JPH0936119A - Semiconductor device, its manufacture and semiconductor unit using the semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the exfoliation of a semiconductor device and sealing resin caused by the stress generated by the difference in thermal expansion coefficient of a semiconductor device, a circuit board and sealing resin and the cracks of the sealing resin itself. SOLUTION: An electrode pad 3 is formed on a semiconductor device (IC board) 6. A protruding electrode (bump) 7 is formed on the electrode pad 3. A conductive bonding agent 5 is applied to the tip part of the bump 7 of the IC board 6 as a binding layer using a transfer method or a printing method. Then, the manufactured IC chips are aligned in a face-down state in such a manner that the bumps 7 are opposing to the input-output terminal electrode 8 of a circuit board 9, and the IC chips are mounted on the circuit board 9. The conductive bonding agent 5 is hardened in the above-mentioned state, and the IC board 6 and the circuit board 9 are electrically connected. Then, sealing resin 4 is filled in such a manner that the binding layer (conductive bonding agent 5) is surrounded, and the sealing resin 4 is hardened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device capable of enhancing adhesion with a sealing resin during mounting, a method of manufacturing the same, and a semiconductor unit using the semiconductor device.

[0002]

2. Description of the Related Art Heretofore, a wire bonding method using soldering has been often used in mounting a semiconductor device on an input / output terminal electrode of a circuit board. However, in recent years, due to the miniaturization of the package of the semiconductor device and the increase in the number of connection terminals, the space between the connection terminals has become narrower, and it has become increasingly difficult to cope with this with conventional soldering techniques.

Therefore, recently, a method has been proposed in which a semiconductor device such as an integrated circuit chip is directly mounted on the input / output terminal electrodes of a circuit board to reduce the mounting area and improve efficiency. Among them, the method of flip-chip mounting the semiconductor device on the circuit board in a face-down state is that the electrical connection between the semiconductor device and the circuit board can be performed at once, and the mechanical strength after connection is strong,
It is said to be a useful method.

For example, Industrial Research Committee, January 15, 1980
Published by Japan Microelectronics Association, "IC
The "mounting technology" describes a mounting method using a solder plating method. Hereinafter, this mounting method will be described.

FIG. 8A is a sectional view showing a solder bump in a conventional semiconductor device, and FIG. 8B is a sectional view showing a conventional semiconductor unit. As shown in FIG. 8, the electrode pad 1 of the semiconductor device (hereinafter referred to as “IC substrate”) 116.
When connecting 13 to the input / output terminal electrode 118 of the circuit board 119, first, the electrode pad 113 of the IC board 116 is
An adhesion metal film 112 and a diffusion prevention metal film 111 are sequentially formed on the upper surface by an evaporation method. Then, the diffusion prevention metal film 1
An electrical connection contact (hereinafter referred to as "solder bump") 110 made of solder is formed on 11 by a plating method (above, FIG. 8A), and an IC chip is manufactured. Next, the IC chip thus manufactured is positioned face down so that the solder bumps 110 contact the input / output terminal electrodes 118, and the IC chip is mounted on the circuit board 119. (FIG.8 (b)). Next, the mounting body (semiconductor unit) of this semiconductor device is heated to a high temperature to fuse the solder bumps 110 to the input / output terminal electrodes 118 of the circuit board 119.

Recently, a method of mounting a semiconductor device using a conductive adhesive has been proposed. FIG. 9 is a sectional view showing a semiconductor unit using a conventional conductive adhesive. As shown in FIG. 9, first, a semiconductor device (hereinafter referred to as “IC
Substrate. ) 126, the electrical connection contact (Au bump) 120 is formed on the electrode pad 123 of 126 by a wire bonding method or a plating method. Then this Au
The bump 120 is connected to the input / output terminal electrode 128 of the circuit board 129 via the conductive adhesive (bonding layer) 125. In such a semiconductor unit, the semiconductor device 126
After the conductive adhesive 125 is transferred to the Au bumps 120, the alignment is performed so that the conductive adhesive 125 contacts the input / output terminal electrodes 128 of the circuit board 129, and the conductive adhesive 125 is cured. , Semiconductor device 12
6 and the circuit board 129 are electrically connected.

