JPH08213425A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a mounting structure in which a semiconductor element is directly connected to a circuit board wiring by bump. CONSTITUTION: The semiconductor device comprises a semiconductor chip 1 provided with a first bump 8 on its electrode pad 2, a wiring circuit board 5 provided at a second bump 9 connected to the bump 8 on the chip 1 on a board wiring 6, and sealing resin 7 filled in the gap between the chip 1 and the board 5, wherein the bumps 8, 9 are connected in contact between the chip 1 and the board 5 at a high bump 10. According to the structure, adhesive is eliminated, the chip 1 can be connected to the board, and the connecting structure of the element 1 to the board 6 corresponding to a thermal stress can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a bump (projection electrode) connection structure between a semiconductor chip and a printed circuit board, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the tendency of high density mounting of semiconductor elements is remarkable, and C for directly bonding semiconductor elements onto a printed wiring board is used.
The OB (Chip On Board) method has been widely used. In addition, the number of connection terminals in MPU / logic devices tends to increase, and QFP, which has been commonly used in the past, is used in ultra-high pin semiconductor devices with more than 200 pins.
If the outer lead pitch is 0.65 mm or more, which is easy to mount when assembled into a package, etc., the external dimensions will be extremely large, and if the outer lead pitch is 0.5 mm or less, mounting will be very difficult. As a semiconductor device, CSP (ChipSize Packag) is used to bond the semiconductor element on the intermediate board and mount it on the board with grid-shaped outer leads.
e) and other packages have been proposed. In these steps, in addition to the conventional connection by the wire bonding method, a flip chip method in which the bumps are directly mounted on the substrate may be adopted, and the present invention relates to the proposal of a new flip chip method.

An example of a conventional mounting structure of a semiconductor device by bump connection will be described with reference to FIG. In FIG. 5, the conventional mounting structure is the electrode pad 2 of the semiconductor chip 1.
It is joined to the board wiring 6 on the printed circuit board 5 by the conductive adhesive 4 through the bumps 3 made of gold, solder or the like formed above. Then, the sealing resin 7 is applied to the gap between the semiconductor chip 1 and the printed circuit board 5 and the periphery thereof to complete the mounting structure.

[0004]

However, in the above-mentioned conventional structure, the conductive adhesive is used for bonding the bump and the substrate wiring, and the step of applying the conductive adhesive evenly to all the tops of the bumps is required. Yes, in the case of using a method such as a squeegee to transfer the adhesive in a thin film, the adhesive is likely to harden, so a method to constantly remove the adhesive film and re-form it for continuous production, etc. Therefore, it was necessary to lengthen the open time. Further, due to the same reason, there is a problem in reliability that the characteristics of the adhesive are likely to change and the adhesive strength varies.

[0005]

In order to solve the above problems, the semiconductor device of the present invention has bumps (protruding electrodes) formed on both the electrode pads of the semiconductor chip and the substrate wiring of the printed circuit board. In this mounting structure, these bumps are brought into contact, pressure contact, thermocompression bonding, and fusion contact with each other. That is, the first
Of the semiconductor element having the protruding electrode of the second electrode provided on the electrode pad, and the second protruding electrode connected to the first protruding electrode on the semiconductor element.
Is a semiconductor device including a printed circuit board having protruding electrodes provided on the board wiring and a sealing resin filling a gap between the semiconductor element and the printed circuit board. Is characterized in that the first bump electrode and the second bump electrode are in contact with each other and joined to each other to form a high-height bump. In addition, a semiconductor element having a first two-step protruding electrode provided on its electrode pad and a second two-step protruding electrode joined to the first two-step protruding electrode on the semiconductor element are provided on the substrate wiring. A wiring circuit board, and a sealing resin that fills a gap between the semiconductor element and the wiring circuit board, wherein a first two-step protruding electrode and a first step electrode are provided between the semiconductor element and the wiring circuit board. It is characterized in that a substantially drum-shaped high-back bump whose central portion is constricted is provided by abutting and joining the two two-stage protruding electrodes.

