JP3238256B2 - Semiconductor device, image sensor device, and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device on which a semiconductor element is mounted and a method of manufacturing the same, and further relates to an image sensor device for reading image information such as a manuscript and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a technique for mounting a semiconductor element such as an LSI on a wiring board, a wire bonding method, a flip chip bonding method, a film carrier bonding method, a beam lead bonding method and the like are known. In the wire bonding method, a semiconductor element (chip) is fixed on a substrate on which a circuit conductor layer is formed with a conductive adhesive, and electrodes on the chip and the circuit conductor layer are connected by a thin metal wire such as gold or aluminum. However, in such a wire bonding method, it is difficult to perform a wiring operation using a thin metal wire, and since the electrodes on the chip need to be formed around the chip, it is difficult to reduce the pitch between the electrodes. It is difficult to respond to density mounting. In order to solve such a problem, as a technology for mounting a semiconductor device by wireless bonding, a mounting technology for an image sensor device is disclosed in U.S. Pat. No. 5,065,006 and U.S. Pat.
No. 138,145.

A method of manufacturing the image sensor device disclosed in these patents will be described with reference to FIGS. FIG. 7 is a cross-sectional view of an image sensor device in which the image sensor chip 16 is mounted face down on the transparent substrate 11. The image sensor device is manufactured as follows. First, a photocurable insulating resin 18 is applied on the transparent substrate 11 on which the circuit conductor layer 12 is formed.
The electrode 15 having the bump 14 and the light receiving element 1
The image sensor chip 16 having the image 9 is pressed in a face-down state, and ultraviolet light is irradiated through the transparent substrate 11 while applying pressure. The photocurable insulating resin 18 is cured by the irradiation of ultraviolet rays, and the image sensor chip 16 is fixed to the substrate. Thereafter, a protective film 17 is formed by applying a resin such as silicon, and the image sensor device is completed.

[0004] As shown in FIG. 8, an electrode 15 on an image sensor chip 16 has a bump 14 provided with an annular projection 20 at the tip. Image sensor chip 16
Are mounted face down on the substrate 11 such that the bumps 14 come into contact with the circuit conductor layer 12 on the substrate 11. When the image sensor chip 16 is pressed from above, the annular protrusion 20 is crushed, so that the circuit conductor layer 12 and the bump 14 are connected so as to be in close contact with each other.

[0005]

As described above, in the prior art, the photocurable insulating resin 18 is cured by irradiating ultraviolet rays through the transparent substrate 11.
The portion of the insulating resin 18 which is shaded by the circuit conductor layer 12 disposed on the transparent substrate 11 may not be completely cured because the ultraviolet rays are not sufficiently irradiated. If the curing of the insulating resin 18 is incomplete, the strength of the semiconductor device on which the semiconductor element (image sensor chip) 16 is mounted cannot be sufficiently obtained, so that the durability of the device decreases. Further, there is a problem that a connection failure between the element 16 and the circuit conductor layer 12 is likely to occur. Furthermore, when the semiconductor device is an image sensor device, there is a problem caused by the inhomogeneous optical characteristics of the insulating resin 18 if the insulating resin 18 is not completely cured. For example, when a portion having a different refractive index of the insulating resin 18 occurs, refraction or scattering of incident light occurs, and an error occurs in reading an image by the light receiving element 19 or resolution is reduced.

In addition, the pressure must be applied at a pressure higher than the pressure required to crush the annular projection 20 of the bump 14, and the image sensor chip 16 and the transparent substrate 11 may be broken. In addition, since the connection is made by mechanical deformation, the adhesion is incomplete, or the electrode 15 or the bump 14,
Since the variation in the height of the circuit conductor layer 12 and the warpage of the image sensor chip 16 and the transparent substrate 11 cannot be completely absorbed, the electrical connection may be incomplete.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to completely cure an insulating resin, and to further form an electrode on a semiconductor element (chip) and a circuit conductor on a substrate. An object of the present invention is to provide a highly reliable semiconductor device and an image sensor device by reliably and electrically connecting layers, and to provide a method for manufacturing the semiconductor device and the image sensor device.

[0008]

According to the present invention, there is provided a semiconductor device comprising:
A light-transmitting substrate having first and second surfaces, a circuit conductor layer formed on the first surface of the light-transmitting substrate, and a first surface of the light-transmitting substrate having electrodes on its surface A semiconductor element mounted face-down above, and a photo-thermosetting insulating resin layer for fixing the semiconductor element to the light-transmitting substrate are provided, and a plating metal layer is provided on at least a part of the circuit conductor layer. The electrodes of the semiconductor element are connected to the circuit conductor layer via the plating metal layer, and the plating metal is once melted on the circuit conductor layer and re-solidified on the joint surface between the plating metal layer and the circuit conductor layer. An alloy layer is formed, thereby achieving the above object.

