JPH09115958A - Ic chip and peripheral wiring method of ic chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an IC chip and its peripheral wiring method for drastically improving integration density as compared with before and for reducing manufacturing cost. SOLUTION: Au ultra-fine particles are sprayed from a nozzle into a film formation room, an IC chip which is provided oppositely is supported so that it can rotate around a center shaft 30, Au ultra-file particles start to be deposited from a pad 32 on the surface, and a first conductive film 34 is formed to one edge of the surface of a substrate 31 of an IC chip 8. Then, a side surface B is formed continuously to the first conductive film 34 and a third conductive film is formed continuously to the second conductive film 35 on a reverse side C after rotating by 90 degrees. A conductive film can be formed on the front surface, side surface, and reverse surface of the IC chip continuously by a single gas deposition device, thus reducing manufacturing cost and increasing the integration density by forming a continuous conductive film on the front and rear surfaces and the side surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC chip and a peripheral wiring method for the IC chip.

[0002]

2. Description of the Related Art In a conventional IC chip, a terminal for external connection is provided on the outer periphery of one surface of a built-in integrated circuit, and a fine terminal is provided for connection with the contact. Pitch special connection jig (lead frame with inner / outer leads, film-like TA
B) was required.

Further, in the conventional gas deposition apparatus, the film formation on the base material or the substrate is mainly a film formation within one surface, and a film is formed in a part of a hole in the depth direction. I was just there. That is, the film formation is XY of the base material.
-It was done by driving the Z-axis and rotating around a vertical axis in one plane.

In order to connect the built-in integrated circuit and external wiring, the IC chip is provided with a terminal for connection on the outer peripheral portion of one surface of the IC chip. Conventionally, for connection with the one-sided contact, a special connection jig with a fine pitch of the same size as the IC chip (lead frame with inner / outer leads, film-like TAB, etc.)
Used to connect. The connection was only using one side of it, and the other side was never used to connect to the outside.

Further, the required area in the plane for mounting is I
This increases in proportion to the number of C chips, and if the packaging density per unit area is increased, the degree of integration within the IC chip wiring will be increased. On the other hand, for example, if IC chips are stacked and mounted, not only the connection with sandwiching jigs is required, but also a complicated process is required, and it also goes against the thinning of the IC chips in the thickness direction.

Further, in the conventional gas deposition apparatus, the film formation is carried out by driving the substrate in the XYZ axis directions and rotationally driving the substrate about a vertical axis.
When forming a film on the back surface, the substrate was taken out once and set again, which was a batch process.

[0007]

In the conventional IC chip, in order to connect the built-in integrated circuit and external wiring,
A terminal for connection is provided only on the outer peripheral portion of one surface of the IC chip, and only one side is used for connection, and the other side is not used for connection with the outside. . According to the present invention, the IC chip and the IC chip can be mounted by increasing the mounting density per unit area and stacking the IC chips to each other, and enabling the mounting substrate to be thinned in the thickness direction.
It is an object to provide a peripheral wiring method for a C chip.

[0008]

The above objects are achieved by an IC chip characterized in that a conductive film is continuously formed on the front surface of the substrate, the side surface of the substrate and the back surface of the substrate. It

Further, the above object is to provide an electrical connection pad on the surface of the substrate for forming an external wiring circuit line, and a first conductive film, a first conductive film, and a first conductive film which are continuously formed from the pad to one end of the surface.
A second conductive film is formed continuously from the conductive film up to one end of the side surface of the substrate, and then a third conductive film is formed continuously from the second conductive film on the back surface of the substrate. This is achieved by an IC chip peripheral wiring method characterized by the above.

[0010]

[Function] When the chip is rotated using the gas deposition device, wiring is formed from the one-sided terminal on the substrate surface through the substrate end surface (side surface) and the back surface, and further bumps and pads are continuously formed on the back surface. Not only can the IC circuit be wired (routed) to the back surface, but also by stacking IC chips, it can be used for high-density mounting technology and IC mounting of a multilayer structure.

