WO2014054082A1 - Semiconductor device, proximity sensor equipped with same, and semiconductor device manufacturing method - Google Patents

Abstract

Provided is a semiconductor device, or the like, that is capable of effectively preventing light from leaking into a light-receiving element from a light-emitting element, while being compact and easy to manufacture. The semiconductor device (10) is formed by mounting a light-emitting element (12) and a light-receiving element (13) on a common package substrate (11). At least one of the light-emitting element (12) and the light-receiving element (13) is mounted at the bottom (15a) of an inverse truncated cone-shaped groove (15), which is formed in the package substrate (11), so as to be set in said groove (15).

Description

SEMICONDUCTOR DEVICE, PROXIMITY SENSOR HAVING THE SAME, AND METHOD FOR PRODUCING SEMICONDUCTOR DEVICE

The present invention relates to a semiconductor device in which a light emitting element and a light receiving element are mounted on a common substrate, a proximity sensor provided with the semiconductor device, and a method for manufacturing the semiconductor device.

Conventionally, an optical device in which a light shielding member is disposed between a light emitting element and a light receiving element is known as this type of semiconductor device (see Patent Document 1).
This opto-device seals a substrate, a light emitting element and a light receiving element mounted on the substrate, a light emitting element and a light receiving element with a translucent resin, and a light transmitting element and a light receiving element facing the light emitting element. A mold part including a receiving lens; a groove formed between the transmitting lens and the receiving lens in the mold part; and a light shielding member that is provided in the groove and shields light from the light receiving element. .
Light emitted from the light emitting element and traveling through the mold portion toward the light receiving element is blocked by a light blocking member provided in the groove. Accordingly, it is possible to prevent the light from flowing from the light emitting element to the light receiving element in the mold part without requiring a new mold or the like.

JP 2009-10157 A

In such a conventional optical device (semiconductor device), since the light shielding member is provided in the mold portion, a step of forming a groove in the mold portion and a step of filling or fitting and fitting the light shielding member into the groove There is a problem that the number of steps in the manufacturing process increases. In addition, it is necessary to secure a space for providing a light shielding member between the light emitting element and the light receiving element mounted on the substrate, and there is a problem that the device is enlarged accordingly.

The present invention relates to a semiconductor device capable of effectively preventing light from sneaking from a light emitting element to a light receiving element while maintaining miniaturization and ease of manufacture, and a proximity sensor including the semiconductor device and a method of manufacturing the semiconductor device The issue is to provide.

The semiconductor device of the present invention is a semiconductor device in which a light emitting element and a light receiving element are mounted on a common package substrate, and at least one of the light emitting element and the light receiving element is immersed in a concave groove formed in the package substrate. It is implemented in.

According to this configuration, for example, when the light emitting element is mounted in the groove, the emitted light is appropriately reflected in the groove and emitted from the opening side of the groove. For this reason, the emitted light from the light emitting element has directivity, and the light (the amount of light) reaching the light receiving element as noise light can be suppressed. Further, for example, when light emission and light reception are performed on the object through the panel body, the emitted light of the light emitting element having directivity enters the panel body at a deep angle. For this reason, noise light reflected from the panel body can also be suppressed. In addition, the efficiency of extracting emitted light from the light emitting element can be improved by the concave groove. Further, when the light receiving element is mounted in the concave groove, the light emitted from the light emitting element toward the light receiving element passes through the opening, so that the amount of light reaching the light receiving element as noise light can be suppressed. . On the other hand, the groove formed in the package substrate can be easily drilled with a drill bit or the like. Therefore, it is possible to effectively prevent light (noise light) from wrapping around from the light emitting element to the light receiving element while maintaining the miniaturization and the ease of manufacture. The “package substrate” is a concept including a lead frame.

In this case, the concave groove is preferably formed in an inverted truncated cone shape, and at least one of the light emitting element and the light receiving element is preferably mounted on the groove bottom of the concave groove.

According to this configuration, the groove can be easily formed by a commercially available drill bit having a truncated cone shape. In addition, the light emitting element and / or the light receiving element can be easily mounted by an existing technique.

