JPH11340276A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device with high connection reliability for preventing a bump from flowing onto a conductor pattern at the time of melting, a semiconductor chip is mounted on a tape carrier with the bump. SOLUTION: This manufacturing method of the semiconductor device is composed of joining the semiconductor chip 21 onto the tape carrier with the bump, for which a metal bump 13 is composed of a columnar body provided with a side face practically vertical to the surface of a conductor pattern 12. It is provided with a process for coating flux to the electrode surface of the semiconductor chip 21 or the peak part of the metal bump 13, a process for positioning the semiconductor chip 21 and the tape carrier so as to make the electrode of the semiconductor chip 21 correspond to the metal bump 13 of the tape carrier, a process for fixing the electrode of the semiconductor chip 21 and the metal bump 14 of the tape carrier by a fixing material 23, and a process for heating and melting the metal bump 13 of the tape carrier and connecting the electrode of the semiconductor chip 21 and the metal bump 13 of the tape carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device in which a semiconductor chip is mounted on a tape carrier with bumps.

[0002]

2. Description of the Related Art In order to respond to demands for miniaturization, weight reduction, high speed, and high functionality of electronic devices, semiconductor packages include:
Various forms have been developed. As such a semiconductor package technology, in particular, in order to achieve both the demand for a higher pin count due to the higher integration of the semiconductor chip and the miniaturization of the device, a semiconductor chip is formed on a metal pattern formed on an insulating film via a solder bump. There is known a package technology based on a so-called tape carrier method for joining the tapes.

One example of such a tape carrier type packaging technique is disclosed in Japanese Patent Application Laid-Open No. Hei 8-64636. In this packaging technique, as shown in FIG. 4, a conductor pattern 2 is formed on a polyimide tape 1, and a solder bump 3 is formed on the conductor pattern 2. This solder bump 3 is thermally joined to a metal electrode (metal pad) 6 formed on one main surface of the semiconductor chip 4 corresponding to the solder bump 3. The tape carrier on which the semiconductor chip 4 is mounted in this manner is
Then, they are cut out individually.

[0004] In this tape carrier system, since a thin and transparent polyimide tape is used, there is an advantage that stress applied to a solder joint is alleviated even in a heat cycle, and solder bumps can be observed from the back surface.

[0005] However, solder bumps are generally formed by cream solder printing or a method of transferring solder balls. However, in such a method, the solder bumps 3 must be spherical as shown in FIG. . When the pitch between the solder bumps becomes smaller and the distance between the solder bumps becomes shorter, there is a problem that a solder bridge is formed when a semiconductor chip is mounted on a spherical solder bump. In addition, there is a problem that it is difficult to fill the underfill resin.

In addition, when a flux is applied to the tape carrier by a normal method when joining the solder bumps of the tape carrier to the metal pads of the semiconductor chip, the flux is covered up to the conductor pattern other than the solder bumps, and the molten metal is melted. Sometimes, the solder flows on the conductor pattern.
As a result, the bump height decreases, and it becomes difficult to maintain the gap between the semiconductor chip and the tape carrier. Further, the solder becomes spherical, and the above-mentioned bridge is formed.

Further, when a flux having a high solid content and a high viscosity is used for the purpose of temporarily fixing the semiconductor chip, a flux residue is generated between the semiconductor chip and the tape carrier, and the flux residue is cleaned in a later step. There is a need to.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when a semiconductor chip is mounted on a tape carrier with bumps, when the bumps are melted, the metal constituting the bumps is formed on the conductor pattern. To prevent the metal bumps from flowing into the tape carrier with accurate positioning.
An object of the present invention is to provide a method for manufacturing a semiconductor device having high connection reliability.

[0009]

In order to solve the above problems, the present invention provides an insulating film, a conductive pattern formed on the insulating film, and a metal bump for connecting a semiconductor chip formed on the conductive pattern. A method for manufacturing a semiconductor device, comprising: bonding a semiconductor chip on a bumped tape carrier made of a columnar body having side surfaces substantially perpendicular to the conductor pattern surface, wherein the metal bumps are provided. Applying a flux to the electrode surface of the semiconductor chip or the top of the metal bump, positioning the semiconductor chip and the tape carrier such that the electrode of the semiconductor chip corresponds to the metal bump of the tape carrier, Fixing the semiconductor chip and the tape carrier with a fixing material; The rear metal bump is melted, to provide a method of manufacturing a semiconductor device characterized by comprising the step of connecting the metal bump electrode and the tape carrier of the semiconductor chip.

