JP2000228419A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of a crack in a PIQ film (a polyimide resin) due to stress of a BLM(ball limiting metallization) film, contamination of a chamber due to sputter-etching, occurrence of a overhang shape of the BLM film due to side etching of the PIQ film upon removal of a resist and the like in the process of fabricating a semiconductor device. SOLUTION: When a CCB(controlled collapse bonding) solder is formed in this under-filled BGA(ball grid array) package such as a logic LSI, memory LSI, etc., a BLM film 13 for CCB solder 1 bonding is formed on metal wiring 11 of an LSI chip (step 302) and then a PIQ film 15 is formed on a portion other than the CCB solder 1 bonding portion on the BLM film 13 (step 303). Consequently, the BLM film 13 is not formed on the PIQ film 15, that is, no processing of the BLM film 13 onto the PIQ film 15 is required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing technique, and more particularly to an underfill type BGA (Ball Grid A).
The present invention relates to a semiconductor device suitable for preventing cracks in a protective film and the like in a manufacturing process of a PRA (Pin Grid Array) package and a technique effective when applied to a manufacturing method thereof.

[0002]

2. Description of the Related Art For example, as a technique studied by the present inventors, in an underfill type package, an LSI
(Large Scale Integration) chip is CCB (Contro
led Collapse Bonding) Solder is used to obtain electrical continuity with the substrate, and a P film is formed on the main surface of this LSI chip as a protective film.
A structure that forms an IQ (polyimide resin: manufactured by Hitachi) film is conceivable. This PIQ film also has a role of ensuring adhesiveness with the underfill resin.

[0003] As a technique related to a semiconductor device such as such an underfill type package, for example, “Practical Course V” published by Nikkei BP on May 31, 1993.
LSI packaging technology (upper), (lower) ".

[0004]

By the way, in the underfill type package as described above, for example, as shown in FIG.
5 and a BLM (Ball Limiting Metallization) for joining the CCB solder 1 on the PIQ film 15.
The structure is such that the film 13 is formed.

In the manufacturing process of such a package structure, the PIQ film 15 due to the stress of the BLM film 13 is used.
Cracks, contamination of the chamber by sputter etching, overhang of the BLM film 13 by side etching of the PIQ film 15 at the time of resist removal (ashing) (FIG. 7), and securing of coverage of the BLM film 13 There is a problem that the photosensitive PIQ film 15 must be used (a non-photosensitive PIQ film cannot be used).

Accordingly, an object of the present invention is to change the structure in which a BLM film is formed on a protective film such as a PIQ from a structure in which a protective film is formed on a BLM film, thereby improving the above-described manufacturing process. An object of the present invention is to provide a semiconductor device and a method for manufacturing the same, which can solve the problems.

[0007] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0008]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the semiconductor device according to the present invention has a structure in which a BLM film for CCB solder bonding is formed on a metal wiring of an LSI chip mounted on a substrate, and a protective film is formed on the BLM film. It is. In particular, LSI
An underfill type BGA, in which a bonding portion between a chip and a substrate is filled with an underfill resin and solder balls or lead pins serving as external terminals are arranged on the back side of the substrate,
This is applied to a PGA package. The protective film is a polyimide resin film such as PIQ.

In the method of manufacturing a semiconductor device according to the present invention, a BLM film for bonding a CCB solder is formed on a metal wiring of an LSI chip, and a protective film is formed on a portion of the BLM film except for a CCB solder bonding portion. And the CC on the BLM film
Form the CCB solder at the B solder joint, mount the LSI chip with the CCB solder on the board, fill the joint between the LSI chip and the board with underfill resin, and form external terminals on the back side of the board And includes the respective steps.

[0011] Alternatively, C on the metal wiring of the LSI chip
After forming a BLM film for CB solder bonding, a CCB solder is formed on the CCB solder bonding portion on the BLM film, and then a protective film is formed on a portion of the BLM film other than the CCB solder bonding portion. The same process as described above is performed.

Therefore, according to the semiconductor device and the method of manufacturing the same, since the formation of the BLM film on the protective film such as the PIQ is eliminated, it is possible to eliminate the occurrence of cracks in the protective film. Since the BLM film is not processed, the contamination of the chamber due to sputter etching does not occur. Since the BLM film is not processed on the protective film, the BLM is not processed.
Since the overhang shape of the film does not occur and the coverage of the BLM film does not need to be considered, effects such as the use of both photosensitive and non-photosensitive protective films are obtained.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, the same members are denoted by the same reference numerals, and the description thereof will not be repeated.