Further, the light emitting element and the light receiving element are preferably sealed by potting with a sealing resin.

The sealing resin shrinks when it is cured. At that time, the thick part contracts greatly, and the small part contracts small.
According to said structure, the recessed groove part of sealing resin shrink | contracts large, and another part shrinks small. For this reason, the concave groove portion of the sealing resin has a concave surface shape with respect to the other portions. For example, when the light emitting element is mounted in the concave groove, the emitted light is diffused on the surface of the recessed sealing resin, and is emitted as detection light having the same spread as when there is no concave groove. On the other hand, when the light receiving element is mounted in the concave groove, the reflected light from the object is focused on the surface of the recessed sealing resin, reaches the light receiving surface of the light receiving element, and is detected. Further, as long as the sealing function is not impaired, the thickness of the sealing resin (device) can be freely adjusted, and customization can be easily performed.

Furthermore, it is preferable that the light emitting element and the light receiving element are sealed by molding with a sealing resin, and the surface of the sealing resin is formed in a concave lens shape.

According to this configuration, the emitted light of the light emitting element is refracted in the direction away from the light receiving element as a whole on the surface of the sealing resin. For this reason, for example, when a panel body is provided on the front surface, the light on the light receiving element side of the refracted light is incident on the panel body at a deep angle, and its reflection is suppressed. Therefore, light reaching the light receiving element as noise light can be suppressed.

On the other hand, the light emitting element and the light receiving element are preferably sealed by molding with a sealing resin, and the surface of the sealing resin is preferably formed in an uneven shape.

According to this configuration, the light emitted from the light emitting element, reflected by the surface of the sealing resin (interface with air) and directed to the light receiving element, in particular, the light reflected on the recess does not go to the light receiving element. Accordingly, noise light to the light receiving element can be suppressed.

A proximity sensor according to the present invention includes the above-described semiconductor device in which at least a light-emitting element of a light-emitting element and a light-receiving element is mounted so as to be immersed in a concave groove formed in a package substrate, and a translucent panel body It is characterized by sensing the relative approach of an object through

According to this configuration, radiated light having directivity from the light emitting element is incident on the panel body at a deep incident angle. For this reason, reflection from the panel body is suppressed, and accordingly, noise light incident on the light receiving element based on this reflection can be reduced. Therefore, erroneous detection and the like can be prevented.

In this case, it is preferable that the panel body is mounted on the mobile terminal and the panel body is a touch panel of the mobile terminal.

According to this configuration, since the light (noise light) from the light emitting element to the light receiving element can be prevented from being circulated, it is possible to satisfactorily perform sensing with the human body as an object.

The method for manufacturing a semiconductor device according to the present invention is the above-described method for manufacturing a semiconductor device, wherein a concave groove in which at least one of a light emitting element and a light receiving element is mounted is formed on a package substrate immediately before the formation of a wiring pattern. Groove forming step, mounting step for chip-mounting the light emitting element and the light receiving element on the package substrate after the groove forming step, and bonding step for wire bonding the light receiving element and wire bonding of the light receiving element after the mounting step And a potting step of potting the light emitting element and the light receiving element with a sealing resin after the bonding step.

According to this configuration, a groove forming step is added to the previous manufacturing process. In the groove forming step, the concave groove formed in the package substrate can be easily formed with a drill bit or the like. Therefore, it is possible to effectively prevent light (noise light) from wrapping around from the light emitting element to the light receiving element while maintaining the miniaturization and the ease of manufacture.

It is sectional drawing of the state which mounted the semiconductor device which concerns on embodiment as a proximity sensor in the portable terminal. 1 is a cross-sectional view of a semiconductor device according to a first embodiment. It is sectional drawing of the semiconductor device which concerns on 2nd Embodiment. It is sectional drawing of the semiconductor device which concerns on 3rd Embodiment. It is explanatory drawing which shows the groove | channel formation process in a substrate frame. It is explanatory drawing which shows the groove | channel formation process in a lead frame. It is sectional drawing of the semiconductor device which concerns on 4th Embodiment. It is sectional drawing of the semiconductor device which concerns on 5th Embodiment.

