CN113394179A

CN113394179A - Electronic component with multilayer carrier structure

Info

Publication number: CN113394179A
Application number: CN202110525078.5A
Authority: CN
Inventors: 黄渊; 王建荣; 葛飞虎
Original assignee: Nantong Huada Microelectronics Group Co ltd
Current assignee: Nantong Huada Microelectronics Group Co ltd
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2021-09-14
Anticipated expiration: 2041-05-14
Also published as: CN113394179B

Abstract

The invention discloses an electronic element with a multilayer slide structure, which is provided with a multilayer connection structure of a lead frame slide holder, a silver coating layer, a dot matrix layer and a chip; the lattice layer is a plurality of pit lattice structures which are arranged at intervals and have certain height, each pit has certain height, and the slide holder is not directly contacted with the chip. The multilayer structure of the invention ensures that the chip has good heat dissipation and the heat transfer and heat dissipation characteristics can be controlled.

Description

Electronic component with multilayer carrier structure

Technical Field

The invention relates to a chip packaging technology of a microelectronic device.

Background

The chip package is a housing for mounting a semiconductor integrated circuit chip, and has functions of mounting, fixing, sealing, protecting the chip, and enhancing the electrothermal performance. The chip package is a bridge for communicating the internal world of the chip with an external circuit, the chip is firstly connected with the lead frame, the connection point of the chip is connected to the pin of the lead frame by a lead, then the chip and the part of the pin are packaged in the shell, and the pin is connected with other devices by the lead on the printed board. The package plays an important role in CPU and other LSI integrated circuits, the pin number is increased, the pin pitch is reduced, the weight is reduced, the reliability is improved, and the use is more convenient.

Application No.: 2010101679613 discloses a dual lead frame multi-chip common package and its manufacturing method, comprising two lead frames; the chip comprises a plurality of chips, a first chip, a second chip and a third chip; the first chip is arranged on the first lead frame, the second chip and the third chip are arranged on the second lead frame together, and the third chip is a bypass capacitor; and the two connecting pieces are respectively a top connecting piece and a three-dimensional connecting piece, the top connecting piece is connected with the top contact area of the second chip and the external pin of the first lead frame, and the top connecting piece is simultaneously connected with the top contact area of the third chip. The present invention does not refer to the technology of forming a multi-layer structure by a single chip and a stage.

Application No.: 2020204249404 discloses a slide holder for chip detection, which comprises a plate body, the plate body is provided with the location boss, all is provided with clamp plate mechanism on the plate body that is located location boss both sides, and clamp plate mechanism includes first clamp plate and second clamp plate, and first clamp plate is articulated mutually with the plate body through first round pin axle, and the second clamp plate is articulated mutually with the plate body through second round pin axle. The utility model discloses a chip heat dissipation is good inadequately, and heat transfer cooling mode remains to improve.

Application No.: 2013105500841 discloses a plastic package lead frame with pockmarks, which is composed of a plurality of lead frame units in a single row, wherein the substrate is provided with a heat radiating fin and a bonding area, the bonding area is provided with 200 and 250 uniformly distributed pockmarks, and the pockmarks in the bonding area are polymer adhesives, which are helpful for heat radiation but do not have good up-and-down heat transfer effect; the arrangement and combination structure of the pockmarks is single, and the components of different parts of the pockmarks have no special design and special effect.

Disclosure of Invention

The invention content is as follows:

the electronic element with the multilayer slide structure has the advantages of fast heat transfer, good heat dissipation and strong designability of the chip.

The technical scheme is as follows:

the electronic element with the multilayer slide structure provided by the invention has a multilayer connection structure of a lead frame slide holder, a silver coating (or a structure for increasing the conductivity and the corrosion resistance), a dot matrix layer and a chip (the bottom of the chip can also be plated with silver, so that the conductivity is increased or the heat conduction and heat transfer effects are improved).

The lattice layer is a plurality of pit lattice structures which are arranged at intervals and have certain height, each pit has certain height, the lower end of the pit is ensured to be contacted with the chip carrying platform, the upper end of the pit is contacted with the chip, but the chip carrying platform is not directly contacted with the chip.

Moreover, a certain distance is reserved between the pits and bonding points (connection points of the chip and bonding wires or electrode connection points) of the chip (the bonding points of the chip are preferably arranged on the upper surface of the chip, the pits are only contacted with the bottom of the chip, the periphery of the bonding points is preferably provided with an insulating frame (formed by injection of a substrate material or later-stage epitaxy and sputtering technology) made of a high-purity silicon material or a non-conductive high polymer material, the peripheral height of the insulating frame is further preferably larger than the inner peripheral height, short circuit caused by the fact that a dot matrix layer material is turned upwards to contact the middle bonding part of the upper layer of the chip is avoided, meanwhile, a tight locking structure with the smooth surface and the inward concave inner surface of a plastic sealing layer is formed after packaging, and good insulation between the bonding points and the pits is guaranteed.

The function of the lattice layer: gaps are formed among the chip carrying table and the chip, the electric conduction and the heat conduction and the pits for air cooling and heat dissipation (ventilation in the horizontal direction and heat transfer in the plumb direction).

The material of the lattice layer has the following composition: 90-97% of tin, 1-3% of silver and 0.5-8% of copper, wherein the tin has better weldability and lower cost, the silver has good electric and thermal conductivity, and the copper has higher heat resistance.

