KR100790461B1 - Method for manufacturing electronic package - Google Patents

Abstract

A method for manufacturing an electronic package is provided to simplify processes and to improve reliability by forming a thermal conductive layer through an ink jet manner. An electronic device is prepared(S11). A thermal conductive adhesive ink is coated on a surface of the electronic device by using an ink jet manner(S12). The thermal conductive adhesive ink is made of an adhesive medium and a thermal conductive particle. A heat release unit is coupled to the surface of the electronic device on which the thermal conductive adhesive ink is coated(S13). The thermal conductive adhesive ink is filtered. The heat release unit is coupled through a thermo-compression bonding. The heat release unit is comprised of a heat release plate coupled to the surface of the electronic device and a heat release fin formed on the heat release plate.

Description

Method for Manufacturing Electronic Package

1 is a cross-sectional view showing an electronic package manufactured by the prior art.

2 is a flowchart illustrating a method of manufacturing an electronic package according to a first embodiment of the present invention.

3 is a flowchart illustrating a method of manufacturing an electronic package according to a first embodiment of the present invention.

4 is a cross-sectional view showing a piezoelectric inkjet head.

5 is a flowchart illustrating a method of manufacturing an electronic package according to a second embodiment of the present invention.

6 is a flowchart illustrating a method of manufacturing an electronic package according to a second embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: substrate 120: adhesive film

130: electronic device 140: inkjet head

148: heat conductive adhesive ink 150, 250: heat dissipation

The present invention relates to a method for manufacturing an electronic package.

In order to use efficient heat transfer in electronic parts or semiconductors, a heat conduction layer is formed between the heat sink and the parts, and the material used is generally called a TIM (Thermal Interface Material). The contact surface of the heat sink and the part is not perfectly flat in physical terms, but has surface roughness observed at the microscope level. This surface roughness reduces the contact area, so TIM is used to fill this gap.

The diffusion characteristics of the TIM determine the ability to fill or remove voids between the part and the heat sink under the pressure of the installed heat sink. Because air is a material with very low thermal conductivity, the better the conductivity is, the better the air is removed to fill the voids.

The method of forming the thermal conductive layer by applying the TIM can be largely divided into two methods. A method of forming a heat conductive layer by applying a grease type TIM by dispensing, and a method of forming a heat conductive layer by attaching and curing a pad or tape type TIM.

In the dispensing method, applying an appropriate amount is an important part of the process. Because heat transfer is inversely proportional to the thickness of the grease applied to the part, too small amounts will degrade the thermal conductivity, and too much may leak some at the system's operating temperature, potentially contaminating other components and causing errors. .

As the method of dispensing, a nozzle discharge method using an applicator is used. The method is that the TIM, which is a fluid in gel state, is stored in a syringe and is released by an auger screw to be supplied to the dispensing needle, and the TIM supplied to the dispensing needle is dispensed to a predetermined thickness.

However, in this method, in order to optimally adjust the thickness of the thermally conductive adhesive material, the amount of dispensing of the fluid discharged to the syringe must be adjusted at every operation.If the syringe is left for a long time after the operation, the TIM is auger screwed. Dispensing is hindered by the fluid that remains in the cured fluid or, in the worst case, the syringe is not operated by hardening.

Patent application 10-2001-0039726, which is representative of FIG. 1, relates to a method of attaching a tape-like material, and discusses an electronic package using a tape-type TIM and a method of manufacturing the same. This provides a semiconductor package using a tape-type TIM 1 formed by applying a TIM to a tape by screen printing to overcome the disadvantages of the conventional dispensing method. This tape TIM has the advantage of having an overall uniform thickness and no risk of dispensing being disturbed by the cured fluid.

However, such a method of attaching a tape-like material has problems such as the use and processing of release paper, which is inevitably required for the manufacture of pads or tapes, the necessity of dedicated equipment, a decrease in applicability to specially shaped portions, and limitation of thinning. have. In addition, there is a problem in that it is difficult to apply to a thin-oriented electronic component because it has a thickness of about 50 μm because there is a limitation in forming the minimum thickness due to the film coating.

The present invention is to provide a method for manufacturing an electronic package that enables the process, automation and mass production of the process by forming a thermal conductive layer using an inkjet method.

According to an aspect of the present invention, a method of manufacturing an electronic package including an electronic device coupled to a substrate, comprising: (a) providing an electronic device; (b) applying a thermally conductive adhesive ink to one surface of the electronic device using an inkjet method; And (c) coupling a heat dissipation unit to one surface of the electronic device to which the thermal conductive adhesive ink is applied.

The thermally conductive adhesive ink may be filtered prior to application, and step (c) may be performed through thermocompression.

Meanwhile, the heat dissipation unit may include a heat dissipation plate coupled to one surface of the electronic device, and a heat dissipation wing formed on the heat dissipation plate.

On the other hand, the heat dissipation unit may be formed of a lid (lid) to cover the electronic device, and a heat sink to receive heat from the lead, the heat dissipation blade may be formed.

At this time, the lead (lid) covering the electronic device to the (c1) electronic device is coupled, (c2) the thermal conductive layer is formed on the lead, and (c3) the heat conduction layer to the heat radiation plate by combining the lead and the heat sink formed with the thermal conductive layer You can combine wealth.

Meanwhile, step (c2) may be performed by applying a thermally conductive adhesive ink by an inkjet method.