Further, a semiconductor unit sealed with a sealing resin has been proposed to reinforce the connection. In this case, a step of further encapsulating the sealing resin and a step of curing the sealing resin are required.

[0008]

However, the above-described conventional semiconductor device and its mounted body (semiconductor unit) have the following problems.

That is, in the temperature difference during the semiconductor unit manufacturing process or the reliability test, there is a difference in the thermal expansion coefficient of the semiconductor device, the circuit board, and the sealing resin. As a result, the adhesive strength is reduced and cracks and peeling occur in the bulk part. And
When a crack or peeling occurs in the bulk portion in this manner, the bonding interface becomes unstable, and the electrical connection point (Au bump) 120
There is a possibility that the resistance value of will increase. In addition, if peeling occurs at the boundary between the semiconductor device and the sealing resin or cracks occur in the sealing resin itself, there is a problem that deterioration is accelerated and the reliability life is significantly impaired.

In order to solve the above problems in the prior art, the present invention enhances the adhesive force between the semiconductor device and the sealing resin,
An object of the present invention is to provide a semiconductor device capable of suppressing deterioration, a manufacturing method thereof, and a semiconductor unit using the semiconductor device.

[0011]

In order to achieve the above object, a semiconductor device according to the present invention has a structure in which a semiconductor device is mounted on a circuit board in a face-down state, and the circuit of the semiconductor device is excluded. At least a part of the surfaces has at least one surface selected from a concave surface and a convex surface.

A semiconductor device manufacturing method according to the present invention is a method for manufacturing a semiconductor device mounted on a circuit board in a face-down state, wherein at least a part of a surface of the semiconductor device excluding a circuit is In addition, abrasive grains of the same material or inorganic material as the semiconductor device are heated and sprayed.

The structure of the semiconductor unit according to the present invention is a semiconductor unit including a circuit board having terminal electrodes and a semiconductor device having protruding electrodes and mounted on the circuit board in a face-down state. The semiconductor device has at least one surface selected from a concave surface and a convex surface on at least a part of the surface excluding the circuit, and the protruding electrode of the semiconductor device has a bonding layer on the terminal electrode of the circuit board. And a side surface of the semiconductor device and a side surface of the semiconductor device are mechanically reinforced by a sealing resin.

Further, in the structure of the semiconductor unit of the present invention, it is preferable that the protruding electrode is made of Au, Cu, Al, solder or an alloy thereof. Further, in the configuration of the semiconductor unit of the present invention, it is preferable that the bonding layer is made of a conductive adhesive.

In the structure of the semiconductor unit of the present invention, it is preferable that the bonding layer is made of an anisotropic conductive material.

[0016]

According to the configuration of the semiconductor device of the present invention, a semiconductor device mounted on a circuit board in a face-down state, wherein at least a part of a surface of the semiconductor device excluding a circuit is Since the semiconductor device has at least one surface selected from a concave surface and a convex surface, when the semiconductor device is mounted on a circuit board, the contact area between the semiconductor device and the sealing resin increases, and the semiconductor device and the sealing resin increase. The adhesion strength with

Further, according to the structure of the method for manufacturing a semiconductor device of the present invention, there is provided a method for manufacturing a semiconductor device mounted on a circuit board in a face-down state, wherein at least a surface of the semiconductor device excluding a circuit is included. Since the abrasive grain of the same material or inorganic material as that of the semiconductor device is heated and sprayed on a part of the semiconductor device, an uneven surface is easily formed on at least a part of the surface of the semiconductor device excluding the circuit.

