JP3109757B2 - Connection method between tape carrier package and circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package in which an LSI chip is connected to a tape film by TAB (tape automated bonding) technology, that is, a tape carrier package (hereinafter, also referred to as TCP).
In particular, the present invention relates to a method for connecting a TCP and a circuit board suitable for performing outer lead bonding in a short time and obtaining high-strength connection.

[0002]

2. Description of the Related Art Conventionally, as a method of the outer lead bonding, it has been general practice to use a heating tool and to perform thermocompression bonding using a solder or an anisotropic conductive film for connection. FIG. 8 shows a liquid crystal display substrate (hereinafter, LC
5), an adhesive anisotropic conductive film is adhered on 5), a lead portion of TCP1 is overlapped thereon, and the overlapped connection portion is used by using a heater head 70 for bonding with a heater 71 attached. Pressurize and heat
It is a perspective view which shows the state which carries out thermocompression bonding. In this case, T
Since the tape film in CP1 is generally based on polyimide, it is necessary to melt the anisotropic conductive film from the viewpoint of thermal conductivity and to reduce the temperature of about 130 which is necessary for the connection portion to be welded.
It takes 15 to 20 seconds to reach a temperature of about ° C. For this reason, once the positioning of the leads of the connection portion is performed, a plurality of (for example, about 10) TCP1s are temporarily connected only by pressing at room temperature using the adhesive force of the anisotropic conductive film, and then the next step is performed. And heat them to the above temperature
A two-stage connection method in which main connection is performed by applying pressure has been put to practical use.

Further, a lead made of copper foil in TCP1 and a polyimide-based tape for bonding the copper foil are used.
Since the film has a different thermal expansion coefficient from that of the film, the connected lead portion is warped due to thermal deformation, and has a problem that a foot of the lead is lifted or a contact between the leads occurs. In order to solve such a problem, the connecting portion positioned with the anisotropic conductive film interposed therebetween is separately provided with a pressing means comprising a holding rod and a heating means using an infrared lamp as a heat source. An outer lead bonding method has been proposed in which an anisotropic conductive film is heated, melted and solidified, and then the pressure is released (see, for example, Japanese Patent Application Laid-Open No.
-131592).

On the other hand, unlike heating by heat conduction through a tape or film using the heater head, ultrasonic vibration is used as an energy source for heating and melting the anisotropic conductive film, and short-time bonding is performed. An outer lead bonding apparatus has been proposed which enables the formation of thermal deformation at a connection portion and prevents the occurrence of thermal deformation (for example, JP-A-63-262894).

[0005]

SUMMARY OF THE INVENTION Among the above prior arts,
The bonding method shown in FIG. 8 is a two-stage connection of a temporary connection by pressurization at room temperature and a main connection to be heated to a temperature of about 130 ° C. and re-pressurized. There is a problem that the deformation, the pressurized state and the like are unlikely to be the same, so that a positional shift in the connecting portion is likely to occur. After the welding of the anisotropic conductive film, the connection is controlled by controlling the temperature of the heater head 70 to a temperature equal to or lower than the welding temperature of the anisotropic conductive film, and after the solidification of the welded portion is completed, the connection is completed by removing the pressure. In this case, a large number of bubbles are generated in the welded portion, and the true bonding area of the connection portion connected via the welded anisotropic conductive film is considerably reduced. For this reason, the necessary connection strength of the connection portion cannot be obtained, and there has been a problem particularly regarding stability and safety in long-term use.

Further, the above-mentioned method, in which a pressing means comprising a pressing rod and a heating means using an infrared lamp as a heat source are separately provided, comprises the steps of: In order to heat, the heating by the infrared rays is performed by a pressurizing means (in the case of the conventional technique,
Pressing rod) is used to irradiate the anisotropic conductive film on the part other than the pressurized part.
Irradiation will be performed from a position further than the length to avoid the holding rod. For this reason, it is not possible to directly irradiate the aligned connection to be bonded, and the infrared heat source must be away from the connection by a distance to avoid the presser rod, thereby lowering the heating efficiency and increasing the heating. There was a problem of prolonging the time. Further, since pressurization and heating are separate means, each means is operated separately, which is one of the causes of prolonged operation time.