(First Embodiment) FIG. 1 is a schematic sectional view showing a semiconductor device according to a first embodiment of the present invention, FIG. 2 is a schematic plan view and a schematic bottom view showing the semiconductor device according to the first embodiment, FIG. 3 shows the semiconductor device according to the first embodiment in which LS
Flow chart showing a method of forming CCB solder on an I chip,
FIG. 4 is a flowchart showing a method of manufacturing a package.

First, an example of a schematic configuration of the semiconductor device of the first embodiment will be described with reference to FIGS.

The semiconductor device of the first embodiment is an underfill type BGA package such as a logic LSI or a memory LSI, and has an LSI chip 2 on which CCB solder 1 is formed, and this LSI chip 2 has a face-down structure. Substrate 3 to be mounted, LSI chip 2 and substrate 3
Underfill resin 4 filling the joint portion with
The BGA package has a structure in which it is electrically connected to the CCB solder 1 of the I chip 2 and is arranged on the back surface of the substrate 3 and the like, and the BGA package is mounted on a product base by surface mounting.

In the LSI chip 2, for example, a logic
An integrated circuit (not shown) such as a memory is formed, and a plurality of CCB solders 1 are arranged on a main surface.
The B solder 1 is electrically connected to the input / output unit of the integrated circuit.

The substrate 3 is composed of, for example, a multi-layer wiring board, and is provided with a plurality of pads for power supply and signal (not shown), and through these pads, wiring of each layer and through holes penetrating through each layer. Solder balls 5 on the back
Are electrically connected to each other.

The underfill resin 4 is made of, for example, an epoxy resin material, and reduces the difference in thermal expansion in a temperature cycle, and the stress concentrated on the joint portion between the CCB solder 1 of the LSI chip 2 and the substrate 3 causes the underfill resin 4 to lose its stress. It is alleviated by the fill resin 4.

The solder balls 5 are, for example, spherical CCBs.
The substrate 3 which is made of solder or the like and is arranged on the back surface of the substrate 3 as external terminals, and on which the LSI chip 2 is mounted via the solder balls 5, is surface-mounted on a product base.

Next, with respect to the operation of the first embodiment, a method of forming the CCB solder 1 on the LSI chip 2 will be described with reference to the flow of FIG. In FIG. 3, the figure on the right side is a cross-sectional view of the LSI chip 2 corresponding to each step.

First, in a wiring step (step 301), a metal wiring 11 is formed at the joint of the CCB solder 1 on the main surface side of the LSI chip 2, and the metal wiring 11 is formed.
After forming a protection film 12 on the surface of
A hole is formed in the joint of the solder 1. This state is an initial state when the CCB solder 1 is formed on the LSI chip 2.

Subsequently, a BLM film forming step (step 30)
2) First, the metal wiring 1 of the LSI chip 2 is formed by the sputtering process of the BLM film 13 (Step 302a).
A BLM film 13 for joining the CCB solder 1 is formed on the first BLM film 1. Then, a resist 14 is applied to the bonding portion of the CCB solder 1 on the BLM film 13 by a photoresist process (step 302b), and is exposed.

Thereafter, in this BLM film forming step,
By etching the BLM film 13 (step 302c), the portion of the BLM film 13 where the resist 14 is not applied is etched. Then, the resist 14 is removed by a resist removal process (Step 302d).

For example, this BLM film 13 is made of Cr / N
It is formed of an i / Au metal film, and the thickness of each metal film is about 70/400/100 nm. In addition, the protruding distance below the PIQ film formed below requires that the PRO film underlying the PIQ film is not exposed.

Subsequently, a PIQ film forming step (step 30)
In 3), first, the PIQ film 15 is coated and baked (step 303a) to form a PIQ film on the BLM film 13.
A film 15 is applied, and the PIQ film 15 is baked.
The baking temperature is, for example, about 200 ° C. or less, which is the heat resistant temperature of the BLM film 13. Then, the PQ film 15 is exposed and developed (step 303b),
After exposing the joint portion of the CCB solder 1 on the IQ film 15 and developing it, the PIQ film 15 is formed on a portion of the BLM film 13 excluding the joint portion of the CCB solder 1.

Further, in the CCB solder forming step (step 304), the CCB solder 1 is formed on the BLM film 13 at the joint of the CCB solder 1. Thus, L
The CCB solder 1 is formed on the SI chip 2 and this CCB
The LSI chip 2 on which the solder 1 is formed can be completed.

