阅读说明：本技术 Cof封装方法 (COF packaging method ) 是由 奚耀鑫 于 2019-10-29 设计创作，主要内容包括：本发明揭示了一种COF封装方法,所述方法包括：S1、提供一待封装柔性线路基板,在所述柔性线路基板的线路面上形成若干个第一引脚；以及提供一待封装芯片,并在封装芯片上形成若干个第二引脚；S2、使得并保持柔性线路基板的线路面始终朝下放置,以及使得并保持封装芯片设置有配合第一引脚的第二引脚的面始终朝上放置,并使得柔性线路基板和封装芯片上互相配合的第一引脚和第二引脚相对设置；S3、对柔性线路基板施加一自上至下的压力,和/或对所述封装芯片施加一自下至上的压力,同时高温加热以使得第一引脚和第二引脚采用融合共晶的方式进行焊接。本发明提升产品良率及稳定度。(The invention discloses an COF packaging method which comprises the steps of S1, providing a flexible circuit substrate to be packaged, forming a plurality of pins on the circuit surface of the flexible circuit substrate, providing chips to be packaged, forming a plurality of second pins on the packaged chips, S2, enabling the circuit surface of the flexible circuit substrate to be placed downwards all the time, enabling the surfaces of the packaged chips, which are provided with the second pins matched with the pins, to be placed upwards all the time, enabling the pins and the second pins matched with each other on the flexible circuit substrate and the packaged chips to be arranged oppositely, S3, applying pressure from top to bottom to the flexible circuit substrate and/or pressure from bottom to top to the packaged chips, and heating at high temperature to enable the pins and the second pins to be welded in a eutectic fusion mode.)

A COF packaging method of , comprising:

s1, providing flexible circuit substrates to be packaged, and forming a plurality of pins on the circuit surfaces of the flexible circuit substrates, providing chips to be packaged, and forming a plurality of second pins on the packaged chips;

s2, enabling and keeping the circuit surface of the flexible circuit substrate to be placed downwards all the time, enabling and keeping the surface of the packaging chip provided with the second pin matched with the pin to be placed upwards all the time, and enabling the pin and the second pin matched with each other on the flexible circuit substrate and the packaging chip to be arranged oppositely;

and S3, applying pressure from top to bottom to the flexible circuit substrate and/or applying pressure from bottom to top to the packaged chip, and simultaneously heating at high temperature to enable the pin and the second pin to be welded in a eutectic fusion mode.

2. The COF packaging method according to claim 1, wherein the step S3 specifically comprises:

and keeping the position of the flexible circuit substrate fixed, applying pressure from bottom to top to the packaged chip, and simultaneously heating the packaged chip at high temperature to enable the pin and the second pin to be welded in a mode of eutectic fusion.

3. The COF packaging method of claim 2, further comprising:

providing a hot-pressing head under the packaged chip, and arranging the adsorption surface of the hot-pressing head upwards;

adsorbing the surface of the packaged chip without the second pin through the adsorption surface of the hot-pressing head;

the thermal head is driven to move to provide a bottom-up pressure to the packaged chips while the packaged chips are heated at a high temperature.

4. The COF packaging method according to claim 3, wherein after the step S3, the method further comprises: and releasing the adsorption force of the adsorption surface to enable the hot-pressing head to be separated from the packaged chip and removed.

5. The method of claim 1, further comprising providing a base platform on top of the flexible circuit substrate, and fixing the side of the flexible circuit substrate not provided with the th lead on the base platform.

6. The COF packaging process of claim 5, wherein the base platform is made of a transparent and temperature resistant material.

7. The COF packaging process of claim 6, wherein the pedestal platform is made of quartz.

8. The method of claim 5, further comprising providing a CCD imager device on the base platform.

9. The COF packaging method of claim 8, wherein the step S2 further comprises observing the flexible circuit substrate through a CCD imaging device, monitoring whether the th pin on the flexible circuit substrate is disposed opposite to the second pin on the packaged chip, if yes, proceeding to the next step , if no, adjusting the flexible circuit substrate and/or the packaged chip, and proceeding to the next step when the th pin and the second pin are disposed opposite to each other.

10. The COF packaging method of claim 1, wherein after step S3, the method further comprises: performing plastic packaging between the flexible circuit substrate and the packaging chip to form a semi-packaging body; and cutting the half-package body to form a single COF packaging structure.

Technical Field

The invention belongs to the field of semiconductor manufacturing, and particularly relates to COF packaging methods.

Background

With the increase of the density of integrated circuits, chip packaging technologies are becoming more and more diversified, and since a flip chip technology (FC for short) has advantages of reducing the chip packaging volume and shortening the signal transmission path, is widely applied in the field of chip packaging.

The flip chip packaging technique is to bond a bare die (bardie) with a substrate in a surface-down manner. The specific process is to form bumps (bump) on the surface of the chip, and to electrically and mechanically connect the bumps on the chip with the circuit on the circuit substrate by using the techniques such as thermocompression bonding, and then to electrically connect the chip with the external electronic device through the internal circuit of the circuit substrate.

