CN102469693A - Flip chip packaging structure, portable communication device thereof and chip sealing process - Google Patents

Abstract

A flip-chip packaging structure and a process method for sealing a portable communication device and chip, the flip-chip packaging structure includes: a flexible substrate, a chip, a barrier layer and a sealing layer. The chip is electrically connected to the flexible substrate; the barrier layer is arranged around the chip and forms a gap with the chip; the sealing layer covers the chip, and the sealing layer fills the gap between the barrier layer and the chip, so that the chip and the flexible substrate adhere to each other. Applying this flip-chip packaging structure in a portable communication device can not only save the process cost of the existing packaging process, but also effectively improve the alignment rate of the chip during bonding and the appearance accuracy of the overall package.

Description

Flip-chip package structure and process method for portable communication device and chip encapsulation

technical field

The invention relates to a portable communication device, in particular to a portable communication device whose chip module is a flip-chip packaging structure.

Background technique

With the vigorous development of wireless communication, various communication devices and communication products have gradually played an indispensable role in the life of modern people. For example, portable communication devices have become the mainstream of the current market due to their characteristics of wireless communication and portability, especially portable mobile phones (or mobile phones).

Generally speaking, common mobile phones have an important distinguishing mark in structure, which is the Subscriber Identity Module (SIM), usually called "SIM card", which is the user ID card for storing mobile phone services. Smart card for identification data. A mobile phone can only function or make a call after installing a SIM card; in addition, the SIM card can also be used to store SMS data and phone numbers. Generally speaking, the SIM card is mainly used for the Global System for Mobile Communications (GSM) system, but compatible modules can also be used for the UE (USIM) and integrated digital Efficient Network (Integrated Digital Enhanced Network, IDEN) phone.

The SIM card is mainly provided with a chip (Integrated Circuit, IC), and consists of a central processing unit (Central Processing Unit, CPU), a read-only memory (Read-Only Memory, ROM), a random access memory (Random-Access Memory, RAM), electronic erasable programmable read-only memory (Electrically-Erasable Programmable Read-Only Memory, EEPROM) and input and output (Input/Output, I/O) and other microcircuits to form the user and mobile phone media for information exchange and connection. After the design of the chip is completed and bonded to the circuit flexible substrate, the packaging method is usually a sealing process after wire bonding (Wire Bond). A stencil is arranged around the chip, and the sealant is directly coated on the stencil to attach the chip to the circuit flexible substrate and at the same time achieve the effect of protecting the integrated circuit. However, since the thickness and quality of the sealant is actually one of the important specifications of the SIM card module, this kind of sealant process cannot achieve the effect of accurately controlling the sealant appearance in terms of the quality of the chip coating and sealant.

Secondly, when adopting the existing encapsulation process of soft film flip chip, the eutectic phase is produced by hot pressing. The temperature of this process is as high as 400°C, which will not only cause the thermal expansion effect of the extension of the flexible substrate, but also increase the alignment error during chip bonding. , the appearance accuracy and yield rate after the overall packaging are not as expected.

Therefore, in summary, how to propose a sealing process method to solve the above-mentioned existing problems and deficiencies and to have better quality is one of the important research directions in the development and evolution of the relevant fields.

Contents of the invention

In view of the above problems, the purpose of the present invention is to provide a flip-chip packaging structure suitable for portable communication device chips and a process method for chip encapsulation, so as to solve the existing problems.

The present invention proposes a chip sealing process, comprising the steps of: providing a flexible substrate; disposing a chip on the flexible substrate; forming a barrier layer around the chip, and forming a gap between the barrier layer and the chip; And covering the adhesive layer on the chip. Wherein, the sealant layer fills the gap between the barrier layer and the chip, so that the chip and the flexible substrate are adhered to each other.

The present invention also proposes a flip-chip packaging structure, including: a flexible substrate, a chip, a barrier layer and a sealant layer. Among them, the chip is electrically connected to the flexible substrate; the barrier layer is arranged around the chip and forms a gap with the chip; the sealant layer covers the chip, and the sealant layer fills the gap between the barrier layer and the chip The gap allows the chip and the flexible substrate to adhere to each other.