Further, according to the structure of the semiconductor unit of the present invention, the semiconductor unit is provided with the circuit board having the terminal electrodes, and the semiconductor device having the protruding electrodes and mounted on the circuit board in a face-down state. The semiconductor device has at least one surface selected from a concave surface and a convex surface on at least a part of the surface excluding the circuit, and the protruding electrode of the semiconductor device is bonded to the terminal electrode of the circuit board. The semiconductor device is electrically connected via a layer, and the gap between the semiconductor device and the circuit board and the side surface of the semiconductor device are mechanically reinforced by a sealing resin. When is mounted on a circuit board, the contact area between the semiconductor device and the sealing resin increases, and the adhesion strength between the semiconductor device and the sealing resin increases. As a result, the peeling between the semiconductor device and the sealing resin and the cracking of the sealing resin itself due to the stress generated by the difference in the thermal expansion coefficients of the semiconductor device, the circuit board, and the sealing resin are prevented.

Further, in the above-mentioned structure of the semiconductor unit of the present invention, according to a preferable example in which the bonding layer is made of a conductive adhesive or an anisotropic conductive material, the life of reliability is extended. This is because the semiconductor unit or the substrate expands or contracts due to the change in temperature, but the conductive adhesive or the anisotropic conductive material has a flexible property, so that the thermal stress can be relaxed. .

[0020]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. <First Embodiment> FIG. 1 shows a first semiconductor device according to the present invention.
6 is a cross-sectional view showing a protruding electrode in the example of FIG. FIG.
Shows one of a plurality of electrical connection points in a part of the semiconductor device. As shown in FIG. 1, an electrode pad 3 is formed on a semiconductor device (hereinafter referred to as “IC substrate”) 6. A bump electrode (hereinafter referred to as “bump”) 7 is formed on the electrode pad 3.
The bump 7 has a two-step structure including a first bump 7 ′ and a second bump 7 ″ which is formed on the first bump 7 ′ and is smaller than the first bump 7 ′. (Hereinafter simply referred to as “bump 7”). Further, the IC substrate 6 has
An uneven surface is formed on the end surface 1 and a portion 2 from the end surface on the electrode pad 3 side to the electrode pad 3 (see FIG. 2). That is, an uneven surface is formed on the surface of the IC substrate 6 excluding the circuits.

The uneven surface is formed as follows, for example. That is, as shown in FIG. 7, by polishing the end surface 1 of the IC substrate 6 with abrasive grains 10 of the same material as that of the IC substrate 6 or an inorganic material, for example, SiO ₂ at a temperature of 300 ° C. or higher and combining them, the uneven surface is Easily formed.

FIG. 2 shows a first semiconductor unit according to the present invention.
It is sectional drawing which shows Example of (a). Here, the semiconductor device described above (FIG. 1) is used as the semiconductor device. The method of manufacturing this semiconductor unit is as follows. First, I
The conductive adhesive 5 as a bonding layer is applied to the tip of the bump 7 of the C substrate 6 by a transfer method or a printing method. If the bumps 7 having the two-stage structure as described above are used, it is possible to prevent more than the necessary amount of the conductive adhesive 5 from adhering to the tip portions of the bumps 7. It can be applied. Then, I prepared as described above
The C chip is positioned face down so that the bumps 7 face the input / output terminal electrodes 8 of the circuit board 9 and the IC chip is placed on the circuit board 9. When the conductive adhesive 5 is cured in this state, the IC substrate 6 and the circuit substrate 9 are electrically connected. Next, the sealing resin 4 is enclosed so as to surround the bonding layer (conductive adhesive 5) and the sealing resin 4 is cured. As a result, the IC substrate 6
A semiconductor unit is obtained in which the gap between the circuit board 9 and the side surface 1 of the IC board 6 is mechanically reinforced by the sealing resin 4.

In this case, since the uneven surface is formed on the surface of the IC substrate 6 excluding the circuit as described above, the IC
The contact area between the substrate 6 and the sealing resin 4 increases, and the IC substrate 6
The adhesion strength between the resin and the sealing resin 4 is increased. As a result, peeling between the IC substrate 6 and the sealing resin 4 and cracks in the sealing resin 4 themselves due to stress generated by the difference in thermal expansion coefficient between the IC substrate 6, the circuit board 9 and the sealing resin 4 are prevented. In addition, since they are bonded via the conductive adhesive 5, the reliability life is extended. This is because the semiconductor adhesive and the substrate may expand or contract due to changes in temperature, but the conductive adhesive 5 has a flexible property, so that thermal stress can be relaxed.