In the field of liquid crystal display circuit packaging, currently, tape Carrier On Film (COF) is mostly used, and this kind of flip chip packaging technology uses a flexible circuit substrate as a carrier for packaging a chip, that is, uses the flexible circuit substrate as the above-mentioned circuit substrate, and then uses a thermal compression technology to bond a bump on the chip with an inner pin of the flexible circuit substrate.

Disclosure of Invention

The present invention aims to provide COF packaging methods for solving the above technical problems.

In order to achieve the above object, the embodiment of the invention provides COF packaging methods, which include S1, providing flexible circuit substrate to be packaged, forming a plurality of -th pins on the circuit surface of the flexible circuit substrate, providing chip to be packaged, and forming a plurality of second pins on the packaged chip;

s2, enabling and keeping the circuit surface of the flexible circuit substrate to be placed downwards all the time, enabling and keeping the surface of the packaging chip provided with the second pin matched with the pin to be placed upwards all the time, and enabling the pin and the second pin matched with each other on the flexible circuit substrate and the packaging chip to be arranged oppositely;

and S3, applying pressure from top to bottom to the flexible circuit substrate and/or applying pressure from bottom to top to the packaged chip, and simultaneously heating at high temperature to enable the pin and the second pin to be welded in a eutectic fusion mode.

As a further improvement of the embodiment of the present invention, step S3 specifically includes:

and keeping the position of the flexible circuit substrate fixed, applying pressure from bottom to top to the packaged chip, and simultaneously heating the packaged chip at high temperature to enable the pin and the second pin to be welded in a mode of eutectic fusion.

As a further improvement of the embodiment of the invention, the method further comprises providing a hot press head under the packaged chip, placing the suction surface of the hot press head upward, sucking the surface of the packaged chip without the second leads through the suction surface of the hot press head, and driving the hot press head to move to provide a bottom-to-top pressure to the packaged chip while heating the packaged chip at a high temperature.

As a further improvement of the embodiment of the invention, after step S3, the method further includes releasing the suction force of the suction surface, and detaching and removing the thermal head from the packaged chip.

As a further improvement of the embodiment of the invention, the method further includes providing a base platform above the flexible circuit substrate, and securing a face of the flexible circuit substrate not provided with the th pin to the base platform.

In a further improvement of the embodiment of the present invention, the base platform is constructed of a transparent, high temperature resistant material.

In a further improvement of the embodiment of the present invention, the susceptor platform is constructed of quartz.

As a further improvement of the embodiment of the invention, the method further includes providing a CCD imager above the base platform.

As a further improvement of the embodiment of the present invention, step S2 further includes observing the flexible circuit substrate through a CCD imaging device, monitoring whether the th pin on the flexible circuit substrate is disposed opposite to the second pin on the package chip, if yes, continuing to perform the next steps, if no, adjusting the flexible circuit substrate and/or the package chip, and performing the next steps when the th pin and the second pin are disposed opposite to each other.

As a further improvement of the embodiment of the present invention, after step S3, the method further includes performing plastic encapsulation between the flexible circuit substrate and the packaged chip to form a half package, and cutting the half package to form a single COF package structure.

Compared with the prior art, the COF packaging method provided by the invention has the advantages that the flexible circuit substrate and the packaged chip are subjected to position exchange and are turned over, and then packaging is carried out, so that Particle generated by movement of equipment above the flexible circuit substrate can be prevented from falling onto pins of the flexible circuit substrate and/or among the pins in the packaging process, and the yield and stability of products are improved.

Drawings

Fig. 1 is a schematic flow chart of a COF packaging method according to an embodiment of the present invention;

fig. 2 is a schematic view of a COF package according to the present invention.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

It should be noted that, the term "position" used herein refers to an absolute position in space, where upper means "upper" and lower means "lower" and "lower" are not interchangeable. The terms spatial absolute position, in the sense that the structure is oriented as shown in the drawings during use or operation, are not intended to be inverted or interchanged in practice.

Referring to fig. 1 and 2, an embodiment of of the present invention provides COF packaging methods, including:

s1, providing to-be-packaged flexible circuit substrate 10, forming a plurality of pins 11 on the circuit surface of the flexible circuit substrate 10, providing to-be-packaged chip 20, and forming a plurality of second pins 12 on the packaged chip 20;

s2, enabling and keeping the circuit surface of the flexible circuit substrate 10 to be placed downwards all the time, enabling and keeping the surface of the packaged chip 20 provided with the second pin 12 matched with the pin 11 to be placed upwards all the time, and enabling the pin 11 and the second pin 12 matched with each other on the flexible circuit substrate 10 and the packaged chip 20 to be arranged oppositely;

and S3, applying pressure from top to bottom to the flexible circuit substrate 10, and/or applying pressure from bottom to top to the packaged chip 20, and simultaneously heating at high temperature to enable the pin 11 and the second pin 12 to be welded in a mode of eutectic fusion.

, after the step S3, the method further includes the steps of performing plastic package between the flexible circuit substrate 10 and the package chip 20 to form a semi-package body, and cutting the semi-package body to form a single COF package structure.

