JP2785536B2 - Multi-chip module and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a multi-chip module used in a workstation or a computer.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for miniaturization of workstations and computers. To meet these requirements, LSI implementation
The development of multi-chip modules that directly mount the IC has been actively carried out.

An example of a method for manufacturing the above-mentioned conventional multichip module will be described below with reference to the drawings.

FIG. 4 is a sectional view of a conventional multi-chip module. In FIG. 4, reference numeral 1 denotes a circuit board made of ceramic, glass epoxy or the like, 2 denotes an electrode for connecting an LSI chip, 3 denotes an electrode for connecting an external lead, 4 denotes an electrode for connecting a chip component, 5 denotes an LSI chip, and 6 denotes a chip component. , 7 are bonding wires, 8 is a sealing resin, and 9 is an external lead.

[0005] A method of manufacturing the multichip module configured as described above will be described.

First, an LSI chip 5 is die-bonded to one side of a circuit board 1 made of ceramic, glass epoxy, or the like, and the electrodes of the LSI chip 5 are connected to the LSI chip connecting electrodes 2 of the circuit board 1 by bonding wires 7. After all the LSI chips 5 are connected, L
The SI chip 5 is molded. Next, chip components 6 such as resistors and capacitors are connected to the back surface of the circuit board 1 by solder reflow. Finally, external leads 9 made of Cu, 42 alloy or the like are connected to external electrodes of the circuit board 1 by soldering.

[0007]

However, in the above-described configuration, since the LSI chip and the chip component are connected to the same circuit board by different connection methods, that is, wire bonding and soldering, the processes are series. The number of steps increases and the efficiency is low. In addition, the external leads need to be newly connected after the connection of the LSI chip and the chip components to the circuit board is completed, which has a problem that the number of steps is large and the cost is high.

The present invention has been made in view of the above problems, and provides a low-cost, high-density multi-chip module.

[0009]

In order to solve the above-mentioned problems, a multi-chip module according to the present invention comprises a plurality of semiconductor chips electrically connected to a first circuit board having conductor wiring and external electrodes on the periphery. Connecting electronic components to a second circuit board having leads formed by projecting conductive wires on the flexible film from the periphery of the flexible film. An intermediate portion of the lead of the second circuit board is connected to the external electrode of the first circuit board, and the first circuit board and the second circuit board form one circuit module, and The method includes a step of using a portion protruding from the first circuit board as an external lead of the circuit module.

[0010]

According to the present invention, the chip component is connected to the film carrier by solder reflow and the intermediate portion of the lead of the film carrier is connected to the external electrode of the first circuit board to which the LSI chip is connected. Since the circuit board composed of the film carrier and the first circuit board are connected to form one circuit module and the external leads of the module are formed, the connection of the LSI chip and the connection of the chip components can be performed in parallel and the external Since there is no need to newly connect only the leads, a multi-chip module with low man-hours and low cost and high density can be obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a multichip module according to one embodiment of the present invention will be described below with reference to the drawings.

(FIG. 1) is a sectional view of each step of a method of mounting an LSI chip on a circuit board in an embodiment of the present invention. (FIG. 2) is a sectional view of each step of a method of mounting a chip component on a film carrier. FIG. 3) is a sectional view of a circuit module according to an embodiment of the present invention. In FIG. 1 (FIG. 2) (FIG. 3), 11 is a circuit board, 12 is an external electrode of the circuit board, 13 is an electrode for connecting an LSI chip, 14 is an insulating resin, 15 is an LSI chip, and 16 is an LSI chip. Bump, 17 is a pressure tool, 18 is ultraviolet light, 21 is a film carrier,
22 is a chip component connection electrode, 23 is a film lead,
Reference numeral 24 denotes a chip component, and 25 denotes solder.

An embodiment of the present invention will be described below with reference to the drawings. First, as shown in FIG. 1A, an insulating resin 14 is applied on an LSI chip connection electrode 13 of a circuit board 11 made of ceramic, silicon, or the like. The conductor wiring of the circuit board 11 has a multi-layer structure and connects the LSI chips to be connected later. The electrode 13 for connecting the LSI chip is made of Al, Cu, Au or the like.
It is about 1 μm to 10 μm. The insulating resin 14 is epoxy, silicone, acrylic, or the like, and the type of curing is light curing, heat curing, room temperature curing, or the like. Next, as shown in FIG. 1B, the bumps 16 of the LSI chip 15 are aligned with the electrodes 13 for connecting the LSI chip, and the LSI chip 15 is mounted on the circuit board 11. Thereafter, the LSI chip 15 is pressed by the pressing tool 17. At this time, the insulating resin 14 existing between the LSI chip connection electrode 13 and the bump 16 is pushed out to the periphery and the bump 16 of the LSI chip 15 and the LS
The I-chip connection electrode 13 is in electrical contact. The position of the bump 16 of the LSI chip 15 and the electrode 13 for connecting the LSI chip can be aligned with high accuracy by using a two-view camera or the like.
The pressing force by the pressing tool 17 is 1 gram / bump to 50
Grams / bumps. Next, the insulating resin 14 is cured while the LSI chip 15 is pressed. Insulating resin 1
4 is cured by irradiating ultraviolet rays 18 from the side surface of the LSI chip 15 when the insulating resin 14 is a photo-curing type. In the case of a thermosetting type, the heating is performed by providing the pressing tool 17 with a heating mechanism. Next, the pressing tool 17 is released and the LSI chip 15 is attached to the circuit board 11.
And the bumps of the LSI chip 15 and the LSI
The chip connection electrodes 13 are electrically connected. Next, FIG.
As shown in FIG.
1 and the mounting of the LSI chip on the circuit board 11 is completed.

