JPH05226676A - Semiconductor device - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To improve the connection with the optical signal cable in a semiconductor device in which at least one of the light emitting element and the light receiving element is sealed with resin or the like together with the optical signal wire. .. [Structure] The semiconductor chip 10 is configured to include an electric signal processing circuit and a light receiving element therein, and includes an optical signal bonding pad 10b. Lead frame 25
A groove formed by a U-shaped cut pattern 13 is provided at a position facing the optical signal wire 11. The optical signal wire 11 reaches the side rail portion 23 along the cut pattern 13 and is bonded to a predetermined position. Further, in the cut pattern 13, a film 15 made of polyimide or the like with an adhesive is attached in advance to the surface of the lead frame 25 opposite to the bonding surface of the optical signal wire 11 before bonding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly, to a semiconductor substrate having at least one of a light emitting element and a light receiving element and capable of processing an electrical signal and an optical signal. The present invention relates to a semiconductor device configured by sealing with a resin or the like.

[0002]

2. Description of the Related Art Generally, a resin-sealed semiconductor is used as a kind of semiconductor device manufactured by packaging a semiconductor substrate which is generally formed as a semiconductor chip having an IC (integrated circuit) element, a light emitting element, a light receiving element and the like. There is a device. In such a semiconductor device, a semiconductor substrate mounted on a lead frame is provided with a predetermined optical connection for optical signals so that not only electric signals but also optical signals can be processed. It is resin-sealed together with wires.

The structure and manufacturing method of this type of semiconductor device will be described with reference to FIG. FIG. 7 shows the internal structure of this type of semiconductor device in a state of one manufacturing process thereof.

In FIG. 7, a semiconductor chip 50, which is an example of a semiconductor substrate, is mounted on a die pad of a lead frame 55. The electrical signal wire 61 is a bonding pad for electrical signal formed on the semiconductor chip 50.
Connection is made between 50a and the terminal portion 62 of the lead frame 55.

On the other hand, the optical signal wire 51 is a semiconductor chip.
Bonding pad 50b for light signal of light emitting element or light receiving element of 50 and side rail portion of lead frame 55
It is connected to 63. The side rail 63
Is located outside the package body when the device is completely assembled, and is separated from the package body.

After wire-bonding the wires 51, 52 in this way, the semiconductor chip 50, the wires 51, 52
Members such as 52 are transfer-molded and sealed with epoxy resin or the like, that is, package side surfaces 64 shown by broken lines in the figure
Forming a package body having Further, external terminals are cut and formed by a lead frame 55 on the outside of the package body, and a surface treatment for soldering is applied to the external terminals.

When the package thus manufactured is cut off from the side rail portion 63 of the lead frame 55,
The optical signal wire 51 is cut near the surface of the package side surface 64.

After that, the optical signal wire 51 on the surface of the package resin corresponding to the thickness of the lead frame 55 on the parting surface of the die is polished together with the resin on the surface of the package, and the optical communication cable for external connection is formed. Then, the semiconductor device assembling process is completed.

[0009]

Generally, in this type of semiconductor device, it is important to further enhance the stability and reliability of optical signal communication. Therefore, when connecting the optical signal cable used for optical connection between a plurality of semiconductor devices and each semiconductor device, it is necessary to perform accurate positioning between them. It is extremely important to lead out the optical signal wire to a predetermined position on the surface of the package.

However, according to the above-mentioned conventional technique, there is no suitable positioning means for the optical signal wire 51 inside the package. Therefore, the lead-out position of the optical signal wire 51 on the package surface may deviate from a predetermined lead-out position, or the angle of the optical signal wire 51 with respect to the polishing surface may deviate. As a result, when the optical signal cable is connected to the semiconductor device, an optical axis shift occurs between the optical signal cable and the optical signal wire, so that the optical signal is normally conducted. There was a problem that there were cases where it could not be secured.

Further, the above-mentioned polished area to be surface-polished is covered with the transfer mold resin, and the silica powder contained in the resin also exists around the lead-out position of the optical signal wire. Therefore, in the manufacturing stage, at the time of surface polishing of the predetermined optical signal wire lead-out position on the package surface, the silica powder as the filler in the resin hits the surface to be polished, which hinders smooth polishing, resulting in There is also a problem in that the manufactured semiconductor device cannot be optically connected favorably to the optical signal cable.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a semiconductor device which can be satisfactorily connected to an optical signal cable.

