This application claims priority under 35 USC 119 from Japanese Patent Application No. 2007-337749, the disclosure of which is incorporated by reference herein.
1. Field of the Invention
The present invention relates to a semiconductor device fabricating method.
2. Description of the Related Art
A Tape-BGA package type semiconductor device is known as a package structure of a semiconductor device. This device has a structure in which a frame-shaped, metal member called a stiffener (reinforcing material) is disposed so as to surround a semiconductor chip. The stiffener is disposed at the reverse of a TAB tape having an inner lead that is connected by inner lead bonding to an electrode of the semiconductor chip, and functions to correct the warping thereof and ensure planarity.
There has been disclosed a technique that uses a stiffener molded from a synthetic resin material in order to make such a Tape-BGA package type semiconductor device lighter-weight and to simplify the fabricating processes thereof (refer to Japanese Patent Application Laid-Open (JP-A) No. 11-307592).
Other than in Tape-BGA package type semiconductor devices, a stiffener is used also in BAG package type semiconductor devices. For example, for the purposes of reducing the amount of warping of the substrate at the time of mounting, and, at the time of temperature cycle testing, preventing destruction of the solder bumps and the like that connect a semiconductor chip and the mounting substrate and suppressing cracking of the mounting substrate, there has been proposed a semiconductor device having a reinforcing material, where the thermal expansion coefficient of the resin of an underfill portion provided at the lower portion of the semiconductor chip and the thermal expansion coefficient of a sealing resin used for sealing the gap between the semiconductor chip and the reinforcing material are small (see, for example, JP-A No. 2004-260138).
However, semiconductor devices provided with conventional stiffeners are fabricated via a process of respectively placing stiffeners corresponding to the individual semiconductor chips on the substrate to which the semiconductor chips are mounted. Therefore, at the time of fabricating a semiconductor device, there is the need to place the stiffeners corresponding to the individual semiconductor chips on the substrate, and the production efficiency is poor.
Further, due to the existence of the stiffener, warping of the semiconductor device that is finally obtained is suppressed. However, in the semiconductor device fabrication processes, at the stage before the individual semiconductor devices are cut-out by cutting, the individual stiffeners are independent. Therefore, after the resin layer for sealing is formed on the substrate that is in the state in which the plural semiconductor chips are mounted thereon, warping may arise in the substrate overall due to contraction of this resin layer. Depending on the structure of the semiconductor devices and on the fabricating process thereof as well, the occurrence of such warping may give rise to various bad effects. For example, in a case of fabricating semiconductor devices by flip-chip joining the semiconductor chips, it is easy for poor flip-chip joining to arise, and, as a result, a decrease in the yield of the semiconductor devices may be brought about.
The present invention was made in view of the above-described circumstances, and an object thereof is to provide a semiconductor device fabricating method that has high production efficiency and suppresses the occurrence of warping in the fabricating processes as well.
This object is achieved by the present invention as follows. Namely, the present invention provides a semiconductor device fabricating method for forming a plurality of semiconductor devices that each include one semiconductor chip and a metal plate having an opening portion that surrounds a region where the semiconductor chip is provided, the method comprising cutting, at regions where a frame portion exists, a plate-shaped member that includes:
a wiring layer including a wiring portion and an insulating portion;
a plurality of semiconductor chips disposed on one surface of the wiring layer;
a metal plate disposed at a surface of the wiring layer at a side at which the semiconductor chips are provided, and having a plurality of opening portions that surround regions where the semiconductor chips are provided and the frame portion that forms the opening portions; and
a sealing resin layer provided to seal at least gaps between the semiconductor chips and the metal plate.
As described above, in accordance with the present invention, there can be provided a semiconductor device fabricating method that has high production efficiency and suppresses the occurrence of warping in the fabricating processes as well.
Preferred exemplary embodiments of the present invention will be described in detail based on the following figures, wherein:
The present invention does not use metal plates corresponding respectively to individual semiconductor chips. Therefore, the efficiency of fabricating the plate-shaped member can be improved. As a result, the efficiency of producing semiconductor devices also can be improved. Further, at the time of fabricating the plate-shaped member, warping that is caused by contraction of resin in a case in which a sealing resin layer is formed, also can be suppressed. Therefore, various bad effects (e.g., a decrease in yield due to the occurrence of poor joining in a case of flip-chip joining the semiconductor chips, and the like) that accompany the occurrence of warping of the plate-shaped member that is in the midst of fabrication or in a completed state, can be suppressed.
Note that, from the standpoints of improving the production efficiency and suppressing warping, it is particularly preferable that the metal plate be formed from a single member (a member having opening portions that correspond to the total number of semiconductor chips mounted to the plate-shaped member) that corresponds to the size of the plate-shaped member.