Next, in the method using the ultrasonic vibration, it is said that the ultrasonic vibration is applied when the pressure reaches a set value. However, most anisotropic conductive films have metal particles inside. Is a viscoelastic polymer material in which is dispersed, and usually requires a melting temperature of 150 to 180 ° C. That is, even if the anisotropic conductive film made of a rubber material (resin material) is pressed and vibrated while being sandwiched between the TCP and the LCD, the anisotropic conductive film absorbs the vibration. Therefore, it is extremely difficult to raise the connection to the predetermined temperature. Furthermore, by minimizing the pitch between terminals, by applying pressure and applying ultrasonic vibration,
There is an undesirable problem that the leads of the TCP and the leads of the LCD come into contact with each other.

The present invention has been made in view of the above-mentioned problems of the prior art,
An object of the present invention is to provide a method of connecting a TCP and a circuit board, which can perform outer lead bonding in a short time and can obtain high connection strength.

[0009]

According to the present invention, a tape carrier package is mounted on a circuit board via an anisotropic conductive film, and the two leads are connected by thermocompression bonding. The method for connecting a tape carrier package to a circuit board includes: (1) adsorbing the tape carrier package before being mounted on the circuit board to the pressure / heating block for thermocompression bonding of the two, and (2) adsorbing the tape carrier. The package is preheated to a preset temperature by a heater built in the pressurizing / heating block and mounted on a circuit board preheated by the heater or another heater. (3) The mounted tape carrier package Two, one
So that the end side is located on the pressing surface of the pressing / heating block.
The built in pressure and heat block, the other end side is irradiating infrared rays to be output through the connected bundle of glass fibers to the infrared generating device as illumination light, obtained by (4) the irradiation (5) Pressing the positioning unit with the pressurizing / heating block and simultaneously pressing / heating infrared rays for heating the positioning unit. (6) After the anisotropic conductive film is melted under the pressurized state, the infrared rays are cut off and cold air is blown to the melted portion. (7) After the curing, the pressure / heating block is removed to release the pressurized state.

The mounting of the tape carrier package on the circuit board is preferably performed on a circuit board preheated to a set temperature lower than the melting temperature of the anisotropic conductive film. Irradiation of infrared light outputted through the glass fiber is desirably performed on a contact surface between the pressure / heating block and the tape carrier package with one end of the glass fiber positioned on the pressing surface of the pressure / heating block.

Further, it is preferable that the irradiation of the infrared ray for heating the positioning portion is performed through a coating material that absorbs the infrared ray according to the peak of the wavelength spectrum of the infrared ray. And the coating material absorbing the infrared rays,
A method of coating the surface of the tape carrier package to be pressed / heated, a method of coating the lead portion of the circuit board and a peripheral portion thereof, a method of coating the surface of the anisotropic conductive film, or a method thereof. It is desirable to combine them, and a configuration may be adopted in which the coating material that absorbs the infrared ray is blended inside the anisotropic conductive film.

[0012]

[Function] With the above configuration, the pressure and pressure for thermocompression bonding can be reduced.
The TCP adsorbed on the heating block has a TC
Until P is mounted on the circuit board and irradiated with infrared rays for thermocompression bonding, it is preheated to a set temperature by a heater built in the pressurizing / heating block. On the other hand, the circuit board mounted on the support is also preheated to a set temperature by a heater or another heater built in the pressurizing / heating block or by warm air in parallel with the preheating of TCP. In this case, the preheating set temperature is set to a temperature slightly lower than the melting temperature of the anisotropic conductive film. The TCP mounted on the circuit board is irradiated with low-output infrared rays as illumination light by a bundle of glass fibers incorporated in the pressurizing / heating block. With this irradiation, T
The image pattern between the CP and the circuit board is photographed by a camera, compared with the alignment mark, and the amount of the shift is XY.
The correction is performed via a table or the like, and the connection portion is aligned.