Hereinafter, a semiconductor device, a proximity sensor including the semiconductor device, and a method for manufacturing the semiconductor device according to an embodiment of the present invention will be described with reference to the accompanying drawings. This semiconductor device includes a light emitting element and a light receiving element, and is used as a proximity sensor. For example, this proximity sensor is mounted on a portable terminal (smart phone) and detects whether or not the user is talking. For this reason, in order to reliably receive the weak reflected light reflected from the human body, the light is prevented from wrapping around from the light emitting element to the light receiving element as much as possible.

FIG. 1 is a cross-sectional view when the semiconductor device according to the embodiment is mounted on a smartphone as a proximity sensor. As shown in the figure, the smartphone 1 is provided with a touch panel 2 over the entire front surface thereof, and a receiver 4 is disposed inside the touch panel 2 so as to be mounted on a circuit board 3. A proximity sensor 5 is disposed adjacent to the receiver 4 so as to be mounted on the circuit board 3.

That is, the proximity sensor 5 of the embodiment is disposed in the gap between the touch panel 2 and the circuit board 3 and emits infrared rays (in the embodiment, near infrared rays) that serve as detection light via the touch panel 2. When the user of the smartphone 1 brings the ear E close to the receiver 4 so as to shift to a call state, the infrared rays radiated from the proximity sensor 5 are reflected by the portion of the ear E or the like and a part of the infrared rays is reflected on the proximity sensor 5. Incident. In the proximity sensor 5, incident light (infrared rays) is photoelectrically converted and amplified, and output to a determination circuit (not shown) on the circuit board 3. In the determination circuit, the amount of received light (current value) is compared with a threshold, and when the threshold is exceeded, the human body (ear E) is detected, that is, the call state is detected. Then, when a call state is detected, mode switching that disables the operation of the touch panel 2 is performed.

As described above, the proximity sensor 5 according to the embodiment detects an extremely close target (ear E or the like), the light emission amount is suppressed to reduce power consumption, and the light reception amount is extremely small compared to the light emission amount. Must be detected reliably. Therefore, in the semiconductor device 10 of the present embodiment constituting the proximity sensor 5, noise light is reduced as much as possible in order to improve the S / N ratio.

FIG. 2 is a cross-sectional view of the semiconductor device 10A according to the first embodiment. As shown in the figure, the semiconductor device 10A includes a package substrate 11 composed of a substrate frame and a lead frame (a substrate frame in the embodiment), a light emitting element 12 and a light receiving element having a chip configuration mounted on the package substrate 11. 13 and a translucent sealing resin 14 that seals the light emitting element 12 and the light receiving element 13. The light receiving element 13 is mounted (mounted) on the package substrate 11, while the light emitting element 12 is mounted in a concave groove 15 formed in the package substrate 11.

The package substrate 11 (substrate frame) is made of a glass epoxy or organic material substrate, and on both the front and back surfaces, a light emitting side wiring pattern 21 (electrodes and the like) on which the light emitting element 12 is mounted and conducted, and a light receiving element Light receiving side wiring patterns 22 (electrodes and the like) on which 13 is mounted and conducted are formed. Further, an inverted frustoconical groove 15 is formed in a portion of the package substrate 11 where the light emitting element 12 is mounted. The light emitting element 12 is mounted on a light emitting side wiring pattern 21 (die pad) that also serves as a heat sink provided on the groove bottom 15a of the concave groove 15. A reflective film is preferably formed on the inner peripheral surface of the concave groove 15.

The light emitting element 12 is composed of a light emitting diode chip that emits infrared rays (near infrared rays) from the light emitting surfaces at both ends. And the electrode pad 12a of the light emitting element 12 and the land 21a of the light emission side wiring pattern 21 are connected by the bonding wire 24 (a gold wire, a copper wire, an aluminum wire, etc.). The light emitting element 12 is disposed so as to be completely immersed in the groove 15 formed in the package substrate 11. The light emitting element 12 may have an upper surface as a light emitting surface.

