JPH11195870A - Manufacture of integrated circuit assembly and bonder therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect the terminal of a flexible printed circuit board against damage. SOLUTION: In a method for manufacturing an integrated circuit assembly by connecting the terminal 3 having an arcuate solder bump 4 on the circuit board 2 of an integrated circuit module constituting the read/write IC amplifier of hard disc drive with the terminal 41 (FPC terminal) of a flexible printed circuit formed on a flexible printed wiring board through fusion of the solder 4 by hot press, pressure is varied a plurality of times at the time of hot press. The FPC terminal 41 is preheated by blowing heat air before pressure is applied. The fused solder 4 is cooled and hardened during final stage of pressure application and pressure application is ended under a state where the fused solder 4 is hardened. Initial pressure is set at a lowest level which is lower than a level for causing damage on the FPC terminal 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing an integrated circuit assembly in which an integrated circuit module incorporating a semiconductor chip or the like is mounted on a flexible wiring board, for example, a small hard disk drive (HD).
The present invention relates to a technique which is effective when applied to a technique for manufacturing a read / write IC amplifier assembly (integrated circuit assembly) fixed to a carriage D).

[0002]

2. Description of the Related Art A read / write IC amplifier assembly for a small hard disk drive is composed of a read / write IC on a flexible wiring board (flexible printed wiring board).
It has a structure in which an integrated circuit module constituting a C amplifier is mounted.

[0003] In the manufacture thereof, an electrode terminal of a circuit board of the integrated circuit module (hereinafter referred to as a circuit board terminal) and an electrode terminal of a flexible printed wiring board [hereinafter referred to as a flexible printed circuit (Flexible Printed Circuit)].
ircuit) terminals: referred to as FPC terminals] by means of thermocompression bonding using a heat tool. An arc-shaped solder is provided on the surface of the circuit board terminal, and the two terminals are joined by melting the solder.

[0004] Regarding the small hard disk drive, for example, "Microcomputer Handbook" published by Ohm Co., Ltd., published on December 25, 1985, P426-P429,
"Nikkei Electronics" published by Nikkei BP June 16, 1997
JP, P92-P98 and the same magazine, July 1, 1996, P91-P
111.

[0005] For flexible printed wiring boards, see "Electronic Materials", October 1997 issue,
64 to P67.

[0006] The FP of the flexible wiring board is connected to the circuit board terminal of the pre-soldered wiring board (circuit board).
As a device for soldering the C terminal, for example, "Skillless FPC bonding device: FOM-101 / 102" manufactured by Osaki Engineering Co., Ltd. is known.

In this apparatus, a flexible printed circuit board is superimposed on a circuit board so that an FPC terminal overlaps a circuit board terminal, and then a tool (heat tool) having a predetermined temperature is applied to the flexible printed circuit board and a predetermined pressure is applied to the flexible printed circuit board. This is a device for thermocompression bonding a circuit board terminal and an FPC terminal.

The catalog issued by the company states that the apparatus is configured to perform thermocompression bonding by a predetermined soldering condition (temperature, time, pressure) and a sequence operation. In addition, a constant heat is adopted as a heating method.

[0009]

In the manufacture of a read / write IC amplifier assembly (integrated circuit assembly) for a small hard disk drive, a heat tool at a predetermined temperature is pressed against a flexible printed circuit board with a predetermined pressure, and an FPC terminal and a circuit are pressed. When the board terminals are thermocompressed, FP
The C terminal may be cracked and a wiring failure may occur.

As a result of analyzing and examining the cause of the occurrence of the defect, the present inventors have found the following facts.

[0011] The circuit board of the integrated circuit module constituting the read / write IC amplifier is formed of a metal core board having good thermal conductivity.

FP is connected to a circuit board terminal provided on the circuit board.
A flexible printed wiring board is superimposed on the circuit board so that the C terminal overlaps, pressure is applied from above the flexible printed wiring board with a heat tool, and the solder on the surface of the circuit board terminal is melted to connect the circuit board terminal and the FPC terminal. However, since pressure is applied immediately after the heat tool contacts the flexible printed wiring board, heat is not sufficiently transmitted to the solder and the solder does not melt inside,
The circuit board on which the FPC terminals are provided is formed of a metal core board having good thermal conductivity, and heat transmitted to the solder escapes from the circuit board terminal portion through the metal core board;
The FPC terminals are formed of a flexible and easily deformable resin tape. Further, since the surface of the solder has an arc shape and the center portion is highest, the FPC terminal is formed by etching a copper foil. The bent FPC terminal may be broken by a large bending stress.