In the semiconductor device according to the present invention, it is further preferable that an alloy layer formed by melting the plating metal once on the electrode and re-solidifying it is formed on the joint surface between the electrode and the plating metal layer. .

It is preferable that the plating metal is made of solder.

Further, in the semiconductor device according to the present invention, the electrodes of the semiconductor element have metal bumps, the metal bumps are connected to the circuit conductor layer via the plated metal layer, and the bonding surface between the metal bump and the plated metal layer is provided. Preferably, an alloy layer is formed by melting and re-solidifying the plating metal once.

It is preferable that the metal bump is an Au bump.

According to a method of manufacturing a semiconductor device of the present invention, a step of forming a circuit conductor layer on a first surface of a light-transmitting substrate having first and second surfaces; Forming a plated metal layer;
Forming a photo-thermosetting insulating resin layer on the surface of, and arranging the semiconductor element having an electrode on the surface in a face-down state such that the electrode is located on the plated metal layer; and A first curing step of irradiating the light-curable insulating resin with ultraviolet light from the second surface of the light-transmitting substrate through the light-transmitting substrate while pressing the light-transmitting substrate, thereby curing the light-curable insulating resin; And a step of further curing the photothermosetting insulating resin by maintaining the translucent substrate on which the semiconductor element is disposed at a certain temperature for a certain period of time, the temperature being the melting point of the metal of the plating metal layer and the photothermal curing. A second curing step at a temperature higher than the curing temperature of the mold insulating resin, thereby achieving the above object.

It is more preferable that the second hardening step includes a step of melting a plating metal and forming an alloy on a joint surface between the plating metal layer and the circuit conductor layer.

The electrode of the semiconductor element has a metal bump, and the second curing step melts the plating metal to bond the metal bump to the plating metal layer and to bond the plating metal layer to the circuit conductor layer. Preferably, the method includes a step of forming an alloy on each surface.

It is preferable that the second curing step is performed while pressing the semiconductor element against the light-transmitting substrate.

The step of forming the circuit conductor layer includes a step of depositing the conductor layer on the first surface of the light-transmitting substrate, and a step of patterning the conductor layer by photolithography, thereby forming a circuit conductor layer. It is preferable to include the steps.

Further, the step of forming the circuit conductor layer includes:
A step of forming a circuit conductor layer by attaching a flexible printed board to the first surface of the light-transmitting substrate may be employed.

An image sensor device according to the present invention includes a light-transmitting substrate having first and second surfaces, a circuit conductor layer formed on the first surface of the light-transmitting substrate, electrodes and a light receiving element. An image sensor element having a surface and mounted face-down on a first surface of a light-transmitting substrate, and a photothermosetting insulating resin layer for fixing the image sensor element to the light-transmitting substrate. A plating metal layer is provided on at least a part of the circuit conductor layer, and an electrode of the image sensor element is connected to the circuit conductor layer via the plating metal layer, and on a joint surface between the plating metal layer and the circuit conductor layer, An alloy layer is formed by melting and re-solidifying the plated metal once on the circuit conductor layer, thereby achieving the above object.

In the image sensor device of the present invention, it is more preferable that an alloy layer formed by melting the plating metal once on the electrode and re-solidifying it is formed on the joint surface between the electrode and the plating metal layer.

It is preferable that the plating metal is made of solder.

In the image sensor device according to the present invention, the electrodes of the image sensor element have metal bumps. The metal bumps are connected to the circuit conductor layer via the plated metal layer, and the metal bump is bonded to the plated metal layer. It is preferable that an alloy layer formed by melting and re-solidifying the plating metal once is formed on the surface.

The metal bump is preferably an Au bump.

It is preferable that the total thickness of the light-transmitting substrate and the photo-thermosetting insulating resin layer is 150 μm or less.

According to a method of manufacturing an image sensor device of the present invention, a step of forming a circuit conductor layer on a first surface of a light-transmitting substrate having first and second surfaces, and at least a portion of the circuit conductor layer Forming a plated metal layer, forming a photothermosetting insulating resin layer on the first surface of the light-transmitting substrate, and forming an image sensor element having electrodes and light-receiving elements on the surface. A step of arranging the image sensor element in a face-down state so as to be positioned on the plated metal layer, and pressing the image sensor element against the light-transmitting substrate while passing the light-transmitting substrate from the second surface of the light-transmitting substrate A first method of irradiating the photothermosetting insulating resin with ultraviolet light to cure the photothermosetting insulating resin.
A curing step and a step of further curing the photothermosetting insulating resin by maintaining the translucent substrate on which the image sensor element is disposed at a certain temperature for a certain period of time, the temperature being the melting point of the metal of the plating metal layer. And a second curing step at a temperature higher than the curing temperature of the photothermosetting insulating resin, thereby achieving the above object.