In addition, in the film forming process of the gas deposition apparatus, in addition to driving the XYZ-θ axis (vertical axis) of the base material, the base material may be rotated during film formation on the back surface or the like. Since the inside-out mechanism is added, not only can wiring from the terminal on the front surface of the substrate (Si) to the substrate end surface (side surface) and the back surface be formed continuously in one step, but also bumps or pads on the back surface can be formed in one step. Can be formed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus and method for forming a metal partial film on an IC chip according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing the entire metal partial film forming apparatus according to the embodiment. The apparatus generally includes an ultrafine particle generation chamber 1, a film formation chamber 2, and a transfer pipe 3 connecting them.
And vacuum pumps 15 and 16 for returning and supplying He (helium) gas in the film formation chamber 2 and the ultrafine particle generation chamber 1 to the bottom of the ultrafine particle generation chamber 1 and a He gas recycling mechanism 17. .

A carbon crucible 6 (inner diameter: 5 mmφ, outer diameter: 20 mmφ) is provided as an evaporation source in the ultrafine particle generation chamber 1, and Au (gold) is accommodated as an evaporation material 22. A coil 7C for induction heating is wound around the carbon crucible 6, and both ends thereof are connected to a high frequency power source (150 kHz) 7 provided outside the ultrafine particle generation chamber 1. The high frequency induction heating method is adopted for the following reason. That is, in the resistance heating method, the crucible is heated by Joule heat, and the evaporation material inside is heated by heat transfer from the crucible. Although the molten metal may convect, the viscosity is high, heating may be non-uniform and bumping may occur, and the particle size distribution of the generated ultrafine particles is large.
On the other hand, in the high-frequency induction heating method, eddy current is generated in the crucible and the evaporation material to heat the crucible and the evaporation material, so that the heating is uniform and the particle size distribution of the generated ultrafine particles is uniform.

Directly above the carbon crucible 6 is arranged the lower end of a vertical conveying pipe 3 (inner diameter 1.6 mm), and above the lower end thereof, a large-diameter suction pipe sharing the axis with the conveying pipe 3. A tube 5 is provided. The annular space between the suction pipe 5 and the transfer pipe 3 is connected to the suction side of the vacuum pump 16 via the valve 13. The suction pipe 5 is provided so as to suck the ultrafine particles staying in the ultrafine particle generating chamber 1 other than the portion directly above the carbon crucible 6. Further, a shutter mechanism 9 is provided to support the bottom of the carbon crucible 6. The shutter mechanism 9 is shown in FIG.
As shown in, the position where the carbon crucible 6 is directly below the transfer tube 3 and 30 mm from this position in the direction indicated by the arrow a.
2B, the carbon crucible 6 is moved between two positions, that is, a position directly below the annular space formed by the suction pipe 5 and a position (not shown) programmed to open / close the carbon crucible 6 as shown in FIG. 2B. . That is, the metal vapor from the carbon crucible 6 is cooled to He gas as a carrier of the atmosphere, and rises into ultrafine particles. 2
2 is sucked into the carrier pipe 3 when the opening of A of FIG.
The state of being sucked into the suction pipe 5 when closed is shown. Further, the ultrafine particle generation chamber 1 is provided with a vacuum gauge 1G.

An upper end portion of the transfer tube 3 and a nozzle 4 attached to the transfer tube 3 are inserted into the film forming chamber 2, and an IC attached to a substrate holder 10 having a heater unit built therein is disposed close to the tip of the nozzle 4. Chip 8 is facing. It can be scanned by a digital programmable controller (not shown). Since the carrier tube 3 has a volume, it takes 0.1 seconds to reach the outlet of the nozzle 4 after the ultrafine particles are sucked in. Therefore, even when the scanning of the IC chip 8 is stopped at a certain point and the shutter mechanism 9 is closed to move to the next point, the time until the ultrafine particles come out of the carrier tube 3 is passed to the next point. Programmed to move. That is, the formed metal partial film does not have a tail. Even when the next point is reached and the shutter mechanism 9 is opened, the movement is started after a lapse of time until the ultrafine particles are ejected from the tip of the nozzle 4. As described above, the heater unit for heating the IC chip 8 is built in the substrate holder 10, and the IC chip 8 is supplied with a temperature signal from the thermocouple 11 attached to the IC chip 8.
Is maintained at a predetermined temperature. Film forming chamber 2
Is connected to the intake side of a vacuum pump 15 via a valve 14, and the film forming chamber 2 is provided with a vacuum gauge 2G.