In the manufacturing method, the step of forming the first protruding electrode on the electrode pad on the semiconductor element, and the first protruding electrode formed on the semiconductor element on the substrate wiring on the printed circuit board. Forming a second projecting electrode at a position facing each other, joining the first projecting electrode on the semiconductor element to the second projecting electrode on the printed circuit board, and the semiconductor element and the printed circuit board. And a step of pouring a sealing resin into the gap between the and. In addition, a step of forming the first gold protruding electrode on the electrode pad on the semiconductor element, and a step of forming a first gold protruding electrode on the substrate wiring on the printed circuit board at a position facing the first protruding electrode formed on the semiconductor element. The step of forming the second gold bump electrode on the semiconductor element and the second gold bump electrode on the wiring circuit board is performed by applying pressure while keeping the temperature of the semiconductor element and the wiring circuit board low. And a step of forming a high back protrusion electrode for connecting between the semiconductor element and the printed circuit board by pressure welding, and a step of pouring and filling a sealing resin into a gap between the semiconductor element and the printed circuit board. Is characterized by. Further, a step of forming a first two-step gold bump electrode on an electrode pad on the semiconductor element, and a first two-step gold bump electrode formed on the semiconductor element on the substrate wiring on the printed circuit board. Forming a second two-step gold bump electrode on the semiconductor element and pressing the wire while keeping the temperature of the semiconductor element and the printed circuit board low. A step of pressure-bonding a second two-step gold bump electrode on the substrate to form a high-back bump electrode having a substantially drum shape with a constricted central portion connecting the semiconductor element and the printed circuit board; And a step of pouring and filling a sealing resin into a gap between the element and the printed circuit board.

[0007]

With the above construction, the conductive adhesive for joining is not required, so that the conventional uniform adhesive coating mechanism is not required and the facility can be simplified. In addition, there is no need to manage the conductive adhesive, and stable production is possible even if there is little consideration at the mass production plant. In this case, by forming both bumps with gold (Au) having an excellent plastic deformation function,
It is possible to perform pressure welding while keeping the joining temperature low. Furthermore, the gold bumps are formed into a two-step shape by a method applying a ball bonding method of gold wires, and by bonding each of them, an hourglass shape that is advantageous for alleviating the stress generation at the bonding portion when the temperature changes. It is possible to obtain a connection portion having a shape close to that of, and improve the reliability of the joint portion.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the process-like structure,
The manufacturing method will be described.

1 and 2 are sectional views showing a first embodiment of the present invention. As shown in FIG. 1, the first bump 8 is formed on the electrode pad 2 of the semiconductor chip 1, and the second bump 9 is formed on the substrate wiring 6 on the printed circuit board 5. The material of the first bump 8 and the second bump 9 is gold,
First bump 8 made of copper, solder, aluminum, or the like
The second bump 9 and the second bump 9 may be made of the same material or different materials. Further, the first bump 8 and the second bump 9 may be appropriately plated to improve the bondability by forming a eutectic crystal. First bump 8 and second bump 9
As a method of forming the
It is formed by a ball bonding method using a fine metal wire with a ball bonder used at the time of wire bonding.

Next, as shown in FIG. 2, the printed circuit board 5
Is placed on an appropriate stage, the semiconductor chip 1 is vacuum-sucked by a tool, and the first bumps 8 on the semiconductor chip 1 and the second bumps 9 on the printed circuit board 5 are brought into contact with each other to obtain electrical conduction. . As a result, the first bump 8 and the second bump 9 are provided between the semiconductor chip 1 and the printed circuit board 5.
Thus, the high bump 10 is formed. After that, the sealing resin 7 is applied to the gap between the semiconductor chip 1 and the printed circuit board 5 and the periphery thereof to complete the mounting structure.

In the mounting structure of this embodiment shown in FIG. 2, the semiconductor chip 1 having the first bumps 8 provided on the electrode pads 2 thereof and the second bumps 8 bonded to the first bumps 8 on the semiconductor chip 1 are provided. The bump 9 of the wiring circuit board 5 provided on the substrate wiring 6 and the sealing resin 7 filling the gap between the semiconductor chip 1 and the wiring circuit board 5. The first bump 8 and the second bump 9 are in contact with each other and bonded to each other, and a high bump 10 is provided therebetween.

It should be noted that the first bump 8 and the second bump 9 are made of gold having excellent plastic deformation function, and are easily pressed by pressing with a pressing tool while keeping the temperature of the wiring circuit board 5 and the semiconductor chip 1 low. In addition, the first bump 8 and the second bump 9 can have a pressure contact structure. Further, at this time, the pressing tool can be heated to form a thermocompression bonding structure, and the first bumps 8 and the second bumps 9 are selected from low melting point metals such as solder or metals having a eutectic formation composition such as gold and tin. By doing so, it is also possible to obtain a bonded portion (high bump) having a fused contact structure.

