JPH0799218A - Semiconductor device, image sensor and their production - Google Patents

Abstract

PURPOSE:To provide a highly reliable semiconductor and image sensor by curing an insulation resin completely and connecting securely and electrically an electrode on a semiconductor element or image sensor element and a circuit conductive layer on a translucent board. CONSTITUTION:A plating metallic layer 3 is formed on a circuit conductive layer 2, and further an alloy layer is formed on the joint surface between an electrode 5 and the layer 2 on a translucent board 1 through a second curing process by heat treatment, thereby securing electrical connection thereof. Furthermore, a photothermosetting type insulation resin layer is completely cured through a first curing process by irradiating it with an ultraviolet ray and a second curing process by heat treatment.

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, a method for manufacturing the same, an image sensor device for reading image information of a document or the like to which the same is applied, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a wire bonding method, a flip chip bonding method, a film carrier bonding method, a beam lead bonding method, etc. are known as a technology for mounting a semiconductor element such as an LSI on a wiring board. 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 an electrode on the chip and a circuit conductor layer are connected by a fine metal wire such as gold or aluminum. However, in such a wire bonding method, wiring work using a fine metal wire is difficult, and it is difficult to reduce the pitch between electrodes because it is necessary to form the electrodes on the chip around the chip. It is difficult to support high density mounting. In order to solve such a problem, as a mounting technology of a semiconductor element by wireless bonding, a mounting technology of an image sensor element is described in US Pat. No. 5,065,006 and US 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 shows a 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, the photocurable insulating resin 18 is applied on the transparent substrate 11 on which the circuit conductor layer 12 is formed.
On top of that, the electrode 15 having the bump 14 and the light receiving element 1
The image sensor chip 16 having 9 is pressure-bonded in a face-down state, and ultraviolet rays are emitted 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. After that, a resin such as silicon is applied to form the protective film 17, and the image sensor device is completed.

As shown in FIG. 8, the electrode 15 on the image sensor chip 16 has a bump 14 having an annular protrusion 20 at its tip. Image sensor chip 16
Is mounted face down on the substrate 11 so 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 it with ultraviolet rays through the transparent substrate 11.
The part of the insulating resin 18 that is shaded by the circuit conductor layer 12 disposed on the transparent substrate 11 may not be completely cured because it is not sufficiently irradiated with ultraviolet rays. If the insulating resin 18 is not completely cured, the strength of the semiconductor device on which the semiconductor element (image sensor chip) 16 is mounted cannot be sufficiently obtained, and the durability of the device is reduced. There is also a problem that a connection failure between the element 16 and the circuit conductor layer 12 is likely to occur. Further, in the case where the semiconductor device is an image sensor device, if the insulating resin 18 is not completely cured, there is a problem caused by the nonuniform optical characteristics of the insulating resin 18. For example, a portion of the insulating resin 18 having a different refractive index causes refraction or scattering of incident light, which causes an error in reading an image by the light receiving element 19 or lowers the resolution.

In addition, pressure must be applied at a pressure higher than the pressure required to crush the annular protrusion 20 of the bump 14, and the image sensor chip 16 and the transparent substrate 11 may be destroyed. In addition, since the connection is made by mechanical deformation, the adhesion may be incomplete, or the electrodes 15, bumps 14,
In some cases, the electrical connection may be incomplete because variations in height of the circuit conductor layer 12 and warpage of the image sensor chip 16 and the transparent substrate 11 cannot be absorbed.

The present invention has been made in order to solve the above problems, and its purpose is to completely cure an insulating resin and further to form electrodes on a semiconductor element (chip) and circuit conductors on a substrate. An object of the present invention is to provide a highly reliable semiconductor device and image sensor device by electrically and reliably connecting the layers, and to provide a manufacturing method thereof.

[0008]

The semiconductor device of the present invention comprises:
A transparent substrate having first and second surfaces, a circuit conductor layer formed on the first surface of the transparent substrate, and a first surface of the transparent substrate having electrodes on the surface. A semiconductor element mounted face down on top and a photothermosetting insulating resin layer for fixing the semiconductor element to a transparent substrate are provided, and a plated 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 plated metal layer, and the plated metal is once melted and re-solidified on the circuit conductor layer at the joint surface between the plated metal layer and the circuit conductor layer. The alloy layer is formed, and thereby the above-mentioned object is achieved.

It is further preferable that the semiconductor device of the present invention has an alloy layer formed by melting and re-solidifying the plating metal on the electrode once on the bonding surface between the electrode and the plating metal layer. .