Next, the mounting of chip components on a film carrier will be described with reference to FIG. First, a film carrier 2 which is a flexible film as shown in 2a
The cream solder 26 is printed on one chip component connection electrode 22. The base film of the film carrier 21 is made of polyimide or polyester and has a thickness of 50 μm or more.
It is about 125 μm. The chip component connecting electrode 22 and the external lead 23 are formed by etching a copper foil adhered to a base film, and have a thickness of 12 μm or more.
It is about 50 μm. Next, as shown in FIG. 2B, the chip component 24 such as a resistor and a capacitor is mounted by a chip mounter or the like and reflowed to connect the chip component 24 to the chip component connection electrode 22 by soldering. Next, FIG.
The external leads 23 are formed using a mold as shown in FIG. Middle part 2 of formed external lead 23
3a is a region to be connected to the external electrode 12 of the circuit board 11 later, and the tip portion 23b is a region to be an external lead of the module. In addition, mounting of chip components on the film carrier 21 is performed by a normal TAB (Tape Automa).
As in the case of the TD (Ted Bonding) method, it may be carried out in a tape form on a reel-to-reel basis.

Next, as shown in FIG.
The intermediate portion 23a of one external lead 23 is connected to the external electrode 12 of the circuit board 11. The connection method is performed by soldering with a heating tool or laser. By connecting the film carrier 21 and the circuit board 11, one multi-chip module is completed and the external leads 23b of the multi-chip module are simultaneously formed. Therefore, unlike the related art, it is not necessary to newly attach external leads, and the number of steps can be reduced. In this embodiment, L
Although the method of connecting the SI chip and the circuit board face-down using an insulating resin has been described by a so-called micro-bump bonding method, a wire bonding method or a flip-chip method using solder bumps may be used.

[0016]

As described above, according to the present invention, the chip components are connected to the film carrier by solder reflow, and the intermediate portions of the leads of the film carrier are connected to the external electrodes of the first circuit board to which the LSI chip is connected. As a result, the circuit board composed of the film carrier and the first circuit board are connected to form a single circuit module, and at the same time the external leads of the module are formed. In addition, it is not necessary to newly connect only the external leads, so that the number of steps is small, and a low-cost and high-density multichip module can be obtained. In addition, since a film carrier lead is used as the external lead, a multi-terminal external lead can be formed at a fine pitch, and high density can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of each step of a method for mounting on a first circuit board in a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of each step of a chip component on a film carrier in the embodiment.

FIG. 3 is a sectional view of the circuit module in the embodiment.

FIG. 4 is a cross-sectional view of a conventional multi-chip module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Circuit board 12 External electrode of circuit board 13 LSI chip connection electrode 14 Insulating resin 15 LSI chip 16 Bump 17 Pressure tool 18 Ultraviolet 21 Film carrier 22 Chip component connection electrode 23 Film lead 24 Chip component 25 Solder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 25/00 H01L 23/32

Claims (2)

(57) [Claims] 1. A plurality of semiconductor chips are electrically connected,
A first circuit board having conductor wiring and external electrodes on the periphery, a conductor having conductor wiring on a flexible film, and the conductor having leads extending from the periphery of the flexible film; A second circuit board having an electronic component connected to wiring, wherein the first circuit board and the second circuit board overlap each other with the extended leads of the second circuit board in an overlapping state; A multi-chip module, wherein an intermediate portion is connected to the external electrode of the first circuit board, and an end of the extended lead becomes an external lead. 2. A step of electrically connecting a plurality of semiconductor chips to a first circuit board having a conductor wiring and an external electrode around the conductor wiring, the conductor wiring on a flexible film, and the conductor wiring being flexible. Connecting an electronic component to a second circuit board having leads extending from the periphery of the conductive film, placing the second circuit board on the first circuit board, A method of connecting a middle part of the extended lead to the external electrode of the first circuit board and using an end of the extended lead as an external lead.