Semiconductor device and method of manufacturing the same, circuit board and electronic instrument
A method of manufacturing a semiconductor device, including a first step of placing a resin between one surface of a semiconductor chip, having a plurality of electrodes formed thereon, and a substrate having a wiring pattern formed thereon and defining at least one through-hole in a region in which the semiconductor chip is to be mounted on the substrate, to form a space therebetween that opens into the through-hole, and a second step of pressing either one of the semiconductor chip and the substrate against the other to thereby bond the semiconductor chip to the substrate.
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This is a Divisional of application Ser. No. 09/794,666 filed Feb. 28, 2001. The entire disclosure of the prior application is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION1. Field of Invention
The present invention relates to a semiconductor device and a method of manufacturing it, and to a circuit board and electronic instrument incorporating the semiconductor device.
2. Description of Related Art
One known type of CSP (chip scale/size package) semiconductor device, is a face-down bonding (flip chip bonding) structure with semiconductor chips on a substrate. For example, it is known to fabricate a semiconductor device by providing an anisotropic conductive material on the entire surface of a substrate on which semiconductor chips are to be mounted, followed by mounting semiconductor chips thereon.
However, the anisotropic conductive material provided on the entire surface of the substrate, on which semiconductor chips are to be mounted, extends around the semiconductor chips mounted on the substrate due to the stress applied thereto when the semiconductor chips are mounted on the substrate, and will often form bubbles around the edges of the mounted semiconductor chips. In addition, since the contact area between the two is large, bubbles may also be formed somewhere therein. These bubbles often reduce the reliability of the semiconductor device.
SUMMARY OF THE INVENTIONThe invention solves the above problems, and its object is to provide a highly reliable semiconductor device and a method of manufacturing it, and also a circuit board and electronic instrument incorporating the semiconductor device.
A method of manufacturing a semiconductor device in accordance with the invention includes:
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- a first step of placing a resin between one surface of a semiconductor chip, having a plurality of electrodes formed thereon, and a substrate having a wiring pattern formed thereon and having at least one through-hole in a region in which the semiconductor chip is to be mounted on the substrate, to form a space therebetween that opens into the through-hole, and
- a second step of pressing at least one of the semiconductor chip and the substrate against the other to thereby bond the semiconductor chip to the substrate.
A semiconductor device in accordance with the invention includes:
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- a semiconductor chip having a plurality of electrodes,
- a substrate having a wiring pattern formed thereon, with the semiconductor chip being face-down bonded thereto, and having at least one through-hole in a region in which the semiconductor chip is mounted on the substrate, and
- a resin placed at least between the semiconductor chip and the substrate, the resin being placed therebetween to form a space that opens into the through-hole.
A method of manufacturing a semiconductor device in accordance with a first characteristic of the invention includes;
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- a first step of placing a resin between one surface of a semiconductor chip, having a plurality of electrodes formed thereon, and a substrate having a wiring pattern formed thereon and having at least one through-hole in a region in which the semiconductor chip is to be mounted on the substrate, to form a space therebetween that opens into the through-hole, and
- a second step of pressing at least one of the semiconductor chip and the substrate against the other to thereby bond the semiconductor chip to the substrate.
According to this structure, the resin is made to extend inside the region in which the semiconductor chip is to be mounted on the substrate, and the amount of the resin that may extend outside the region can be reduced. Accordingly, this structure obviates bubbles that may be formed by the resin extending outside the region to engulf the edge of the semiconductor chip. In addition, since the contact area between the semiconductor chip and the resin is small, few bubbles are formed between the two. Even when some bubbles are formed, they may be removed through the through-hole of the substrate. Accordingly, highly reliable semiconductor devices can be manufactured.
Embodiments of the invention are mentioned below.
(1) In the method of manufacturing a semiconductor device in accordance with the first characteristic of the above invention, the resin is placed on the substrate in the first step to form a recessed or holed space thereon that opens into the through-hole.
According to this structure, the resin forms a recess or a hole that opens into the through-hole, and it is made to extend inside the region in which the semiconductor chip is to be mounted on the substrate. The resin flow toward the recess or the hole can be promoted by removing air through the through-hole that opens into the recess or the hole.
(2) In the method of manufacturing a semiconductor device in accordance with the first characteristic of the above invention, as the electrodes are formed along the two opposite sides of the semiconductor chip, and
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- in the first step, the resin is placed along the two sides.
In this structure, the resin is placed along the two opposite sides of the semiconductor chip along which the electrodes are formed. Accordingly, it is easy to place a smaller amount of the resin in the intended region.