The aligned connecting portion is pressed from the TCP side by the pressing / heating block, and simultaneously melts the anisotropic conductive film from the glass fiber built in the pressing / heating block under the pressing. Is irradiated. Here, since the irradiation of the infrared rays is performed from the glass fiber whose end is located on the TCP pressing surface of the pressing / heating block, it is possible to directly heat the connection portion to be bonded, and the temperature of the TCP can be increased. Is raised rapidly and efficiently. The heat of the TCP whose temperature has increased is transmitted to the anisotropic conductive film, and the anisotropic conductive film can be rapidly melted in combination with the preheating of the TCP and the circuit board. Due to the melting of the anisotropic conductive film, the distance between the TCP and the circuit board is further reduced, and at the same time, the conductive particles of the anisotropic conductive film that have penetrated between the two leads are pressed to conduct the connection.

The time of the infrared irradiation for the preheating and the melting has been confirmed in advance by experiments.
The time from the start of infrared irradiation to the completion of conduction is known, and when the conduction of the connection portion is completed, the generation of infrared rays is cut off and irradiation is stopped. Then, by blowing cold air to the connection portion at the same time as the stop of the irradiation, the temperature of the connection portion can be immediately and rapidly lowered to the curing temperature. This rapid hardening prevents the lead from rising due to the warpage or undulation of the TCP. After the connection is cured, the pressurizing / heating block is removed, the pressurized state by the pressurizing / heating block is released, and the outer lead bonding is completed. , And the rapid hardening of the melted portion by cutting off the generation of infrared rays and blowing the cold air, the pressurization and heating time of the outer lead bonding is performed in a short time (for example, about 2 seconds) and with high connection strength. It becomes possible.

Further, by coating the aligned connection portion with a material that absorbs infrared rays according to the peak of the wavelength spectrum of infrared rays, the emitted infrared rays can be absorbed more efficiently. , It is possible to obtain higher thermal energy generation.

Further, by adding a coating material which absorbs infrared rays in accordance with the peak of the wavelength spectrum of infrared rays into the inside of the anisotropic conductive film, heat energy can be generated by the anisotropic conductive film itself. In addition, high thermal energy can be generated without using radiant heat generated by heating the TCP and the circuit board.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. 1 is an overall front view of the outer lead bonding apparatus, FIG. 2 is an enlarged sectional view of a portion A in FIG. 1, FIG. 3 is a view showing a state before mounting a TCP on an LCD, and FIG. FIG. 5 is an enlarged view of a connection portion between the TCP and the LCD, FIG. 6 is an external view showing an example of an LCD equipped with the TCP, and FIG. 7 is an external view of a TCP provided with a coating material at the connection portion. It is.

In FIG. 1, reference numeral 1 denotes a TCP, and 2 denotes a pressure / heating block for vacuum-sucking the TCP 1 before being mounted on the circuit board 5 and thermocompressing the sucked TCP 1 onto the circuit board 5. . 3 is a heater built in the pressurizing / heating block 2, and 4 is a bundled glass fiber also having one end built in the pressurizing / heating block 2, and the end of the glass fiber 4 is shown in FIG. As shown, it is located on the surface of the pressing / heating block 2 on which the TCP 1 is pressed. 6
Is a suction device that supports the pressure / heating block 2 and moves integrally with the pressure / heating block 2. A suction port 6 a for vacuum suction of the TCP 1 is provided at the lower end surface of the suction device 6. . Reference numeral 7 denotes an infrared ray generator to which the other end of the glass fiber 4 is connected. The infrared ray generator 7 includes a xenon lamp and the like, and is attached to the gantry 13.

