JPH0997857A - Semiconductor device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the thermal resistance of a package. SOLUTION: An IC chip 2 is fixed to one main surface of a metal plate 1 and at the same time a wire 4 which is electrically connected to the pad of the chip 2 is fixed via an insulation sheet 8, and a solder ball 6 which becomes a protruding electrode to be electrically connected to the wire 4 is adhered also onto the other main surface of the metal plate 1 via the insulation sheet 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method for manufacturing the same, and more particularly to a BGA (Ball Grid Arr).
The present invention relates to a structure of an ay) type integrated circuit package and a manufacturing method thereof.

[0002]

2. Description of the Related Art A semiconductor device provided with this type of package is suitable for a case where an extremely large number of external terminals are required.

Incidentally, "NIKKEI MICRODEVICES" (199 which describes this type of package)
8 (March 4, issue, page 62), this semiconductor device has an IC chip 3 fixed to the upper main surface of a printed circuit board 35 and arranged on the main surface of the IC chip 30. The numerous pads formed and the wiring formed on the main surface of the printed circuit board 35 are connected to each other by bonding wires, and at least the IC chip 30 and the wires 31 are covered with the molding resin 32. Printed circuit board 3
On the back surface (lower main surface) of FIG. 5, a large number of solder bumps 34, which will be the protruding electrodes, are arranged in a grid pattern, and on the inner surface, a large number of through-holes 33 made of a metal conductor will be used. Are electrically connected to the wiring connected to. This semiconductor device is placed on a mounting substrate (motherboard), the solder bumps 34 are melted by reflowing or the like, and are connected to the electrodes on the mounting substrate.

The printed circuit board 35 used in such a semiconductor device has an insulating synthetic resin substrate because of its good workability, easy formation of through holes, inexpensive raw materials, and the like. Is used.

However, such a printed circuit board 3
In No. 5, since the thermal conductivity is not good, the thermal resistance from the IC chip 30 to the mounting substrate becomes high, and especially the IC chip 30
If the power consumption is large, the junction temperature rises, which causes problems such as malfunction and short life.
The C chip 30 may be destroyed by heat. In particular, the amount of current of the IC chip 30 that operates at high speed is large, and an increase in power consumption cannot be avoided. In addition, power consumption increases with high integration.

Therefore, it is conceivable to provide the package itself with a large heat sink, but this not only has the disadvantage of increasing the mounting deposition, but also may make it impossible to store the package in the mounting housing.

[0007]

In view of the above problems and the like, the present invention has the following problems. (1) To reduce the thermal resistance of the package and to easily diffuse the heat generated in the IC chip. (2) Even if high-speed operation and high integration of IC chips are advanced,
Do not cause a malfunction or shorten the life of the product. (3) The heat generated by the IC chip should be easily dissipated mainly through the mounting board. (4) Make sure that the external dimensions of the semiconductor package do not increase. (5) To suppress the rise in junction temperature of the IC chip,
To provide a semiconductor device with high reliability.

[0008]

The first structure of the present invention is as follows.
The semiconductor chip is fixed to one main surface of the metal plate, and the first wiring electrically connected to the pad of the semiconductor chip is fixed to the other main surface of the metal plate through the insulating sheet. In addition, a protruding electrode electrically connected to the second wiring is fixed via an insulating sheet.

Particularly, on the side surface of the metal plate, the first,
Wirings connecting the second wirings to each other are fixed via an insulating sheet, and further, the insulating sheet on the one main surface, the insulating sheet on the side surface, and the insulating on the other main surface. Another feature is that the seat and the seat are integrated.

Further, in particular, the metal plate is characterized in that a metal base body mainly made of copper is plated with gold.

Further, in particular, the side surface of the metal plate is a curved surface or a flat surface chamfered between the side surface of the metal plate and the side surface of the metal plate. A feature is that a gap is provided between the insulating sheet and the insulating sheet.

In addition to the first structure, an insulating frame is attached so as to cover at least the wiring on the side surface of the metal plate.