As shown in FIG. 2, in the light emitting element 12 mounted in the groove 15 of the package substrate 11, infrared light is reflected from the both ends of the small edge to the inner surface of the groove 12 and emitted from the opening. For this reason, the infrared rays used as detection light are radiated with the radiation angle narrowed down (focused) and directivity. Thereby, the reflection of infrared rays on the upper surface (interface with air) of the sealing resin 14 and the lower surface (interface with air) of the touch panel 2 is suppressed. That is, noise light to the light receiving element 13 is suppressed.

The light receiving element 13 is composed of a photodiode chip mounted on the package substrate 11 with the upper surface serving as a light receiving surface. The electrode pad 13a of the light receiving element 13 and the land 22a of the light receiving side wiring pattern 22 are connected by a bonding wire 26 (gold wire, copper wire, aluminum wire, etc.). Note that a phototransistor may be used instead of the photodiode.

The sealing resin 14 is made of an epoxy resin or silicon resin that is transparent to infrared rays, and covers the light emitting element 12, the light receiving element 13, and the bonding wires 24 and 26 (sealing). In this case, the sealing resin 14 may be formed by molding, but the embodiment is formed by potting (details will be described later). That is, the sealing resin 14 is formed by thermosetting the liquid sealing resin 14 that is poured so as to cover the light emitting element 12 and the light receiving element 13.

In this case, the sealing resin 14 has a property of shrinking by thermosetting, and the portion of the concave groove 15 of the thick sealing resin 14 contracts greatly, and the other portion having no thickness contracts small ( (See FIG. 2). For this reason, the concave groove 15 portion of the sealing resin 14 has a concave surface shape with respect to the other portion, that is, a concave lens-like surface shape. For this reason, the emitted light of the light emitting element 12 squeezed by the concave groove 15 is diffused on the surface of the recessed sealing resin 14 and is emitted as detection light having the same spread as when there is no concave groove 15.

Further, in this semiconductor device 10A, the thickness (resin amount) of the sealing resin 14 can be adjusted by potting so as to be compatible with the smartphone 1 in which the gap width between the touch panel 2 and the circuit board 3 is different. Specifically, as long as the sealing function is not impaired, the thickness of the sealing resin 14 (device) is adjusted so as to make the gap between the touch panel 2 as small as possible.

In the semiconductor device 10A of the first embodiment configured as described above, the emitted light of the light emitting element 12 is appropriately reflected in the concave groove 15 and emitted from the opening side of the concave groove 15. For this reason, the emitted light from the light emitting element 12 is emitted so as to be reduced, and the amount of light reaching the light receiving element 13 as noise light in the sealing resin 14 can be suppressed. Further, the narrowed radiated light is hard to be reflected on the touch panel 2, and also in this respect, the amount of light reaching the light receiving element 13 as noise light can be suppressed. Therefore, it is possible to effectively prevent the light (noise light) from entering from the light emitting element 12 to the light receiving element 13. In addition, the concave groove 15 can improve the extraction efficiency of the radiated light from the light emitting element 12. On the other hand, the groove 15 formed in the package substrate 11 can be easily drilled with a drill bit or the like. Accordingly, it is possible to effectively prevent light (noise light) from wrapping from the light emitting element 12 to the light receiving element 13 while maintaining miniaturization and ease of manufacture.

Next, with reference to FIG. 3, the semiconductor device 10 </ b> B according to the second embodiment will be described mainly with respect to differences from the first embodiment. As shown in the figure, in the semiconductor device 10B, unlike the first embodiment, the light emitting element 12 is mounted (mounted) on the package substrate 11, while the light receiving element 13 is mounted in the concave groove 15 of the package substrate 11. Has been. That is, the light emitting element 12 is mounted on the light emitting side wiring pattern 21 formed on the package substrate 11, and the light receiving element 13 is received on the groove bottom 15 a of the concave groove 15 so as to be immersed in the concave groove 15. Mounted on the side wiring pattern 22.