In the method of manufacturing a semiconductor device, the heating for melting the metal bumps can be performed by the following method. (1) The surface of the semiconductor chip opposite to the surface on which the electrodes are provided is heated by a heat tool.

(2) The tape carrier to which the semiconductor chip is fixed is passed through a heating furnace. Further, the present invention includes an insulating film, a conductive pattern formed on the insulating film, and a metal bump for semiconductor chip connection formed on the conductive pattern, wherein the metal bump is formed on the conductive pattern surface. A method of manufacturing a semiconductor device, comprising joining a semiconductor chip onto a bumped tape carrier made of a columnar body having substantially vertical side surfaces,
Applying a flux to the electrode surface of the semiconductor chip or the top of the metal bump, positioning the semiconductor chip and the tape carrier such that the electrode of the semiconductor chip corresponds to the metal bump of the tape carrier, By heating the surface of the semiconductor chip opposite to the surface on which the electrodes are provided by a heat tool, the metal bumps of the tape carrier are melted, and the electrodes of the semiconductor chip and the metal bumps of the tape carrier are melted. And a method for manufacturing a semiconductor device.

In the above method of the present invention, the space between the semiconductor chip and the tape carrier is filled with an underfill resin. Further, a metal layer connectable to a metal bump is formed on an electrode of the semiconductor chip.

Here, the tape carrier with bumps used in the method of the present invention will be described. The tape carrier with bumps used in the method of the present invention is an insulating film, and a conductor pattern formed on the insulating film,
A metal bump for semiconductor chip connection formed on the conductor pattern, wherein the metal bump is formed of a pillar having a side surface substantially perpendicular to the conductor pattern surface.

In such a tape carrier, the conductor pattern has a terminal at a position electrically connected to the pad of the circuit board in the vertical direction, and the insulating film on the lower side of the terminal has a smaller size than the terminal. A hole having a diameter can be formed. A bonding electrode in which metal is embedded by plating or the like is formed in a portion of the conductor pattern exposed in the hole, and the connection with the circuit board is performed via a solder ball or cream solder supplied to the bonding electrode. Can be performed. Cu, N
i, solder or the like can be used.

The material constituting the metal bump is as follows:
Although Sn and solder (Sn alloy etc.) are mentioned, solder is particularly preferable. Each of the metal bumps and the bonding electrodes can have a multilayer structure. in this case,
The metal bump and the bonding electrode are composed of an uppermost layer made of solder and a metal having a melting point higher than that of solder, for example, Cu, N
and a lower layer made of i.

In the tape carrier with bumps used in the present invention as described above, since the metal bumps are formed by pillars having side surfaces substantially perpendicular to the conductor pattern surface, a conventional spherical solder is used. Unlike a bump, a solder bridge is not formed when a semiconductor chip is mounted, and an underfill resin can be easily filled.

In mounting the semiconductor chip on the tape carrier with bumps described above, the flux is applied only to the electrode surface of the semiconductor chip or the top of the metal bump of the tape carrier. Therefore, even if the solder is melted, it does not occur that the molten solder flows on the conductor pattern of the tape carrier and the height of the bump is reduced. Accordingly, it is not necessary to perform the conventional treatment with the solder resist for preventing the flow of the solder onto the conductor pattern.

Further, when mounting the semiconductor chip on the tape carrier with bumps, since the semiconductor chip is not displaced by fixing the both with a fixing material, the semiconductor chip can be joined by passing through a heating furnace. It can be joined by heating with a heat tool.

Further, after the semiconductor chip is positioned and mounted on the tape carrier with bumps, a heating tool such as a hot plate is appropriately pressed from above the semiconductor chip and heated to fix the semiconductor chip. Even without this, it is possible to perform accurate joining without causing displacement.
The pressing pressure allows an arbitrary distance to be maintained so that the bump is not completely crushed.

