JP2002368159A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

(57) [Problem] To provide a method of manufacturing a semiconductor device capable of reducing manufacturing cost and realizing highly reliable electrode connection. SOLUTION: A chip electrode 3 is formed on one surface 11, and a protruding electrode 8 protruding from the surface 11 on the surface of the chip electrode 3.
And the chip-side electrode 3 on one surface 2a.
A circuit board 2 made of a resin on which a circuit board side electrode 4 corresponding to the above is formed is prepared.
Then, the wafer 10 and the circuit board 2 are heated while being pressurized, so that the protruding electrodes 8 and the circuit board side electrodes 4 are pressed and the resin forming the circuit board 2 is softened, The one surface 11 of the wafer 10 and the one surface 2a of the circuit board 2 in the portion where no 4 is formed are adhered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device mounted on a printed circuit board and a method for manufacturing the same, and more particularly to a chip size package (CSP) having substantially the same size as a chip. Things.

[0002]

2. Description of the Related Art Conventionally, a CSP having a size substantially equal to or slightly larger than a semiconductor chip has been used to reduce the size of a multi-terminal IC package. The CSP is packaged for each chip cut out from a wafer. FIG.
FIG. 3 shows a schematic cross-sectional configuration of two types of CSPs in a conventional structure, and electrode bonding of the CSPs is generally performed by wire bonding shown in FIG. 3A or flip chip shown in FIG.

The manufacturing process of a CSP for performing electrode bonding by wire bonding is performed as follows. First, a semiconductor chip J1 formed by cutting a wafer is mounted on a circuit board J.
2, a chip-side electrode J3 and a circuit-board-side electrode J4 are connected by bonding with an Au wire J5. Next, a resin J6 for sealing the chip J1 is applied and cured. Finally, a protruding electrode J8 is formed on the outer electrode J7 on the opposite side of the chip mounting side of the circuit board J2.

[0004] A manufacturing process of a CSP for performing electrode bonding by flip chip is performed as follows. First, the chip J1 is formed by cutting a wafer in which the projecting electrode J3a is formed on the chip-side electrode J3 in advance, and connecting the projecting electrode J3a and the circuit-board-side electrode J4 by soldering or the like. Assemble to J2. Next, a resin J6 for sealing the chip J1 is injected between the chip J1 and the circuit board J2 to be cured. Finally, a protruding electrode J8 is formed on the outer electrode J7 on the opposite side of the chip mounting side of the circuit board J2.

[0005] As described above, the conventional CSP requires electrode bonding by wire bonding, flip chip, and the like, and chip sealing with resin, etc., and thus has a problem that the assembling process becomes longer and the package cost becomes higher. Was.

In order to reduce the cost of the CSP, Japanese Patent Application Laid-Open Nos. Hei 9-82850 and Hei 10-507
There is a semiconductor device described in Japanese Patent Publication No. 72-72. However, in the semiconductor device described in Japanese Patent Application Laid-Open No. 9-82850, a process of forming a wiring from a surface electrode on a chip to an external connection terminal portion and a process of sealing the chip surface with a resin are separate, and the whole There is a problem that the process becomes long.

Further, in the semiconductor device described in Japanese Patent Application Laid-Open No. 10-50772, external connection terminals extending outward from a surface electrode on a chip must be formed one by one by wire bonding. There was a problem that it took time.

On the other hand, Japanese Unexamined Patent Publication No. Hei 8-335565 discloses a semiconductor device in which wiring from a surface electrode on a chip to an external connection terminal and resin sealing of the chip surface are simultaneously performed. FIG. 4 shows the configuration of this semiconductor device.

This semiconductor device has an auxiliary wiring board (circuit board) J in which a protruding electrode J4a is formed on a circuit board side electrode J4.
2 and the chip J1 on which the chip-side electrode J3 is formed, are bonded via a heat-fusible polyimide resin J6. Thus, the chip-side electrode J3 and the circuit-board-side electrode J4 are connected, and the heat-fusible polyimide resin J is connected.
6 seals the gap between the chip J1 and the circuit board J2.

[0010] However, Japanese Patent Application Laid-Open No. 8-33565 described above.
In the semiconductor device described in Japanese Patent Publication No. 3 (1995), a heat-fusible polyimide resin J6 for resin encapsulation is required in addition to the circuit board J2, and the bonding of the semiconductor chip J1 to the circuit board J2 is performed for each chip. However, there is a problem that productivity is low.