The silver component in the pits in the middle part of the optimized lattice is more, the center of the chip generates more heat, the heat transfer is fast, and the chip is not easy to overheat and damage; the peripheral pockmarks have more tin components, low cost and easy welding repair welding.

Or, the density of the pits in the middle of the optimized dot matrix is low, so that transverse ventilation and heat dissipation are facilitated; the peripheral density degree is higher, and the reliability of the connection between the chip and the slide holder is enhanced.

The heat transfer and heat dissipation data of each part of the chip can be calculated, and electronic components with different heat resistance, heat transfer effects and heat dissipation structures can be designed accordingly.

The manufacturing process comprises the following steps:

firstly, screen printing solder with sieve pores on a slide holder, or injecting a high molecular adhesive by adopting a mould with the sieve pores; then, heating the dot matrix layer and cooling to solidify the solder or solidify the high molecular components (such as rosin, welding auxiliary soldering tin and other high molecular adhesives which are not purely adhesive) in the dot matrix layer by adopting proper process temperature, pressure (preferably negative pressure) and time; then, a chip is welded or bonded (rosin assisted bonding) on the lattice layer.

The re-welding or bonding of the chip is to use the material of the dot matrix layer as a connecting material, and the heating welding temperature is 20-30 ℃ higher than the process temperature after printing by heating (when the solder is printed and dried for the first time, the solder resist volatilizes, so that the soldering flux is lacked, and the melting point of the solder is improved); or the high polymer component is a hot-melt high polymer, and the heating melting temperature is 5-10 ℃ higher than the melting point of the adhesive (so as to avoid complete melting and pockmark lattice collapse).

Preferably, the melting time is controlled to be longer and the viscous flow property is controlled to be higher in the silk screen with the screen holes, so that the three metal components are settled according to the specific gravity, and the different position proportions of silver, copper and tin are ensured. The bottom layer has more silver and copper, high melting point and high welding temperature with the slide holder, and the welding is sufficient; the upper layer has more tin, low melting point and low temperature for welding with the chip, thereby avoiding the chip from being excessively heated and damaged.

Has the advantages that:

the chip with the multi-layer structure of the lattice layer structure has good ventilation effect and good heat dissipation, and different pockmark material components have different heat transfer characteristics, so that the heat transfer and dissipation are controllable, the service life of the chip is prolonged, and the chip is not easy to be damaged. And the connection of the pit layer, the slide holder and the chip is firm and reliable, and the phenomenon of unsoldering or infirm bonding is not easy to occur.

Drawings

FIG. 1 is a schematic top view of a portion of a slide according to the present invention;

FIG. 2 is a side view of FIG. 1;

fig. 3 is a schematic structural diagram of the pockmark.

In the figure, 1-slide holder; 2-lattice layer; 3-chip; 21-lower end of pockmark; 22-upper end of pockmark.

Detailed Description

The electronic component with the multilayer chip carrier structure shown in fig. 1 and fig. 2 has a multilayer connection structure of a lead frame chip carrier, a dot matrix layer and a chip; the lattice layer is a plurality of pockmark lattice structures which are arranged at intervals and have certain height; the bonding points of the chip are arranged on the upper surface of the chip, and the pits are only contacted with the bottom of the chip.

The product adopts the following manufacturing process in sequence:

firstly, screen printing solder with sieve pores on a slide holder; heating the lattice layer and cooling to solidify the solder or solidify the polymer by adopting proper process temperature, pressure and time; then, the chip is soldered on the lattice layer.

Claims

1. An electronic component having a multilayer carrier sheet structure, comprising: the multi-layer connection structure comprises a lead frame slide holder, a dot matrix layer and a chip; the lattice layer is a plurality of pockmark lattice structures which are arranged at intervals and have certain height; the bonding point of the chip is arranged on the upper surface of the chip, and the pockmark is only contacted with the bottom of the chip; material composition of the lattice layer: 90-97% of tin, 1-3% of silver and 0.5-8% of copper.

2. An electronic device having a multilayer carrier sheet structure as claimed in claim 1, wherein: the periphery of the chip bonding point is provided with an insulating frame made of high-purity silicon material or non-conductive high polymer material.

3. The electronic component having a multilayer carrier sheet structure as claimed in claim 1, wherein: the silver component in the pits in the middle part of the lattice is redundant with the pits in the peripheral part, and the tin component in the peripheral pits is more than that in the middle part.

4. A manufacturing process of an electronic element is characterized in that: fabricating the electronic device with a multilayer carrier structure of claim 1 by the following sequential fabrication process:

firstly, screen printing solder with sieve pores on a slide holder, or injecting a high molecular adhesive by adopting a mould with the sieve pores; heating the lattice layer and cooling to solidify the solder or solidify the polymer by adopting proper process temperature, pressure and time; then, the chip is welded or adhered on the lattice layer.

5. The process for manufacturing an electronic component according to claim 4, wherein: the re-welding or bonding of the chip is to use the material of the dot matrix layer as a connecting material, and heating the connecting material to ensure that the heating welding temperature is 20-30 ℃ higher than the process temperature after printing; or the high-molecular adhesive is hot-melt high-molecular adhesive, and the heating and melting temperature is 5-10 ℃ higher than the melting point of the adhesive.

6. The process for manufacturing an electronic component according to claim 4, wherein: controlling the melting time and the viscosity to enable the three metal components to settle according to specific gravity, and ensuring different position proportions of silver, copper and tin; the bottom layer has more silver, the middle layer has more copper and the upper layer has more tin.