Preferably, the second hardening step includes a step of melting the plating metal and forming an alloy on the joint surface between the plating metal layer and the circuit conductor layer.

The electrode of the image sensor element has a metal bump, and the second curing step melts the plating metal to form a bonding surface between the metal bump and the plating metal layer, and between the plating metal layer and the circuit conductor layer. Preferably, the method includes a step of forming an alloy on each joint surface.

Preferably, the second curing step is performed while pressing the image sensor element against the light transmitting substrate.

It is preferable that the total thickness of the translucent substrate and the photothermosetting insulating resin layer is 150 μm or less.

The step of forming the circuit conductor layer includes a step of depositing the conductor layer on the first surface of the light-transmitting substrate, and a step of patterning the conductor layer by photolithography, thereby forming the circuit conductor layer. It is preferable that the method includes the steps of:

Further, the step of forming the circuit conductor layer includes:
The circuit conductor layer may be formed by attaching a flexible printed board to the first surface of the light-transmitting substrate.

Further, the step of forming the circuit conductor layer comprises:
The circuit conductor layer may be formed by thick-film printing on the first surface of the translucent substrate.

[0033]

According to the semiconductor device or the image sensor device of the present invention, the plating metal layer is provided on the circuit conductor layer, and the bonding surface between the electrode on the semiconductor element or the image sensor element and the plating metal layer, and the light transmitting property. By providing the alloy layer on the joint surface between the circuit conductor layer and the plated metal layer on the substrate, these elements can be reliably and electrically connected to the circuit conductor layer. Thus, a highly reliable semiconductor device or image sensor device can be provided.

According to the method of manufacturing a semiconductor device or an image sensor device of the present invention, a semiconductor element is formed by forming an alloy layer through a step of forming a plated metal layer on a circuit conductor layer and a second curing step (heat treatment). Also, the electrodes on the image sensor element and the circuit conductor layer on the translucent substrate can be electrically reliably connected. Thus, a highly reliable method for manufacturing a semiconductor device or an image sensor device can be provided. Further, the photo-thermosetting insulating resin is completely cured by the first curing step (light irradiation) and the second curing step (heat treatment), and the semiconductor element and the image sensor element can be securely mounted on the light-transmitting substrate. Yield can be greatly improved. By ensuring that the element is mounted by the first and second curing steps,
Deterioration of the semiconductor device and the image sensor device can be prevented, and the durability of the device can be increased.

[0035]

Embodiments of the present invention will be described below.

FIG. 1 shows the structure of the semiconductor device of the present invention. The translucent substrate 1 uses a glass substrate. The translucent substrate 1 is made of polyarylate (PA), polyether sulfone (PAS), polyethylene terephthalate (PE).
T) or a transparent substrate such as polyethylene naphthalate (PEN). The translucent substrate 1 has first and second surfaces. On the first surface 1a, a circuit conductor layer 2 formed of a metal such as copper or aluminum is provided. The semiconductor element 6 has the electrode 5 on the surface. Various elements may be formed on the semiconductor element 6. The electrode 5 of the semiconductor element 6 has the metal bump 4. The metal bump 4 is an Au bump. Although the metal bump 4 is not an essential element of the present invention, the present invention will be described with respect to an embodiment in which the metal bump 4 is provided.

The semiconductor element 6 is mounted face-down on the first surface 1a of the translucent substrate 1. A photo-thermosetting insulating resin layer 8 for fixing the semiconductor element 6 to the light-transmitting substrate 1 is provided between the semiconductor element 6 and the light-transmitting substrate 1. The photothermosetting insulating resin is an acrylate-based transparent resin. In addition, for example, a methacrylate-based resin can be used. Generally, a photocurable insulating resin is cured by irradiating light, and some of them are not cured by heating. However, in the present invention, an insulating resin that is cured not only by light but also by heating is used.

A plating metal layer 3 is provided on at least a part of the circuit conductor layer 2, and the electrode 5 of the semiconductor element 6 is connected to the circuit conductor layer 2 via the plating metal layer 3.
The plating metal layer 3 is once melted and re-solidified on the circuit conductor layer 2, so that an alloy layer is formed on the joint surface between the plating metal layer 3 and the circuit conductor layer 2. In this embodiment,
As the plated metal layer 3, In / Ga group, In / Ga
Solder of Sn group, Pb / Sn group or the like is used. The metal bumps 4 are connected to the circuit conductor layer 2 via the plating metal layer 3. The plating metal layer 3 is once melted and re-solidified on the joint surface between the metal bump 4 and the plating metal layer 3. Has an alloy layer formed.
When the metal bumps 4 are not provided, an alloy layer is formed on the bonding surface between the electrode 5 and the plated metal layer 3 in a narrow sense.