It is preferable that the plated metal is composed of solder.

Further, in the semiconductor device of the present invention, the electrodes of the semiconductor element have metal bumps, and 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 connected. Further, it is preferable that an alloy layer is formed by melting and resolidifying the plated metal once.

The metal bumps are preferably Au bumps.

A method of manufacturing a semiconductor device according to the present invention comprises a step of forming a circuit conductor layer on a first surface of a transparent substrate having first and second surfaces, and a step of forming a circuit conductor layer on at least a part of the circuit conductor layer. A step of forming a plated metal layer, and a first step of forming a transparent substrate.
The step of forming a photothermosetting insulating resin layer on the surface of, the step of arranging the semiconductor element having an electrode on the surface in a face-down state so that the electrode is located on the plated metal layer, and the semiconductor element A first curing step of curing the photothermosetting insulating resin by irradiating the photothermosetting insulating resin with ultraviolet rays from the second surface of the translucent substrate through the translucent substrate while pressing against the translucent substrate. And a step of further curing the photothermosetting insulating resin by maintaining the translucent substrate on which the semiconductor element is placed at a certain temperature for a certain time, the temperature being the melting point of the metal of the plating metal layer and the photothermosetting. The second curing step, which is a temperature higher than the curing temperature of the mold insulating resin, is included, whereby the above object is achieved.

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

The electrode of the semiconductor element has a metal bump, and in the second curing step, the plating metal is melted to bond the metal bump to the plating metal layer, and to bond the plating metal layer to the circuit conductor layer. It is preferable to include 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 transparent substrate.

In the step of forming the circuit conductor layer, the step of depositing the conductor layer on the first surface of the translucent substrate and the patterning of the conductor layer by the photolithography technique to form the circuit conductor layer. It is suitable to include a process.

The step of forming the circuit conductor layer includes
It may be a step of forming a circuit conductor layer by pasting a flexible printed board on the first surface of the transparent substrate.

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

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

It is preferable that the plated metal is composed of solder.

In the image sensor device of the present invention, the electrode of the image sensor element has a metal bump, and the metal bump is connected to the circuit conductor layer through the plated metal layer, and the metal bump and the plated metal layer are joined together. It is preferable that the surface has an alloy layer formed by melting and re-solidifying the plating metal once.

The metal bumps are preferably Au bumps.

The total thickness of the translucent substrate and the photothermosetting insulating resin layer is preferably 150 μm or less.

The method of manufacturing an image sensor device according to the present invention comprises a step of forming a circuit conductor layer on the first surface of a transparent substrate having first and second surfaces, and at least a part of the circuit conductor layer. The step of forming a plated metal layer, the step of forming a photothermosetting insulating resin layer on the first surface of the translucent substrate, and the step of forming an image sensor element having an electrode and a light receiving element on the surface. The step of arranging in a face-down state so that it is located on the plated metal layer, and pressing the image sensor element against the translucent substrate from the second surface of the translucent substrate through the translucent substrate. First, the photothermosetting insulating resin is irradiated with ultraviolet rays to cure the photothermosetting insulating resin.
A curing step and a step of further curing the photothermosetting insulating resin by keeping the translucent substrate on which the image sensor element is placed at a certain temperature for a certain period of time, the temperature being the melting point of the metal of the plated 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.

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

The electrodes of the image sensor element have metal bumps, and the second curing step melts the plating metal to bond the metal bumps with the plating metal layer, and the plating metal layer and the circuit conductor layer. It is preferable to include a step of forming an alloy on each of the joint surfaces.

It is preferable that the second curing step is performed while pressing the image sensor element against the transparent substrate.

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

In the step of forming the circuit conductor layer, the step of depositing the conductor layer on the first surface of the translucent substrate and the patterning of the conductor layer by the photolithography technique, thereby forming the circuit conductor layer. It is preferable that the step of

The step of forming the circuit conductor layer includes
The circuit conductor layer may be formed by sticking a flexible printed board on the first surface of the transparent substrate.

The step of forming the circuit conductor layer includes
The circuit conductor layer may be formed on the first surface of the transparent substrate by thick film printing.

[0033]

According to the semiconductor device or the image sensor device of the present invention, the plated metal layer is provided on the circuit conductor layer, the bonding surface between the electrode on the semiconductor element or the image sensor element and the plated metal layer, and the translucency. 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 electrically and reliably connected to the circuit conductor layer. As a result, a highly reliable semiconductor device or image sensor device can be provided.