Further, by appropriately pressing, it is possible to prevent the tape carrier from being bent, prevent the connection from being opened due to the bending, and ensure the parallelism of the semiconductor chip.

However, in this case, it is necessary to precisely control the height position of the semiconductor chip with respect to the bumped tape carrier so that the metal bumps are not excessively crushed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, with reference to the drawings, the joining of a semiconductor chip to a tape carrier according to an embodiment of the present invention will be described. FIG. 1 is a sectional view showing a tape carrier with bumps used in an embodiment of the present invention.
In FIG. 1, a copper pattern 12 is formed on an insulating film 11, and Au, Sn,
Metal bumps 13 made of solder (Sn alloy or the like) are formed. In the insulating film 11, a hole having a smaller diameter than a terminal of the copper pattern 12 (see FIG. 5 described later) is formed in a portion connected to the circuit board, and the metal embedded in the hole forms the bonding electrode 14. Has formed. The bonding electrode 14 can be formed by plating of nickel, solder, or the like, and is connected to a conductor of a circuit board via a solder ball or cream solder supplied on the bonding electrode.

FIG. 5 is a perspective view of the tape carrier. The upper part of FIG. 5 shows a view from the front side, and the lower part shows a view from the back side. In FIG. 5, the copper pattern 12 has terminals 31 at locations electrically connected to the conductors of the circuit board in the vertical direction, and the insulating film 11 below these terminals 31 has a diameter smaller than that of the terminals 31. Small holes are formed. The metal formed in this hole forms the bonding electrode 14. A solder ball (not shown) is formed on the bonding electrode 14, and is connected to a conductor of a circuit board via the solder ball.

In the thus configured tape carrier with bumps, the metal bumps 13 have a cylindrical shape with straight sides. The cross section is not limited to a cylinder, but may be a prism having a polygonal cross section. As described above, since the metal bumps 13 have a columnar shape with a straight side surface, the pitch between the metal bumps is small unlike the spherical metal bumps of the conventional tape carrier shown in FIG. Even if the distance between them becomes shorter, no bridge is formed, and the filling of the underfill resin does not become difficult.

Further, the metal bump can be formed directly on the copper pattern without providing a solder resist for preventing the bridge of the metal bump and preventing the flow of the molten solder on the conductor pattern. There is an advantage that the metal bumps need not be formed, the formation of the metal bumps is easy, and the formation time is short.

As described above, the circuit board has terminals at positions electrically connected to the conductors in the vertical direction,
In a structure in which a bonding electrode formed by plating with Cu, Ni, or the like is formed in a hole having a smaller diameter than the terminal formed in the insulating film below these terminals, the bonding electrode serves as reinforcement, and a copper pattern is formed. Breakage is prevented.

A semiconductor chip is bonded to the tape carrier as described above, and a semiconductor device is obtained. less than,
Two methods for joining will be described. FIG. 2 is a cross-sectional view showing a step of joining a semiconductor chip to a tape carrier by the first method. First, a semiconductor chip 21 as shown in FIG. 2A is prepared. This semiconductor chip 21
Has an electrode 22 on the periphery, and this electrode 22
The surface of the aluminum pad is subjected to electroless Ni / Au plating. A flux is applied to the electrode 22. The flux may be applied to the entire surface of the semiconductor chip on which the electrodes are provided. As the flux, those having a low viscosity are preferable. For example, F-50F
(Manufactured by Harima Chemicals) can be used.

On the other hand, a tape carrier with bumps as shown in FIG. 2B is prepared. This tape carrier has a structure as shown in FIG. Next, the adhesive 23 was supplied to the center of the tape carrier by a dispenser, and the semiconductor chip 21 shown in FIG. 2A was mounted thereon. When mounting the semiconductor chip 21, the metal bumps 13 of the tape carrier and the electrodes 2 of the semiconductor chip 21 are used.
2 was performed. And, in the heating furnace,
The semiconductor chip 21 was fixed on the tape carrier by heating at 10 ° C. for 10 minutes to cure the fixing material 23. In addition, as the fixing material 23, EH-0515L8 (manufactured by HYSOL)
Was used.