Reference numeral 8 denotes a TCP 1 supply unit, and the supply unit 8
It comprises a jig 9 on which P1 is placed, a cylinder 10 for horizontally moving the jig 9, a base 11 having a rail 11 a for movably supporting the jig 9, and the like. A pin 9a for positioning the TCP 1 is fixed on the jig 9. 12 is T on the jig 9
When the CP1 is adsorbed to the pressurizing / heating block 2, the camera captures the adsorbed TCP1.

Reference numeral 14 denotes X and Z
XZ moving mechanism 14 for moving in the X direction.
Is a cylinder 16 for moving the pressurizing / heating block 2 together with the suction tool 6 in the Z direction, and the guide rail 1 for the Z direction movement.
7a, guide rails 18a, 18b for moving the block 17 in the X direction, and the guide rail 18 together with the suction tool 6 and the pressurizing / heating block 2
a, a ball screw 19 for moving in the X direction along 18b,
A motor 20 for rotating the ball screw 19 and the like
And is arranged on a frame 15 fixed to.
Reference numeral 17b denotes a nut fixed to the block 17 and fitted to the ball screw 19.

Reference numeral 21 denotes an XY table for positioning the LCD 5 in the X and Y directions.
Support base 22 for supporting the connection with CP1, ball screw 2
An X table 24 moves in the X direction by the rotation of 3, and a Y table 26 provided on the X table 24 that moves in the Y direction by the rotation of the ball screw 25, and is arranged on the gantry 13. The LCD 5 is a Y table 26
It is placed on the table 27 provided on the upper side, and at this time, the upper surface of the table 27 and the upper surface of the support table 22 are configured to be on the same horizontal plane.

Next, a method of connecting the TCP 1 and the LCD 5 will be described. First, the TCP 1 is placed on the jig 9. In this case, the TCP 1 is provided with positioning reference holes 28 and 29 as shown in FIG.
Positioning is performed by inserting the pins 9a into 8, 29. Next, the cylinder 10 is extended to make the TCP 1 face the camera 12. Next, the suction tool 6 is moved onto the TCP 1 via the XZ moving mechanism together with the pressurizing / heating block 2 to vacuum-suction the TCP 1. The adsorbed TCP
1 is photographed by the camera 12, and the shift amount between the video pattern and the reference alignment pattern is calculated by an arithmetic unit (not shown). This shift amount is sent to the XY table 21 as a position correction value, and the direction in which the position of the LCD 5 is adjusted to the TCP 1, that is, X,
An X table 2 is provided so as to correct the deviation amount in each direction of Y and θ.
4, each motor of the Y table 26 is driven. Then,
The suction tool 6 descends, and the TCP 1 that is being sucked is displayed on the LCD 5.
Mounted on the top of In this case, as shown in FIG. 4, an anisotropic conductive film 30 is adhered to the lower surface of the TCP 1 including the tape film 1a and the lead 1b,
The anisotropic conductive film 30 is formed on the substrate 5 forming the LCD 5.
a on the lead 5b.

The TCP 1 mounted on the LCD 5 is a bundle of glass fibers 4 built in the pressure / heating block 2.
Irradiates low-output infrared light as illumination light. With this irradiation, the image pattern of the TCP 1 and the LCD 5 at the connection portion is photographed by the camera 12 or another camera, compared with the alignment mark, and the shift amount is XY.
The correction is made via the table 21 and the final alignment of the connection portion is performed.

On the other hand, during the handling, positioning, etc., from the time of the suction to the time when the TCP 1 is mounted on the LCD 5 and irradiated with infrared rays for thermocompression bonding, as shown in FIG. Heater 3 built in block 2
Is preheated to a set temperature (about 100 ° C.). The preheating time is, for example, 5 to 7 seconds. On the other hand, the LCD 5 placed on the support base 22 is also preheated to the set temperature by the heater 3 or another heater built in the pressurizing / heating block 2 or by the warm air in parallel with the preheating of the TCP 1. You. In this case, the preheating set temperature is set to a temperature slightly lower than the melting temperature (150 ° C. to 180 ° C.) of the anisotropic conductive film.