According to the method of manufacturing the semiconductor device or the image sensor device of the present invention, the semiconductor element is formed by forming the plated metal layer on the circuit conductor layer and forming the alloy layer through the second hardening step (heat treatment). Also, the electrodes on the image sensor element and the circuit conductor layer on the transparent substrate can be electrically and reliably connected. This makes it possible to provide a highly reliable method for manufacturing a semiconductor device or an image sensor device. In addition, since the photothermosetting insulating resin is completely cured by the first curing step (light irradiation) and the second curing step (heat treatment), the semiconductor element and the image sensor element can be reliably mounted on the translucent substrate. The yield can be significantly improved. The element is reliably mounted by the first and second curing steps,
Deterioration of the semiconductor device and the image sensor device is prevented, and the durability of the device can be increased.

[0035]

EXAMPLES Examples of the present invention will be described below.

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

The semiconductor element 6 is mounted face down on the first surface 1a of the transparent substrate 1. A photothermosetting insulating resin layer 8 for fixing the semiconductor element 6 to the transparent substrate 1 is provided between the semiconductor element 6 and the transparent substrate 1. The photothermosetting insulating resin is an acrylate-based transparent resin, but other than this, for example, a methacrylate-based resin or the like can be used. Generally, the photo-curable insulating resin is cured by irradiating light, but some of them are not cured by heating. However, in the present invention, an insulating resin that is cured by heating as well as light is used.

A plated 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 plated metal layer 3.
An alloy layer is formed on the joint surface between the plated metal layer 3 and the circuit conductor layer 2 by once melting and re-solidifying the plated metal layer 3 on the circuit conductor layer 2. In this embodiment,
As the plated metal layer 3, In / Ga group, In /
Solder such as Sn group and Pb / Sn group is used. The metal bump 4 is connected to the circuit conductor layer 2 via the plated metal layer 3, and the plated metal layer 3 is once melted and re-solidified at the joint surface between the metal bump 4 and the plated metal layer 3. Has an alloy layer formed by.
When the metal bump 4 is not provided, an alloy layer is formed on the joint surface between the electrode 5 in the narrow sense and the plated metal layer 3.

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

First, various devices (not shown) and the 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 bumps 4 are Au bumps. After that, this 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 transparent substrate 1 which is a glass substrate. The transparent substrate 1 is made of polyarylate (PA), polyether sulfone (PAS), polyethylene terephthalate (PE).
It may be a transparent substrate such as T) or 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 a vapor deposition method, a sputtering method or the like, and then patterning the deposited metal layer by a photolithography technique. It The circuit conductor layer 2 can also be formed using foil or the like. Alternatively, the circuit conductor layer 2 may be formed by sticking a flexible printed board on the first surface 1 a of the transparent substrate 1.

Further, the plated metal layer 3 is formed at a predetermined position of the circuit conductor layer 2 by a method such as electrolytic or electroless. Next, by applying a predetermined amount of an acrylate-based transparent photothermal combined curing type insulating resin at a predetermined position on the first surface 1a of the transparent substrate 1 by a stamping method or a screen printing method, The curable insulating resin layer 8 is formed. On top of that, the semiconductor element 6 having the electrode 5 and the like on its surface is placed so that the electrode 5 contacts the plated metal layer 3.
Place it face down. Then, the semiconductor element 6
While pressing the transparent substrate 1 against the transparent substrate 1,
From the side of the second surface 1b where the circuit conductor layer 2 is not formed, the photothermosetting insulating resin layer 8 is irradiated with ultraviolet rays through the transparent substrate 1 to cure the photothermosetting insulating resin (first Curing process). In the first curing step, the semiconductor element 6
From above, a pressure of 0.5 kgf to 2.5 kgf is applied. Ultraviolet rays are irradiated at an intensity of 200 mW to 500 mW for about 0.5 minutes to 2.0 minutes.

After that, the light-transmissive substrate 1 on which the semiconductor element 6 is placed 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 plated metal layer 3 and the curing temperature of the photothermosetting insulating resin. When eutectic solder is used as the plated metal layer 3, heat treatment is performed at 185 ° C. to 200 ° C. for about 5 minutes to 30 minutes. In this example, heat treatment was performed at 190 ° C. for about 10 minutes. In the second curing step, since the plated metal melts, alloys are formed on the joint surface between the metal bump 4 and the plated metal 3 and the joint surface between the plated metal 4 and the circuit conductor layer 2, respectively.