A method for manufacturing the above semiconductor device will be described below.

First, various elements (not shown) and a main body of the extraction electrode 5 are formed on a single crystal silicon substrate (wafer) by a semiconductor process. On the body of the electrode 5,
The metal bumps 4 are formed by an electroplating method, a ball bonding method, or the like. The metal bump 4 is an Au bump. After that, the wafer is cut by a high-precision dicing technique to manufacture the semiconductor element 6.

Next, the circuit conductor layer 2 is formed on the first surface 1a of the translucent substrate 1, which is a glass substrate. The translucent substrate 1 is made of polyarylate (PA), polyether sulfone (PAS), polyethylene terephthalate (PE).
T) or a transparent substrate such as polyethylene naphthalate (PEN). The circuit conductor layer 2 is formed by depositing a metal such as copper or aluminum on the translucent substrate 1 using an evaporation method, a sputtering method, or the like, and then patterning the deposited metal layer by a photolithography technique. You. The circuit conductor layer 2 can also be formed using a foil or the like. Alternatively, the circuit conductor layer 2 may be formed by attaching a flexible printed board to the first surface 1a of the light-transmitting substrate 1.

Further, a plated metal layer 3 is formed at a predetermined position of the circuit conductor layer 2 by, for example, an electrolytic or electroless method. Next, a predetermined amount of an acrylate-based transparent photo-thermo-curable insulating resin is applied to a predetermined position on the first surface 1a of the translucent substrate 1 by a stamping method, a screen printing method, etc. The curable insulating resin layer 8 is formed. A semiconductor element 6 having an electrode 5 or the like on its surface is placed thereon so that the electrode 5 contacts the plated metal layer 3.
Place it face down. And the semiconductor element 6
Is pressed against the light transmitting substrate 1 while the light transmitting substrate 1 is pressed.
The photothermosetting insulating resin layer 8 is irradiated with ultraviolet rays from the side of the second surface 1b where the circuit conductor layer 2 is not formed through the translucent substrate 1 to cure the photothermosetting insulating resin (first). Curing step). In the first curing step, the semiconductor element 6
From above, a pressure of 0.5 kgf to 2.5 kgf is applied. The ultraviolet light is irradiated at an intensity of 200 mW to 500 mW for about 0.5 to 2.0 minutes.

Thereafter, the light transmissive substrate 1 on which the semiconductor element 6 is disposed is placed in an electric furnace and kept at a certain temperature for a certain period of time to further cure the photothermosetting insulating resin (second curing step). . This temperature is higher than the melting point of the metal of the plating metal layer 3 and the curing temperature of the photothermosetting insulating resin. When eutectic solder is used as the plating metal layer 3, heat treatment is performed at 185 ° C. to 200 ° C. for about 5 minutes to 30 minutes. In this embodiment, heat treatment was performed at 190 ° C. for about 10 minutes. In the second hardening step, the plating metal is melted, so that an alloy is formed on the joining surface between the metal bump 4 and the plating metal 3 and on the joining surface between the plating metal 4 and the circuit conductor layer 2, respectively.

The following effects can be obtained by melting the plating metal once in the second curing step. When the plating metal layer 3 becomes liquid, it becomes in a state conforming to the fine shape of the joint surface of the electrode 5, so that the contact area between them increases, and the adhesion along the joint surface increases. The alloy layer on the joining surface is also more easily formed, and the connection can be made reliably. In addition, even when organic dirt is present on the surface, such dirt can be removed.

In the second curing step, in the first curing step, the uncured portion of the photothermosetting insulating resin which is shaded by the circuit conductor layer 2 formed on the light-transmitting substrate 1 is removed. It is completely cured, and the mounting of the semiconductor element 6 is completed. Note that the heat treatment in the second curing step is performed while applying a pressure of 0 to 1.0 kgf from above to press the semiconductor element 6 against the translucent substrate 1.

After the mounting of the semiconductor element 6 is completed, a resin such as silicon is applied with a dispenser or the like to form a coating resin 7, and the semiconductor device is completed.

As described above, by curing the photothermosetting insulating resin in the first curing step and the second curing step, the photothermosetting insulating resin portion that cannot be completely cured only by the first curing step alone. Can be completely cured by further curing in the second curing step. Further, in the second curing step, an alloy layer is formed on the joint surface between the plated metal layer 3, the metal bump 4, and the circuit conductor layer 2, thereby forming the semiconductor element 6
Can be more reliably electrically connected to the circuit conductor layer 2. Thus, the semiconductor element 6 can be more reliably mounted on the translucent substrate 1.