The aligned connection portion is pressurized in the direction of the arrow from the TCP 1 side by the pressurizing / heating block 2 as shown in FIG. Infrared rays for melting the anisotropic conductive film 30 are irradiated from the tip of the glass fiber 4. In this case, since the irradiation of the infrared rays is performed by positioning the end of the glass fiber 4 on the TCP pressing surface of the pressing / heating block 2, the tape / film 1a of the TCP 1 to be bonded is directly heated, and FIG. As shown, the temperature can be increased rapidly, for example, in about 2 seconds. The heat absorbed by the tape film 1a due to the rapid rise in temperature is transmitted to the anisotropic conductive film 30 via the lead 1b, and is combined with the preheating of the TCP 1 and the LCD 5 to cause the anisotropic conductive film 30 to be heated. Melts rapidly.
TCP1 and LCD by melting anisotropic conductive film 30
5, the conductive particles in the anisotropic conductive film 30 which have penetrated between the leads 1b and 5b are pressed together to conduct the connection, and the anisotropic conductive melted in the gap between them. The film 30 is filled.

After the conduction of the connection portion is completed, it is necessary to cure the molten anisotropic conductive film 30 in order to prevent the lead 1b from floating due to warpage or undulation of the TCP 1. For this reason, when the conduction of the connecting portion is completed, the generation of infrared rays is cut off to stop the irradiation, and at the same time, the cool air is blown to the connecting portion. The time required for the infrared rays to be cut off and cooled by the cool air is pre-heated for the TCP 1 and the LCD 5 and the time required for the infrared irradiation for melting the anisotropic conductive film 30 is confirmed in advance by experiments. Is known, it is possible to perform the operation continuously and instantly after the conduction is reliably completed. By the cooling, the temperature of the connection portion is reduced as shown in FIG.
As shown in (1), it becomes possible to immediately lower the curing temperature to about 100 ° C. in about 1 second after the infrared rays are cut off. This rapid curing can reliably prevent the lead 1b of the TCP 1 from rising.

After the connection is hardened, the pressurizing / heating block 2 is removed, and the pressurized state by the pressurizing / heating block 2 is released to complete the outer lead bonding. A connection with a high connection strength can be made in about 3 seconds, and also in a short time of about 10 seconds or less, which is 1/2 or less as compared with the related art, from the start of the preheating to the completion of the outer lead bonding.

At the time of the connection, as shown in FIG. 7, the connection portion to be bonded is coated with a coating material 27 made of, for example, a black carbon-based material which absorbs infrared rays in advance according to the peak of the wavelength spectrum of the infrared rays. Thereby, absorption of the irradiated infrared rays is performed more efficiently, and high heat energy is generated. Therefore, melting of the anisotropic conductive film 30 does not increase the lamp output in the infrared ray generating device 7. Can be performed in a shorter time. Here, the coating material 27 may be formed in a black film shape. And, the coating is a TCP shown in FIG.
In addition to 1, the same effect as described above can be obtained when the method is applied to any of the leads 5b of the LCD 5 and its peripheral portion, the surface of the anisotropic conductive film 30, and the like, or may be used in combination.

Further, by blending the coating material 27 inside the anisotropic conductive film 30, heat energy can be generated by the anisotropic conductive film 30 itself, so that the TCP 1 or the LCD 5 is heated. Even without using radiant heat, high heat energy can be generated, and the anisotropic conductive film 30 can be melted in a shorter time.

In the above embodiment, the connection target of the TCP 1 has been described as the LCD 5, but it is needless to say that the connection can be made to other circuit boards in the same manner as described above.

[0031]

As described above, according to the present invention, when the TCP is mounted on the circuit board, the outer lead bonding can be performed in a short time and the high connection strength can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall front view of an outer lead bonding apparatus according to one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a portion A in FIG.

FIG. 3 is a diagram showing a state before a TCP is mounted on an LCD.

FIG. 4 is an enlarged view of a connection portion between a TCP and an LCD.