The following effects can be obtained by once melting the plating metal in the second curing step. When the plated metal layer 3 becomes a liquid, it becomes in a state of conforming to the fine shape of the bonding surface of the electrode 5, so that the contact area between the both increases and the adhesion along the bonding surface increases. The alloy layer on the joint surface is more easily formed, and reliable connection can be achieved. Further, even when organic matter stains are present on the surface, such stains can be removed.

In the second curing step, a portion of the photothermosetting insulating resin which is behind the circuit conductor layer 2 formed on the transparent substrate 1 in the first curing step and which is uncured is removed. It is completely cured, and the mounting of the semiconductor 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 semiconductor element 6 against the transparent substrate 1.

After the mounting of the semiconductor element 6 is completed, a resin such as silicon is applied by a dispenser or the like to form the 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 could not be completely cured only by the first curing step. Can be completely cured by further curing in the second curing step. Further, in the second curing step, an alloy layer is formed on each of the bonding surfaces of the plated metal layer 3, the metal bumps 4, and the circuit conductor layer 2, so that the semiconductor element 6 is formed.
Can be electrically and more reliably connected to the circuit conductor layer 2. This allows the semiconductor element 6 to be mounted on the translucent substrate 1 more reliably.

Next, the structure 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 designated by the same reference numerals. 3 is a view of the image sensor device viewed from above, and FIGS. 4 and 5 are views shown in FIG.
It is sectional drawing along the -A line and the BB line.

The transparent substrate 1 is made of polyarylate (P
A), a transparent substrate such as polyether sulfone (PAS), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). The transparent substrate 1 may be a glass substrate, as in the case of the semiconductor device. The thickness of the transparent substrate 1 in the case of the contact image sensor device is 0.5 mm to 2.0 mm. In the case of the perfect contact type image sensor device, the thickness Ts of the transparent substrate 1 is 1
0 μm to 200 μm, preferably 10 μm to 7
It is 5 μm.

On the first surface 1a of the transparent substrate 1, copper,
A circuit conductor layer 2 formed 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, a photodiode or the like, and the other elements are CCD, MOS,
An access circuit such as a bipolar IC. Light receiving element 9
Form a light receiving element array as shown in FIGS. Metal bumps 4 are provided on the body of the electrodes 5 of the image sensor element 6. Metal bump 4 is A
u bump. The thickness Tb of the Au bump is 3 μm to 6 μm.
It is 0 μm. The metal bump 4 is not an essential component of the present invention, but the present invention will be described with reference to an example in which the metal bump 4 is provided.

The image sensor element 6 is mounted face down on the first surface of the transparent substrate 1. A photothermosetting insulating resin layer 8 for fixing the image sensor element 6 to the transparent substrate 1 is provided between the image sensor element 6 and the transparent substrate 1. The photothermosetting insulating resin is an acrylate-based transparent resin, but in addition to this,
For example, a methacrylate type can be used. A plated 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 plated metal layer 3. An alloy layer is formed on the joint surface between the plated metal layer 3 and the circuit conductor layer 2 by once melting and re-solidifying the plated metal layer 3 on the circuit conductor layer 2. In this embodiment, the plated metal layer 3 is made of solder such as In / Ga group, In / Sn group and Pb / Sn group. The thickness Tm of the plated metal layer 3 is 2 μm to 20 μm.
The metal bumps 4 are formed on the circuit conductor layer 2 via the plated metal layer 3.
And an alloy layer formed by melting and re-solidifying the plating metal once is provided on the joint surface between the metal bump 4 and the plating metal layer 3. When the metal bump 4 is not provided, an alloy layer is formed on the joint surface between the electrode 5 in the narrow sense and the plated metal layer 3.

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

The reason why the distance T is limited in this way is that the lens is not used in the case of the perfect contact type image sensor device, so that the resolution of the image sensor device is This is because it largely depends on the distance T from the second surface 1b) to the light receiving element 9. This relationship is shown in FIG. The vertical axis of FIG. 6 indicates the MTF (Modulation-Trans).
fer-function) value, which is a measure of resolution. In practice, the MTF value is 4 lp / mm, and 30 to 40% or more is required. Therefore, as described above, the light receiving element 9 to the transparent substrate 1 are used.
The distance to the second surface 1b of is limited. A method of manufacturing the image sensor device will be described below.

First, a phototransistor as a light receiving element 9, a drive circuit (not shown), and an extraction electrode 5 are formed on a single crystal silicon substrate (wafer) by a semiconductor process.
Form the body of. On the main body of the electrode 5, the Au bump 4 is formed by the electroplating method, the ball bonding method or the like. Then, this wafer is cut by a high-precision dicing technique to manufacture the image sensor element 6.