In this embodiment, since the first bumps 8 on the semiconductor chip 1 and the second bumps 9 on the printed circuit board 5 are joined together, it is possible to use an adhesive means such as a conductive adhesive. The semiconductor chip can be directly mounted on the substrate. A high bump 10 is formed between the semiconductor chip 1 and the printed circuit board 5 by the first bump 8 and the second bump 9.
Since the gap is larger than that in the case of one bump, when filling the gap between the semiconductor chip 1 and the printed circuit board 5 with the sealing resin 7, even if the sealing resin 7 having a high viscosity is used, bubbles or the like are generated in the gap. Generation can be suppressed and sufficient filling can be performed.

Next, FIGS. 3 and 4 are sectional views showing a second embodiment of the present invention. As shown in FIG. 3, the semiconductor chip 1
The first two-stage bump 11 and the second two-stage bump 12 are formed on the electrode pad 2 and the substrate wiring 6 of the printed circuit board 5, respectively. Since the two-step bump 12 is formed by the ball bonding method using a fine metal wire with a ball bonder,
It is a two-stage high-profile bump.

Next, as shown in FIG. 4, the printed circuit board 5
On a suitable stage, the semiconductor chip 1 is vacuum-sucked by a tool, and the first two-stage bump 11 on the semiconductor chip 1 and the second two-stage bump 12 on the printed circuit board 5 are brought into contact with each other. To obtain electrical continuity. As a result, a high bump 13 is formed between the semiconductor chip 1 and the printed circuit board 5 by the first two-stage bump 11 and the second two-stage bump 12. After that, the sealing resin 7 is applied to the gap between the semiconductor chip 1 and the printed circuit board 5 and the periphery thereof to complete the mounting structure.

In the mounting structure of this embodiment shown in FIG. 4, the semiconductor chip 1 in which the first two-stage bumps 11 are provided on the electrode pads 2 thereof, and the first two-stage bumps 1 on the semiconductor chip 1 are provided.
The second two-stage bump 12 bonded to the wiring board 1 is composed of the wiring circuit board 5 provided on the board wiring 6, and the sealing resin 7 filling the gap between the semiconductor chip 1 and the wiring circuit board 5. There is a substantially drum-shaped high bump 13 in which the first two-stage bump 11 and the second two-stage bump 12 are in contact with each other and bonded to each other between the semiconductor chip 1 and the printed circuit board 5 and the central portion is constricted. Is provided.

As in the case of the first embodiment, the first two-stage bump 11 and the second two-stage bump 12 are formed of gold having excellent plastic deformation functions, and the temperature of the printed circuit board 5 and the semiconductor chip 1 is controlled. By keeping pressure at a low value and applying pressure with a pressing tool, the first two-stage bump 11 and the second two-stage bump 12 can be easily brought into a pressure contact structure. Further, at this time, the pressing tool can be heated to form a thermocompression bonding structure, and the first two-stage bump 11 and the second two-stage bump 12 are formed of a low melting point metal such as solder, or a eutectic such as gold and tin. By selecting a metal having a forming composition, it is possible to obtain a joint having a fusion-welded structure.

In the present embodiment, since the first two-stage bumps 11 on the semiconductor chip 1 and the second two-stage bumps 12 on the printed circuit board 5 are joined together, a conductive adhesive or the like is adhered. The semiconductor chip can be directly mounted on the substrate without using a chemical means. Further, a high bump 13 is formed between the semiconductor chip 1 and the printed circuit board 5 by the first two-stage bump 11 and the second two-stage bump 12, and the gap is larger than that in the case of one bump. The sealing resin 7 is used as the semiconductor chip 1
When the gap between the wiring circuit board 5 and the printed circuit board 5 is filled, even if the sealing resin 7 having a high viscosity is used, the gap can be filled sufficiently while suppressing the generation of bubbles and the like.

The shape of the high bump 13 formed by the first two-stage bump 11 and the second two-stage bump 12 is as follows.
The semiconductor chip 1 has a drum-like shape with the central portion constricted.
The shape is advantageous for absorbing the difference in the coefficient of thermal expansion due to the difference in the materials of the circuit board 5 and the circuit board 5. Therefore, the high bumps 13 can improve the reliability of the joint portion between the semiconductor chip and the printed circuit board.

The embodiment of the present invention has been described above. For example, when the material of the first bump 8, the second bump 9, the first two-stage bump 11 and the second two-stage bump 12 is gold. It is also possible to apply ultrasonic waves to the tool to improve the bondability and obtain a strong bonded portion as a fusion-bonded structure at low temperatures. Further, instead of the ball bonding method, a plating method may be used in which the resist film is used a plurality of times as a means for forming the two-tiered high-height bump in the second embodiment.