The exhaust side pipes of the vacuum pump 15 and the vacuum pump 16 are integrated into one, which is connected to the He gas recycling mechanism 17 through the valve 19, and further, the valve 1
It is connected to the bottom of the ultrafine particle generation chamber 1 via 2 and He gas is fed as a carrier.
Further, the valve 12 has a purity of 99.
A 99% He gas cylinder 18 is connected. In addition,
A branch pipe 20 provided with a valve 20 is provided in the middle of the vacuum pumps 15 and 16 and the valve 19 and adjacent to the valve 19.

Although the mounting mechanism of the holder 10 and the IC chip 8 is not shown in FIG. 1, the holder 10 and the IC chip 8 attached to the holder 10 are not shown in the figure, and the IC chip 8 is changed from the state shown by the rotation driving mechanism. 8
Can be set apart from the substrate holder 10, and the rotation driving mechanism can rotate the IC chip 8 around the central axis along the longitudinal direction thereof as shown in FIG. At this time, the thermocouple 11 may be I
It may be detachable from the C chip 8. However, according to the present embodiment, since the rotation of 180 degrees is reversed and repeated, its attachment to the IC chip 8 does not come off, and it is not twisted and unusable. Further, although not shown, an objective lens of an optical microscope is provided in a part of the film forming chamber 2 so that the IC chip 8 can be observed.

The apparatus for forming a metal conductive film of this embodiment is constructed as described above, and its operation will be described below.

(Embodiment 1) Referring to FIG. 1, a valve 12,
Open 13, 14, 20 and close valves 19, 21
The entire system including the ultrafine particle generation chamber 1 and the film formation chamber 2 is exhausted to a pressure of 10 ⁻⁴ Pa by vacuum pumps 15 and 16. Next, while continuing the operation of the vacuum pumps 15 and 16, the valve 20 is closed, the valves 19 and 21 are opened, a predetermined amount of He gas having a purity of 99.99% is introduced from the He gas cylinder 18, and the valve 21 is closed. To do. This starts the circulation of He gas as a carrier in the direction indicated by the arrow,
By adjusting the opening of the valve 13, a pressure of 2 kg / cm ² is generated in the ultrafine particle generation chamber 1 and a pressure of about 1 torr is generated in the film forming chamber 2 to generate a differential pressure of about 2 kg / cm ² between the chambers. Let

In this state, He gas flows from the ultrafine particle generation chamber 1 to the carrier pipe 2 at 2 atm or about 10 SLM (standard state liters per minute), and to the suction pipe 5 about 30 S.
It is distributed to LM and flows. The reason why the flow rate to the suction pipe 5 is large is that the ultrafine particle generation chamber 1 is not sucked into the transfer pipe 3.
If there are ultrafine particles staying inside, they become aggregates during staying, and sometime they are transported via the transport tube 3 and adversely affect the film being formed, so to prevent the formation of these aggregates. Is.

After the above condition is established, the carbon crucible 6 is subjected to high frequency induction heating together with the evaporation material 22 contained in advance, namely Au, to melt and evaporate Au at about 1550 ° C. Au vapor is He as a carrier
It collides with gas and is cooled and condensed into ultrafine particles. Most of the generated ultrafine particles of Au are sucked into the carrier tube 3 together with He gas, and are jetted upward from the nozzle 4. The IC chip 8 is previously heated to 200 ° C. by the heater unit, and an Au film of ultrafine particles is formed on the surface thereof.

At this time, the film forming rate of Au, that is, the film thickness forming speed or the film deposition height speed is about 10 μm / sec.
Since the IC chip 8 on which the Au film is formed with a film thickness of 0.1 μm can be scanned in the X-axis direction and the Y-axis direction within the plane, the intermittent transfer of Au ultrafine particles due to the operation of the shutter mechanism 9 is performed. By combining with, it is possible to form a partial film having an arbitrary pattern from an arbitrary position on the IC chip 8 to an arbitrary position.