A second structure of the present invention is a method for manufacturing a semiconductor device, which uses a tape in which wirings electrically connected to pads of a semiconductor chip are arranged on one surface of an insulating sheet. A protrusion electrode for electrically connecting to the wiring and for connecting to an electrode of a substrate on which the semiconductor device is mounted is formed on the same surface as one surface.

In particular, the portion of the tape on which the protruding electrodes are formed is bent by sandwiching a metal plate to which a semiconductor chip is fixed, and is fixed to the metal plate. It is also characterized in that the metal plate is fixed to the tape at a predetermined angle so that the portion in which is formed can be bent.

According to the first configuration of the present invention, since most of the total deposition of the semiconductor device can be carried out by the metal plate, the heat capacity of the metal plate can be increased, and the main surface and side surface of the metal plate can be increased. Since heat can be dissipated from the package, the package has extremely low thermal resistance.

In particular, since the insulating sheet and the wiring can be manufactured at once without separately manufacturing them, the number of manufacturing steps does not increase and it is not necessary to form the through holes. Further, since the side surface of the metal plate is a curved surface or the like, there is no fear of damaging the insulating sheet and the wiring.

Further, it is easy to set the arrangement of the protruding electrodes at a more correct position in the portion where the gap is provided. When the insulating frame is attached, there is no risk of damaging the wiring in handling.

According to the second structure of the present invention, the portion for forming the protruding electrode and the portion for connecting to the semiconductor chip can be formed on the same insulating sheet, so that the tape can be easily manufactured.

In particular, since it is only necessary to bend the tape, it is not necessary to separately manufacture a through hole or the like. Further, since it is sufficient to set the angle of the metal plate so that it can be bent, it is suitable for automation without increasing the number of special manufacturing steps.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the plan view of FIG. 1 showing a first embodiment of the present invention, this semiconductor device is in a manufacturing stage. First, a TAB tape 3 and a lower part thereof are located. The metal plate 1 is prepared.

The metal plate 1 is a metal substrate mainly made of copper, which has good heat conductivity, and is plated with gold. The metal plate 1 has a square upper main surface and a lower main surface, and has a constant thickness (0.5 mm to 5 mm). ．
0 mm). An IC chip 2 is fixed to the center of the metal plate 1. The four side surfaces of the metal plate 1 have a curved cross section such as a semicircular cross section described later.

The TAB tape 3 has a square outer shape,
Good electrical insulation like polyimide film, 1
An elastic synthetic resin insulating sheet 8 which can be easily bent by about 0 μ to 30 μ is selected. On the upper surface of this film, lands to which solder balls 6 serving as protruding electrodes are fixed are arranged at predetermined intervals, from which wirings 4 extend and are electrically connected to inner leads 5. The wiring 4 and the inner leads 5 are preferably made of gold having a thickness of 10 μm to 30 μm.
The central portion of the insulating sheet 8 has a rectangular opening 13 slightly larger than the IC chip 2, and a notch 9 is provided in the middle of each side. The cut 9 has a planar shape of a combination of a triangle and a circle so that the tape 3 can be easily bent in a later step and a dimensional clearance is secured. The portion of the inner lead 5 does not have the insulating sheet 8 and serves as the opening 13.

First, the metal plate 1 is accurately aligned with the center of the TAB tape 3 at a plane angle of 45 degrees, and then the inner leads 5 and the electrodes on the main surface of the IC chip are thermocompression bonded. Etc. are electrically connected to each other. At this time, it is preferable that the TAB tape 3 and the heat dissipation plate 1 are already bonded.

Next, the TAB tape 3 is the bending line 1
The metal plate 1 is wrapped along 1, 2 so as to be a so-called mountain fold.