[0013]

In order to achieve the above-mentioned object, a semiconductor device of the first invention of the present application has a semiconductor substrate having at least one of a light receiving element and a light emitting element, and a package for sealing the semiconductor substrate. A main body, a lead frame to which a semiconductor substrate is attached inside the package main body, one end inside the package main body is connected to the semiconductor substrate, and the other end is outside the package main body. A lead-out optical signal wire, and a fixing means for fixing the optical signal wire to the lead frame to position the optical signal wire with respect to the package body. To do.

In order to achieve the above-mentioned object, the semiconductor device of the second invention of the present application is composed of a semiconductor substrate having at least one of a light receiving element and a light emitting element and a mold resin, and seals the semiconductor substrate. A package body, a lead frame to which a semiconductor substrate is attached inside the package body, one end of the package body connected to the semiconductor substrate, and the other end of the package body. It has an optical signal wire led out of the main body,
It is characterized in that the periphery of the lead-out position of the optical signal wire is covered with a resin containing no hard filler.

[0015]

In general, the cause of the positional deviation of the optical signal wire from the predetermined lead-out position on the package surface and the angular deviation from the polishing surface of the package is mainly the optical signal wire when the optical signal wire is bonded. The lack of reproducibility of the bonding loop shape causes the deformation of the bonding loop shape due to the vibration in a later step or the resin being pushed by the resin at the time of resin sealing.

According to the first invention of the present application, the package is
Inside the main body of the package, one end is connected to the semiconductor substrate and the other end is led out to the outside of the package main body. Since the optical signal wire is fixed to the frame, the optical signal wire can be led out to a predetermined position on the surface of the package body. As a result, the positioning required for the connection between the optical signal wire and the optical signal cable led out from the package can be accurately performed, and the optical connection with the optical signal cable can be favorably performed. ..

In the first aspect of the invention, the groove formed in the lead frame into which the optical signal wire is fitted and the lead frame to cover the groove from the side opposite to the side where the optical signal wire is fitted are covered. -If the fixing means is composed of a film with an adhesive, which is attached to the groove portion of the optical signal and the optical signal wire is adhered in the groove, the optical signal is used when the semiconductor device is resin-sealed. Since the wire can be temporarily fixed at a predetermined position, it is possible to easily and extremely accurately position the wire.

According to the second invention of the present application, since the package body is made of the mold resin containing the hard filler and the like, the semiconductor substrate can be physically well-sealed. On the other hand, on the other hand, one end of the package body is connected to the semiconductor substrate and the other end is around the lead-out position of the optical signal wire led out of the package body,
Since it is covered with a resin that does not contain a hard filler, at the manufacturing stage, when polishing near the lead-out position of the optical signal wire on the surface of the package body, the surface to be polished with silica powder etc. in the mold resin Allows smooth polishing without damaging the surface. As a result, good optical connection with the optical signal cable can be achieved.

From the following examples of the present invention, such an effect of the present invention will be made clearer, and further other effects of the present invention will be made clear.

[0020]

Embodiments of the present invention will be described in detail below with reference to the drawings.

First, the structure and manufacturing method of the semiconductor device of this embodiment will be described with reference to FIG. FIG. 1 shows the internal structure of the semiconductor device of this embodiment in a state in one manufacturing process thereof.

In FIG. 1, a semiconductor chip 10, which is an example of a semiconductor substrate, is configured to include an electric signal processing circuit and a light emitting element or a light receiving element inside, and an electric signal is communicated on the surface thereof. Bonding pad for 10
a and a bonding pad 10b for communicating an optical signal. The semiconductor chip 10 is mounted on the die pad of the lead frame 25 with, for example, a silver epoxy adhesive.

The lead frame 25 is made of a material such as a copper-based material or 42 alloy.
The portion to which the gold wire 21 is bonded is previously plated with silver.

The electrode pad 10a of the semiconductor chip 10 and the terminal portion 22 of the lead frame 25 are connected by a gold wire 21 using, for example, a nail head bonding technique which also uses ultrasonic waves.

The optical signal wire 11 is made of flexible plastic for optical transmission. Bonding pad 10b for light emitting element or light receiving element of semiconductor chip 10
And the side rail portion 23 of the lead frame 25 are connected by the optical signal wire 11 using, for example, a nail head bonding technique. In this way, an optical signal wire optically connected to the light emitting element or the light receiving element
11 is led out of the package.