The IC chip 8 has a shape as shown in FIG. 3, but is a substantially rectangular parallelepiped Si (silicon) substrate 3.
A square pad 32 made of Au for external connection is attached to the surface of 1. The gold (Au)
In the state shown in FIG. 3, the surface A faces the nozzle 4 in FIG. 1 in the state shown in FIG. Since there is one nozzle 4, a conductive film is formed one by one as described later. In the following description, the conductive film of the IC chip 8 is formed on the front surface, the side surface, and the back surface as shown in the drawing, but a case where three pairs of left and right pairs are formed is shown. A large number of terminals are formed at a pitch, and a conductive film is sequentially formed with a single nozzle by a method described later, and the portion indicated by the alternate long and short dash line in the figure shows a gold conductive film. The part shown by the other solid line shows the situation where it is formed.
This shows a situation in which a conductive film has already been formed by a method similar to the method described later. In the state shown in FIG. 1, the holder 10 can move in the X direction or in the Y direction perpendicular thereto as shown by the arrow. First, the IC chip 8 is moved from the position facing the pad 32 in the X direction to a predetermined speed. Then, ultrafine gold powder is deposited up to the edge of the surface A. As a result, the band-shaped first
The conductive film 34 is formed. Here, the drive mechanism (not shown) is stopped and the shutter mechanism 9 is operated to operate the nozzle 4
To stop the eruption of gold from. The IC chip 8 is rotated 90 degrees about the shaft 30 to take the position shown in FIG. Here, the end portion of the first conductive film 34 is observed by an optical microscope, and after the IC chip 8 is aligned as the case may be, the shutter mechanism 9 is opened and the ultrafine gold powder is ejected from the nozzle 4 again. Deposit on B. Therefore,
The second conductive film 35 is formed continuously with the first conductive film 34. When gold is deposited up to the edge of the side wall B, the shutter mechanism 9 is operated to stop the ejection of gold from the nozzle 4 and the IC chip 8 is rotated 90 degrees around the central axis 30 as shown by an arrow. Let As a result, the state shown in FIG. 5 is obtained, and the back surface C is positioned to face the nozzle 4. The shutter mechanism 9 is opened, and the ultrafine gold powder is ejected from the nozzle 4 again. At the same time, the ultrafine gold powder is moved at a predetermined speed in the direction indicated by the arrow in FIG. 1 to deposit the ultrafine gold powder on the back surface C. Therefore, the third conductive film 36 is formed and stopped at the position of the pad 32b shown in FIG. That is, the end of the third conductive film 36 is deposited on the pad 32b made of gold on the back surface C. Therefore, it is rotated about the central axis 30 in the opposite direction by 180 degrees to reverse the front and back, and the predetermined pitch in the direction of the central axis 30, that is, the pitch between the conductive films 33 is moved as shown in FIG. Then, the same operation as described above is repeated. Therefore, the gold conductive film 33 as shown in FIGS. 3 to 5 is formed on the front surface A and the back surface C of the IC chip 8 and the side surface B.

In FIG. 6, the IC chip 8 having the conductive film 33 thus formed is formed on the common substrate 40.
1 and 42 show a state of being electrically connected. Although not shown, a predetermined conductive film pattern is formed on the common substrate 40 in FIG. 6, so that similar IC chips can be electrically connected as shown in FIG.

7 to 10 show an IC chip 8'according to a second embodiment of the present invention, to which the same gas deposition apparatus as in FIG. 1 is applied, but in this embodiment the back surface of the IC chip 8'is used. , A wart-shaped or protrusion-shaped bump 37 made of gold of the same material is formed as a terminal for connection to another electrode. That is, the conductive film 3 shown in FIGS.
3'is formed similarly to the first embodiment, but the third conductive film 3 is formed.
The formation of 0 ′ is stopped by the XY driving mechanism, and the bumps 37 are formed by the ultrafine Au powder. In the IC chip 8'formed with the gold conductive film 33 ', the bumps 37 are formed on the conductive patterns 41' and 42 'formed on the substrate 40 as shown in FIG. It is electrically connected. In this connection, the same applies to the first embodiment,
For example, the connection may be made by applying pressure.

Although the respective embodiments of the present invention have been described above, the present invention is not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiments, the common substrate 40
Conductive patterns 41, 42 or 41 ', 4 formed above
Although the IC chip 8 or 8'is electrically connected to the 2 ', instead of this, the same IC chip 8 or 8'is electrically connected by stacking on the IC chip 8 or 8'. May be. Of course, in this case, the gold pads 32 formed on the front surface or the back surface are electrically connected to each other. Of course, the bumps 37 and the pads 32 may be arranged in an overlapping manner so as to be electrically connected to each other. Further, although Au has been described as the ultrafine powder in the above-mentioned embodiments, it is needless to say that other commonly used metals such as silver and nickel can be applied as the conductive film.