Next, a method of manufacturing a BGA package will be described with reference to FIG.
Description will be made based on the flow of FIG. In FIG. 4, the figure on the right side is a cross-sectional view of the BGA package corresponding to each step.

First, an LSI chip mounting process (Step 4)
In 01), the LSI chip 2 on which the CCB solder 1 is formed is mounted on the main surface side of the substrate 3, and the pads of the substrate 3 and the CCB solder 1 of the LSI chip 2 are soldered through reflow.

Further, in an underfill resin filling step (step 402), the joint between the LSI chip 2 and the substrate 3 is filled with the underfill resin 4, and the underfill resin 4 is baked.

Subsequently, in a solder ball forming step (step 403), solder balls 5 are formed on the back surface of the substrate 3. As a result, the LSI chip 2 is mounted on the substrate 3 and a BGA package in which external terminals are formed is completed.

Then, in the package mounting step (step 404), this BGA package is
By mounting it along with other packages, electronic components, and the like on the main surface side of 1 and soldering it through reflow, it is possible to complete a product base 21 incorporated in various devices such as a computer.

Therefore, according to the semiconductor device of the first embodiment, in forming the CCB solder 1 on the LSI chip 2, the PIQ film 15 is formed after the BLM film 13 is formed, so that the PIQ film 15 Since the formation of the BLM film 13 is eliminated, the occurrence of cracks in the PIQ film 15 can be eliminated. Further, BL on the PIQ film 15
Since the processing of the M film 13 is not performed, contamination of the chamber due to sputter etching does not occur, and an overhang shape of the BLM film 13 does not occur. Further, since it is not necessary to consider the coverage of the BLM film 13, both the photosensitive and non-photosensitive PIQ films 15 can be used.

That is, the problems that have occurred in the current manufacturing process are the generation of cracks in the PIQ film 15,
Chamber contamination, overhanging shape of the BLM film 13,
However, these are all on the BLM film 13 on the PIQ film 15.
Is generated to form Therefore, in the present embodiment, after the BLM film 13 is formed, the PIQ
By forming the film 15, these problems can be solved.

(Embodiment 2) FIG. 5 is a schematic sectional view showing a semiconductor device according to Embodiment 2 of the present invention, and FIG. 6 shows a semiconductor device according to Embodiment 2 of the present invention.
It is a flowchart which shows the formation method of B solder.

The semiconductor device according to the second embodiment is an underfill type PGA package such as a logic LSI or a memory LSI. The difference from the first embodiment is that a PGA package structure is used instead of the BGA package structure. The difference is that the method of forming the CCB solder on the LSI chip is different.

That is, as shown in FIG. 5, the PGA package according to the second embodiment includes an LSI chip 2 on which CCB solder 1 is formed, and a substrate 3 on which the LSI chip 2 is mounted in a face-down structure. An underfill resin 4 for filling a joint between the LSI chip 2 and the substrate 3;
It comprises lead pins 31 electrically connected to the CCB solder 1 of the SI chip 2 and arranged on the back surface of the substrate 3.

Further, the method of forming the CCB solder 1 on the LSI chip 2 is performed as shown in the flow of FIG. First, similarly to the first embodiment, a wiring process (step 601), a sputtering process for the BLM film 13 (step 602a), and a photoresist process (step 602)
b), etching of the BLM film 13 (Step 602)
c) and a BLM film forming step (step 602) by a resist removal processing (step 602d).

Subsequently, before performing the PIQ film forming step, CC
A B solder forming step is performed. In this CCB solder forming step (step 603), the CCB on the BLM film 13 is removed.
The CCB solder 1 is formed at the joint of the solder 1. Thereafter, in the PIQ film forming step (step 604), P
By applying and baking the IQ film 15 (step 604a), the PIQ film 15 is formed on the BLM film 13 except for the joint portion of the CCB solder 1. Thereby, CCB
The LSI chip 2 on which the solder 1 is formed can be completed.