After fixation, reflow heating was performed at 230 ° C. for 1 minute in a heating furnace to join the electrode 22 and the metal bump 13. As a heating method, heat and pressure can be applied from the fixed semiconductor chip side using a heat tool.

Finally, a semiconductor device (semiconductor package) in which a thermosetting resin 25, for example, an underfill resin made of an epoxy resin is filled between the semiconductor chip 21 and the tape carrier, and the semiconductor chip is mounted on the tape carrier. Obtained.

When the semiconductor chip is joined to the tape carrier, the flux may be applied only to the top of the metal bump on the tape carrier side instead of applying the flux to the electrode surface side of the semiconductor chip. In order to apply the flux only to the top of the metal bump, for example, a so-called transfer method of transferring the flux to the top of the metal bump by bringing the plastic sheet coated with the flux into contact with the surface of the tape carrier on which the metal bump is provided is performed. be able to.

In the step of bonding the semiconductor chip to the tape carrier according to the first method described above, since no flux is applied on the copper (conductor) pattern, even if the copper pattern is not protected by the solder resist, the reflow heating can be performed. In this case, there is no inconvenience such as the solder flowing on the copper pattern, narrowing the gap between the semiconductor chip and the tape carrier, or generating an open connection, and the semiconductor chip is fixed on the tape carrier by the fixing material. By doing so, the gap between the semiconductor chip and the tape carrier was not narrowed, and good joining without displacement was achieved even in a state where a liquid flux having a small solid content was thinly applied.

Next, the joining of the semiconductor chip to the tape carrier by the second method will be described. FIG.
FIG. 7 is a cross-sectional view showing a step of joining a semiconductor chip to a tape carrier by the method of (1). First, a semiconductor chip 21 as shown in FIG. 3A is prepared. This semiconductor chip 21
Has an electrode 22 in a peripheral portion, and the electrode 22 is obtained by applying an electroless Ni / Au plating to a surface of an aluminum pad, similarly to the first method shown in FIG.

Next, in the same manner as in the first method, the electrode 22
Apply flux to the surface of. As the flux, those having a low viscosity are preferable. For example, F-50F
(Manufactured by Harima Chemicals) can be used.

On the other hand, a tape carrier with bumps as shown in FIG. 3B is prepared. This tape carrier also has a structure as shown in FIG. Thereafter, positioning is performed so that the electrodes of the semiconductor chip correspond to the metal bumps of the tape carrier, and a heat tool 35 is placed on the semiconductor chip 21 as shown in FIG.
The semiconductor chip 21 was heated while being appropriately pressed. At this time, the temperature of the heat tool 35 was 230 ° C., and the heating time was 1 minute. The pressing pressure allows an arbitrary distance to be maintained so that the bump is not completely crushed.

As a result, the metal bump 13 was melted and joined to the electrode 22. Finally, a thermosetting resin 25, for example, an underfill resin made of an epoxy resin was filled between the semiconductor chip 21 and the tape carrier, and a semiconductor device (semiconductor package) having the semiconductor chip mounted on the tape carrier was obtained.

When the semiconductor chip is bonded to the tape carrier, the flux is applied in the same manner as in the first method, instead of applying the flux to the electrode surface side of the semiconductor chip, the metal bump on the tape carrier side is used. The flux can be applied only to the top.

In the bonding step of the semiconductor chip to the tape carrier according to the second method described above, the same effects as those of the first method can be obtained, and the following advantages can be obtained. That is, even if the fixing by the fixing material is not performed,
Accurate joining can be performed without causing displacement. In addition, by appropriately pressing the tape carrier, bending of the tape carrier does not occur, connection opening due to the bending can be prevented, and parallelism of the semiconductor chip can be ensured.

[0039]

As described above in detail, according to the present invention, since the metal bump is formed of a columnar body having a side surface substantially perpendicular to the conductor pattern surface,
Unlike a conventional spherical solder bump, a bridge is not formed when a semiconductor chip is mounted, and the underfill resin can be easily filled.