(3) In the method of manufacturing a semiconductor device in accordance with the first characteristic of the above invention, the electrodes are formed in the peripheral area of the semiconductor chip, and
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- in the first step, the resin is placed in the site corresponding to the region that is inside the region of the semiconductor chip in which the electrodes are formed.
In this structure, the range of the resin to extend outside can be reduced. Accordingly, for example, the resin can be kept within the range of the region in which the semiconductor chip is to be mounted on the substrate. Therefore, since the resin does not engulf the edge of the semiconductor chip, this structure is more effective for preventing the formation of bubbles around the edge of the semiconductor chip.
(4) In the method of manufacturing a semiconductor device in accordance with the first characteristic of the above invention, the resin is placed within a range so as not to overstep the region in which the semiconductor chip is to be mounted on the substrate in the second step.
In this structure, the resin is placed within a range not overstepping the region in which the semiconductor chip is to be mounted on the substrate. Specifically, since the resin does not engulf the edge of the semiconductor chip, this structure is more effective for preventing the formation of bubbles around the edge of the semiconductor chip.
(5) In the method of manufacturing a semiconductor device in accordance with the first characteristic constitution of the above invention, the resin contains conductive particles, and
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- in the second step, the conductive particles are made to be between the electrodes and the wiring pattern. In this case, the resin may be an anisotropic conductive film.
According to this structure, the electrodes can be electrically connected with the wiring pattern.
(6) The invention is also intended to cover a semiconductor device manufactured according to any of the above-mentioned semiconductor device-manufacturing methods.
(7) A semiconductor device in accordance with the invention includes:
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- a semiconductor chip having a plurality of electrodes,
- a substrate having a wiring pattern formed thereon, with the semiconductor chip being face-down bonded thereto, and having at least one through-hole in a region in which the semiconductor chip is mounted on the substrate, and
- a resin placed at least between the semiconductor chip and the substrate, the resin being placed therebetween to form a space that opens into the through-hole.
In this structure, the resin is made to extend in the space that opens into the through-hole of the substrate, and the amount of the resin that may extend outside the region in which the semiconductor chip is mounted on the substrate can be reduced. Accordingly, this structure obviates bubbles that may be formed by the resin extending outside the region to engulf the edge of the semiconductor chip. In addition, since the contact area between the semiconductor chip and the resin is small, few bubbles are formed between the two. Even when some bubbles are formed, they may be removed through the through-hole of the substrate. Moreover, in the subsequent packaging step, moisture may be removed from the semiconductor device through the space surrounded by the resin to open into the through-hole of the substrate. Accordingly, highly reliable semiconductor devices can be provided.
(8) In the above semiconductor device (7), the space is larger than the through-hole.
An advantage of this structure is that, in the subsequent packaging step, moisture can be removed more readily from the semiconductor device. Specifically, since the space surrounded by the resin is larger than the through-hole of the substrate, moisture can be removed more surely, for example, from the resin.
(9) In the above semiconductor device (7), the resin is placed so as not to overstep the range of the region in which the semiconductor chip is mounted on the substrate.
In this structure, the resin is placed so as not to overstep the range of the region in which the semiconductor chip is mounted on the substrate. Specifically, since the resin does not engulf the edge of the semiconductor chip, this structure is more effective for preventing the formation of bubbles around the edge of the semiconductor chip.
(10) In the above semiconductor device (7), the resin contains conductive particles, and
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- the conductive particles are placed between the electrodes and the wiring pattern.
In this case, the resin may be an anisotropic conductive film.
In this structure, the electrodes can be electrically connected with the wiring pattern.
(11) The invention is also intended to cover a circuit board having thereon, any of the above semiconductor devices (7) to (10).
(12) The invention is also intended to cover an electronic instrument having therein any of the above semiconductor devices (7) to (10).
Some preferred embodiments of the invention are described hereinunder with reference to the drawings attached hereto, which, however, are not intended to restrict the scope of the invention.
(First Embodiment)
As shown in
As shown in
The wiring pattern 22 is formed on one or both surfaces of the substrate 20. In many cases, the wiring pattern 22 has a multi-layered structure. For example, any of copper (Cu), chromium (Cr), titanium (Ti), nickel (Ni) and titanium-tungsten (Ti—W) may be layered to form the wiring pattern 22. The wiring pattern 22 may be formed through photolithography, sputtering or plating. A part of the wiring pattern may form a land (not shown) of which the area is larger than the wiring area. The land ensures electric connection in the device, and is often formed to act as an electric contact with the electrodes 12 of the semiconductor chip 10 or with external terminals 40.