According to the flip-chip package structure of the present invention, the sealant layer can be formed on the chip by dispensing an epoxy resin liquid glue.

The present invention further proposes a portable communication device, which includes a main body and a flip-chip packaging structure, wherein the flip-chip packaging structure is disposed inside the main body, so that the portable communication device can perform a communication function accordingly. The flip-chip packaging structure includes: a flexible substrate, a chip, a barrier layer and a sealant layer. Among them, the chip is electrically connected to the flexible substrate; the barrier layer is arranged around the chip and forms a gap with the chip; the sealant layer covers the chip, and the sealant layer fills the gap between the barrier layer and the chip The gap allows the chip and the flexible substrate to adhere to each other.

Therefore, according to the portable communication device proposed in the present invention, and the process method of the flip-chip packaging structure and chip sealing, the gap between the chip and the chip is first formed through the barrier layer, and then the sealing layer is coated on the gap. In order to bond the chip and the flexible substrate.

The purpose of the present invention includes, under the premise of saving complicated procedures and costs of the process, effectively achieving a better alignment rate during chip bonding and an overall packaging appearance accuracy.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

Fig. 1 is a process flow chart of a chip sealing process according to an embodiment of the present invention;

2A is a schematic top view of a flip-chip package structure according to an embodiment of the present invention;

2B is a schematic side view of a flip chip package structure according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a portable communication device according to another embodiment of the present invention.

Among them, reference signs

12 electrical pins

14 contacts

202 flexible substrate

204 chips

206 barrier layer

208 sealing layer

300 subjects

302 flexible substrate

304 SIM card chip

310 flip chip package structure

Detailed ways

The detailed features and advantages of the present invention are described in detail below in the embodiments, the content of which is sufficient to enable any person skilled in the art to understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in this specification, the scope of claims and the drawings , any person skilled in the art can easily understand the related objects and advantages of the present invention.

FIG. 1 is a flow chart of a process for chip encapsulation according to an embodiment of the present invention. For the following description of the present invention, please refer to FIG. 2A and FIG. 2B together, which are respectively a top view and a side view of a flip-chip package structure according to an embodiment of the present invention.

The process method of chip encapsulation proposed by the present invention includes step S102, step S104, step S106 to step S108, each of which is to provide a flexible substrate 202 according to FIG. 2A and FIG. forming a barrier layer 206 around the chip 204 ; and covering the encapsulant layer 208 on the chip 204 .

Wherein, according to an embodiment of the present invention, the flexible substrate 202 may be but not limited to a flexible printed circuit board (Flexible Printed Circuit, FPC), and the chip 204 may be but not limited to a Subscriber Identity Module (SIM ) card communication chip. As shown in FIG. 2B , a plurality of electrical pins (pins) 12 are disposed on one side of the flexible substrate 202, and the side of the chip 204 corresponding to the flexible substrate 202 is also provided with electrical pins corresponding to the plurality of electrical pins. The contact 14 of the pin 12 to complete the electrical conduction between the two.

Wherein, the contact 14 may be a metal bump arranged on the side of the chip 204 corresponding to the flexible substrate 202, which is connected to the electrical circuit on the flexible substrate 202 through the wiring layer and the aluminum pad (not shown) on the chip 204 respectively. pin 12. Here, not only can the pressure-receiving area of the flexible substrate 202 be increased, but also the chip 204 can be easily electrically disposed on the flexible substrate 202 .

The barrier layer 206 is formed around the chip 204 and forms a gap d between the chip 204 and the chip 204 . Wherein, the width of the gap d is not intended to limit the scope of the invention, and the designer can determine the size of the gap d by himself according to the actual application situation. For example, the barrier layer 206 may be, but not limited to, a high-viscosity epoxy resin liquid encapsulant, so as to form the appearance size of the colloid.