The side rail portion 23 is located outside the package body and separated from the package body after the assembly of the device is completed.

In order to secure the bondability with the wire 11, the wire 11, the bonding pad 10b, and the lead frame 25 are formed on the surfaces of the semiconductor chip 10 side and the lead frame 25 side to be bonded in advance before bonding. You may make it perform the coating process by the film with good adhesiveness. In this case, at least the semiconductor chip 10 side must use a light-transmitting coating film in order to make the light emitting element or the light receiving element function. Further, as the translucent coating film, a translucent organic film such as an acrylic resin may be used, but in this case, the heating temperature during bonding is
It is desirable to carry out at 100 ° C or lower.

Further, the optical signal wire 11 is attached to the semiconductor chip 10.
At the time of bonding, in order to prevent oxidative deterioration of the wire 11 due to heating, the energy of the laser beam is applied to the ball forming portion in the tip region of the wire 11 in a state of being sprayed with an inert gas to heat and melt the wire 11. It is preferable to form a wire ball by doing so.

In the present embodiment, particularly, the lead frame is
At the position facing the optical signal wire 11, the groove 25 is provided with a groove formed by a U-shaped cut pattern 13 which constitutes an example of a fixing means.

As shown in FIGS. 1 and 2, after the bonding between the optical signal wire 11 and the bonding pad 10b is completed, the optical signal wire 11 is formed into a U-shape for wire positioning. The side rail portion 23 is reached along the cut pattern 13 and the bonding is performed at a predetermined position.

Therefore, in this embodiment, the optical signal wire 11 is used.
It is configured so that the optical signal wire 11 does not move from a predetermined position on the surface of the package body and does not deviate from the predetermined position on the surface of the package body and the angle with respect to the polishing surface after the optical signal wire 11 is bonded by sandwiching the optical signal wire 11 from both sides with the lead frame 25. Has been done.

In this embodiment, in particular, for the purpose of wire positioning, the U-shaped cut pattern 14 is also formed in the side rail portion 23 which is separated from the package after the assembly is completed. Therefore, such wire positioning can be performed more accurately.

Further, in this embodiment, the U-shaped cut pattern 13 in the package further has a film 15 made of polyimide or the like with an adhesive on the surface of the lead frame 25 opposite to the bonding surface of the optical signal wire 11. Is attached in advance before bonding. Accordingly, in the manufacturing stage, the optical signal wire 11 can be temporarily fitted by the groove of the U-shaped cut pattern 13 of the lead frame 25 and the film 15 with the adhesive.

By thus setting the wire bond conditions so that a part of the optical signal wire 11 contacts the adhesive film 15 in the groove portion, the wire loop shape can be further stabilized.

Also, in order to prevent the light propagating in the optical signal wire 11 from leaking from the wire side surface to the used optical signal wire 11, the wire side surface portion reflects the light. It is uniformly coated with a film.

In this way, after the bonding is completed, as shown in FIGS. 2 and 3, the periphery of the lead-out portion 12 of the optical signal wire 11 of the groove is filled with a hard filler which hinders the polishing of silica powder or the like. An agent-free resin, such as a hard powder free epoxy resin 16 having a diameter of more than 1 micron, is potted and heat cured. That is, in the subsequent sealing step, the transfer mold resin 17 is covered with the resin 16 in order to prevent the transfer mold resin 17 from reaching the area to be polished.

After that, the resin is molded with an epoxy transfer mold resin to complete the sealing, the external terminals are cut and molded, and the surface treatment for soldering is performed and the packaging is performed. At this time, when the package is cut off from the side rail portion 23 of the lead frame 25, the optical signal wire 11 is cut near the surface of the package side surface 24.

Thereafter, as shown in FIG. 4, a package corresponding to the plate thickness of the lead frame 25 on the mold parting surface 26.
The optical signal wire 11 on the resin surface is mechanically polished together with the resin on the package surface by a specified amount (for example, several tens of microns), and the surface to be polished is a smooth surface with a depth of about 0.5 microns.
Forming 18. Here, the resin portion to be polished is
Since it is made of resin 16, the polishing surface is not damaged. As a result, good optical connection with the optical communication cable for external connection can be achieved.

As described above, the semiconductor device 31 configured as a semiconductor package as shown in FIG. 5 is completed.