In the present embodiment, the bump 7 is formed in the shape of a protrusion having a two-step structure, but the shape is not necessarily limited to this shape. In addition, in this embodiment,
Although the uneven surface is formed on the surface of the IC substrate 6 excluding the circuit, it is not necessarily limited to this structure. IC
If the surface of the substrate 6 excluding the circuit has at least one surface selected from a concave surface and a convex surface, the contact area between the IC substrate 6 and the sealing resin 4 increases, so that the IC substrate 6 and the sealing resin 4 are sealed. The adhesion strength with the resin 4 can be increased. This also applies to the following second to fifth embodiments.

In this embodiment, the uneven surface is formed on the entire surface of the IC substrate 6 excluding the circuit, but the present invention is not limited to this structure, and the surface of the IC substrate 6 excluding the circuit is not limited thereto. It is sufficient to form the uneven surface on at least a part of.

The protruding electrodes (bumps) 7 are made of Au, C
It is preferably made of u, Al, solder or an alloy thereof. <Second Embodiment> FIG. 3A is a sectional view showing an electrical connection contact in a second embodiment of the semiconductor device according to the present invention. FIG. 3A shows one of a plurality of electrical connection points in a part of the semiconductor device. FIG. 3 (a)
As shown in FIG. 3, the electrode pad 33 is formed on the semiconductor device (hereinafter referred to as “IC substrate”) 36.
Further, an adhesion metal film 37 is formed on the IC substrate 36 so as to cover the peripheral portion of the electrode pad 33. A diffusion prevention metal film 40 is formed on the electrode pad 33 and the adhesion metal film 37 by a vapor deposition method. Further, on the diffusion preventing metal film 40, an electrical connection contact (hereinafter referred to as “solder bump”) 30 made of solder is formed by a plating method. Further, the IC substrate 36 has an end surface 3
1 and the uneven surface is formed in the portion 32 from the end surface on the electrode pad 33 side to the electrode pad 33 (see FIG. 3B).

FIG. 3B is a sectional view showing a second embodiment of the semiconductor unit according to the present invention. Here, the semiconductor device described above (FIG. 3A) is used as the semiconductor device. The method of manufacturing the semiconductor unit is as follows.
First, the conductive adhesive 35 as a bonding layer is applied to the tip of the solder bump 30 of the IC substrate 36 by a transfer method or a printing method. Next, the IC chip thus manufactured is positioned face down so that the solder bumps 30 face the input / output terminal electrodes 38 of the circuit board 39, and the IC chip is placed on the circuit board 39. Place it.
When the conductive adhesive 35 is cured in this state, the IC substrate 36 and the circuit substrate 39 are electrically connected. Next, the sealing resin 34 is encapsulated so as to surround the bonding layer (conductive adhesive 35), and the sealing resin 34 is cured. As a result, a semiconductor unit in which the gap between the IC board 36 and the circuit board 39 and the side surface 1 of the IC board 36 are mechanically reinforced by the sealing resin 34 is obtained.

<Third Embodiment> FIG. 4A is a sectional view showing a protruding electrode in a third embodiment of the semiconductor device according to the present invention. FIG. 4A shows one of a plurality of electrical connection points in a part of the semiconductor device. FIG.
As shown in (a), an electrode pad 43 is formed on a semiconductor device (hereinafter referred to as “IC substrate”) 46. A protruding electrode (hereinafter referred to as “bump”) 47 is formed on the electrode pad 43. Further, the IC substrate 46 has an uneven surface formed on the end surface 41 and a portion 42 from the end surface on the electrode pad 43 side to the electrode pad 43 (see FIG. 4B).