Therefore, according to the semiconductor device of the second embodiment, the PIQ film 15 is formed after the BLM film 13 is formed in the same manner as in the first embodiment.
Since no BLM film 13 is formed on
The generation of cracks in the Q film 15 can be eliminated. Furthermore, since the processing of the BLM film 13 on the PIQ film 15 is not performed, contamination of the chamber due to sputter etching does not occur, and the overhang shape of the BLM film 13 does not occur. Further, since it is not necessary to consider the coverage of the BLM film 13, both the photosensitive and non-photosensitive PIQ films 1
5 can be used. In particular, in the second embodiment, by forming the PIQ film 15 after the CCB solder 1 is formed, it is possible to prevent the penetration of the solder into the PIQ film 15.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiment, and various modifications may be made without departing from the gist of the invention. It goes without saying that it is possible. For example, as a semiconductor device, a logic LSI,
In addition to a memory LSI and the like, the present invention can be widely applied to a system LSI and the like in which a logic and a memory are mounted. Further, in addition to the PIQ film, another resin such as a polyimide resin can be used as the protective film.

[0042]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) BLM on metal wiring of LSI chip
With the structure in which the film is formed and the protective film is formed on the BLM film, the formation of the BLM film on the protective film is eliminated, so that the occurrence of cracks in the protective film can be prevented.

(2) According to the above (1), BLM on the protective film
Since the film is not processed, it is possible to prevent occurrence of contamination of the chamber due to sputter etching.

(3) According to the above (1), BLM on the protective film
Since the film is not processed, it is possible to prevent the BLM film from being overhanged.

(4) According to the above (1), it is not necessary to consider the coverage of the BLM film, so that it is possible to use both photosensitive and non-photosensitive protective films.

(5) According to the above (1) to (4), B
By adopting a structure in which a protective film is formed on a BLM film instead of a structure in which an LM film is formed, a problem in a manufacturing process can be solved, so that the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a semiconductor device according to a first embodiment of the present invention.

FIGS. 2A and 2B are a schematic plan view and a schematic bottom view showing the semiconductor device according to the first embodiment of the present invention; FIGS.

FIG. 3 shows a semiconductor device according to the first embodiment of the present invention;
FIG. 4 is a flowchart showing a method of forming CCB solder on an LSI chip.

FIG. 4 shows a semiconductor device according to the first embodiment of the present invention;
It is a flowchart which shows the manufacturing method of a package.

FIG. 5 is a schematic sectional view showing a semiconductor device according to a second embodiment of the present invention;

FIG. 6 shows a semiconductor device according to a second embodiment of the present invention;
FIG. 4 is a flowchart showing a method of forming CCB solder on an LSI chip.

FIG. 7 shows a semiconductor device according to the present invention;
It is a schematic sectional drawing which shows the formation part of CCB solder of an I chip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CCB solder 2 LSI chip 3 Substrate 4 Underfill resin 5 Solder ball 11 Metal wiring 12 Protection film 13 BLM film 14 Resist 15 PIQ film 21 Product base 31 Lead pin

Claims (6)

[Claims] 1. A package structure having an LSI chip and a substrate on which the LSI chip is mounted, wherein a main surface side of the LSI chip and a main surface side of the substrate are electrically connected by CCB solder. A semiconductor device, wherein the LSI
A semiconductor device having a structure in which a BLM film for CCB solder bonding is formed on metal wiring on a main surface side of a chip, and a protective film is formed on the BLM film. 2. The semiconductor device according to claim 1, wherein a joining portion between a main surface of the LSI chip and a main surface of the substrate is filled with an underfill resin, and an external terminal is provided on a rear surface of the substrate. A semiconductor device having a structure in which are arranged. 3. The semiconductor device according to claim 2, wherein said external terminal is a solder ball or a lead pin. 4. The semiconductor device according to claim 1, wherein said protective film is a polyimide resin film. 5. A step of forming a BLM film for CCB solder bonding on a metal wiring on a main surface side of an LSI chip, and a step of forming a protective film on a portion of the BLM film other than a CCB solder bonding portion. Forming a CCB solder on a CCB solder joint on the BLM film; mounting an LSI chip on which the CCB solder is formed on a main surface of the substrate; A step of filling the joint portion with the main surface side with an underfill resin,
Forming an external terminal on the back side of the substrate. 6. A step of forming a BLM film for CCB solder bonding on a metal wiring on a main surface side of an LSI chip, a step of forming CCB solder on a CCB solder bonding portion on the BLM film, and a step of forming the BLM film. A step of forming a protective film on a portion excluding the upper CCB solder joint, a step of mounting the LSI chip on which the CCB solder is formed on a main surface side of the substrate, and a step of mounting the LSI chip on the main surface side of the LSI chip and the substrate. A step of filling the joint portion with the main surface side with an underfill resin,
Forming an external terminal on the back side of the substrate.