Next, the first surface 1a of the transparent substrate 1 which is a transparent substrate made of polyarylate (PA), polyether sulfone (PAS), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or the like. The circuit conductor layer 2 is formed thereon. The transparent 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 a vapor deposition method, a sputtering method or the like, and then patterning the deposited metal layer by a photolithography technique. It The circuit conductor layer 2 can also be formed using 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 is
A flexible printed board may be attached to the first surface of the translucent substrate or may be formed by thick film printing.

Further, the plated metal layer 3 is formed at a predetermined position on the circuit conductor layer 2 by a method such as electrolytic or electroless.

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

Image sensor element 6 used in this embodiment
Has 15 electrodes 5 per element, and a pressure of 0.5 kgf to 2.5 kgf per element is applied from above. Simultaneously with applying the above-mentioned pressure, ultraviolet rays having an intensity of 100 mW to 1500 mW were irradiated from below the second surface 1b of the transparent substrate 1 for 20 seconds to 100 seconds. Considering the effect of mass production, it is desirable to complete the first curing in 20 to 40 seconds.

Then, the light-transmissive substrate 1 on which the image sensor element 6 is arranged 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 the plating metal layer 3
The temperature is higher than the melting point of the metal and the curing temperature of the photothermosetting resin. When using eutectic solder as the plating metal,
Heat treatment is performed at 185 ° C. to 200 ° C. for about 5 minutes to 30 minutes.
In this example, heat treatment was performed at 190 ° C. for about 10 minutes. In the second curing step, since the plated metal layer 3 melts, an alloy layer is formed on each of the joint surface between the metal bump 4 and the plated metal layer 3 and the joint surface between the plated metal layer 3 and the circuit conductor layer 2. It is formed.

The effect obtained by once melting the plated metal layer 3 in the second curing step is the same as in the case of the above-described embodiment of the semiconductor device. The plating metal layer 3 which has become liquid by melting the plating metal layer 3 once
Is in a state of 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 joint surface increases. Therefore, the alloy layer is more likely to be formed on the bonding surface, so that the image sensor element 6 can be reliably connected. Further, even when organic matter stains are present on the surface, such stains can be removed.

In the second curing step, the photo-thermosetting insulation of the portion which is behind the circuit conductor layer 2 formed on the translucent substrate 1 in the first curing step and is incompletely cured. 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 transparent 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 coating resin 7 is formed to complete the image sensor device. 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 will occur in the subsequent environmental test and the like. Table 1 shows the results of the environmental test in the case where only the photo-curing (first curing step) is performed and the case where the photo-curing and the thermal curing (first and second curing steps) are performed, respectively. Comparing the test results of the two cases, constant temperature and humidity (85 ℃, 8
5%) and heat shock (-30 ℃ ~
In any case of applying + 70 ° C., when the photothermosetting insulating resin is cured by ultraviolet irradiation and heat treatment, no defective product is generated in the test product. However, when the photothermosetting insulating resin is cured only by UV irradiation, about 40% to 60% of defective products are produced. As described above, by performing the two-stage curing of the photo-curing and the heat treatment, the mounting yield of the device can be improved. Further, as is clear from the test results in Table 1, it is understood that the two-stage curing of photocuring and heat treatment can prevent deterioration of the image sensor device and increase the durability of the image sensor device.

[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 and reliably connected to the circuit conductor layer, and the semiconductor device or the image sensor device is highly reliable. Can be provided.

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

[Brief description of 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 schematic view from above of the image sensor device of the present invention.

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

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

FIG. 6 shows the MTF value of the perfect contact image sensor device,
6 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 diagram showing a part of a mounting process of an image sensor element of a conventional example.

[Explanation of symbols]

 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

Claims (25)