A semiconductor device described in Japanese Patent Application Laid-Open No. 2001-24086 has been proposed as a solution to the above-mentioned problems such as troublesome steps and reduced productivity in the conventional publications.

This device is formed on each chip on the wafer side by forming flat electrodes on the surface of a circuit board formed of, for example, a thermoplastic resin material, and pressing and heating the circuit board against the wafer. By connecting the flat electrode and the electrode on the circuit board side at the same time, the chip surface (wafer surface) and the resin portion on the circuit board surface are bonded to each other at the part where no electrode is formed. The sealing is performed at the same time.

[0013]

However, according to the study by the present inventors, in the semiconductor device described in Japanese Patent Application Laid-Open No. 2001-24086, the chip side electrode and the circuit board side electrode are in contact with each other. At the same time, since the surface of the chip and the surface of the circuit board are in contact with each other where the electrodes are not formed, the softened resin on the surface of the circuit board enters between the chip-side electrode and the circuit-board-side electrode, resulting in good contact. It was found that electrode connection could not be performed.

The present invention has been made in view of the above problems, and has as its object to provide a semiconductor device capable of reducing manufacturing costs and realizing highly reliable electrode connection, and a method of manufacturing the same.

[0015]

According to the first aspect of the present invention, a first electrode (3) is formed on one surface (11), and the first electrode (3) is formed on the surface of the first electrode. Substrate (1) on which a protruding electrode (8) projecting from
0) and a step of preparing a circuit board (2) made of a resin in which a second electrode (4) corresponding to the first electrode is formed on one surface (2a), and the one surface of the semiconductor substrate and the circuit board And the step of contacting the protruding electrode and the second electrode with each other, and heating the semiconductor substrate and the circuit board while applying pressure, thereby crimping the protruding electrode and the second electrode, A resin forming the circuit board is softened, and a portion of the one surface of the semiconductor substrate on which the first electrode is not formed is bonded to a portion of the one surface of the circuit substrate on which the second electrode is not formed; And bonding the circuit board and the circuit board.

According to this, a projecting electrode (8) is formed on the first electrode (3) which is a chip-side electrode, and first, this projecting electrode and a second electrode (4) which is a circuit board-side electrode are connected. After the contact, the surface (11) of the semiconductor substrate (10) and the surface (2)
a), the softened resin on the surface of the circuit board can be prevented from entering between the protruding electrode and the second electrode.

After the step of bringing the protruding electrode (8) into contact with the second electrode (4), which is a circuit board side electrode, the surface (11) of the semiconductor substrate (10) is formed at a portion where the electrode is not formed. Performing the step of bringing the substrate into contact with the surface (2a) of the circuit board (2) can be performed with almost no difference in time, as compared with the case of performing both steps simultaneously.

Therefore, according to the present invention, it is possible to provide a method of manufacturing a semiconductor device (S1) capable of reducing manufacturing cost and realizing highly reliable electrode connection.

Here, the semiconductor substrate may be a wafer (10) or a chip (1). In the case of a wafer, after the step of bonding the semiconductor substrate and the circuit board, both bonded substrates may be cut into chips.

According to a second aspect of the present invention, in the manufacturing method of the first aspect, in the step of bonding the semiconductor substrate (10) and the circuit board (2), the semiconductor substrate and the circuit board are added. After the pressing, it is preferable to heat both substrates while maintaining the pressurized state.

When the above-mentioned pressurization and heating are performed simultaneously, the difference in thermal displacement between the semiconductor substrate (10) and the circuit board (2) due to the difference in linear expansion coefficient between the two substrates (2, 10) causes the difference. A positional shift easily occurs between the two substrates.

In this regard, according to the present invention, both substrates (2, 1
Since the heating is performed after pressing 0) to press and press each other to be in a state of being restrained by each other, it is possible to surely suppress the displacement due to the difference in displacement between both substrates due to heat.

According to the third aspect of the present invention, the semiconductor chip (1) having the first electrode (3) formed on at least one surface (1a) side and the first chip (1) on at least one surface (2a) side.
And a circuit board (2) made of a resin on which a second electrode (4) corresponding to the first electrode is formed. The first electrode has a protruding electrode (8) projecting from the one surface of the semiconductor chip toward the circuit board. ) Is formed, the protruding electrode and the second electrode are in contact with and electrically connected to each other, and further, the portion of the one surface of the circuit board where the second electrode is not formed is connected to the semiconductor chip side. A semiconductor device is provided in which a first electrode is not formed on the one surface of the semiconductor chip in a raised state.