FIG. 5 is a graph showing a relationship between time and temperature at the time of connection according to the present invention.

FIG. 6 is an external view showing an example of an LCD equipped with TCP.

FIG. 7 is a TC of the present invention in which a coating material is provided on a connection portion.
It is an external view of P.

FIG. 8 is a view showing a thermocompression bonding state using a conventional heater.

[Explanation of symbols]

1 ... TCP, 2 ... Pressure / heating block, 3 ... Heater,
4 ... Glass fiber, 5 ... LCD, 6 ... Adsorber, 7 ... Infrared ray generator, 8 ... TCP supply unit, 9 ... Jig, 12 ...
Camera, 14 ... XZ moving mechanism, 21 ... XY table, 2
7 ... Coating material, 28, 29 ... Reference hole for positioning, 30 ... Anisotropic conductive film.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Tabe 3300 Hayano Mobara-shi, Chiba Pref., Hitachi, Ltd.Mobara Plant, Hitachi, Ltd. 56) References JP-A-58-137222 (JP, A) JP-A-61-131539 (JP, A) JP-A-3-38846 (JP, A) JP-A-57-173952 (JP, A) Hei 3-112938 (JP, U) Japanese Utility Model Hei 5-38881 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/603 H01L 21/60 311

Claims (8)

(57) [Claims] 1. A method for connecting a tape carrier package to a circuit board, wherein the tape carrier package is mounted on a circuit board via an anisotropic conductive film, and the leads of the tape carrier package are connected by thermocompression bonding. The tape carrier package before being mounted on the circuit board is adsorbed to both of the pressure / heating blocks for thermocompression bonding, and (2) the adsorbed tape carrier package is previously adsorbed by a heater built in the pressure / heating block. with preheated to the set temperature and mounted on a circuit board which is preheated by the heater or other heater, a tape carrier package mounted (3) the one
So that the end side is located on the pressing surface of the pressing / heating block.
The built in pressure and heat block, the other end side is irradiating infrared rays to be output through the connected bundle of glass fibers to the infrared generating device as illumination light, obtained by (4) the irradiation (5) Pressing the positioning unit with the pressurizing / heating block and simultaneously pressing / heating infrared rays for heating the positioning unit. (6) After the anisotropic conductive film is melted under the pressurized state, the infrared rays are cut off and cold air is blown to the melted portion. (7) After the curing, the pressure / heating block is removed to release the pressurized state, and the tape carrier package and the circuit board are characterized in that: Connection method. 2. The tape carrier package according to claim 1, wherein the mounting of the tape carrier package on the circuit board is performed on a circuit board preheated to a set temperature lower than a melting temperature of the anisotropic conductive film. How to connect to the circuit board. 3. Irradiation of infrared light output through the glass fiber causes one end of the glass fiber to be compressed and pressed.
3. The method of connecting a tape carrier package to a circuit board according to claim 1, wherein the connection is performed at a contact surface between the pressure / heating block and the tape carrier package by being positioned on a pressing surface of the heating block. 4. The tape carrier according to claim 1, wherein the irradiation of the infrared ray for heating the positioning portion is performed through a coating material that absorbs the infrared ray according to the peak of the wavelength spectrum of the infrared ray. Connection method between package and circuit board. 5. The method for connecting a tape carrier package to a circuit board according to claim 4, wherein the coating material for absorbing the infrared rays is coated on the surface of the tape carrier package to be pressed and heated. 6. The method for connecting a tape carrier package to a circuit board according to claim 4, wherein the coating material for absorbing the infrared rays is coated on a lead portion of the circuit board and a peripheral portion thereof. 7. The method for connecting a tape carrier package to a circuit board according to claim 4, wherein the coating material absorbing the infrared rays is coated on a surface of the anisotropic conductive film. 8. The method for connecting a tape carrier package to a circuit board according to claim 1, wherein the anisotropic conductive film contains a coating material for absorbing the infrared ray.