FIGS. 15 (a) to 15 (c) are schematic views showing a mechanism in which the FPC terminal is damaged.

As shown in FIG. 15A, a circuit board terminal 3 is provided on a back surface 2b (an upper surface in the figure) of a circuit board 2 constituting the integrated circuit module 1. On the surface of the circuit board terminal 3, a solder 4 is greeted and laid as solder. Since the solder 4 is formed by, for example, screen printing and a molding process by heating, the solder 4 has a structure that swells in an arc shape due to the surface tension of the solder.
Although not shown, chip components such as resistors and capacitors and semiconductor chips are mounted on the main surface 2a of the circuit board 2.

The flexible printed circuit board 40 superposed on the circuit board 2 is positioned, and the flexible printed circuit terminals (FPC terminals) 41 provided on the main surface 40a side of the flexible printed circuit board 40 are respectively connected to the circuit board. It is located directly above the terminal 3.

A heat chip 51 for maintaining a predetermined temperature at the tip (lower end) of the heat tool 50 is relatively positioned on an area where soldering is performed.

As shown in FIG. 15B, when the heat tool 50 is lowered, the pressing surface 52 on the lower surface of the heat chip 51 is changed to the lower surface 40 of the flexible printed circuit board 40.
b, and the flexible printed wiring board 40 is pressed against the circuit board 2.

Since the heat chip 51 is at a predetermined temperature, the solder 4 formed on the surface of the circuit board terminal 3 of the circuit board 2 is melted, and the melted solder 4 is used to melt the circuit board terminal 3.
And the FPC terminal 41 are thermocompression-bonded.

However, the heat chip 51 contacts the flexible printed circuit board 40 and the FPC terminal 4
1 is not melted at the moment of pressing the solder 4 on the solder 4, and when viewed microscopically, heat transmitted from the heat chip 51 melts from the surface layer portion of the solder 4 sequentially toward the inside. Since the substrate 2 is formed of a metal core substrate having good thermal conductivity, the heat transmitted to the solder 4 escapes from the solder 4 through the metal core substrate, and the temperature rise is delayed.

As a result, the inside of the solder 4 is hardened even if the surface of the solder 4 starts to soften, the surface of the solder 4 has an arc shape, and the flexible printed wiring board 40 supporting the FPC terminals 41 Since the FPC terminal 41 is formed of a flexible and deformable resin, the FPC terminal 41 is partially supported as shown in FIG. 15B, and a bending stress acts on the FPC terminal 41. And break it to break.

This phenomenon is not eliminated even when the heat tool 50 is raised and the joining operation is completed [FIG. 15 (c)].
Reference], and the connection state between the circuit board terminal 3 and the FPC terminal 41 may be deteriorated, resulting in poor connection.

An object of the present invention is to provide a technique for joining a flexible printed circuit terminal of a flexible printed circuit board and a circuit board terminal provided on a circuit board of an integrated circuit module by soldering to prevent damage to the flexible printed circuit terminal. Another object of the present invention is to provide a technique for manufacturing an integrated circuit assembly having a highly reliable terminal junction.

It is another object of the present invention to provide a technique for manufacturing a read / write IC amplifier assembly for a small hard disk drive having high reliability of connection between a circuit board terminal and a flexible printed circuit terminal. 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.

[0024]

The following is a brief description of an outline of typical inventions disclosed in the present application. (1) A circuit board terminal provided on a circuit board of an integrated circuit module constituting a read / write IC amplifier of a hard disk device and having solder bulged in an arc shape on a surface and a flexible printed circuit terminal provided on a flexible printed wiring board Are connected by melting the solder by thermocompression bonding to manufacture an integrated circuit assembly, wherein the pressurization at the time of thermocompression is performed by changing the pressing force a plurality of times. Before the pressurization, the flexible printed circuit terminal is preheated by blowing a heated gas. Cooling and curing the melted solder in the final stage of pressure,
Thereafter, the pressurization is completed in a state where the solder is cured. The plurality of pressurizations are set such that the initial pressurizing force is the smallest and is smaller than the pressurizing force at which the flexible printed circuit terminal is damaged.