As can be seen from FIG. 5, the semiconductor device 31 is
An outer lead 33 for communicating an electrical signal is provided along the outer periphery of the outer lead 33, and a lead-out portion 12 of the optical signal wire 11 is exposed from the package body on the polishing surface.

After the semiconductor device 31 thus constructed is mounted on a printed circuit board or the like, it is connected to an optical cable 41 which is provided with a connector 40 and is composed of an optical fiber as shown in FIG. Then, it is connected to another semiconductor device through the optical cable 41.

At this time, according to this embodiment, the lead-out portion 12 of the optical signal wire 11 is accurately positioned, and the polished surface 18 of the package surface is scarcely scratched. The optical connection with the optical cable 41 can be performed very well.

[0043]

As described in detail above, according to the first invention of the present application, the optical signal wire led out to the outside of the package body is repositioned by the fixing means with respect to the package body. -Because I fixed it on the dframe,
The optical signal wire can be led out to a predetermined position on the surface of the package body. As a result, the positioning required for the connection between the optical signal wire and the optical signal cable led out from the package can be accurately performed, and the optical connection with the optical signal cable can be favorably performed. ..

Further, according to the second aspect of the present invention, since the periphery of the lead-out position of the optical signal wire led out of the package body is covered with the resin containing no hard filler, the package When polishing near the lead-out position of the optical signal wire on the surface of the main body, it is possible to perform a smooth polishing process without damaging the surface to be polished with silica powder etc. in the mold resin. Good connection.

As a result, according to the present invention, both electric signals and optical signals can be processed, and extremely stable and reliable communication can be performed for both of them, which is excellent in mass productivity and is inexpensive. A semiconductor device can be realized.

[Brief description of drawings]

FIG. 1 shows an internal structure of a semiconductor device according to an embodiment of the present invention,
It is the top view shown in the state in the one manufacturing process.

FIG. 2 is a partial cross-sectional view showing the vicinity of a lead portion of the optical signal wire of the embodiment of FIG.

FIG. 3 is a plan view showing the internal structure of the embodiment of FIG. 1 in a state in another manufacturing process.

FIG. 4 is a side view showing the vicinity of the lead-out portion of the optical signal wire of the embodiment of FIG.

5 is a perspective view showing a completed state of the embodiment of FIG. 1. FIG.

6 is a perspective view showing a state in which the optical cables of the embodiment of FIG. 6 are connected.

FIG. 7 is a plan view showing an internal structure of a conventional semiconductor device in a state in a manufacturing process thereof.

[Explanation of symbols]

 10 Semiconductor chip 11 Optical signal wire 12 Optical signal wire lead-out portion 13 U-shaped notch pattern in the package 14 U-shaped notch pattern in the side rail 15 Adhesive film 16 Potting resin that does not contain hard filler 17 Transfer mold resin 18 Area to be polished on package surface 21 Gold wire 22 Terminal part of lead frame 23 Side rail part of lead frame 24 Side surface of package molded with mold resin 25 Lead frame 26 Mold parting surface 31 Semiconductor device 40 Optical cable connector 41 Optical cable

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H01L 33/00 M 8934-4M N 8934-4M

Claims (3)

[Claims] 1. A semiconductor substrate having at least one of a light receiving element and a light emitting element, a package main body for sealing the semiconductor substrate, and a lead frame having the semiconductor substrate attached inside the package main body. And an optical signal wire, one end of which is connected to the semiconductor substrate inside the package body and the other end of which is led out of the package body, for the optical signal. A semiconductor device comprising fixing means for fixing the optical signal wire to the lead frame so as to position the wire with respect to the package body. 2. The fixing means covers the groove formed in the lead frame and into which the optical signal wire is fitted, and the groove from the side opposite to the side where the optical signal wire is fitted. 2. A semiconductor device according to claim 1, further comprising: a film with an adhesive, which is adhered to the groove portion of the lead frame and the optical signal wire is adhered in the groove. 3. A semiconductor substrate having at least one of a light receiving element and a light emitting element, a package body made of a mold resin for sealing the semiconductor substrate, and the package body inside the package body. A lead frame to which a semiconductor substrate is attached, and an optical signal wire whose one end is connected to the semiconductor substrate inside the package body and the other end is led to the outside of the package body. And a semiconductor device characterized in that the periphery of the lead-out position of the optical signal wire is covered with a resin containing no hard filler.