The sealant layer 208 fills the gap d between the barrier layer 206 and the chip 204, and covers the chip 204. Here, the chip 204 and the flexible substrate 202 are adhered to each other to complete a chip on chip (Chipon Film, COF) flip-chip packaging structure. Wherein, according to an embodiment of the present invention, the sealant layer 208 may be formed by direct dispensing of low-viscosity epoxy resin liquid glue to cover the chip 204 to fill the body of the sealant 208 . Therefore, according to the flip-chip packaging structure of the embodiment of the present invention, and the process method of chip encapsulation, it uses the barrier layer 206 around the chip 204 to form a gap d between the chip 204 and the encapsulant layer 208. in the gap d, thereby not only effectively reducing the thickness of the package required for the chip 204, but also improving the appearance accuracy of the overall package structure, and ensuring that the chip 204 is bonded to the flexible substrate 202 in the subsequent high-temperature process steps The alignment rate remains good, greatly increasing its production competitiveness.

FIG. 3 is a schematic structural diagram of a portable communication device according to another embodiment of the present invention. The portable communication device may be, but not limited to, a personal mobile phone (Mobile Phone), a smart phone (Smart Phone), a personal digital assistant (Personal digital assistant, PDA), a tablet computer (Tablet PC) and other portable communication devices. For the following description, the portable communication device of the embodiment of the present invention is a personal mobile phone as the following description, however, the type of the portable communication device is not limited thereto.

The portable communication device has a main body 300 , and the main body 300 can be equipped with input/output devices such as a screen, keys, and audio transceivers on its surface, so as to facilitate the user's application and operation. There is a flip-chip package structure 310 inside the main body 300, which is composed of SIM card chip 304, flexible substrate 302 and other components, so that the portable communication device can perform its communication function. Wherein, the flexible substrate 302 , the SIM card chip 304 and the formed flip-chip package structure 310 are the same as the SIM card formed by the flip-chip package structure in the previous embodiment of the present invention, so it will not be repeated here. Therefore, to sum up, according to the flip-chip packaging structure of the embodiment of the present invention, not only can form a SIM card with communication function, but also can be applied to portable communication devices, greatly increasing its industrial applicability.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention.

Claims (9)

1. A process method for chip sealing, characterized in that, comprising: providing a flexible substrate; configuring a chip on the flexible substrate; forming a barrier layer around the chip, forming a gap between the barrier layer and the chip; and Covering the adhesive layer on the chip; Wherein, the sealant layer fills the gap between the barrier layer and the chip, so that the chip and the flexible substrate are adhered to each other. 2 . The process method of chip encapsulation according to claim 1 , wherein the flexible substrate is a flexible circuit board. 3 . 3 . The process method of chip sealing according to claim 1 , wherein the sealing layer is an epoxy resin liquid glue. 4 . 4. A flip-chip packaging structure, characterized in that it comprises: a flexible substrate; a chip electrically connected to the flexible substrate; a barrier layer disposed around the chip and forming a gap with the chip; and The sealant layer is covered on the chip, and the sealant layer fills the gap between the barrier layer and the chip, so that the chip and the flexible substrate are adhered to each other. 5. The flip chip package structure according to claim 4, wherein the flexible substrate is a flexible circuit board. 6 . The flip chip package structure according to claim 4 , wherein the sealant layer is an epoxy resin liquid glue. 7. A portable communication device, comprising: a subject; and A flip-chip packaging structure is arranged inside the main body so that the portable communication device can perform a communication function. The flip-chip packaging structure includes: a flexible substrate, a chip, a barrier layer and an adhesive layer, The chip is electrically connected to the flexible substrate; the barrier layer is arranged around the chip and forms a gap with the chip; the sealant layer covers the chip, and the sealant layer fills the barrier The gap between the layer and the chip makes the chip and the flexible substrate adhere to each other. 8. The portable communication device according to claim 7, wherein the flexible substrate is a flexible circuit board. 9. The portable communication device according to claim 7, wherein the sealant layer is an epoxy liquid glue.

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