This integrated circuit assembly is manufactured by a joining apparatus having the following configuration. What is claimed is: 1. A joining apparatus comprising: a stage; and a heat tool that moves toward and away from the stage and presses and heats a workpiece placed on the stage, and heats the workpiece on the stage. A heating mechanism and a cooling mechanism for cooling the workpiece on the stage are provided. The heating mechanism and the cooling mechanism are configured to blow gas onto the workpiece. The blowing amount of the gas and the pressing force of the heat tool are configured to be controllable.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

(Embodiment 1) FIGS. 1 to 14 are diagrams relating to the manufacture of an integrated circuit assembly according to an embodiment (Embodiment 1) of the present invention.

In the first embodiment, the flexible printed circuit terminals (FPC terminals) of the flexible printed circuit board and the circuit board terminals provided on the circuit board of the integrated circuit module are formed in an arc shape provided on the surface of the FPC terminal. A method of joining the raised solder by thermocompression will be described.

First, the integrated circuit assembly 10 manufactured by the manufacturing method of the first embodiment, that is, the hard
A read / write IC amplifier assembly of a disk device (HDD) will be described.

FIG. 2 is a plan view of the integrated circuit assembly, and FIG.
Is a front view.

Read / write IC amplifier assembly 10
Has a structure having a flexible printed wiring board 40 reinforced at each location with reinforcing plates 42a to 42c, and an integrated circuit module 1 joined to the flexible printed wiring board 40, that is, a read / write IC amplifier 1. I have.

As shown in FIG. 8, the flexible printed wiring board 40 includes a base film 43 made of an insulating resin, a wiring 44 formed on the main surface of the base film 43, and an insulating material covering the wiring 44. And a cover film 45 made of the above resin. The base film 43 and the cover film 45 are made of a resin having excellent flexibility (flexibility), for example, a polyimide resin.

The wiring 44 is connected to the base film 43.
Is formed by selectively etching the copper foil formed on the main surface of the substrate.

As shown in FIGS. 8 and 9, a plurality of rectangular holes called wing cuts 46 are formed in the base film 43. The portion between the wing cuts 46 in each wing cut row is a flexible printed circuit terminal (FPC terminal) 41 of the flexible printed wiring board 40, and the circuit board terminal of the read / write IC amplifier 1 is fixed. Part.

Through the wing cut 46, the FPC
The quality of the solder joint between the terminal 41 and the circuit board terminal can be visually inspected and inspected.

In FIG. 9, wing cuts 46 and F
A joint 47 between a PC terminal and a circuit board terminal is schematically shown.

As shown in FIG. 2, the flexible printed wiring board 40 has a long guide portion 70 having a constant width and extending linearly. One end portion of the guide portion 70, that is, the left end portion shown in FIG.
This is a portion where the C amplifier 1 is joined, and the wing cut 46 and the FPC terminal 41 are provided as described above.

The other end of the guide portion 70, that is, the right end portion shown in FIG.
Is overhanging. The linking section 71 includes a connector 72.
Is attached. The connector 72 is composed of, for example, a female connector, and is connected to a male connector fixed to a motherboard (not shown) of the hard disk drive.

Although not shown, the wiring 44 on the flexible printed wiring board 40 is formed so as to connect the connector 72 to the FPC terminal 41 and the like.

The reinforcing plate 42a is a frame-like body partially cut away so as to surround the wing cut 46 group.
As shown in FIG. 8, the flexible printed wiring board 40 is fixed to the back surface 40 b with an insulating adhesive 73.

The reinforcing plate 42c is connected to the link 71 by an adhesive.
The reinforcing plate 42b is fixed to an end portion of the side guide portion 70, and the reinforcing plate 42b is fixed at a position separated by a predetermined distance from the reinforcing plate 42a with an adhesive.