FIG. 4B is a sectional view showing a third embodiment of the semiconductor unit according to the present invention. Here, as the semiconductor device, the one described above (FIG. 4A) is used. The method of manufacturing the semiconductor unit is as follows.
First, the conductive adhesive 45 as a bonding layer is applied to the tip of the bump 47 of the IC substrate 46 by a transfer method or a printing method. Next, the IC chip thus manufactured is placed face down in the bump 47 on the circuit board 49.
The IC chip is placed on the circuit board 49 by performing alignment so as to face the input / output terminal electrode 48 of. When the conductive adhesive 45 is cured in this state, the electric connection between the IC board 46 and the circuit board 49 is realized. Next, the sealing resin 4 is formed so as to surround the bonding layer (conductive adhesive 45).
4 is encapsulated and the sealing resin 44 is cured. This allows
A semiconductor unit is obtained in which the gap between the IC board 46 and the circuit board 49 and the side surface 1 of the IC board 46 are mechanically reinforced by the sealing resin 44.

<Fourth Embodiment> FIG. 5 is a sectional view showing a fourth embodiment of the semiconductor unit according to the present invention. As shown in FIG. 5, a semiconductor device (hereinafter referred to as “IC substrate”).
An electrode pad 53 is formed on 56. Also,
A protruding electrode (hereinafter referred to as “bump”) 57 is formed on the electrode pad 53. Further, the IC substrate 56 has an uneven surface formed on the end surface 51 and a portion 52 from the end surface on the electrode pad 53 side to the electrode pad 53.

The method of manufacturing the semiconductor unit is as follows. First, in the IC chip manufactured as described above, the bumps 57 are placed on the circuit board 59 in a face-down state.
The IC chip is placed on the circuit board 49 via the anisotropic conductive material 55 as a bonding layer, so that the IC chip faces the input / output terminal electrode 58. If the anisotropic adhesive 55 is cured in this state, the IC substrate 56 and the circuit substrate 59
An electrical connection with is realized. Then, the sealing resin 54 is enclosed so as to surround the bonding layer (anisotropic conductive material 55),
The sealing resin 54 is cured. As a result, the IC substrate 56
A semiconductor unit in which the gap between the circuit board 59 and the side surface 51 of the IC board 56 is mechanically reinforced by the sealing resin 54 is obtained.

In the present embodiment, since they are bonded via the anisotropic conductive material 55, the reliability life is extended. This is because the semiconductor unit or the substrate expands or contracts due to the change in temperature, but the anisotropic conductive material 55 has a flexible property, so that the thermal stress can be relaxed.

<Fifth Embodiment> FIG. 6 is a sectional view showing a fifth embodiment of a semiconductor unit according to the present invention. As shown in FIG. 6, a semiconductor device (hereinafter referred to as “IC substrate”).
Electrode pads 63 are formed on 66. Also,
A protruding electrode (hereinafter referred to as “bump”) 67 is formed on the electrode pad 63. Further, the IC substrate 66 has an uneven surface formed on the end surface 61 and a portion 62 from the end surface on the electrode pad 63 side to the electrode pad 63.

The method of manufacturing the semiconductor unit is as follows. First, in the IC chip manufactured as described above, the bump 67 is placed on the circuit board 69 in a face-down state.
The IC chip is placed on the circuit board 69 through the anisotropic conductive material 65 as a bonding layer, so that the IC chip faces the input / output terminal electrode 68. If the anisotropic conductive material 65 is cured in this state, the IC board 66 and the circuit board 69 are formed.
An electrical connection with is realized. Here, before the IC chip is placed on the circuit board 69, the anisotropic conductive material 6
5 has a thickness equal to or larger than the gap between the IC substrate 66 and the circuit substrate 69. Therefore, the anisotropic conductive material 65 is filled between the IC board 66 and the circuit board 69.
A stable connection state is realized as compared with the fourth embodiment. Next, the sealing resin 64 is enclosed so as to surround the bonding layer (anisotropic conductive material 65) and the sealing resin 64 is cured. As a result, a semiconductor unit is obtained in which the gap between the IC substrate 66 and the circuit substrate 69 and the side surface 61 of the IC substrate 66 are mechanically reinforced by the sealing resin 64.