The present invention is formed by using the manufacturing method of the first aspect, and the effect is the same as that of the first aspect.

The reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0026]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 is a view showing the overall configuration of a semiconductor device S1 according to the present embodiment, in which FIG.
(B) is an arrow A view of (a) (viewed from the lower side of (a)). The semiconductor device S1 is of a CSP (chip size package) type.

The semiconductor device S1 is formed from a semiconductor chip 1 made of a semiconductor such as silicon and a circuit board 2 made of a resin. The semiconductor chip 1 is a wafer 10 described later.
2 (see FIG. 2), a plurality of first electrodes (chip-side electrodes) 3 are formed on one surface 1a.

Here, the chip-side electrode 3 is formed so as to be flat with respect to one surface 1a of the semiconductor chip 1. A plurality of second electrodes (circuit board-side electrodes) 4 corresponding to the chip-side electrodes 3 are formed on the surface 2a of the circuit board 2 to which the chip 1 is bonded.

A flat outer electrode 5 is also formed on a surface 2b of the circuit board 2 opposite to the chip bonding side, and the circuit board side electrode 4 and the outer electrode 5 are formed in the circuit board 2. Internal wiring 6 for electrical connection is formed. Further, bumps 7 made of solder or the like for connection to a printed board (not shown) as a motherboard are formed on the outer electrode 5.

The circuit board 2 is formed of, for example, a thermoplastic resin material. In this embodiment, the circuit board 2 is formed of a polyimide resin. The chip-side electrode 3 is formed of, for example, Al, and the circuit board-side electrode 4 is formed of, for example, a metal material such as Sn or Au.

Here, on the surface of the chip-side electrode (first electrode) 3, a projecting electrode 8 is formed which protrudes from the one surface 1 a of the semiconductor chip 1 toward the circuit board 4. The protruding electrodes 8 can be made of, for example, Ni-Au bumps (Ni is used as a core material and the Ni surface is covered with Au) formed by electroless plating.

The protruding electrode 8 and the circuit board side electrode 4 are in contact, adhered or joined. In this example, Au constituting the surface of the bump electrode 8 and Sn or Au constituting the circuit board side electrode 4 are connected by solid phase diffusion.

A portion of the surface 1a of the semiconductor chip 1 where the chip-side electrode 3 is not formed (hereinafter, referred to as an electrode-free portion of the semiconductor chip 1) and a surface 2a of the circuit board 2
The portion (a) where the circuit board side electrode 4 is not formed (hereinafter, referred to as an electrode non-formed portion of the circuit board 2) is directly adhered, and the semiconductor chip 1 and the circuit board 2 are adhered.

The electrode non-formed portion of the semiconductor chip 1 is covered with a protection film such as an inorganic material (nitride film or the like) or an organic material, though not shown. On the other hand, the electrode non-formed portions of the circuit board 2 are made of a resin material such as the above-described thermoplastic resin. The resin on the one surface 2a side of the circuit board 2 rises toward the chip 1 side from the circuit board side electrode 4 at the opposing portion of both electrode non-formed portions and directly adheres to the electrode non-formed portion of the chip 1, and Connections 3, 4, and 8 are sealed.

Next, a method of manufacturing the semiconductor device S1 having the above configuration will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view illustrating a manufacturing process of the semiconductor device according to the present embodiment. First, as shown in FIG. 2A, the wafer (semiconductor substrate according to the present invention) 10 and the circuit board 2 are prepared.

The wafer 10 is not cut into chips as the semiconductor chip 1, and a plurality of chip-side electrodes 3 are formed on one surface 11 (corresponding to one surface 1 a of the semiconductor chip 1). . The portion of the one surface 11 of the wafer 10 where the chip-side electrode 3 is not formed (the electrode non-formed portion of the wafer 10) is a portion corresponding to the above-described electrode non-formed portion of the semiconductor chip 1, and has the above-described protective film. Is provided.

In this wafer 10, the chip-side electrode 3
A protruding electrode 8 projecting from one surface 11 of the wafer 10 is formed on the surface of the wafer 10. On the other hand, one surface 2a of the circuit board 2 has a plurality of circuit board-side electrodes 4 corresponding to the chip-side electrodes 3.
Are formed.

The wafer 10 can be manufactured through an ordinary semiconductor process, and the bump electrodes 8 can be easily formed, for example, as the Ni-Au bumps by a plating process in the semiconductor process.