The holes drilled in the reinforcing plates 42a to 42c correspond to the read / write IC amplifier assembly 10.
Mounting holes 74a to 7a used when fixing the
4e.

As shown in FIGS. 4 to 6, a read / write IC amplifier (integrated circuit module) 1 includes a semiconductor chip 20 constituting a read / write IC amplifier and a chip resistor 21a on a main surface of a rectangular circuit board 2. , 21b and chip capacitors 22a to 22d are fixed. Further, a circuit board terminal 3 is provided on the back surface of the circuit board 2.
The circuit board terminals 3 are provided corresponding to the FPC terminals 41 and are arranged in three columns and five rows.

As shown in FIG. 7, the circuit board 2 includes a metal plate 23 made of copper, insulating resin films 24a and 24b provided on the front and back surfaces of the metal plate 23, and the resin films 24a and 24b. Wirings 25a formed on the surface of
25b and solder resists 26a and 26b covering the wirings 25a and 25b.

The wirings 25a and 25b are formed by etching a copper foil into a desired pattern, and have mounting pads 25e and 25e for fixing the semiconductor chip 20 in addition to the originally fine wiring.
Wire connection pads 25f for connecting wires, the chip resistors 21a and 21b and the chip capacitors 22a to 22d.
25g, a circuit board terminal 3, a ground 25h, and the like for fixing the electrode portions of the above.

On the surface of the circuit board terminal 3, FIG.
As shown in (a), a solder 4 is provided. Since the solder 4 is formed by, for example, screen printing and a molding process by heating, the solder 4 has a structure that swells in an arc shape due to the surface tension of the solder.

The electrodes 27 (see FIG. 4) of the semiconductor chip 20 and the wire connection pads 25f are connected by conductive wires 28.

A frame 30 made of resin is provided so as to surround the entire wire connection pad 25f provided around the wire connection pad 25f. The area inside the frame 30 is filled with the insulating resin 31. That is, the semiconductor chip 20, the wire 2
8. The wire connection pads 25f and the like are covered and protected by the resin 31.

As shown in FIG. 4, an external terminal 32 is provided on the main surface side of the circuit board 2 by the wiring 25a. These external terminals 32 are connected to terminals of a flexible printed circuit board connected to a read / write head.

A short flexible printed circuit board 33 is connected so as to be electrically connected to a ground 25 h provided on the back surface of the circuit board 2. The flexible printed circuit board 33 is connected to a ground line (not shown) of the guide unit 70.

The circuit board 2 has the mounting holes 7.
Holes 34a and 34b corresponding to 4a and 74b are provided.

The apparatus for manufacturing the read / write IC amplifier assembly 10 having the above structure, that is, the bonding apparatus according to the present invention for bonding the read / write IC amplifier 1 and the flexible printed wiring board 40 is shown in FIGS. The configuration is as shown in FIG.

FIG. 10 is a schematic cross-sectional view showing a main part of the FPC bonding apparatus according to the first embodiment. FIG. 11 is a part of an FPC bonding apparatus on which an integrated circuit module as a workpiece and a flexible printed circuit board are mounted. FIG. 1 is a schematic sectional view showing
2 is a schematic plan view similarly. FIG. 13 is a schematic plan view of a part of the joining apparatus showing a state where the joining portion between the circuit board terminal and the flexible printed circuit terminal is cooled and the solder is hardened.

The joining apparatus of the first embodiment is different from the conventional seed joining apparatus in that a heating mechanism for preheating the FPC terminals of the flexible printed wiring board, a cooling mechanism for forcibly cooling the solder forming the joint, and a heat tool A pressurization control mechanism for controlling the pressurizing force even during pressurization is newly added.

As shown in FIG. 10, the joining apparatus has a stage 55 on which a workpiece is placed. On the stage 55, for example, the above-described read / write IC amplifier 1 and the flexible printed wiring board 40 to be joined to the read / write IC amplifier 1 are placed as workpieces.

