preferable that it is a shape which has. For example, in the modification shown in FIGS. 9A to 9E, the planar shape of the pellet 10 is substantially square, and the planar shape of the lead terminal 21 is the side 10a facing the lead terminal 21 in the outer periphery of the pellet 10. The case where it is a pentagon which has the one side 21a parallel to is shown. Also, the lead terminals 22 to 24 are shown as pentagons similar to the lead terminals 21.
Thereby, since the separation distance between the pellet 10 and each of the lead terminals 21 to 24 can be increased, even when an inexpensive magnetic material such as nickel is used for the lead terminals 21 to 24, the magnetic material is formed in the pellet 10. The influence of the applied magnetism can be further reduced.

Second Embodiment
In said 1st Embodiment, the case where the insulating layer 40 with the adhesive of a die attach film (namely, dicing die-bonding integrated film) was used as an insulating layer which covers the back surface of the pellet 10 was demonstrated. However, in the present invention, the insulating layer is not limited to the adhesive insulating layer of the die attach film. For example, an insulating paste may be used as the insulating layer. In the second embodiment, this point will be described.

(Constitution)
10A to 10E are a plan view showing a configuration example of a magnetic sensor 300 according to a second embodiment of the present invention, a side view seen from the short side, a side view seen from the long side, It is a back view and a perspective view. In FIGS. 10A to 10E, in order to easily understand the internal configuration of the magnetic sensor 300, a state where the mold resin is seen through is virtually illustrated.

As shown in FIGS. 10A to 10E, the magnetic sensor 300 has a pellet 10, a lead frame 120, a plurality of fine metal wires 31 to 34, and a surface opposite to the surface having the electrode portions 13 a to 13 d of the pellet 10. An insulating paste covering at least a part of the side surface (that is, the surface) and a mold resin 50 are provided.
Among these, the insulating paste 240 includes, for example, an epoxy thermosetting resin as its components and silica (SiO ₂ ) as a filler. In the second embodiment, the insulating paste 240 covers, for example, the entire back surface of the pellet 10 (that is, the surface opposite to the surface having the active layer 12). The thickness of the portion of the insulating paste 240 covering the back surface of the pellet 10 is determined by the filler size, and is, for example, 5 μm or more. The configuration of the magnetic sensor 300 other than the insulating paste 240 is the same as that of the magnetic sensor 100 described in the first embodiment, for example. The operation of the magnetic sensor 300 is the same as that of the magnetic sensor 100.

(Production method)
Next, a method for manufacturing the magnetic sensor 300 will be described.
FIGS. 11A to 11C are plan views showing the manufacturing process of the magnetic sensor 300. FIG. In the second embodiment, a lead frame 120 as shown in FIG. 11A is prepared by the same method as in the first embodiment.
Next, as illustrated in FIG. 11B, an insulating paste 240 is applied to a region surrounded by the lead terminals 21 to 24 on the surface 121 a of the copper plate 121. Here, in the completed magnetic sensor 300, for example, the application conditions of the insulating paste 240 (for example, the application range and the applied thickness are set so that a part of the back surface of the pellet 10 is not exposed from the mold resin 50. Etc.).

  Next, a pellet pick-up step is performed in the same manner as in the first embodiment. Then, as shown in FIG. 11 (c), the pellet 10 is placed in the region of the surface 121a of the copper plate 121 where the insulating paste 240 is applied (ie, die bonding is performed). Further, a heat treatment (that is, curing) is performed after bonding, and the insulating paste 240 is cured. The subsequent steps are the same as those in the first embodiment.

That is, wire bonding is performed as shown in FIG. 6B, and resin sealing is performed as shown in FIG. Next, as shown in FIG. 6D, the copper plate 121 is separated from the insulating paste 240 and the mold resin 50. And as shown in FIG.6 (e), the mold resin 50 is diced similarly to 1st Embodiment. Through these steps, the magnetic sensor 300 shown in FIGS. 10A to 10E is completed.
In the second embodiment, the insulating paste 240 corresponds to the “insulating layer” of the present invention. Other correspondences are the same as those in the first embodiment.

(Effect of 2nd Embodiment)
The second embodiment has the same effects as the effects (1) to (7) of the first embodiment.
(Modification)
The modifications (1) and (2) described in the first embodiment may be applied to the second embodiment.
<Others>
The present invention is not limited to the embodiments described above. Based on the knowledge of those skilled in the art, design changes or the like may be added to each embodiment, and the embodiments may be arbitrarily combined, and such changes are also included in the scope of the present invention. It is.

