阅读说明：本技术 基于Flip-Chip技术的小型化毫米波MMIC封装方法 (Miniaturized millimeter wave MMIC packaging method based on Flip-Chip technology ) 是由 李维勤 连全文 秦伟 邱鹏 张军 于 2020-05-12 设计创作，主要内容包括：本发明公开了一种基于Flip-Chip技术的小型化毫米波MMIC封装方法,封装流程包括：前段工艺、中段工艺、后段工艺以及测试；其中,所述前段工艺包括：背面处理、晶元切割和二光检查；所述中段工艺包括：芯片粘接、银浆固化、引线焊接和三光检查；所述后段工艺包括：注塑、激光打标、模后固化、去溢料、电镀、电镀退火和切粒。采用本发明的封装方法,能够使集成度较高的毫米波MMIC结构紧凑、系统集成度高、体积小、馈电简单、方向性高,提高了可靠度,降低了芯片能耗和成本。(The invention discloses a miniaturized millimeter wave MMIC packaging method based on Flip-Chip technology, which comprises the following steps: front-stage process, middle-stage process, back-stage process and test; wherein the front-end process comprises: back processing, wafer dicing and secondary light inspection; the middle section process comprises the following steps: chip bonding, silver paste curing, lead welding and three-light inspection; the back-end process comprises the following steps: injection molding, laser marking, post-mold curing, flash removal, electroplating annealing and grain cutting. The packaging method of the invention can make the millimeter wave MMIC with higher integration level have compact structure, high system integration level, small volume, simple feed and high directivity, improve the reliability and reduce the energy consumption and the cost of the chip.)

1. A method for packaging a miniaturized millimeter wave MMIC based on a Flip-Chip technology is characterized by comprising the following steps: the MMIC packaging process comprises the following steps: front-stage process, middle-stage process, back-stage process and test;

wherein the front-end process comprises: back processing, wafer dicing and secondary light inspection; the middle section process comprises the following steps: chip bonding, silver paste curing, lead welding and three-light inspection; the back-end process comprises the following steps: injection molding, laser marking, post-mold curing, flash removal, electroplating annealing and grain cutting;

the back surface treatment is to grind the back surface of the wafer, and the thickness of the wafer after grinding is 8-10 mils; during grinding, the front surface of the wafer is pasted with an adhesive tape to protect a front surface circuit area;

the wafer dicing process includes: the method comprises the following steps of mounting, cutting and cleaning, wherein the cleaning step is to sequentially use clean water and alcohol for cleaning;

the preparation steps of the chip bonding process comprise silver paste dispensing and bonding, and before the silver paste dispensing process, the silver paste which is preserved in a freezing mode needs to be placed at normal temperature for returning to the temperature.

2. The Flip-Chip technology-based miniaturized millimeter wave MMIC packaging method according to claim 1, characterized in that: in the silver paste curing process, the curing temperature is 175 ℃, and the curing time is 1 h.

3. The Flip-Chip technology-based miniaturized millimeter wave MMIC packaging method according to claim 1, characterized in that: the Lead welding process uses a ceramic cleaver, the interior of the ceramic cleaver is hollow, a gold wire penetrates through the middle of the ceramic cleaver, and a first welding spot and a second welding spot are respectively formed on a Pad of a chip and a Lead of a Lead Frame.

4. The Flip-Chip technology-based miniaturized millimeter wave MMIC packaging method according to claim 1, characterized in that: the injection molding step is to use epoxy resin for plastic package, and a curing agent, a modifier, a release agent, a coloring agent and/or a flame retardant are added.

5. The Flip-Chip technology-based miniaturized millimeter wave MMIC packaging method according to claim 1 or 4, characterized in that: the molding parameters of the injection molding step are as follows: forming temperature: 175 ℃ to 185 ℃, clamping pressure: 3000N-4000N, transfer pressure: 1000psi-1500psi, transfer time: 5s-15s, curing time: 60s-120 s.