The stage 55 is provided with a clearance space 56 and positioning pins 57 for positioning and mounting the read / write IC amplifier 1. In the escape space 56, the frame 30, the resin 31, the chip resistors 21a, 21
b, chip capacitors 22a to 22d, etc., to prevent contact damage of these members. The positioning pin 57 is inserted into the mounting hole 74a (hole 34a) or the mounting hole 74b (hole 34b), and the read / write IC is read.
The positions of the amplifier 1 and the flexible printed circuit board 40 are determined. As a result of this positioning, as shown in FIG. 1A, each FPC terminal 41 is located immediately above each circuit board terminal 3.

At the bottom of the escape space 56, the tip of a gas supply pipe 58 of the cooling mechanism 54 is fixed in a penetrating state. The gas supply pipe 58 blows a cooling gas 60 such as nitrogen gas onto the resin 31 portion of the circuit board 2 by a cooling driving unit 59. A guide plate 53 is provided on the upper side of the stage 55 so that the cooling gas 60 wraps around to the joint by the heat tool 50. Further, the blowing amount of the gas is configured to be controllable.

In order to fix the workpiece placed on the stage 55 to the stage 55, the stage 55 is rotated around a support shaft 61, and the workpiece is moved to the stage 55 at the tip.
And a pressing plate 63 for pressing the workpiece to the stage 55 after processing.

On the other hand, above the stage 55, a heat tool 50 for moving away from and approaching (elevating and lowering) the stage 55 is arranged. A lower portion of the heat tool 50 is a heat chip 51 controlled at a predetermined temperature, and a pressing surface 52 which is a lower surface thereof is brought into contact with a back surface of the surface of the flexible printed wiring board 40 on which the FPC terminals 41 are provided. The terminal 41 is pressed against the circuit board terminal 3 of the circuit board 2.

The heat chip 51 includes a temperature control device 64
Is controlled to a predetermined temperature. The pressure applied to the workpiece of the heat tool 50 is controlled by a pressure control mechanism 65. The pressurizing control mechanism 65 is a type of pressurizing mechanism that pressurizes with a commonly used air cylinder, and is capable of sequentially changing the pressurizing force even during pressurization.

On the other hand, a heating mechanism 66 is provided above the stage 55. The heating mechanism 66 injects a heated heating gas 68 such as nitrogen gas from the tip of the nozzle 67 onto the workpiece. Also,
A guide plate 69 for regulating the flow of the heated gas 68 is provided above the stage 55. The blowing amount of the gas is configured to be controllable.

As a result, the FPC terminals 41 of the flexible printed wiring board 40 are preheated.

The heating mechanism 66 may be of a movable type capable of changing the direction of the nozzle 67, and the guide plate 69 may have a movable inclination.

Next, a method of manufacturing the integrated circuit assembly according to the first embodiment, that is, the circuit board terminals 3 of the read / write IC amplifier 1 and the flexible printed wiring board 40 will be described with reference to FIGS. FPC
A method of joining the terminals 41 by solder will be described.

FIG. 1 is a schematic diagram showing a method of soldering a circuit board terminal and a flexible printed circuit terminal of an integrated circuit assembly, and FIG. 14 shows a temperature profile when the circuit board terminal and the flexible printed circuit terminal are joined. It is a graph.

As shown in FIGS. 1A and 10, the read / write IC amplifier 1 is mounted on the stage 55 of the bonding apparatus.
And the flexible printed wiring board 40 is supplied in an overlapping state.

Next, the heating gas 6 is heated by the heating mechanism 66.
8 is sprayed on the flexible printed circuit board 40. As a result, the FPC terminal 41 located on the lower surface is
As shown in FIG. 4, preheating is performed to a predetermined temperature. The preheating is performed for about 20 to 60 seconds as shown in the graph of FIG. 14, and the FPC terminal 41 is heated to about 120 ° C.

Next, the heat tool 50 is lowered, and the FPC terminal 41 on the lower surface of the flexible printed circuit board 40 is mounted on the upper surface of the circuit board 2 as shown in FIGS. Press against the board terminal 3. Since the solder 4 is provided on the surface of the circuit board terminal 3, the lower surface of the FPC terminal 41 contacts the solder 4.

Since the solder 4 has a structure that rises in an arc shape as described above, when the heat tool 50 is lowered and pressurized with a large force, the FPC terminal 41 is broken by the pressing force. . Therefore, in the first embodiment, pressurization is performed a plurality of times. For example, pressurization is performed twice: first pressurization A and final pressurization B.