[0021]

As described above, in the semiconductor device of the present invention, the bumps formed on both the semiconductor chip and the printed circuit board can be joined to each other to obtain a direct joining structure of the semiconductor chips. It realizes a highly reliable flip chip method.

In the manufacturing method, the semiconductor chip,
Since the bumps formed on both of the wiring circuit boards can be simply joined by pressure contact at a low temperature, the semiconductor chip can be easily joined to the wiring circuit board.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a first embodiment of a semiconductor device of the present invention.

FIG. 2 is a sectional view of a semiconductor device according to a first embodiment of the present invention.

FIG. 3 is a sectional view of a second embodiment of the semiconductor device of the present invention.

FIG. 4 is a sectional view of a second embodiment of the semiconductor device of the present invention.

FIG. 5 is a sectional view of a conventional semiconductor device.

[Explanation of symbols]

 1 Semiconductor Chip 2 Electrode Pad 3 Bump 4 Conductive Adhesive 5 Wiring Circuit Board 6 Board Wiring 7 Sealing Resin 8 First Bump 9 Second Bump 10 High Bump 11 First 2nd Step Bump 12 Second 2nd Step Bump 13 High Bump

Claims (7)

[Claims] 1. A semiconductor element having a first projecting electrode provided on its electrode pad, and a second projecting electrode bonded to the first projecting electrode on the semiconductor element is provided on its substrate wiring. A semiconductor device comprising: a wiring circuit board; and a sealing resin filling a gap between the semiconductor element and the wiring circuit board, wherein the first protruding electrode is provided between the semiconductor element and the wiring circuit board. A semiconductor device, wherein high bumps are provided by being brought into contact with and joined to the second protruding electrodes. 2. The semiconductor device according to claim 1, wherein the material of the first protruding electrode and the second protruding electrode provided on the semiconductor element and the printed circuit board is gold. 3. A semiconductor element having a first two-step protruding electrode provided on an electrode pad thereof, and a second two-step protruding electrode bonded to the first two-step protruding electrode on the semiconductor element of the substrate. A semiconductor device comprising: a wiring circuit board provided on wiring; and a sealing resin filling a gap between the semiconductor element and the wiring circuit board, wherein the semiconductor element and the wiring circuit board are provided with A semiconductor device, wherein the first two-step protruding electrode and the second two-step protruding electrode are in contact with each other to be joined to each other, and a substantially drum-shaped high-back bump having a central portion constricted is provided. 4. The semiconductor according to claim 3, wherein the materials of the first two-step protruding electrode and the second two-step protruding electrode provided on the semiconductor element and the printed circuit board are both gold. apparatus. 5. A step of forming a first projecting electrode on an electrode pad on a semiconductor element, and a substrate wiring on a printed circuit board, facing the first projecting electrode formed on the semiconductor element. Forming a second projecting electrode at a desired position, joining the first projecting electrode on the semiconductor element and the second projecting electrode on the printed circuit board, and the semiconductor element and the wiring circuit. Pour the sealing resin into the gap between the board and
And a step of filling the semiconductor device. 6. A step of forming a first gold protruding electrode on an electrode pad on a semiconductor element, and a step of forming a first gold protruding electrode on a substrate wiring on a printed circuit board, the first protruding electrode being formed on the semiconductor element. A step of forming a second gold bump electrode at a position facing each other, and pressing while keeping the temperature of the semiconductor element and the wiring circuit board low, and the first gold bump electrode on the semiconductor element and the wiring circuit board. A step of pressure-bonding the upper second gold protruding electrode to form a high-back protruding electrode for connecting between the semiconductor element and the wiring circuit board; and a sealing resin in the gap between the semiconductor element and the wiring circuit board. A method of manufacturing a semiconductor device, comprising the steps of pouring and filling. 7. A step of forming a first two-step gold bump electrode on an electrode pad on a semiconductor element, and a first step formed on the semiconductor element on a substrate wiring on a printed circuit board.
A step of forming a second two-step gold bump electrode at a position facing the step gold bump electrode; and pressing while keeping the temperature of the semiconductor element and the wiring circuit board low, A high back protrusion having a substantially drum shape with a central portion constricted by pressure-bonding the stepped gold protruding electrode and the second second step gold protruding electrode on the wiring circuit board to connect between the semiconductor element and the wiring circuit board. A method of manufacturing a semiconductor device, comprising: a step of forming an electrode; and a step of pouring and filling a sealing resin into a gap between the semiconductor element and the printed circuit board.