Next, the configuration of the image sensor device of the present invention will be described with reference to FIGS. Parts corresponding to the respective parts of the semiconductor device shown in FIG. 1 are denoted by the same reference numerals. FIG. 3 is a view of the image sensor device as viewed from above, and FIGS. 4 and 5 respectively show A shown in FIG.
It is sectional drawing which followed the -A line and the BB line.

The translucent substrate 1 is made of polyarylate (P
A), a transparent substrate made of polyethersulfone (PAS), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or the like. The light-transmitting substrate 1 may be a glass substrate as in the case of the semiconductor device. In the case of a contact type image sensor device, the thickness of the light transmitting substrate 1 is 0.5 mm to 2.0 mm. The thickness Ts of the translucent substrate 1 in the case of the complete contact type image sensor device is 1
0 μm to 200 μm, preferably 10 μm to 7 μm
5 μm.

On the first surface 1a of the translucent substrate 1, copper,
A circuit conductor layer 2 made of a metal such as aluminum or a noble metal such as gold or silver-platinum is provided. The thickness To of the circuit conductor layer 2 is formed in the range of 3 μm to 35 μm.

The image sensor element 6 has an electrode 5, a light receiving element 9, and other elements (not shown) on its surface. The light receiving element 9 is a phototransistor or a photodiode, and the other elements are a CCD, a MOS,
It is an access circuit such as a bipolar IC. Light receiving element 9
Form a light receiving element array as shown in FIG. 3 and FIG. The metal bumps 4 are provided on the body of the electrode 5 of the image sensor element 6. Metal bump 4 is A
u It is a bump. The thickness Tb of the Au bump is 3 μm to 6 μm.
0 μm. Although the metal bump 4 is not an essential component of the present invention, the present invention will be described with respect to an embodiment in which the metal bump 4 is provided.

The image sensor element 6 is mounted face-down on the first surface of the light transmitting substrate 1. A photothermosetting insulating resin layer 8 for fixing the image sensor element 6 to the translucent substrate 1 is provided between the image sensor element 6 and the translucent substrate 1. Photo-thermosetting insulating resin is an acrylate-based transparent resin.
For example, a methacrylate type or the like can be used. A plating metal layer 3 is provided on at least a part of the circuit conductor layer 2, and the electrode 5 of the image sensor element 6 is connected to the circuit conductor layer 2 via the plating metal layer 3. The plating metal layer 3 is once melted and re-solidified on the circuit conductor layer 2, so that an alloy layer is formed on the joint surface between the plating metal layer 3 and the circuit conductor layer 2. In the present embodiment, the plating metal layer 3 is made of solder of an In / Ga group, an In / Sn group, a Pb / Sn group, or the like. The thickness Tm of the plating metal layer 3 is 2 μm to 20 μm.
The metal bump 4 is formed on the circuit conductor layer 2 via the plated metal layer 3.
And a bonding surface between the metal bump 4 and the plated metal layer 3 has an alloy layer formed by melting and re-solidifying the plated metal once. When the metal bumps 4 are not provided, an alloy layer is formed on the bonding surface between the electrode 5 and the plated metal layer 3 in a narrow sense.

When the above image sensor device is used as a complete contact type image sensor device, the distance T (T = Ts) from the light receiving element 9 to the second surface 1b of the translucent substrate 1
+ To + Tb + Tm) is 150 μm or less, preferably 100 μm or less.

The reason that the distance T is limited in this manner is that the lens is not used in the case of the completely contact type image sensor device, and the resolution (resolution) of the image sensor device is limited to the original surface (the first surface of the transparent substrate 1). This is because it largely depends on the distance T from the second surface 1b) to the light receiving element 9. FIG. 6 shows this relationship. The vertical axis in FIG. 6 is MTF (Modulation-Trans
fer-Function) value, which is a measure of resolution. In practical use, the MTF value is 4 lp / mm and 30 to 40% or more is required.
Is limited to the second surface 1b. A method for manufacturing the image sensor device will be described below.

First, a phototransistor as a light receiving element 9, a driving circuit (not shown), and an extraction electrode 5 are formed on a single crystal silicon substrate (wafer) by a semiconductor process.
To form a body. An Au bump 4 is formed on the body of the electrode 5 by an electroplating method, a ball bonding method, or the like. Thereafter, the wafer is cut by a high-precision dicing technique, and the image sensor element 6 is manufactured.