Further, the wirings on the IC chip are formed so as to extend in parallel at equal pitches along the central axis 30 as in the above-mentioned embodiment, but of course, the pattern is not limited to such a pattern. The present invention is applicable to all conventionally known patterns. Further, although the pad 32 is already attached to the substrate 31 in the above embodiments, it may be formed by the above gas deposition apparatus.

[0030]

As described above, according to the IC chip and the peripheral wiring method for the IC chip of the present invention, the conductive film is continuously formed on the front surface, the side surface and the back surface by one conductive film forming apparatus. In addition, the IC chip thus formed can significantly increase the integration density of the IC as compared with the conventional one, and when the IC chips are stacked, a complicated insulating structure or a plurality of IC chips can be formed on a common substrate. No complicated lead connection mechanism is required when mounting the IC chip. Therefore, the cost can be significantly reduced as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 is a schematic piping system diagram of a gas deposition apparatus for forming a conductive film of an IC chip according to an embodiment of the present invention.

FIG. 2 shows the operation of the shutter mechanism in the same device,
Indicates an open state and B indicates a closed state.

FIG. 3 is a perspective view in which the surface of an IC chip on which a conductive film is formed in the same device is directed upward.

FIG. 4 is a perspective view of the IC chip shown in FIG. 3 in a state of being rotated 90 degrees around the central axis thereof.

FIG. 5 is a perspective view of the IC chip showing a state in which the back surface is turned downward by rotating the same in the same direction by 90 degrees.

FIG. 6 is a cross-sectional view showing a state of being electrically connected to a common substrate of an IC chip on which a conductive film is formed.

FIG. 7 is a perspective view of an IC chip according to a second embodiment of the present invention with the lower surface thereof facing upward.

FIG. 8 is a perspective view showing a state in which the IC chip is rotated 90 degrees around a central axis.

FIG. 9 is a perspective view of the IC chip, which is further rotated by 90 degrees with the back surface thereof facing upward.

FIG. 10 is a cross-sectional view showing a state where the IC chip is electrically connected to a common substrate.

[Explanation of symbols]

 1 Gas Deposition Device 8 IC Chip 8'IC Chip 32a Pad 32b Pad 33 Conductive Film 33 'Conductive Film 34 First Conductive Film 35 Second Conductive Film 36 Third Conductive Film 37 Bump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuto Saito 800 Miyake, Yasu-cho, Yasu-cho, Yasu-gun, Shiga Prefecture Japan IBM Japan Ltd. Yasu Works (72) Inventor Yoshio Kimura Yasu, Yasu-gun, Shiga Prefecture 800 Miyake-shi, Machi-shi, Japan In the Yasu Plant of IBM Japan, Ltd.

Claims (6)

[Claims] 1. A conductive film is continuously formed on the front surface of the substrate, the side surface of the substrate, and the back surface of the substrate.
C chip. 2. A pad made of the same material as the conductive film on a conductive film formed on the front surface of the substrate, and the same conductive film on the conductive film formed on the back surface of the substrate. 2. The I according to claim 1, wherein the bump made of a material is integrally formed.
C chip. 3. A pad for electrical connection on a surface of a substrate for forming an external wiring circuit line, a first conductive film continuously made of a conductive material from the pad to one end of the surface, and continuous with the first conductive film. A second conductive film is formed of the conductive material up to one end of the side surface of the substrate, and a third conductive film is formed on the back surface of the substrate continuously with the second conductive film. IC chip peripheral wiring method. 4. The method of peripheral wiring of an IC chip according to claim 3, wherein bumps are integrally formed on the third conductive film with the conductive material. 5. An ultrafine particle generation chamber provided with an evaporation source for evaporating a metal, and a lower end of the ultrafine particle generation chamber is provided directly above the evaporation source to convey the generated ultrafine particles. A carrier pipe and a film forming chamber in which a nozzle attached to the upper end of the carrier pipe is inserted. The ultrafine particles are jetted from the ultrafine particle generation chamber to the film forming chamber through the carrier pipe and the nozzle. The peripheral wiring method for an IC chip according to claim 3, wherein the first, second, and third conductive films are formed by using the gas deposition apparatus described above. 6. The IC chip peripheral wiring method according to claim 5, wherein the IC chip peripheral wiring is rotated in the film forming chamber so as to invert the front and back of the IC chip.