In the semiconductor device 10 </ b> B according to the second embodiment configured as described above, the radiated light toward the light receiving element 13 out of the radiated light from the light emitting element 12 passes over the opening of the concave groove 15, and thus the sealing resin 14. The amount of light reaching the light receiving element 13 as noise light can be suppressed. Further, the reflected light from the object (ear E) is appropriately reflected and converged in the concave groove 15 to reach the light receiving surface of the light receiving element 13, and is received with high light efficiency. Therefore, also in this case, it is possible to effectively prevent the light (noise light) from wrapping from the light emitting element 12 to the light receiving element 13 while maintaining the miniaturization and the ease of manufacture.

Next, with respect to the semiconductor device 10C according to the third embodiment, parts different from the first embodiment will be mainly described with reference to FIG. As shown in the figure, in the semiconductor device 10 </ b> C, both the light emitting element 12 and the light receiving element 13 are mounted in the groove 15 of the package substrate 11. That is, the light emitting element 12 is mounted on the light emitting side wiring pattern 21 provided on the groove bottom 15 a of the concave groove 15 so as to be immersed in the concave groove 15, and the light receiving element 13 is immersed in the concave groove 15. The light receiving side wiring pattern 22 provided on the groove bottom 15 a of the concave groove 15 is mounted.

In the semiconductor device 10 </ b> C of the third embodiment configured as described above, the amount of light reaching the light receiving element 13 as noise light from the light emitted from the light emitting element 12 in the sealing resin 14 is suppressed by the respective concave grooves 15. be able to. Therefore, also in this case, it is possible to effectively prevent the light (noise light) from wrapping from the light emitting element 12 to the light receiving element 13 while maintaining the miniaturization and the ease of manufacture.

Next, a method for manufacturing the semiconductor device 10 (10A) according to the embodiment will be described by taking the first embodiment as an example with reference to FIGS.
In this manufacturing method, a groove forming step for forming a concave groove 15 in which the light emitting element 12 is mounted on the package substrate 11 before and after the formation of both the wiring patterns 21 and 22, and the package substrate 11 after the groove forming step. The light-emitting element 12 and the light-receiving element 13 are mounted in a chip, and after the mounting process, the light-emitting element 12 is wire-bonded, and the light-receiving element 13 is wire-bonded. And a potting step of potting the light receiving element 13 with the sealing resin 14.

In the groove forming step, when the package substrate 11 is a substrate frame, the concave groove 15 may be formed in the substrate frame that has been subjected to the front and back plating treatment, The groove 15 may be formed after the pattern formation of the wiring pattern. Further, as shown in FIG. 5, the formation of the groove 15 is preferably performed together with the formation of the through hole 32 using a dedicated drill bit 31. On the other hand, as shown in FIG. 6, when the package substrate 11 is a lead frame (raw material), it is preferable to form the concave groove 15 and both the wiring patterns 21 and 22 simultaneously by etching or the like.

In the mounting process, the light emitting element 12 and the light receiving element 13 are chip-mounted through an adhesive such as silver paste using a known die bonding apparatus.
In the bonding process, the light emitting element 12 and the light receiving element 13 are wire-bonded using a known bonding apparatus, for example, by a ball bonding method.
In the potting process, the sealing resin 14 is potted over the entire upper surface of the package substrate 11 using a dispenser, and then the potted sealing resin 14 is cured by oven heating or the like.
In addition, since the resin sealing of the embodiment is a so-called wafer level package, the semiconductor device 10A as a single unit is completed by dicing after the potting process.

Thus, in the manufacturing method of the semiconductor device 10 (10A) according to the embodiment, the semiconductor device 10 (10A) can be easily manufactured only by adding the groove forming step to the known manufacturing method. In addition, since the formation of the concave groove 15 in the groove forming step can be performed together with the formation of the through hole 32, it can be easily formed by a known drilling machine or the like. Therefore, the semiconductor device 10 (10A) according to the embodiment having good detection sensitivity can be easily manufactured.