6. The Flip-Chip technology-based miniaturized millimeter wave MMIC packaging method according to claim 1, characterized in that: the laser marking step is to carve characters on the front or back of the product by laser, and the carving content comprises the following steps: product name, date of manufacture and batch of manufacture.

7. The Flip-Chip technology-based miniaturized millimeter wave MMIC packaging method according to claim 1, characterized in that: the curing temperature of the post-mold curing is 175 +/-5 ℃, and the curing time is as follows: and 8 h.

Technical Field

The invention belongs to the technical field of production and manufacturing, and particularly relates to a voice-enabled bar code system.

Background

IC packaging belongs to the back-end processing procedure of semiconductor industry, which is mainly to divide the IC on the wafer processed by the front-end processing procedure (i.e. produced by wafer factory), to bond the chip, to wire, to add plastic package and to form. The finished product (package) mainly provides a lead interface, the internal electrical signal can connect the chip to the system through the pin, and the damage and corrosion of the silicon chip by external force, water, moisture, and chemicals can be avoided.

Flip chip, also known as Flip chip, deposits tin-lead balls on I/O pads, then turns the chip over and heats the chip, and utilizes the melted tin-lead balls and ceramic substrate to replace conventional wire bonding, which gradually becomes the mainstream of future packaging, and is mainly applied to high-clock CPU, GPU (graphics processor Unit), Chipset and other products. Compared with COB, the chip structure and the I/O terminals (solder balls) of the packaging form are downward, and the I/O terminals are distributed on the whole chip surface, so that the Flip chip has already reached the peak in packaging density and processing speed, and particularly, the Flip chip can be processed by adopting a means similar to SMT technology, thereby being the final direction of chip packaging technology and high-density mounting. The flip Chip is connected with three main types C4(Controlled Collapse Chip Connection), DCA (direct Chip attach), and FCAA (Flip Chip additive attachment).

Disclosure of Invention

The invention mainly solves the technical problem of providing a miniaturized millimeter wave MMIC packaging method based on Flip-Chip technology, and by adopting the packaging method, the millimeter wave MMIC with higher integration level has compact structure, high system integration level, small volume, simple feed and high directivity, improves the reliability and reduces the energy consumption and the cost of a Chip.

In order to solve the above technical problems, one technical solution adopted by the present invention is as follows:

a miniaturized millimeter wave MMIC packaging method based on Flip-Chip technology, the MMIC packaging process includes: front-stage process, middle-stage process, back-stage process and test;

wherein the front-end process comprises: back processing, wafer dicing and secondary light inspection; the middle section process comprises the following steps: chip bonding, silver paste curing, lead welding and three-light inspection; the back-end process comprises the following steps: injection molding, laser marking, post-mold curing, flash removal, electroplating annealing and grain cutting;

the back surface treatment is to grind the back surface of the wafer, and the thickness of the wafer after grinding is 8-10 mils; during grinding, the front surface of the wafer is pasted with an adhesive tape to protect a front surface circuit area;

the wafer dicing process includes: the method comprises the following steps of mounting, cutting and cleaning, wherein the cleaning step is to sequentially use clean water and alcohol for cleaning;

the preparation steps of the chip bonding process comprise silver paste dispensing and bonding, and before the silver paste dispensing process, the silver paste which is preserved in a freezing mode needs to be placed at normal temperature for returning to the temperature.

Further, in the silver paste curing process, the curing temperature is 175 ℃, and the curing time is 1 h.

In the Lead welding process, a ceramic chopper is used, the inside of the ceramic chopper is hollow, a gold wire penetrates through the middle of the ceramic chopper, and a first welding spot and a second welding spot are respectively formed on a Pad of the chip and a Lead of a Lead Frame.

Furthermore, the injection molding step is to use epoxy resin for plastic package, and a curing agent, a modifier, a release agent, a coloring agent and/or a flame retardant are added.