In an implementation manner of the present invention, the th lead 11 is usually made of Cu (copper) with tin plated on the surface, and the second lead 12 is usually made of Au (gold), so that after the second lead 12 and the th lead 11 are abutted against each other and subjected to high temperature, the Au and the sn of the second lead 12 are melted into eutectic at high temperature, and the flexible circuit board 10 and the package chip 20 are further combined.

For step S2, the positions of the flexible circuit substrate 10 and the packaged chip 20 are exchanged and turned over based on the prior art to keep the th lead 11 always facing downward and the second lead 12 always facing upward during the packaging process.

In a specific application process, since the flexible circuit substrate 10 usually covers the packaged chip 20, when the flexible circuit substrate 10 is located above the packaged chip 20, particles generated during the movement of the device located above the packaged chip 20 will not fall onto the th pin 11 or between the th pins 11, i.e. the location and type of the device driving the movement of the two components will not affect the packaging result.

In a preferred embodiment of , step S3 includes holding the flexible circuit substrate 10 in a fixed position, applying pressure from bottom to top to the packaged chip 20, and heating the packaged chip 20 at a high temperature to solder the pin 11 and the second pin 12 in a eutectic melting manner.

In the embodiment of the invention, the thermal compression head 30 is provided under the packaged chip 20, the absorption surface 31 of the thermal compression head 30 is arranged upward, the surface of the packaged chip 20 without the second leads 12 is absorbed by the absorption surface 31 of the thermal compression head 30, the thermal compression head 30 is driven to move to provide the bottom-up pressure to the packaged chip 20 , and the packaged chip 20 is heated at high temperature.

The thermal head 30 is a well-known device in the art, and the working principle and the specific structure thereof are not further described in step , it should be noted that, in order to match the position of the packaged chip 20, in this specific embodiment, the thermal head 30 is disposed below the packaged chip 20, and meanwhile, the suction surface 31 of the thermal head 30 needs to be disposed upward to match the surface on which the second leads 12 are not disposed on the packaged chip 20.

, when the thermal head 30 is used to transfer the packaged chip 20 and provide pressure to the packaged chip 20 and raise the temperature of the packaged chip 20, after step S3, the method further includes releasing the suction force of the suction surface 31, and removing the thermal head 30 from the packaged chip 20.

With the above structure, when the thermal head 30 moves, since it is under the packaged chip 20, it is possible to further step to prevent particles generated during the movement of the thermal head 30 from falling onto the th pin 11 or between the th pins 11.

In the embodiment of the present invention, the method further comprises providing a base platform 40 above the flexible circuit substrate 10, and fixing the surface of the flexible circuit substrate 10 not provided with the th pin 11 on the base platform 40.

In the specific implementation process of the present invention, the base platform 40 also fixes the flexible circuit substrate 10 by vacuum adsorption, which is not described in detail in step .

Preferably, in the conventional process, the base platform 40 is usually made of metal or ceramic, and the whole body thereof is opaque, so that the offset condition of the leads between the flexible circuit substrate 10 and the package chip 20 cannot be monitored during the bonding process, and accordingly, the offset condition of the thermal bonding between the leads can be checked through the image system after the two are bonded and then transmitted out of the bonding region, which results in lag in the time efficiency and increase of the fraction defective due to short circuit caused by the offset.

Accordingly, in the preferred embodiment of the present invention, the susceptor table 40 is replaced by transparent and heat-resistant materials, such as quartz, for the susceptor table 40.

, the method further includes providing a CCD imaging device 50 located above the base platform 40, observing the flexible circuit substrate 10 through the CCD imaging device 50, monitoring whether the th pin 11 on the flexible circuit substrate 10 is arranged opposite to the second pin 12 on the package chip 20, if yes, continuing to perform the next step, if no, adjusting the flexible circuit substrate 10 and/or the package chip 20, and performing the next step when the th pin 11 and the second pin 12 are arranged opposite to each other.

In summary, the COF packaging method of the invention packages the flexible circuit substrate and the packaged chip after the positions of the flexible circuit substrate and the packaged chip are exchanged and turned over, so that the Particle generated by the movement of the equipment above the flexible circuit substrate can be prevented from falling onto the pins and/or between the pins of the flexible circuit substrate in the packaging process, the yield and the stability of the product can be improved, in addition, the change of the material of the base platform can visually monitor the position of the flexible circuit substrate relative to the packaged chip in the thermal bonding process, and , by additionally arranging the CCD imaging device on the side of the base platform, the deviation of the flexible circuit substrate relative to the packaged chip can be automatically and visually monitored in the thermal bonding process, the packaging quality of the product can be improved, and resources can be saved.

It should be understood that although the present description refers to embodiments, not every embodiment contains independent technical solutions, and this description is only for clarity, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can be combined appropriately to form other embodiments understood by those skilled in the art.

The -series detailed description set forth above is merely a specific description of possible embodiments of the invention and is not intended to limit the scope of the invention, which is intended to include within its scope equivalent embodiments or modifications that do not depart from the technical spirit of the invention.