Next, as shown in FIG. 2B, one surface 11 of the wafer 10 is opposed to one surface 2a of the circuit board while the positions of the chip-side electrode 3 and the circuit-board-side electrode 4 are aligned.
The protruding electrode 8 is brought into contact with the circuit board side electrode 4 (protruding electrode contact step).

Next, as shown in FIG.
And the circuit board 2 are sandwiched. At this time, since the outer electrode 5 of the circuit board 2 is formed flat as described above, it is easy to perform the pressing operation. Then, heating is performed while applying pressure to the wafer 10 and the circuit board 2 (pressurization / heating step).

By this pressurization and heating, the protruding electrodes 8 formed on the chip-side electrodes 3 in the wafer 10 and the circuit board-side electrodes 4 formed on the circuit board 2 are crimped.
8 are electrically connected in the form of contact, adhesion or bonding. Specifically, if the protruding electrode 8 is a Ni-Au bump whose surface is Au as in the present embodiment, and the circuit board side electrode 4 is a metal material such as Sn or Au, Au and Sn or Au are used. The connection between the electrodes is formed by the solid phase diffusion bonding.

Since the circuit board 2 is made of a thermoplastic resin, it is softened by the above-mentioned heating. Then, the resin portion of the electrode non-formed portion of the circuit board 2 rises toward the wafer 10 due to the pressure, and is directly bonded to the electrode non-formed portion of the wafer 10.

Here, since the organic substance such as the polyimide resin used as the circuit board 2 in the present embodiment has a functional group, when the circuit board 2 is heated, the functional group is applied to the chip surface (wafer surface). It is considered that a chemical bond is easily obtained by approaching the atoms of the protective film to form a bonding state.

By bonding the circuit board 2 and the wafer 10 in this manner, the surface of the chip 1 is eventually covered with the resin, so that the electrodes 4 and 8 are connected and at the same time, Sealing with resin can be performed.

The heating temperature in the above pressurizing / heating step is 100 to 300 ° C., particularly preferably 150 to 250 ° C.
The pressurizing time is 30 seconds to 30 minutes, and the pressing force is 5
It is about 00 kPa to 5000 kPa.

Thereafter, as shown in FIG. 2 (d), if necessary for connection to a printed circuit board as a mother board, solder or the like is formed on the outer electrodes 5 on the circuit board side where the wafer 10 is not bonded. The bump 7 is formed. The bumps 7 are formed using, for example, solder balls. Then, a plurality of CSP type semiconductor devices S1 can be obtained by cutting the wafer 10 and the circuit board 2 in chip units (broken lines in FIG. 2D).

According to the above-described manufacturing method, after the protruding electrodes 8 formed on the chip-side electrodes 3 are brought into contact with the circuit board-side electrodes 4, the wafer Since the surface and the surface of the circuit board are in contact with each other, it is possible to prevent the softened resin on the surface of the circuit board from entering between the protruding electrode 8 and the electrode 4 on the circuit board side.

After the step of bringing the protruding electrode 8 into contact with the circuit board side electrode 4 (protruding electrode contact step),
Performing the step (pressing / heating step) of bringing the surfaces of both substrates 2 and 10 into contact with each other in the electrode non-forming portion of No. 10 involves performing these two steps as described in JP-A-2001-24086 described above. Compared to the case of performing them at the same time, they can be performed with little difference in time.

Further, by bonding the surface of the chip where no electrodes are formed and the resin portion of the surface of the circuit board, the resin sealing of the chip can be realized simultaneously with the connection of the electrodes. It becomes unnecessary. Therefore, according to the present embodiment, it is possible to provide a method of manufacturing the semiconductor device S1 that can reduce the manufacturing cost and realize highly reliable electrode connection.

Here, in the above manufacturing method, the semiconductor substrate used may be the wafer 10 or the semiconductor chip 1 after cutting. In the present embodiment, since the assembly is performed in units of wafers, the productivity in manufacturing semiconductor devices can be improved and the package cost can be reduced, as compared with the case of assembling the circuit board 2 in units of chips cut out of a wafer. it can.

In the above-described manufacturing method, in the pressurizing / heating step, pressurizing and heating may be performed simultaneously. However, preferably, the pressing is performed after the wafer 10 and the circuit board 2 are sandwiched. It is desirable to heat the wafer 10 and the circuit board 2 while maintaining the pressure state.