FIG. 2 showing the state of the back surface of the metal plate 1 at this time.
2, the TAB tape 3 covers the back surface of the metal plate 1 so as to wrap it from all sides. At this time, TA
The B tapes 3 are accurately aligned and bonded so that the ends do not overlap each other and the ends do not separate from each other. In this way, the solder balls 6 arranged at predetermined intervals are completed. The solder balls 6 are completed after this step. It should be noted that this solder ball 6 is formed by solder reflow or the like after this step.
You may form. Further, it is preferable that an insulating film is formed on the wiring 4.

Referring to FIG. 3 which is a sectional view taken along the line AA ′ of FIG. 2, the wiring 4 on the upper surface of the TAB tape 3 is formed by the metal plate 1.
Through a side surface 7 having a semicircular cross section, reaching the back surface.

Next, at least the inner lead 5 and the IC
The surface of the chip 2 is covered with the mold resin 10. Incidentally, in FIG. 3, since it has a left-right symmetry with the center line 16 as an axis, only the left side is shown.

In order to arrange the solder balls 6 more accurately, the metal plate 1 is dimensioned so that a gap 14 is formed between the side surface 7 and the TAB tape 3 as shown in the sectional view of FIG. It is reduced by about 10 μ to 100 μ. Due to the presence of the gap 14, there is a dimensional margin in aligning the ends of the tape 3 in FIG. 2, and the adjustment can be easily performed.

According to the first embodiment, the IC chip 2
Are directly adhered to the metal plate 1, and a large number of solder balls 6 are adhered to the metal plate 1 through a thin insulating sheet 8. Therefore, the heat generated in the IC chip 2 is generated by the metal plate 1. Is further conducted to the mounting board and diffused upward, so that the thermal resistance can be made extremely small. Further, since the metal plate 1 is located at a position corresponding to the conventional printed circuit board, the heat capacity is larger than the conventional one. Despite the low thermal resistance, the same external dimensions as the conventional one can be used.
The mounting structure does not become large.

Further, since the inner lead and the protruding electrode can be formed on the same surface of the TAB tape, it is not necessary to separately form the protruding electrode portion, and the increase in manufacturing process can be suppressed as much as possible.

In the first embodiment, the side surface 7 of the metal plate 1 is
Although the cross-sectional shape of the above is a semicircle, the present invention is not limited to this, and the side surface may be perpendicular to the upper surface of the metal plate 1 and the corner may be chamfered. Further, the notch 9 may be enlarged to a region where the wiring 4 is absent and formed to be large. The number of wirings 4, solder balls, etc. can be increased or decreased as necessary.

In the TAB tape 3, it is preferable to cover all the wiring 4 in the portion which does not need to be connected in the subsequent step with an insulating coating.

The plane shapes of the TAB tape 3 and the heat sink 1 are
Although it is limited to a square, any other rectangle may be used. Also in this case, as shown in FIG. 2, the ends are fixed without any gap.

Referring to the cross-sectional view of FIG. 5 showing the second embodiment of the present invention, in this embodiment, the insulating frame 18 mounted on the side surface of the metal plate 1 via the TAB tape 3 is used.
1 is shared with the first embodiment shown in FIGS. 1 to 4.

The insulating frame 18 has four side surfaces of the metal plate 1,
It is a rectangular frame that surrounds the peripheral edge portion and prevents damage during handling of the semiconductor device. It may be removed after mounting on the mounting board, or it may be used as it is mounted. The insulating frame 18 can be attached even when there is the gap 14 as shown in FIG. In this case, since the insulating sheet 8 is deformed, it is preferable to secure a space 19 capable of absorbing this.

The IC chip 2 in the above-described first and second embodiments is fixed to the central portion in a form parallel to each side of the heat dissipation plate 1, but forms an angle of 45 degrees with the TAB tape 3. I am doing it. However, the IC chip 2 may be fixed in a form parallel to each side of the TAB tape 3.

Thus, referring to the plan view of FIG. 5 showing the IC chip parallel to the side of the TAB tape as the third embodiment of the present invention and the plan view of the back surface of FIG. 6, this T
The AB tape 20 has an opening 1 having a side parallel to this side.
An insulating sheet 8'having 3 ', an array of solder balls 6 along the periphery of the heat sink 1', an array of inner leads 5'corresponding to the electrodes of the IC chip 1 ', and an inner lead 5'and solder. And a wire 4'for connecting each of the balls 6 '.