Next, the first surface 1a of the translucent substrate 1, which is a transparent substrate such as polyarylate (PA), polyether sulfone (PAS), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN). The circuit conductor layer 2 is formed thereon. The translucent substrate 1 may be a glass substrate. The circuit conductor layer 2 is formed by depositing a metal such as copper or aluminum on the translucent substrate 1 using an evaporation method, a sputtering method, or the like, and then patterning the deposited metal layer by a photolithography technique. You. The circuit conductor layer 2 can also be formed using a foil or the like. The circuit conductor layer 2 may be formed using a noble metal such as gold or silver-platinum. Alternatively, the circuit conductor layer 2
A flexible printed board may be attached to the first surface of the light-transmitting substrate, or may be formed by thick-film printing.

Further, a plated metal layer 3 is formed at a predetermined position of the circuit conductor layer 2 by, for example, an electrolytic or electroless method.

Next, a predetermined amount of an acrylate-based transparent photo-thermosetting insulating resin is applied to a predetermined position on the first surface 1a of the translucent substrate 1 by a stamping method, a screen printing method, or the like. Then, a photothermosetting insulating resin layer 8 is formed. An image sensor element 6 having an electrode 5, a light receiving element 9, and the like on its surface is disposed face-down thereon so that the electrode 5 contacts the plated metal layer 3. Then, while pressing the image sensor element 6 against the translucent substrate 1, the light is transmitted through the translucent substrate 1 from the side of the second surface 1 b of the translucent substrate 1 where the circuit conductor layer 2 is not formed. The curable insulating resin layer 8 is irradiated with ultraviolet rays to cure the photothermosetting insulating resin (first curing step).

The image sensor element 6 used in this embodiment
Has 15 electrodes 5 per element, and applies a pressure of 0.5 kgf to 2.5 kgf per element from above. Simultaneously with the application of the above pressure, ultraviolet light having an intensity of 100 mW to 1500 mW was irradiated from below the second surface 1b of the light transmitting substrate 1 for 20 seconds to 100 seconds. In consideration of the mass production effect, it is desirable to complete the first curing in 20 to 40 seconds.

Thereafter, the light transmissive substrate 1 on which the image sensor element 6 is disposed is placed in an electric furnace and kept at a certain temperature for a certain period of time to further cure the photothermographic insulating resin (second curing step). ). This temperature depends on the plating metal layer 3
Is higher than the melting point of the metal and the curing temperature of the photothermosetting resin. When using eutectic solder as plating metal,
The heat treatment is performed at 185 ° C. to 200 ° C. for about 5 minutes to 30 minutes.
In this embodiment, heat treatment was performed at 190 ° C. for about 10 minutes. In the second hardening step, since the plating metal layer 3 is melted, an alloy layer is formed on each of the bonding surface between the metal bump 4 and the plating metal layer 3 and the bonding surface between the plating metal layer 3 and the circuit conductor layer 2. It is formed.

The effect obtained by melting the plating metal layer 3 once in the second curing step is the same as that in the above-described embodiment of the semiconductor device. The plating metal layer 3 which has become liquid by temporarily melting the plating metal layer 3
Is in a state conforming to the fine shape of the bonding surface of the electrode 5. As a result, the contact area between the two increases, and the adhesion along the bonding surface increases. Therefore, since the alloy layer on the joining surface is more easily formed, the image sensor element 6 can be reliably connected. In addition, even when organic dirt is present on the surface, such dirt can be removed.

In the second curing step, in the first curing step, the photo-thermosetting insulating portion of the portion which was shaded by the circuit conductor layer 2 formed on the translucent substrate 1 and was incompletely cured was used. The resin is completely cured, and the mounting of the image sensor element 6 is completed. The heat treatment in the second curing step is performed while applying a pressure of 0 to 1.0 kgf from above and pressing the image sensor element 6 against the light transmitting substrate 1.

After the mounting of the image sensor element 6 is completed, a resin such as silicon is applied with a dispenser or the like,
The image sensor device is completed by forming the coating resin 7. As described above, in the first curing step, the photothermosetting insulating resin is cured only by the irradiation of ultraviolet rays, so that an uncured portion remains in the photothermosetting insulating resin. Therefore, when the photothermosetting insulating resin is cured only by the first curing step, a mounting failure occurs in a later environmental test or the like. Table 1 shows the results of environmental tests in the case where only light curing (first curing step) was performed and in the case where light curing and heat curing (first and second curing steps) were performed, respectively. Comparing the test results in the two cases, the temperature and humidity (85 ° C., 8
5%) and heat shock (-30 ° C ~
(+ 70 ° C.), no defective product was found in the test product when the photothermosetting insulating resin was cured by ultraviolet irradiation and heat treatment. However, when the photothermosetting insulating resin is cured only by ultraviolet irradiation, defective products occur in about 40% to 60%. As described above, by performing two-stage curing of light curing and heat treatment, the mounting yield of the device can be improved. Further, as is clear from the test results in Table 1, it can be understood that deterioration of the image sensor device can be prevented and durability of the image sensor device can be increased by two-stage curing of light curing and heat treatment.