However, from the standpoints of ensuring the handling ability and the accuracy of aligning the semiconductor chips and the opening portions, the metal plate may be a member that is, for example, one-half or one-quarter of the size of the plate-shaped member (may be a member having a number of opening portions that is one-half or one-quarter of the total number of the semiconductor chips mounted to the plate-shaped member). Therefore, in a case in which the metal plate is one-half of the size, the plate-shaped member is fabricated by using two metal plates, and in a case in which the metal plate is one-quarter of the size, the plate-shaped member is fabricated by using four metal plates.
However, in a case in which there are plural metal plates structuring the plate-shaped member, if the size of the individual metal plates is small, the production efficiency decreases and it is difficult to suppress warping. Therefore, the surface area of the individual metal plate (this surface area means the surface area including the opening portions and the frame portion) is preferably greater than or equal to ¼ of the surface area of the plate-shaped member, and greater than or equal to ½ is even more preferable.
In the process of forming the plural semiconductor devices by cutting the plate-shaped member at regions where the frame portion exists, a known cutting method can be used, but it is preferable to use dicing.
Further, it is preferable to provide concave portions and/or holes in the frame portion of the metal plate. In this case, in the process of forming the plural semiconductor devices, the cutting speed can be improved by carrying out the cutting of the regions where the frame portion exists, along the portions where the concave portions and/or holes, that are provided in the frame portion, are provided. Moreover, wear of the member that is used in cutting (the dicing blade) also can be suppressed. Note that the concave portions or holes can be formed by using press machining, etching processing, or the like.
The material structuring the metal plate is not particularly limited, and a known metal material can be used. For example, Cu, Al, alloys including these metals, and SUS can be used. There among, it is preferable to use SUS that has a low thermal expansion coefficient.
Note that the method of fabricating the plate-shaped member is not particularly limited, but it is preferable that the plate-shaped member be fabricated through the following processes.
Namely, the plate-shaped member is preferably fabricated via at least following processes (1) through (5):
Note that, in process (4), the sealing resin layer can be formed by a molding method or a potting method. Further, when a molding method is employed, the sealing resin layer can be formed not only at the gap portions between the semiconductor chips and the metal plate, but also so as to cover these both members.
Hereinafter, when implementing above processes (1) through (5) in that order, in process (4), a case that employs a molding method will be called a “first exemplary embodiment”, and a case employing a potting method will be called a “second exemplary embodiment”.
The above five processes can be executed in the order of their numbers as described above, but are not limited to the same.
In a case in which the above five processes are not implemented in the order of their numbers, process (1) among these five processes must be executed first, but the remaining processes (2) through (5) can be executed in an arbitrary order provided that the following conditions are satisfied. First, either of processes (2) and (3) may be executed before the other. However, if process (2) is implemented first, process (3a) is selected, and if process (2) is executed after, process (3b) is selected. Further, process (4) can be executed at an arbitrary time provided that it is after processes (2) and (3) have been executed. Further, process (5) can be executed at an arbitrary time provided that it is after process (1) has been executed.
Other than implementing processes (1) through (5) in that order, another suitable combination of the order of execution when executing processes (1) through (5) is, for example, (1) in the process of preparing the supporting substrate, forming plural opening portions in the wiring layer, (3) placing the metal plate, that has plural opening portions and a frame portion forming the opening portions, at the surface of the supporting substrate at the side at which the wiring layer is provided, at a position of surrounding predetermined regions where the individual semiconductor chips are to be disposed, and thereafter, (5) carrying out the process of removing the semiconductor substrate from the supporting substrate, and (2) then, mounting the plural semiconductor chips to the surface of the wiring layer at the side at which the metal plate is provided, so as to seal the opening portions of the wiring layer, and thereafter, (4) carrying out the process of forming the sealing resin layer (hereinafter, an aspect embodied by this combination is called a “third exemplary embodiment”).
The method of connecting the semiconductor chips to the wiring layer is not particularly limited, and flip-chip joining or wire bonding can be selected. In the case of flip-chip joining, the flip-chip joining is carried out simultaneously with implementation of process (2), by using semiconductor chips with bump electrodes. Further, in the case of carrying out wire bonding, the wire bonding is carried out after process (2) is implemented and before process (3) is implemented.
At the semiconductor device that is fabricated by the semiconductor device fabricating method of the present invention, a heat sink (heat dissipating plate) can be provided at the surface at the side opposite the surface at the side where the wiring layer is provided. A plate formed from metal such as, for example, Cu, Al, alloys including these metals, SUS, or the like, can be used as the heat sink.
A concrete example of the semiconductor device fabricating method of the present invention will be described in further detail hereinafter by using the drawings.
In the drawing, reference numeral 10 is a semiconductor substrate 10 such as a silicon wafer or the like, 12 is an insulating layer formed from polyimide or the like, 14a is conductor rewiring (the first layer), 14b is conductor rewiring (the second layer), 16 is a wiring layer, 20 and 22 are semiconductor chips with bump electrodes, 30 and 32 are underfill, 40 is a metal plate (frame portion), 42 is an opening portion, 50 is a sealing resin layer, and 60 is a terminal.