That is, the initial pressurization is set to a pressure that is the smallest and that is smaller than the pressure at which the FPC terminal 41 is damaged. For example, a pressure of about 0.5 kg / cm ² is applied to the FPC terminal 41 formed by etching a copper foil having a thickness of 35 μm. The time of the first pressurization A is a state in which the softening and melting of the solder 4 proceeds to such an extent that the FPC terminal 41 is not cracked even at a pressure of the final pressurization B, for example, about 1 to ² kg / cm ^2. , For about 0.1 to 0.5 seconds.

Next, the heat tool 50 has a pressure of 1 to
The pressure is increased to about 2 kg / cm ² and the process proceeds to the final stage of pressurization B. In this state, since the solder 4 on the surface of the circuit board terminal 3 of the circuit board 2 is softened and melted, no bending stress is generated in the FPC terminal 41 even if the pressing force by the heat tool 50 is increased. No damage will occur.

FIG. 1B is a view showing a state in which the pressing surface 52 of the heat chip 51 of the heat tool 50 is in contact with the flexible printed wiring board 40, and a state in which the first pressing A is performed. . FIGS. 1C and 11 show a state in which the FPC terminal 41 and the circuit board terminal 3 have entered the pressure B at the final stage by the heat chip 51.

The heat chip 51 may be set at a constant temperature or may be variable. Then, as shown in the graph of FIG. 14, after about 4 to 8 seconds have elapsed since the pressurization by the heat chip 51 was started, FIG.
As shown in (d), the cooling mechanism 54 operates, and the joining portion is cooled by the cooling gas 60. As a result, even when the heat chip 51 is under pressure,
The solder 4 between the C terminal 41 and the circuit board terminal 3 is hardened. Therefore, even when the heat tool 50 is raised, the thickness of the solder 4 for connecting the circuit board terminal 3 and the FPC terminal 41 always becomes constant based on the pressing force of the final stage pressing B. High reliability.

The time of 4 to 8 seconds from the start of pressurization by the heat chip 51 to the start of cooling is the main heat treatment, and the heat chip 51 rises from the main heat treatment and separates from the flexible printed circuit board 40. The time up to this is the cooling processing time.

The cooling processing time is, for example, 5 to 10
Seconds. FIG. 1E shows a state in which the heat chip 51 moves upward, and the circuit board terminal 3 of the circuit board 2 and the FPC terminal 41 of the flexible printed wiring board 40 are joined by the solder 4. 41 is not damaged, and the circuit board terminal 3 and the FPC terminal 41 are reliably connected electrically.

Thereafter, the heating mechanism 66 and the cooling mechanism 54
Is stopped, and the product is removed from the stage 55.

The heating mechanism 66 may be stopped immediately after the main heating, and may be cooled in conjunction with the cooling mechanism 54.

The pressing force, the pressurizing time, the heating temperature, the heating time, the cooling time and the like are not limited to those in the embodiment, but may be set appropriately.

According to the first embodiment, the following effects can be obtained.

(1) In a plurality of pressurizations in thermocompression bonding, the first pressurization causes the arc-shaped solder 4 to be softened and melted, and then the thermocompression bonding is performed with the pressing force further increased. Printed circuit terminals (FPC
The terminal 41 is no longer damaged, and the bonding reliability is improved.

(2) The FPC terminal 41 is not damaged,
The yield is improved, and the manufacturing cost of the read / write IC amplifier assembly 10 can be reduced.

(3) Since the FPC terminal 41 is pre-heated before pressing, when the FPC terminal 41 comes into contact with the solder 4, the solder 4 immediately starts to melt, and the solder 4 is in a hardened state. The resulting FPC terminal 41 is less likely to be damaged.

(4) After cooling and hardening the solder 4 melted in the pressing at the final stage of thermocompression bonding, the heat tool 50 is retracted (elevated) to complete thermocompression bonding. High, and the bonding reliability is high.

(5) The joining apparatus has a heating mechanism 66 for heating the workpiece, and the heating mechanism 66 can freely control the amount of the heating gas blown locally to the workpiece. Therefore, the predetermined portion can be heated accurately without waste.