When the semiconductor chip is mounted on the tape carrier with bumps, the flux is applied only to the electrode surface of the semiconductor chip or to the top of the metal bump on the tape carrier side. In this case, the flow does not flow on the conductor pattern of the tape carrier and the height of the bumps is reduced, so that the bonding failure does not occur. Further, when the semiconductor chip is mounted on the tape carrier with bumps, the semiconductor chip is fixed by the fixing material, so that the semiconductor chip does not displace.

Further, after the semiconductor chip is positioned and mounted on the tape carrier with bumps, a heat tool such as a hot plate is appropriately pressed from above the semiconductor chip and heated to perform the fixing by the fixing material. Even without this, it is possible to perform accurate joining without causing displacement.
In addition, by appropriately pressing the tape carrier, bending of the tape carrier does not occur, connection opening due to the bending can be prevented, and parallelism of the semiconductor chip can be ensured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a tape carrier with bumps used in an embodiment of the present invention.

FIG. 2 is a sectional view showing a manufacturing process of a semiconductor package using the tape carrier with bumps shown in FIG. 1 in the order of steps;

FIG. 3 is a sectional view showing another manufacturing process of the semiconductor package using the tape carrier with bumps shown in FIG. 1 in the order of steps;

FIG. 4 is a cross-sectional view showing a semiconductor package using a conventional tape carrier.

FIG. 5 is a perspective view of the tape carrier with bumps shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Polyimide tape 2 ... Metal layer 3 ... Solder bump 4 ... Electronic device 6, 22 ... Electrode (metal pad) 11 ... Insulating film 12 ... Conductor (copper) pattern 13 ... Metal bump 14 ... Bonding electrode 21 ... Semiconductor chip 23 ... fixing agent 25 ... thermosetting resin 31 ... terminal 35 ... heat tool.

Claims (5)

[Claims] An insulating film, a conductive pattern formed on the insulating film, and a metal bump for connecting a semiconductor chip formed on the conductive pattern, wherein the metal bump substantially corresponds to a surface of the conductive pattern. A method for manufacturing a semiconductor device, comprising joining a semiconductor chip onto a tape carrier with bumps formed of columnar bodies having vertically perpendicular side surfaces, wherein a flux is applied to an electrode surface of the semiconductor chip or a top of the metal bump. A coating step; a step of positioning the semiconductor chip and the tape carrier so that electrodes of the semiconductor chip correspond to metal bumps of the tape carrier; and a step of fixing the semiconductor chip and the tape carrier with a fixing material. And heating to melt the metal bumps of the tape carrier, The method of manufacturing a semiconductor device characterized by comprising the step of connecting the metal bumps of said tape carrier To pole. 2. The semiconductor device according to claim 1, wherein the heating is performed by heating a surface of the semiconductor chip opposite to a surface on which the electrodes are provided by a heat tool. Production method. 3. The method of manufacturing a semiconductor device according to claim 1, wherein said heating is performed by passing a tape carrier to which a semiconductor chip is fixed through a heating furnace. 4. An insulating film, comprising: a conductive pattern formed on the insulating film; and a metal bump for connecting a semiconductor chip formed on the conductive pattern, wherein the metal bump substantially corresponds to a surface of the conductive pattern. A method for manufacturing a semiconductor device, comprising joining a semiconductor chip onto a tape carrier with bumps formed of columnar bodies having vertically perpendicular side surfaces, wherein a flux is applied to an electrode surface of the semiconductor chip or a top of the metal bump. The step of applying, the step of positioning the semiconductor chip and the tape carrier such that the electrodes of the semiconductor chip correspond to the metal bumps of the tape carrier, and the surface of the semiconductor chip on which the electrodes are provided. The opposite side is heated by a heat tool to melt the metal bumps of the tape carrier. A method of manufacturing a semiconductor device characterized by comprising the step of connecting the metal bump electrode and the tape carrier of the semiconductor chip. 5. The method according to claim 1, wherein after the electrodes of the semiconductor chip are connected to the metal bumps of the tape carrier, a resin is filled in a gap between the semiconductor chip and the tape carrier. 13. The method for manufacturing a semiconductor device according to any one of the above items.