[0035]

As described above, according to the present invention,
When the semiconductor device is mounted face down on the circuit board, the contact area between the semiconductor device and the sealing resin increases,
The adhesion strength between the semiconductor device and the sealing resin is increased. As a result, the peeling between the semiconductor device and the sealing resin and the cracking of the sealing resin itself due to the stress generated by the difference in the thermal expansion coefficients of the semiconductor device, the circuit board, and the sealing resin are prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing a protruding electrode in a first embodiment of a semiconductor device according to the present invention.

FIG. 2 is a sectional view showing a first embodiment of the semiconductor unit according to the present invention.

3A is a sectional view showing an electrical connection contact in a second embodiment of a semiconductor device according to the present invention, and FIG. 3B is a sectional view showing a second embodiment of a semiconductor unit according to the present invention. Is.

4A is a sectional view showing a protruding electrode in a third embodiment of a semiconductor device according to the present invention, and FIG. 4B is a sectional view showing a third embodiment of a semiconductor unit according to the present invention. .

FIG. 5 is a sectional view showing a fourth embodiment of the semiconductor unit according to the present invention.

FIG. 6 is a sectional view showing a fifth embodiment of the semiconductor unit according to the present invention.

FIG. 7 is a schematic view showing an example of a method for manufacturing a semiconductor device according to the present invention.

FIG. 8A is a sectional view showing a solder bump in a conventional semiconductor device, and FIG. 8B is a sectional view showing a conventional semiconductor unit.

FIG. 9 is a cross-sectional view showing a semiconductor unit using a conventional conductive adhesive.

[Explanation of symbols]

1, 31, 41, 51, 61 ... Semiconductor device (IC substrate)
End face 2, 32, 42, 52, 62 ... Portion from the end face on the electrode pad side to the electrode pad 3, 33, 43, 53, 63 ... Electrode pad 4, 34, 44, 54, 64 ... Sealing resin 5, 35, 45 ... Conductive adhesive 6, 36, 46, 56, 66 ... Semiconductor device (IC substrate) 7, 67 ... Projection electrode (bump) 7 '... First projection electrode (bump) 7 "... Second Projection electrodes (bumps) 8, 38, 48, 58, 68 ... Input / output terminal electrodes 9, 39, 49, 59, 69 ... Circuit board 10 ... Abrasive grains 30 ... Electrical connection contacts (solder bumps) 37 ... Adhesive metal film 40 ... Diffusion prevention metal film 47 ... Projection electrode (bump) 55 ... Anisotropic conductive material 57 ... Projection electrode (bump) 65 ... Anisotropic conductive material

Claims (6)

[Claims] 1. A semiconductor device mounted on a circuit board in a face-down state, wherein at least a part of the surface of the semiconductor device excluding the circuit has at least one surface selected from a concave surface and a convex surface. Characteristic semiconductor device. 2. A method of manufacturing a semiconductor device mounted on a circuit board in a face-down state, wherein at least a part of a surface of the semiconductor device excluding a circuit is made of the same material as the semiconductor device or an inorganic abrasive grain. A method for manufacturing a semiconductor device, comprising: 3. A semiconductor unit comprising a circuit board having a terminal electrode and a semiconductor device having a protruding electrode and mounted on the circuit board in a face-down state, wherein the semiconductor device does not include a circuit. Has at least one surface selected from a concave surface and a convex surface in at least a portion of the surface, the protruding electrode of the semiconductor device is electrically connected to the terminal electrode of the circuit board via a bonding layer, and A semiconductor unit, wherein a gap between the semiconductor device and the circuit board and a side surface of the semiconductor device are mechanically reinforced by a sealing resin 4. 4. The semiconductor unit according to claim 3, wherein the protruding electrode is made of Au, Cu, Al, solder or an alloy thereof. 5. The semiconductor unit according to claim 3, wherein the bonding layer is made of a conductive adhesive. 6. The semiconductor unit according to claim 3, wherein the bonding layer is made of an anisotropic conductive material.