(6) Since the bonding device is configured so that the pressing force of the thermocompression bonding can be freely controlled, the pressing force can be appropriately selected, and the breakage of the FPC terminal 41 in the first pressing can be prevented. .

(7) According to (1) to (6), the circuit board terminals 3 of the integrated circuit module 1 constituting the read / write IC amplifier and the FPC terminals 41 of the flexible printed wiring board 40 are soldered by thermocompression. In the case of joining, after the FPC terminal 41 is preheated by the heating mechanism 66, the heat tool 50 first presses the FPC terminal 41 with a pressing force that does not damage the FPC terminal 41 to melt the solder 4, and then increases the pressing force to increase the FPC terminal 41. And the circuit board terminals 3 are well wetted with the solder 4, the solder 4 is hardened by the cooling mechanism 54 in the pressurized state, and then the heat tool 50 is retracted to complete the thermocompression bonding, thereby damaging the FPC terminals 41. A highly reliable joining can be performed without the need. Therefore, the yield of joining can be improved.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. Needless to say.

The present invention can be similarly applied to a technique for joining terminals (electrodes) between an integrated circuit module manufactured using at least a wiring board such as a circuit board and a flexible printed wiring board.

[0089]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows. (1) When a flexible printed circuit terminal of a flexible printed circuit board and a circuit board terminal provided on the circuit board of an integrated circuit module and having solder bulged in an arc shape on the surface are joined by thermocompression, pressure is applied by a heat tool. A plurality of times, in the first pressurization, the pressurizing force is reduced so that the flexible printed circuit terminal is not damaged, and the solder is softened and melted. By performing the solder joining of the terminals, the breakage of the flexible printed circuit terminals can be prevented, the reliability of the joining can be improved, and the yield can be improved.

(2) The solder melted in the final stage of press-fitting of the thermocompression bonding is cooled and hardened, and then the heat tool is retracted to complete the thermocompression bonding. Will be higher.

(3) When a read / write IC amplifier assembly for a hard disk drive is manufactured by the method of the present invention, a circuit board terminal of a circuit board of an integrated circuit module constituting the read / write IC amplifier and a flexible printed circuit The flexible printed circuit terminals of the wiring board can be joined with good reproducibility without damaging the flexible printed circuit terminals, thereby improving the reliability of the read / write IC amplifier assembly and reducing the manufacturing cost. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a method of soldering a circuit board terminal and a flexible printed circuit terminal of an integrated circuit assembly according to an embodiment (Embodiment 1) of the present invention.

FIG. 2 is a plan view of the integrated circuit assembly according to the first embodiment.

FIG. 3 is a front view of the integrated circuit assembly according to the first embodiment.

FIG. 4 is a plan view of an integrated circuit module included in the integrated circuit assembly according to the first embodiment.

FIG. 5 is a bottom view of the integrated circuit module.

FIG. 6 is a side view of the integrated circuit module.

FIG. 7 is an enlarged sectional view showing a part of the integrated circuit module.

FIG. 8 is an enlarged cross-sectional view showing a part of a flexible printed circuit board that forms the integrated circuit assembly according to the first embodiment.

FIG. 9 is a schematic diagram illustrating a part of the integrated circuit assembly according to the first embodiment.

FIG. 10 is a schematic cross-sectional view illustrating a main part of a bonding apparatus used for manufacturing the integrated circuit assembly according to the first embodiment.

FIG. 11 is a schematic cross-sectional view showing a part of a bonding apparatus on which an integrated circuit module as a workpiece and a flexible printed circuit board are mounted.

FIG. 12 is a schematic plan view showing a part of a bonding apparatus on which an integrated circuit module and a flexible printed circuit board are mounted.

FIG. 13 is a schematic plan view of a part of the bonding apparatus showing a state where a bonding part between the circuit board terminal and the flexible printed circuit terminal is cooled and the solder is hardened.

FIG. 14 is a graph showing a temperature profile when a circuit board terminal and a flexible printed circuit terminal are joined.