Since the other construction and manufacturing method are common to those of the above-described first and second embodiments, they are only shown with common arithmetic numerals and their explanations are omitted.

The TAB tapes 3 and 20 used in the above-described first to third embodiments are manufactured by continuously connecting those having the same shape, and when fixing the metal plates 1 and 1 '. , Preferably separated.

[0040]

As described above, according to the present invention, a metal plate having a large heat capacity is used with good heat dissipation effect, and a protruding electrode and a wiring connected to a pad of a semiconductor chip are formed on the surface of the same insulating sheet. Therefore, the heat resistance of the package can be reduced, the heat generated in the IC chip can be easily dissipated, and the increase in the number of manufacturing processes can be suppressed as much as possible, and each of the above-mentioned problems can be achieved.

[Brief description of drawings]

FIG. 1 is a plan view showing a TAB tape or the like according to a first embodiment of the present invention.

FIG. 2 is a plan view of the folded state of the TAB tape of FIG. 1, viewed from the back side.

FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG.

FIG. 4 is a cross-sectional view showing another example of FIG.

FIG. 5 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 6 is a plan view showing a TAB tape or the like according to a third embodiment of the present invention.

FIG. 7 is a plan view of the folded state of the tape of FIG. 6 viewed from the back surface.

FIG. 8 is a sectional view showing a conventional semiconductor device.

[Explanation of symbols]

 1,1 'Metal plate 2,2', 30 IC chip 3,15,20 TAB tape 4,4 'Wiring 5,5' Inner lead 6,6 'Solder ball 7 Side surface 8,8' Insulation sheet 9 Notch 10, 32 Mold resin 11, 12 Bending line 13, 13 'Opening 14 Gap 16 Center line 18 Insulating frame 19 Space 31 Wire 33 Through hole 34 Solder bump 35 Printed circuit board

Claims (10)

[Claims] 1. A semiconductor chip is fixed on one main surface of a metal plate, and a first wiring electrically connected to a pad of the semiconductor chip is fixed via an insulating sheet,
A semiconductor device, wherein a protruding electrode electrically connected to the second wiring is fixed on the other main surface of the metal plate via an insulating sheet. 2. The first and second parts on the side surface of the metal plate.
The semiconductor device according to claim 1, wherein the wirings interconnecting the wirings are fixed to each other via an insulating sheet. 3. The semiconductor device according to claim 2, wherein the insulating sheet on the one main surface, the insulating sheet on the side surface, and the insulating sheet on the other main surface are integrated sheets. 4. The semiconductor device according to claim 1, wherein the metal plate is a metal base body mainly made of copper and plated with gold. 5. The semiconductor device according to claim 1, wherein a side surface of the metal plate is a curved surface or a flat surface chamfered between the side surface and the main surface. 6. The semiconductor device according to claim 2, wherein a gap is provided between a side surface of the metal plate and the insulating sheet. 7. The semiconductor device according to claim 2, wherein an insulating frame is attached so as to cover at least the wiring on the side surface of the metal plate. 8. A method of manufacturing a semiconductor device using a tape in which wirings each electrically connected to a pad of a semiconductor chip are arranged on one surface of an insulating sheet, the method comprising: A method of manufacturing a semiconductor device, comprising forming a protruding electrode electrically connected to the wiring and connected to an electrode of a substrate on which the semiconductor device is mounted. 9. The method of manufacturing a semiconductor device according to claim 8, wherein a portion of the tape on which the protruding electrode is formed is bent with a metal plate to which a semiconductor chip is fixed sandwiched between and is fixed to the metal plate. 10. The method of manufacturing a semiconductor device according to claim 9, wherein the metal plate is fixed to the tape at a predetermined angle so that a portion of the tape where the protruding electrode is formed is bent.