DESCRIPTION OF SYMBOLS 10 Pellet 11 GaAs substrate 12 Active layer 13a-13d Electrode part 21 Lead terminal (for example, power supply terminal)
22, 23 Lead terminal 24 Lead terminal (for example, ground terminal)
26 1st plating layer 27 2nd plating layer 28 3rd plating layer 29 4th plating layer 31-34 Metal fine wire 40 Adhesive insulating layer, insulating layer 50 Mold resin 70 Solder 90 Mold die 91 Lower die 92 Upper Mold 93 Dicing tape 100, 100A, 300 Magnetic sensor 120 Lead frame 121 Copper plate 121a Front surface 121b Back surface 123 Resist film 124 Resist pattern 135 Film substrate 140 Die attach film 150 Wiring substrate 160 Semiconductor wafer 170 Blade 180 Pin 190 Collet 200 Magnetic sensor Device 240 Insulating paste 250 Wiring board 251 Wiring pattern

Claims (16)

A pellet having an electrode part;
A lead terminal formed of a plating layer disposed around the pellet;
A conducting wire electrically connecting the electrode part and the plating layer;
An insulating layer covering at least a part of the surface opposite to the surface having the electrode part of the pellet;
A resin member that covers the pellet, the lead terminal, and the conductive wire;
The magnetic sensor according to claim 1, wherein at least a part of a surface of the lead terminal opposite to a surface connected to the conductor and at least a part of the insulating layer are exposed from the resin member.   The magnetic sensor according to claim 1, wherein the plating layer contains nickel. The plating layer is
A first plating layer containing gold or silver;
A third plating layer containing nickel formed above the first plating layer,
The magnetic sensor according to claim 1, wherein at least a part of the first plating layer is exposed from the resin member.   The magnetic sensor according to claim 3, further comprising a second plating layer containing palladium formed between the first plating layer and the third plating layer.   5. The magnetic sensor according to claim 3, further comprising a fourth plating layer containing palladium, gold, or silver formed on the third plating layer. 6.   The magnetic sensor according to any one of claims 3 to 5, wherein the fourth plating layer and the electrode portion are electrically connected by the conducting wire. The back surface of the magnetic sensor is an exposed surface in which at least a part of the lead terminal and at least a part of the insulating layer are exposed from the resin member, respectively.
The surface and the side surface of the magnetic sensor are non-exposed surfaces in which the lead terminals and the insulating layer are not exposed from the resin member, according to any one of claims 1 to 6. Magnetic sensor.   The thickness of the said plating layer is 2 micrometers or more and 50 micrometers or less, The magnetic sensor as described in any one of Claims 1-7 characterized by the above-mentioned.   The magnetic sensor according to any one of claims 1 to 8, wherein the pellet is a magnetoelectric conversion element. A magnetic sensor according to any one of claims 1 to 9,
A wiring board to which the magnetic sensor is attached;
And a solder for electrically connecting the lead terminals of the magnetic sensor to a wiring pattern of the wiring board. A substrate;
Preparing a lead frame comprising a lead terminal having a plating layer formed on one surface of the substrate;
A step of placing pellets via an insulating layer on one surface of the base material and away from the lead terminal;
Connecting the lead terminal and the electrode part of the pellet with a conductive wire;
Supplying a resin member on one surface of the substrate, and covering the pellet, the lead terminal and the conductive wire with the resin member;
Separating the base material from the resin member, the lead terminal, and the insulating layer.   The method of manufacturing a magnetic sensor according to claim 11, further comprising a step of dicing the resin member into pieces after the step of separating the base material.   The method for manufacturing a magnetic sensor according to claim 11 or 12, wherein, in the step of separating the base material, the base material is removed by etching.   The method for manufacturing a magnetic sensor according to any one of claims 11 to 13, wherein the base material is a copper plate. In the step of dividing the resin member into pieces,
The method for manufacturing a magnetic sensor according to claim 11, wherein dicing is performed between the adjacent lead terminals of the resin member. A pellet having an electrode part;
A lead terminal consisting only of a plating layer, disposed around the pellet;
A conducting wire electrically connecting the electrode part and the plating layer;
An insulating layer covering at least a part of the surface opposite to the surface having the electrode part of the pellet;
A resin member that covers the pellet, the lead terminal, and the conductive wire;
The magnetic sensor according to claim 1, wherein at least a part of a surface of the lead terminal opposite to a surface connected to the conductor and at least a part of the insulating layer are exposed from the resin member.

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