In the example shown in
First, the insulating layer 12 is formed on the surface of the semiconductor substrate 10 (
Next, semiconductor chips 20 with bump electrodes, at which bump electrodes are provided on one surface thereof, are readied. These plural semiconductor chips 20 with bump electrodes are disposed on the wiring layer 16 side surface of the supporting substrate such that the surfaces thereof at which the bump electrodes are formed face the wiring layer 16, and are flip-chip joined (
Then, the metal plate 40, that has the plural opening portions 42 and the frame portion that forms these opening portions 42, is disposed at the wiring layer 16 side surface of the supporting substrate at a position such that the opening portions 42 surround the semiconductor chips 20 (
Thereafter, the sealing resin layer 50 is formed by a molding method at the gaps between the semiconductor chips 20 and the metal plate 40, and so as to cover the semiconductor chips 20 and the metal plate 40 (
Then, the semiconductor devices are obtained (not illustrated) by cutting this plate-shaped member by dicing or the like at the portions, that are shown by the dashed lines in the drawing, of the regions where the frame portion 40 exists.
In the drawing, reference numeral 52 is a sealing resin layer, and members denoted by other reference numerals are the same as in
In the example shown in
First, the processes shown in
Then, the semiconductor substrate 10 is peeled off from the wiring layer 16, and the terminals 60 are formed at the surface of the wiring layer 16 at the side where the semiconductor substrate 10 was provided (
Then, the semiconductor devices are obtained (not illustrated) by cutting this plate-shaped member by dicing or the like at the portions, that are shown by the dashed lines in the drawing, of the regions where the frame portion 40 exists.
In the drawing, reference numeral 18 is an opening portion, and members denoted by other reference numerals are the same as in
In the example shown in
First, the insulating layer 12 is formed on the surface of the semiconductor substrate 10, and the opening portions 18 are provided at the portions where the semiconductor chips 20 are to be placed (
Next, the semiconductor chips 20 with bump electrodes, at which bump electrodes are provided on one surface thereof, are readied. Note that the underfill 30 is formed in advance at the surfaces of the semiconductor chips at the sides where the bump electrodes are provided.
Thereafter, the metal plate 40, that has the plural opening portions 42 and the frame portion that forms these opening portions 42, is disposed at the wiring layer 16 side surface of the supporting substrate at a position such that the opening portions 42 surround the predetermined regions where the semiconductor chips 20 are to be disposed (
Next, the plural semiconductor chips 20 with bump electrodes are disposed on the wiring layer 16 side surface of the supporting substrate such that the surfaces thereof at which the bump electrodes are formed close-up the opening portions 18 of the wiring layer 16 (
Thereafter, the sealing resin layer 50 is formed by a potting method at the gaps between the semiconductor chips 20 and the metal plate 40 (
Then, the semiconductor devices are obtained (not illustrated) by cutting this plate-shaped member by dicing or the like at the portions, that are shown by the dashed lines in the drawing, of the regions where the frame portion 40 exists.
Note that, after any of the processes shown in
Further, in the examples shown in
In the example shown in
First, the processes shown in
Next, the semiconductor chips 20 with bump electrodes, at which bump electrodes are provided on one surface thereof, are readied. Note that the underfill 34 is formed in advance at the surfaces of the semiconductor chips 20 at the sides where the bump electrodes are provided.
Thereafter, the metal plate 40, that has the plural opening portions 42 and the frame portion that forms these opening portions 42, is disposed at the wiring layer 16 side surface of the supporting substrate at a position such that the opening portions 42 surround the predetermined regions where the semiconductor chips 20 are to be disposed (
Next, the plural semiconductor chips 20 with bump electrodes are disposed on the wiring layer 16 side surface of the supporting substrate such that the surfaces thereof at which the bump electrodes are formed are at the side opposite the wiring layer 16. Note that the semiconductor chips 20 and the wiring layer 16 are joined via an adhesive. Thereafter, the conductor rewiring 14b, that structures the wiring layer 16, and the semiconductor chips 20 are wire-bonded by the wires 100. Note that the placing of the metal plate 40 on the one hand, and the placing of the semiconductor chips 20 and the wire bonding on the other hand, may be implemented in the reverse order.
Thereafter, the sealing resin layer 54 is formed by filling resin by using a potting method so as to seal the interiors of the opening portions 42 of the metal plate 40 and cover the semiconductor chips 20. Next, the semiconductor substrate 10 is peeled off from the wiring layer 16, and the terminals 60 are formed at the surface of the wiring layer 16 at the side where the semiconductor substrate 10 was provided (
Then, the semiconductor devices are obtained (not illustrated) by cutting this plate-shaped member by dicing or the like at the portions, that are shown by the dashed lines in the drawing, of the regions where the frame portion 40 exists.
Further,
In the example shown in
The concave portions 44, that are rectangular and extend along the cutting lines 80, are provided in the metal plate 40 shown in
The concave portions 44 may be provided at one surface side of the metal plate 40 as shown in
Number | Date | Country | Kind |
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2007-337749 | Dec 2007 | JP | national |