This is because even when the chip-side electrode 3 on the wafer 10 and the circuit-board-side electrode 4 on the circuit board 2 can be aligned at room temperature, the line between the wafer 10 and the circuit board 2 after heating is formed. This is because, since the expansion coefficients are different, a displacement between the chip-side electrode 3 and the circuit-board-side electrode 4 occurs.

On the other hand, if the wafer 10 and the circuit board 2 are sandwiched and pressurized at room temperature, and then heated after being restrained from each other, the positional displacement due to the difference in displacement between the two substrates 2 and 10 due to heat can be prevented. , Can be suppressed to a level without any problem.

Further, usually, the circuit board 2 is deformed due to warpage or the like, and the position of the circuit board side electrode 4 formed on the circuit board 2 may vary vertically. Also in this case, the wafer 10 and the circuit board 2 are sandwiched and pressurized, and then heated to soften the circuit board 2 and eliminate deformation such as warpage. And the circuit board side electrode 4 can be connected well.

In this embodiment, as shown in FIG. 1, the semiconductor chip 1 has the first electrode 3 formed on at least one surface 1a, and corresponds to the first electrode 3 on at least one surface 2a. A circuit board 2 made of a resin on which a second electrode 4 is formed;
The protruding electrode 8 protruding toward the circuit board 2 side from a is formed, and the protruding electrode 8 and the second electrode 4 are in contact with each other and are electrically connected. The semiconductor device S1 is characterized in that the portion is adhered to the electrode non-formed portion of the semiconductor chip 1 in a state where the portion is raised to the semiconductor chip 1 side from the second electrode 4.

According to this semiconductor device S1, since the semiconductor chip 1 is provided with the protruding electrodes 8 projecting from the one surface 1a, the circuit board 2 made of a resin and the semiconductor In bonding to the chip 1, after the protruding electrode 8 is brought into contact with the circuit board side electrode (second electrode) 4, bonding in the electrode non-formed portion can be performed.

Therefore, according to the present embodiment, it is also possible to provide a semiconductor device S1 that can reduce the manufacturing cost and realize highly reliable electrode connection.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing the overall configuration of a semiconductor device according to an embodiment, wherein FIG. 1A is a schematic cross-sectional view, and FIG.

FIG. 2 is a process chart showing a method for manufacturing the semiconductor device shown in FIG.

FIG. 3 is a cross-sectional view illustrating a configuration of a conventional semiconductor device.

FIG. 4 is a cross-sectional view illustrating a configuration of a conventional semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor chip, 1a ... One surface of a semiconductor chip, 2 ... Circuit board, 2a ... One surface of a circuit board, 3 ... 1st electrode (chip side electrode), 4 ... 2nd electrode (circuit board side electrode), 8 …
Protruding electrodes, 10: wafer, 11: one surface of the wafer.

Claims (3)

[Claims] 1. A semiconductor substrate (10) having a first electrode (3) formed on one surface (11) and a protruding electrode (8) protruding from the one surface formed on the surface of the first electrode; A second electrode (4) corresponding to the first electrode on one surface (2a);
A step of preparing a circuit board (2) made of a resin having formed thereon, the one surface of the semiconductor substrate facing the one surface of the circuit board, and the protruding electrode and the second electrode being brought into contact with each other. Heating the semiconductor substrate and the circuit board while pressing the semiconductor substrate and the circuit board, thereby compressing the protruding electrode and the second electrode and softening the resin constituting the circuit board, A portion of the one surface where the first electrode is not formed and a portion of the one surface of the circuit board where the second electrode is not formed, and bond the semiconductor substrate and the circuit substrate. And a method of manufacturing a semiconductor device. 2. In the step of bonding the semiconductor substrate (10) and the circuit board (2), after the semiconductor substrate and the circuit board are pressed, the semiconductor substrate is held while maintaining the pressed state. 2. The method according to claim 1, wherein the heating is performed on the substrate and the circuit board. 3. A semiconductor chip (1) having a first electrode (3) formed on at least one surface (1a) side, and a second electrode (2) corresponding to the first electrode on at least one surface (2a) side. A circuit board (2) made of resin with 4) formed thereon, wherein the first electrode is formed with a protruding electrode (8) projecting from one surface of the semiconductor chip to the circuit board side; The protrusion electrode and the second electrode are in contact with and electrically connected to each other, and a portion of the one surface of the circuit board where the second electrode is not formed is raised toward the semiconductor chip. The first surface on the one surface of the semiconductor chip;
A semiconductor device which is adhered to a portion where no electrode is formed.