As shown in
The substrate 20 may be worked to have via-holes 26 for external connection, in addition to the through-hole 24. Through the via-holes 26, both surfaces of the substrate 20 can be electrically connected with each other. In the case where the substrate 20 has the via-holes 26 formed therethrough, a part of the wiring pattern 22 extends over the via-holes 26. The part of the wiring pattern 22 that extends thereover may be a land (not shown). Irrespective of the profile of the wiring pattern 22 formed on the substrate 20, the via-holes 26, if any, ensure electric connection with the wiring pattern 22 on both sides of the substrate 20.
As shown in
As shown in
As shown in
A plurality of external terminals 40 may be disposed to be in contact with the wiring pattern 22. For example, external terminals 40 may be disposed to be in contact with the wiring pattern 22 through the via-holes 26 formed through the substrate 20, as shown in
The external terminals 40 do not have to be intentionally formed in the manner described above, and solder cream can be applied to the mother board, for mounting the device thereon, to form external terminals. In this case, the solder cream can finally form external terminals due to the surface tension of its melt. The semiconductor device of this type is a land-grid-array device having a land that forms external terminals. If desired, a land may be formed on the surface of the substrate 20 opposite to the surface thereof having the wiring pattern 22 thereon and facing the semiconductor chip 10, and the land may be electrically connected with the wiring pattern 22 via the via-holes 26. Also if desired, the through-hole 26 may be filled with a conductive material, and its surface may serve as a land.
The substrate 20 may be partly extended for external connection at the extended part thereof. A part of the substrate 20 may be a lead for a connector, or a connector may be mounted on the substrate 20, or the wiring pattern 22 formed on the substrate 20 may be directly connected with other electronic instruments.
The method of manufacturing the semiconductor device of this embodiment is described below.
(First Step)
As shown in
In this embodiment, the anisotropic conductive material 30 is disposed to cover the periphery of the region in which the semiconductor chip 10 is to be mounted, thereby forming a frame structure of which the outer periphery is nearly analogous to the periphery of the semiconductor chip 10, as in the plan view of the substrate 20. In this case, the anisotropic conductive material 30 may to a certain degree overstep the region of the substrate 20 in which the semiconductor chip 10 is to be mounted on the substrate 20. Accordingly, the anisotropic conductive material 30 can be easily and surely disposed in the intended area.
The anisotropic conductive material 30 forms a space that opens into the through-hole 24. Precisely, space defines a hole 32 surrounded by the anisotropic conductive material 30. The opening of the hole 32 can be of any size, and it may be determined depending on the profile of the hole 32 to be formed by the anisotropic conductive material 30 that extends toward the hole 32 in the subsequent step.
For example, after the anisotropic conductive material 30 (for example, anisotropic conductive paste) has been spread entirely in the region of the substrate 20 in which the semiconductor chip 10 is to be mounted on the substrate 20, a part of the anisotropic conductive material 30, existing in and around the center of where the through-hole 24 is to be formed, may be removed to form the hole 32. In that manner, for example, when the substrate 20 has a plurality of regions for a plurality of semiconductor chips 10 to be mounted thereon in the form of a matrix (not shown), the anisotropic conductive material 30 can be easily formed on the substrate 20 of that type, and can readily define the hole 32 in every region for each semiconductor chip 10.
(Second Step)
Either one of the semiconductor chip 10 or the substrate 20 can be pressed against the other, whereby the electrodes 12 are electrically connected with the wiring pattern 22 via the conductive particles in the anisotropic conductive material 30. In this step, the semiconductor chip 10 may be heated. In case where the anisotropic conductive material 30 includes a thermosetting resin, the anisotropic conductive material 30 is once melted when heated, and then cured. In the case where the anisotropic conductive material 30 is an anisotropic conductive film, it is once fluidized when heated. In the case where resins which are different from the anisotropic conductive material 30 are used, energy may be imparted to the resins in accordance with the curing mechanism of the resins used.
After being fluidized, the anisotropic conductive material 30 is compressed between the semiconductor chip 10 and the substrate 20, and extends between them. Specifically, the thus-fluidized anisotropic conductive material 30 runs in all directions inside and outside of the region in which the semiconductor chip 10 is mounted on the substrate 20, as in the plan view of the substrate 20. In this embodiment, the hole 32 that opens into the through-hole 24 is defined inside the region in which the semiconductor chip 10 is mounted on the substrate. Therefore, in this step, the anisotropic conductive material 30 can extend not only inside the chip-mounted region but also outside of the chip-mounted region. Specifically, the amount of the anisotropic conductive material 30 extending outside of the chip-mounted region can be reduced, and the anisotropic conductive material 30 extending outside of the semiconductor chip 10 does not engulf the edge of the chip 10. Accordingly, few bubbles are formed around the edge of the semiconductor chip 10. In addition, since the contact area between the semiconductor chip 10 and the anisotropic conductive material 30 is small, few bubbles are formed therein. Even if some bubbles are formed, they can be removed through the through-hole 24 of the substrate 20. Accordingly, highly reliable semiconductor devices can be manufactured.