FIG. 15 is a schematic view showing a method of soldering a circuit board terminal and a flexible printed circuit terminal using a conventional FPC bonding apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Integrated circuit module (Read / Write IC amplifier), 2 ... Circuit board, 2b ... Back surface, 2a ... Main surface, 3 ... Circuit board terminal, 4 ... Solder, 10 ... Integrated circuit assembly (Read / Write IC amplifier assembly) , 20 ... semiconductor chip, 21a, 21b ... chip resistor, 22a-22d ...
Chip capacitor, 23: metal plate, 24a, 24b: resin film, 25a, 25b: wiring, 25e: mounting pad, 25f: wire connection pad, 25g: electrode fixing pad, 25h: ground, 26a, 26b: solder resist, 27 ... Electrode, 28 ... Wire, 30 ... Frame, 31 ... Resin, 32 ... External terminal, 33 ... Flexible printed circuit board, 34a, 34b ... Hole, 40 ... Flexible printed circuit board, 40a ... Main surface, 40b ... Back surface, 41 ... FP
C terminals, 42a to 42c: reinforcing plate, 43: base film, 44: wiring, 45: cover film, 46: wing cut, 47: joint, 50: heat tool, 51 ...
Heat chip, 52 ... Pressing surface, 53 ... Guide plate, 54 ...
Cooling mechanism, 55 stage, 56 escape space, 57 positioning pin, 58 gas supply pipe, 59 cooling drive unit, 6
0 ... cooling gas, 61 ... support shaft, 62 ... holding, 63 ... holding plate, 64 ... temperature control device, 65 ... pressure control mechanism, 66
... Heating mechanism, 67 nozzle, 68 heated gas, 69 guide plate, 70 guide section, 71 linking section, 72 connector, 73 adhesive, 74a-74e mounting hole.

Claims (10)

[Claims] 1. A circuit board terminal provided on a circuit board of an integrated circuit module and having a solder raised in an arc shape on a surface thereof and a flexible printed circuit terminal provided on a flexible printed wiring board by melting the solder by thermocompression bonding. A method of manufacturing an integrated circuit assembly by connecting, wherein the pressurization at the time of thermocompression bonding is performed by changing the pressing force a plurality of times. 2. A circuit board terminal provided on a circuit board of an integrated circuit module and having solder raised in an arc shape on a surface thereof and a flexible printed circuit terminal provided on a flexible printed wiring board by melting the solder by thermocompression bonding. A method of manufacturing an integrated circuit assembly by connecting, wherein the pressurization during the thermocompression bonding is performed by changing the pressurizing force a plurality of times, and the flexible printed circuit terminal is preheated before the pressurization. Manufacturing method of an integrated circuit assembly. 3. The method according to claim 1, wherein the molten solder is cooled and hardened in the final stage of pressurization, and then the pressurization is terminated in a state where the solder is hardened. 5. The method for manufacturing an integrated circuit assembly according to claim 1. 4. The method for manufacturing an integrated circuit assembly according to claim 2, wherein said flexible printed circuit terminal is preheated by blowing heated gas. 5. The pressure application method according to claim 1, wherein the plurality of pressurizations are set to have a minimum initial pressure and a pressure lower than a pressure at which the flexible printed circuit terminal is damaged. Item 5. The method for manufacturing an integrated circuit assembly according to any one of items 4. 6. A read / write I of a hard disk drive.
Manufacturing a read / write IC amplifier assembly by bonding the circuit board terminals provided on the circuit board of the integrated circuit module constituting the C amplifier and the flexible printed circuit terminals provided on the flexible printed circuit board by the thermocompression bonding. 6. The method according to claim 1, wherein:
A method for manufacturing an integrated circuit assembly according to any one of the preceding claims. 7. A bonding apparatus comprising: a stage; and a heat tool that moves toward and away from the stage and pressurizes and heats a workpiece placed on the stage, wherein A heating mechanism for heating the workpiece;
A joining device, wherein a cooling mechanism for cooling a workpiece on the stage is provided. 8. The bonding apparatus according to claim 6, wherein the heating mechanism and the cooling mechanism are configured to blow gas onto the workpiece. 9. The joining apparatus according to claim 8, wherein the blowing amount of the gas is configured to be controllable. 10. The bonding apparatus according to claim 7, wherein a pressure of the heat tool is controllable.