[Claims] 1. 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 the first surface of a substrate; and a photothermosetting insulating resin layer for fixing the semiconductor element to a translucent substrate, the circuit conductor layer comprising: Is provided with a plated metal layer on at least a part of it, the electrode of the semiconductor element is connected to the circuit conductor layer through the plated metal layer, and the plated metal is on the circuit conductor layer at the joint surface between the plated 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 once 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. The electrode of the semiconductor element has a metal bump, and the metal bump is connected to the circuit conductor layer via a plated metal layer, and the plated metal is once melted at the joint surface between the metal bump and the plated metal layer. The semiconductor device according to claim 1, wherein an alloy layer formed by being resolidified is formed. 5. The metal bump is an Au bump.
The semiconductor device according to. 6. A step of forming a circuit conductor layer on the first surface of a transparent substrate having first and second surfaces, and a step of forming a plated metal layer on at least a part of the circuit conductor layer. And a step of forming a photothermosetting insulating resin layer on the first surface of the translucent substrate, and a semiconductor element having an electrode on the surface thereof in a face-down state so that the electrode is located on the plated metal layer. And the semiconductor element is pressed against the translucent substrate, and the photothermosetting insulating resin is irradiated with ultraviolet rays from the second surface of the translucent substrate through the translucent substrate. A first curing step of curing the insulating resin, and a step of further curing the photothermosetting insulating resin by keeping the translucent substrate on which the semiconductor element is placed at a certain temperature for a certain period of time. The melting point of the metal in the metal layer and the photothermal curing 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 the step of melting the plating metal to form an alloy on the 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 plated metal to bond the metal bump to the plated metal layer, and the bonded metal layer to the circuit conductor layer. 7. The method of manufacturing a semiconductor device according to claim 6, including a step of forming an alloy on each surface. 9. The method of manufacturing a semiconductor device according to claim 6, wherein the second curing step is performed while pressing the semiconductor element against the transparent substrate. 10. The step of forming a circuit conductor layer comprises the steps of depositing a conductor layer on the first surface of a transparent substrate and patterning the conductor layer by a photolithography technique, thereby forming a circuit conductor layer. The method for manufacturing a semiconductor device according to claim 6, further comprising: 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 sticking a flexible printed board on the first surface of the transparent 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, an electrode and a light-receiving element on the surface, and First of translucent substrate
An image sensor device comprising an image sensor element mounted face down on a surface of a substrate, and a photothermosetting insulating resin layer for fixing the image sensor element to a translucent substrate. Of the image sensor element is connected to the circuit conductor layer via the plated metal layer, and the plated metal is on the circuit conductor layer at the joint surface between the plated metal layer and the circuit conductor layer. An image sensor device in which an alloy layer formed by melting and re-solidifying is formed. 13. The image sensor device according to claim 12, 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. 14. The image sensor device according to claim 12, wherein the plating metal is solder. 15. The electrode of the image sensor element has a metal bump, and the metal bump is connected to the circuit conductor layer through a plated metal layer, and the plated metal is attached to a joint surface between the metal bump and the plated metal layer. The image sensor device according to claim 12, wherein an alloy layer formed by melting and re-solidifying once 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 the first surface of a transparent substrate having first and second surfaces, and a step of forming a plated metal layer on at least a part of the circuit conductor layer. A step of forming a photothermosetting insulating resin layer on the first surface of the translucent substrate, and an image sensor element having an electrode and a light receiving element on the surface so that the electrode is located on the plated metal layer. The step of arranging in a face-down state and irradiating the photothermosetting insulating resin with ultraviolet rays from the second surface of the transparent substrate through the transparent substrate while pressing the image sensor element against the transparent substrate. And a first curing step of curing the photothermosetting insulating resin, and a step of further curing the photothermosetting insulating resin by maintaining the temperature of the translucent substrate on which the image sensor element is arranged for a certain period of time. , Its temperature is 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 of manufacturing an image sensor device according to claim 18, wherein the second curing step includes a step of melting a plating metal to form an alloy on a joint surface between the plating metal layer and the circuit conductor layer. 20. The electrode of the image sensor element has a metal bump, and in the second curing step, the plating metal is melted to bond the metal bump and the plating metal layer with each other, and between the plating metal layer and the circuit conductor layer. The method of manufacturing an image sensor device according to claim 18, further comprising the step of forming an alloy on each joint surface. 21. The method of manufacturing an image sensor device according to claim 18, wherein the second curing step is performed while pressing the image sensor element against the transparent substrate. 22. The method of manufacturing an image sensor device according to claim 18, wherein the total thickness of the translucent substrate and the photothermosetting insulating resin layer is 150 μm or less. 23. The step of forming a circuit conductor layer comprises the steps of depositing a conductor layer on a first surface of a transparent substrate and patterning the conductor layer by a photolithography technique, thereby forming a circuit conductor layer. The method of manufacturing an image sensor device according to claim 18, further comprising a forming step. 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 pasting a flexible printed board on the first surface of the transparent substrate. Device manufacturing method. 25. The method of manufacturing an image sensor device according to claim 18, wherein the step of forming the circuit conductor layer is to form the circuit conductor layer on the first surface of the transparent substrate by thick film printing. .