After being further heated, the fluidized anisotropic conductive material 30 is cured, and the hole 32 surrounded by the thus-cured material 30 is smaller than the original space surrounded by the non-cured material 30, as shown in
Though not illustrated herein, the amount of the original anisotropic conductive material 30, and the original form of the hole 32 surrounded by the material 30, can be controlled so that the semiconductor device finally produced does not define the hole 32. In the embodiment not illustrated, the hole 32, that was formed in the first step of the manufacture process as shown in
(Subsequent Steps)
After the semiconductor chip 10 has been face-down bonded to the substrate via the anisotropic conductive material 30 or the like, external terminals 40 may be connected with the wiring pattern 22. In order to accomplish this, the external terminals 40 are formed under heat (this is a reflow step). Also in this step, the semiconductor device of this embodiment is effective. For example, in the semiconductor device of
In this embodiment, the resin extends inside the region in which the semiconductor chip 10 is mounted, and the amount of the resin that may extend outside of the region is reduced. Accordingly, the resin extending outside the chip-mounted region does not engulf the edge of the semiconductor chip 10 to form bubbles around the edge thereof. Therefore, highly reliable semiconductor devices can be manufactured.
As shown in
The anisotropic conductive material 50, that extends inside the region in which the semiconductor chip 10 is mounted, is cured by heating it in the subsequent step, whereby a space smaller than the original recess 52 may be formed, as shown in
(Second Embodiment)
The method of manufacturing the semiconductor device of this embodiment is first described below.
In this embodiment, the resin 60 is so disposed that it does not protrude outside of the semiconductor chip 10 in the plan view when the semiconductor chip 10 is combined with the substrate 20.
For example, the first embodiment will be applied to this embodiment. In this embodiment, the resin 60 may be placed at a location that is inside the region of the semiconductor chip 10 in which the electrodes 12 are formed, in the plan view of the substrate 20, thereby forming a frame structure of which the outer periphery is nearly analogous to the periphery of the semiconductor chip 10. This structure may define a hole 62 that opens into the through-hole 24.
Similarly, on the other hand, the modification of the first embodiment will be applied to this embodiment. In this embodiment, the resin 60 may be placed at a location that is inside the region of the semiconductor chip 10 in which the electrodes 12 are formed, thereby forming a recess (not shown) that opens into the through-hole 24. The method for forming the hole 62 or the recess (not shown) and the effect of the hole 62 or the recess (not shown) are the same as those in the above-mentioned embodiments.
The resin 60 thus formed extends in all directions inside and outside the region in which the semiconductor chip 10 is mounted on the substrate, after the semiconductor chip 10 has been pressed against the substrate 20 and the two are heated. In this embodiment, the resin 60 is disposed at a location that is inside the region of the semiconductor chip 10 in which the electrodes 12 are formed. In this embodiment, therefore, the range of the resin 60 that may extend outside can be reduced. Accordingly, for example, the fluidized resin 60 is prevented from protruding outside the semiconductor chip 10 in the plan view of the substrate 20, as shown in
The semiconductor device of this embodiment is manufactured according to the method mentioned above. As shown in
(Third Embodiment)
As shown in
As shown in
In addition to the advantages of the other embodiments mentioned above, the semiconductor device of this embodiment has another advantage in that a smaller amount of resin may be disposed more easily therein.
One example of electronic instruments equipped with the semiconductor device of the invention is a notebook-sized personal computer 200, as shown in
Claims
1. A semiconductor device, comprising:
- a semiconductor chip having a plurality of electrodes;
- a substrate having a wiring pattern formed thereon, the substrate having a region on which the semiconductor chip is face-down bonded, the substrate defining at least one through-hole in the region on which the semiconductor chip is face-down bonded; and
- a resin disposed at least between the semiconductor chip and the substrate, the resin divided by a space that is in communication with the through-hole into at least two parts.
2. The semiconductor device as claimed in claim 1, the resin being disposed within the region in which the semiconductor chip is mounted on the substrate.
3. The semiconductor device as claimed in claim 1, the resin containing conductive particles, the conductive particles being disposed between the electrodes and the wiring pattern.
4. The semiconductor device as claimed in claim 3, the resin being an anisotropic conductive film.
5. A circuit board incorporating the semiconductor device of claim 1.
6. An electronic instrument incorporating the semiconductor device of claim 1.
Type: Application
Filed: Sep 30, 2004
Publication Date: Feb 17, 2005
Applicant: Seiko Epson Corporation (Tokyo)
Inventor: Hideo Miyasaka (Okaya-shi)
Application Number: 10/953,518