Further, the molding parameters of the injection molding step are as follows: forming temperature: 175 ℃ to 185 ℃, clamping pressure: 3000N-4000N, transfer pressure: 1000psi-1500psi, transfer time: 5s-15s, curing time: 60s-120 s.

Further, the laser marking step is to laser engrave characters on the front or back of the product, and the content of the lettering comprises: product name, date of manufacture and batch of manufacture.

Further, the curing temperature of the post-mold curing was 175 ± 5 ℃, the curing time: and 8 h.

The invention has the beneficial effects that:

the packaging method of the invention can make the millimeter wave MMIC with higher integration level have compact structure, high system integration level, small volume, simple feed and high directivity, improve reliability and reduce energy consumption and cost of chips, the bonding of the chips adopts eutectic process and conductive adhesive bonding process, and the bonding of the chip interconnection leads adopts wedge bonding process to reduce parasitic parameters caused by the lead bonding.

The foregoing is a summary of the present invention, and in order to provide a clear understanding of the technical means of the present invention and to be implemented in accordance with the present specification, the following is a detailed description of the preferred embodiments of the present invention.

Detailed Description

The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention and to clearly and unequivocally define the scope of the present invention.

Example (b):

a miniaturized millimeter wave MMIC packaging method based on Flip-Chip technology, the MMIC packaging process includes: front-stage process, middle-stage process, back-stage process and test;

wherein the front-end process comprises: back processing, wafer dicing and secondary light inspection; the middle section process comprises the following steps: chip bonding, silver paste curing, lead welding and three-light inspection; the back-end process comprises the following steps: injection molding, laser marking, post-mold curing, flash removal, electroplating annealing and grain cutting;

the back surface treatment is to grind the back surface of the wafer, and the thickness of the wafer after grinding is 8-10 mils; during grinding, the front surface of the wafer is pasted with an adhesive tape to protect a front surface circuit area;

the wafer dicing process includes: the method comprises the following steps of mounting, cutting and cleaning, wherein the cleaning step is to sequentially use clean water and alcohol for cleaning;

the preparation steps of the chip bonding process comprise silver paste dispensing and bonding, and before the silver paste dispensing process, the silver paste which is preserved in a freezing mode needs to be placed at normal temperature for returning to the temperature.

In the silver paste curing process, the curing temperature is 175 ℃, and the curing time is 1 h.

The Lead welding process uses a ceramic cleaver, the interior of the ceramic cleaver is hollow, a gold wire penetrates through the middle of the ceramic cleaver, and a first welding spot and a second welding spot are respectively formed on a Pad of a chip and a Lead of a Lead Frame.

In this embodiment, the injection molding step is performed by using epoxy resin for plastic package, and adding a curing agent, a modifier, a release agent, a coloring agent and/or a flame retardant.

In this embodiment, the molding parameters of the injection molding step are as follows: forming temperature: 175 ℃ to 185 ℃, clamping pressure: 3000N-4000N, transfer pressure: 1000psi-1500psi, transfer time: 5s-15s, curing time: 60s-120 s.

The laser marking step of the invention is to carve characters on the front or back of the product by laser, and the carving content comprises the following steps: product name, date of manufacture and batch of manufacture.

Wherein the curing temperature of the post-mold curing is 175 + -5 ℃, the curing time is: and 8 h.

The working process and working principle of the invention are as follows:

the packaging method of the invention can make the millimeter wave MMIC with higher integration level have compact structure, high system integration level, small volume, simple feed and high directivity, improve reliability and reduce energy consumption and cost of chips, the bonding of the chips adopts eutectic process and conductive adhesive bonding process, and the bonding of the chip interconnection leads adopts wedge bonding process to reduce parasitic parameters caused by the lead bonding.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations and positional relationships that are conventionally used in the products of the present invention, and are used merely for convenience in describing the present invention and for simplicity in description, but do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications made by the equivalent structures in the present specification or directly or indirectly applied to other related technical fields are included in the scope of the present invention.