Next, with respect to the semiconductor device 10D according to the fourth embodiment, parts different from the second embodiment will be mainly described with reference to FIG. As shown in the figure, the semiconductor device 10D has the same structure as that of the second embodiment in the structure of the package substrate 11, the light emitting element 12, the light receiving element 13, and the recessed groove 15, but in this case, the sealing resin 14 Is formed by molding (mold). The surface of the sealing resin 14 is formed in a concave lens shape. That is, the surface of the sealing resin 14 is formed like a concave lens in a region including the light emitting element 12 and the light receiving element 13.

In such a configuration, the emitted light of the light emitting element 12 is refracted in the direction away from the light receiving element 13 as a whole on the surface of the sealing resin 14. For this reason, light on the light receiving element 13 side in the refracted light is incident on the touch panel 2 at a deep angle, and reflection thereof is suppressed. Therefore, even with this configuration, light reaching the light receiving element 13 as noise light can be suppressed.

Next, with respect to the semiconductor device 10E according to the fifth embodiment, parts different from the first embodiment will be mainly described with reference to FIG. As shown in the figure, the semiconductor device 10E is similar to the first embodiment in the structure of the package substrate 11, the light emitting element 12, the light receiving element 13, and the recessed groove 15, but in this case, the sealing resin 14 Is formed by molding (mold). And the surface of the sealing resin 14 is formed in the small uneven | corrugated shape of a rectangular cross section.

In such a configuration, light that is radiated from the light emitting element 12, reflected by the surface of the sealing resin 14 (interface with air) and directed toward the light receiving element 13, particularly light reflected by the concave and convex portions, is received by the light receiving element 13. Therefore, the noise light to the light receiving element 13 can be suppressed accordingly. Therefore, even with this configuration, it is possible to prevent light from entering the light receiving element 13.

Note that the semiconductor device of the present invention can be applied as an optical device to applications other than the proximity sensor of a smartphone (mobile terminal). In particular, it is useful as an optical device provided over a translucent panel.

1 smart phone, 2 touch panel, 5 proximity sensor, 10, 10A, 10B, 10C, 10D, 10E semiconductor device, 11 package substrate, 12 light emitting element, 13 light receiving element, 14 sealing resin, 15 concave groove, 15a groove bottom, 21 Light emitting side wiring pattern, 22 Light receiving side wiring pattern, 24 bonding wire, 26 bonding wire

Claims (8)

A semiconductor device in which a light emitting element and a light receiving element are mounted on a common package substrate,
At least one of the light emitting element and the light receiving element is mounted so as to be immersed in a concave groove formed in the package substrate. The concave groove is formed in an inverted truncated cone shape,
The semiconductor device according to claim 1, wherein at least one of the light emitting element and the light receiving element is mounted on a groove bottom of the concave groove. The semiconductor device according to claim 1, wherein the light emitting element and the light receiving element are sealed by potting with a sealing resin. The light emitting element and the light receiving element are sealed by molding with a sealing resin,
The semiconductor device according to claim 1, wherein the surface of the sealing resin is formed in a concave lens shape. The light emitting element and the light receiving element are sealed by molding with a sealing resin,
The semiconductor device according to claim 1, wherein a surface of the sealing resin is formed in an uneven shape. 2. The semiconductor device according to claim 1, wherein at least the light emitting element of the light emitting element and the light receiving element is mounted so as to be immersed in a concave groove formed in the package substrate.
A proximity sensor that senses the relative approach of an object through a translucent panel. On mobile devices,
The proximity sensor according to claim 5, wherein the panel body is a touch panel of the mobile terminal. A method of manufacturing a semiconductor device according to claim 3,
A groove forming step for forming a concave groove in which at least one of the light emitting element and the light receiving element is mounted on the package substrate before and after the formation of the wiring pattern;
After the groove forming step, a mounting step of chip-mounting the light emitting element and the light receiving element on the package substrate;
After the mounting step, wire bonding the light emitting element, and a bonding step of wire bonding the light receiving element,
After the said bonding process, the potting process of potting the said light emitting element and the said light receiving element with sealing resin is provided, The manufacturing method of the semiconductor device characterized by the above-mentioned.

Images