[0064]

[Table 1]

[0065]

According to the semiconductor device or the image sensor device of the present invention, the semiconductor device or the image sensor device can be electrically connected to the circuit conductor layer reliably, and the semiconductor device or the image sensor device with high reliability can be obtained. Can be provided.

According to the method of manufacturing a semiconductor device or an image sensor device of the present invention, it is possible to provide a highly reliable method of manufacturing a semiconductor device or an image sensor device, and to greatly improve the mounting yield of the device. Can be. By reliably mounting the elements by the first and second curing steps, deterioration of the semiconductor device and the image sensor device can be prevented, and the durability of the device can be increased.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a semiconductor device of the present invention.

FIG. 2 is a front sectional view of the image sensor device of the present invention.

FIG. 3 is a perspective view of the image sensor device of the present invention from above.

FIG. 4 is a side sectional view of the image sensor device of the present invention, taken along line AA shown in FIG. 2;

FIG. 5 is a side sectional view of the image sensor device of the present invention, taken along line BB shown in FIG. 2;

FIG. 6 shows an MTF value of a perfect contact type image sensor device.
9 is a graph showing a function of a distance from a document surface to a light receiving element.

FIG. 7 is a front sectional view of a conventional image sensor device.

FIG. 8 is a view showing a part of a mounting process of a conventional image sensor element.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 translucent substrate 2 circuit conductor layer 3 plated metal layer 4 bump 5 electrode 6 image sensor element (semiconductor element) 7 coating resin 8 photothermosetting insulating resin layer 9 light receiving element

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-27264 (JP, A) JP-A-2-309643 (JP, A) JP-A-4-6841 (JP, A) JP-A-4- 240741 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/60

Claims (25)

(57) [Claims] A light-transmitting substrate having first and second surfaces; a circuit conductor layer formed on the first surface of the light-transmitting substrate; and a light-transmitting substrate having electrodes on its surface. A semiconductor device comprising: a semiconductor element mounted face-down on a first surface of the semiconductor device; and a photo-thermosetting insulating resin layer for fixing the semiconductor element to a light-transmitting substrate. The plating metal layer is provided on at least a part of the semiconductor element, and the electrode of the semiconductor element is connected to the circuit conductor layer via the plating metal layer, and the plating metal is formed on the connection surface between the plating metal layer and the circuit conductor layer. A semiconductor device having an alloy layer formed by melting and re-solidifying once. 2. The semiconductor device according to claim 1, wherein an alloy layer formed by melting and re-solidifying the plating metal on the electrode is formed on a joint surface between the electrode and the plating metal layer. 3. The semiconductor device according to claim 1, wherein the plating metal is solder. 4. An electrode of a semiconductor device having a metal bump, the metal bump being connected to a circuit conductor layer via a plating metal layer, and the plating metal being once melted on a joint surface between the metal bump and the plating metal layer. 2. The semiconductor device according to claim 1, wherein an alloy layer is formed by re-solidification. 5. The metal bump is an Au bump.
3. The semiconductor device according to claim 1. 6. A step of forming a circuit conductor layer on a first surface of a light-transmitting substrate having first and second surfaces, and a step of forming a plating metal layer on at least a part of the circuit conductor layer. Forming a photo-thermosetting insulating resin layer on the first surface of the light-transmitting substrate; and placing the semiconductor element having electrodes on the surface in a face-down state so that the electrodes are positioned on the plated metal layer. And irradiating the photothermosetting insulating resin with ultraviolet light from the second surface of the translucent substrate through the translucent substrate while pressing the semiconductor element against the translucent substrate. A first curing step of curing the insulating resin, and a step of further curing the photothermosetting insulating resin by maintaining the light-transmitting substrate on which the semiconductor element is disposed at a certain temperature for a certain period of time. Melting point of metal layer and photo-thermosetting type The method of manufacturing a semiconductor device comprises a second curing step at a temperature higher than the curing temperature of the resin. 7. The method of manufacturing a semiconductor device according to claim 6, wherein the second curing step includes a step of melting the plating metal and forming an alloy on a joint surface between the plating metal layer and the circuit conductor layer. 8. The electrode of the semiconductor element has a metal bump, and the second curing step melts the plating metal to bond the metal bump to the plating metal layer and to bond the plating metal layer to the circuit conductor layer. 7. The method for manufacturing a semiconductor device according to claim 6, further comprising a step of forming an alloy on each surface. 9. The method according to claim 6, wherein the second curing step is performed while pressing the semiconductor element against the light-transmitting substrate. 10. The step of forming a circuit conductor layer includes the steps of: depositing a conductor layer on a first surface of a light-transmitting substrate; and patterning the conductor layer by photolithography, thereby forming a circuit conductor layer. 7. The method of manufacturing a semiconductor device according to claim 6, further comprising the steps of: 11. The semiconductor device according to claim 6, wherein in the step of forming the circuit conductor layer, the circuit conductor layer is formed by attaching a flexible printed board on the first surface of the light-transmitting substrate. Manufacturing method. 12. A light-transmitting substrate having first and second surfaces, a circuit conductor layer formed on the first surface of the light-transmitting substrate, electrodes and light-receiving elements on the surface, and The first of the translucent substrate
An image sensor device comprising: an image sensor element mounted face-down on a surface of the substrate; and a photo-thermosetting insulating resin layer for fixing the image sensor element to the light-transmitting substrate. A plating metal layer is provided on at least a part of the circuit, and the electrodes of the image sensor element are connected to the circuit conductor layer via the plating metal layer, and the plating metal is on the circuit conductor layer at the joint surface between the plating metal layer and the circuit conductor layer. An image sensor device in which an alloy layer is formed by melting and re-solidifying once. 13. The image sensor device according to claim 12, wherein an alloy layer is formed on the joint surface between the electrode and the plating metal layer by melting and re-solidifying the plating metal on the electrode. 14. The image sensor device according to claim 12, wherein the plating metal is solder. 15. An electrode of an image sensor element having a metal bump. The metal bump is connected to a circuit conductor layer via a plating metal layer, and a plating metal is formed on a joint surface between the metal bump and the plating metal layer. 13. The image sensor device according to claim 12, wherein an alloy layer formed by melting and re-solidifying is formed. 16. The image sensor device according to claim 15, wherein the metal bump is an Au bump. 17. The image sensor device according to claim 12, wherein the total thickness of the translucent substrate and the photothermosetting insulating resin layer is 150 μm or less. 18. A step of forming a circuit conductor layer on a first surface of a light-transmitting substrate having first and second surfaces, and a step of forming a plating metal layer on at least a part of the circuit conductor layer Forming a photo-thermosetting insulating resin layer on the first surface of the light-transmitting substrate; and forming an image sensor element having electrodes and light-receiving elements on the surface such that the electrodes are located on the plated metal layer. Arranging the image sensor element in a face-down state, and irradiating the photothermosetting insulating resin with ultraviolet light from the second surface of the light-transmitting substrate through the light-transmitting substrate while pressing the image sensor element against the light-transmitting substrate. A first curing step of curing the photothermosetting insulating resin, and a step of further curing the photothermosetting insulating resin by maintaining the translucent substrate on which the image sensor element is disposed at a certain temperature for a certain period of time. The temperature Method of manufacturing includes an image sensor device, the second curing step is a temperature higher than the curing temperature of the melting point and photothermal curable insulating resin of the metal of the metal layer. 19. The method for manufacturing an image sensor device according to claim 18, wherein the second curing step includes a step of melting the plating metal and forming an alloy on a joint surface between the plating metal layer and the circuit conductor layer. 20. An electrode of an image sensor element having a metal bump, wherein a second curing step is performed by melting a plating metal to form a bonding surface between the metal bump and the plating metal layer, and between a plating metal layer and a circuit conductor layer. 19. The method for manufacturing an image sensor device according to claim 18, comprising a step of forming an alloy on each of the bonding surfaces. 21. The method according to claim 18, wherein the second curing step is performed while pressing the image sensor element against the translucent substrate. 22. The method for manufacturing an image sensor device according to claim 18, wherein a total thickness of the light transmitting substrate and the photothermosetting insulating resin layer is 150 μm or less. 23. A step of forming a circuit conductor layer, comprising the steps of: depositing a conductor layer on a first surface of a light-transmitting substrate; and patterning the conductor layer by photolithography, thereby forming the circuit conductor layer. 19. The method for manufacturing an image sensor device according to claim 18, comprising a step of forming. 24. The image sensor according to claim 18, wherein, in the step of forming the circuit conductor layer, the circuit conductor layer is formed by attaching a flexible printed circuit board on the first surface of the light-transmitting substrate. Device manufacturing method. 25. The method according to claim 18, wherein the step of forming the circuit conductor layer comprises forming the circuit conductor layer on the first surface of the light-transmitting substrate by thick-film printing. .