The thermally conductive adhesive ink may be composed of an adhesive medium and thermally conductive particles. The adhesive medium may be formed of silicon or epoxy, and the thermally conductive particles may be formed of a metallic material such as silver (Ag), copper (Cu), or nickel (Ni) when the electrical conductivity is required. If not needed, it is based on a ceramic material such as alumina.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

Hereinafter, a preferred embodiment of the electronic package manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings, in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and Duplicate explanations will be omitted.

2 is a flowchart illustrating a method of manufacturing an electronic package according to a first embodiment of the present invention, and FIG. 3 is a flowchart illustrating a method of manufacturing an electronic package according to a first embodiment of the present invention. Referring to FIG. 3, the substrate 110, the pad 112, the adhesive film 120, the conductive ball 122, the electronic device 130, the electrode 132, the inkjet head 140, and the thermal conductive adhesive ink 148. ), A heat conductive layer 149, a heat dissipation unit 150, a heat dissipation plate 152, and a heat dissipation wing 154 are illustrated.

First, the electronic device 130 is provided (s11). Although the heat dissipation unit 150 may be coupled to the top surface of the electronic device 130 coupled to the substrate 110, the electronic device may be coupled to the substrate after the heat dissipation unit is coupled to the top surface of the electronic device. The device 130 may be coupled to the substrate 110 or may not be coupled to the substrate 110 yet. However, in the present embodiment, for convenience of description and understanding, the description will be made taking the case of providing the electronic device 130 coupled to the substrate 110 as an example.

A process of coupling the electronic device 130 to the substrate 110 will be described with reference to FIGS. 3A to 3C. First, the adhesive film 120 having the conductive balls 122 is laminated on the substrate 110 on which the pads 112 are formed. The adhesive film 120 may be in a form in which an epoxy resin for performing an adhesive function and a conductive ball 122 for transmitting an electric signal are mixed, and do not need to separately form a conductive layer. In this case, the conductive balls 122 may not be mixed. Examples of such an adhesive film include a die bonding film, ACF, NCF, and the like. In this embodiment, for convenience of description and understanding, the description will be made by taking the adhesive film 120 having the conductive ball 122 mixed as an example.

Then, when the electronic device 130 is bonded to the substrate 110 on which the adhesive film 120 is stacked, the electronic device 130 is bonded to the substrate 110 by an epoxy resin and pads are formed by the conductive balls 122. 112 and the electrode 132 are electrically connected to each other. In this way it is possible to provide the electronic device 130 of the type coupled to the substrate 110.

Meanwhile, in the present embodiment, although the adhesive film 120 is provided as a means for bonding the substrate 110 and the electronic device 130, the conductive ball 122 is applied to cure the ink in the form of an epoxy resin embedded therein. Of course, various methods such as the method can be applied.

Thereafter, as illustrated in FIG. 3D, a thermally conductive adhesive ink 148 is coated on the upper surface of the electronic device 130 using the inkjet method (S12). This is a process of forming a heat conductive layer 149 for allowing the heat generated from the electronic device 130 to be moved to a heat dissipation unit, which will be described later.

On the other hand, in the present embodiment has been proposed to apply the thermal conductive ink ink 148 to the upper surface of the electronic device 130, it is a matter of course that the position to apply the thermal conductive ink ink 148 may be different.

Prior to the detailed description of step S12, the piezoelectric inkjet head 140 used in the present embodiment will be briefly described with reference to FIG.

4 is a cross-sectional view illustrating the piezoelectric inkjet head 140. Referring to FIG. 4, a reservoir 141, a restrictor 142, a chamber 143, a nozzle 144, a diaphragm 145, a piezoelectric element 146, and a power source 147 are illustrated.

The reservoir 141 accommodates the thermally conductive adhesive ink and provides the thermally conductive adhesive ink to the chamber 143 through the restrictor 142 which will be described below.

The restrictor 142 communicates with the reservoir 141 and the chamber 143 to be described later, and serves as a flow path for supplying the thermally conductive adhesive ink from the reservoir 141 to the chamber 143. The restrictor 142 is formed to have a smaller cross-sectional area than the reservoir 141, and the amount of thermally conductive adhesive ink supplied from the reservoir 141 to the chamber 143 when the diaphragm 145 vibrates by the piezoelectric element 146. Can be adjusted.

The chamber 143 is connected to the restrictor 142 and communicates with the reservoir 141. In addition, it is connected to the nozzle 154 through the other side other than the side connected to the restrictor 142. Through this structure, the thermal conductive adhesive ink is supplied from the reservoir 141, and the ink is supplied to the nozzle 154 to enable printing.

Meanwhile, one surface of the chamber 143 is covered by the diaphragm 145, and the piezoelectric element 146 is coupled to an upper surface of the diaphragm 145 corresponding to the position of the chamber 143.

The piezoelectric element 146 is coupled to an upper surface of the diaphragm 145 corresponding to the position of the chamber 143, and is a means for generating vibration by the power source 147. The piezoelectric element 146 generates vibration in accordance with the voltage supplied to the piezoelectric element 146 to supply pressure to the chamber 143 through the diaphragm 145.

The nozzle 154 is connected to the chamber 143 to receive a thermally conductive adhesive ink from the chamber 143 and to inject a thermally conductive adhesive ink. When the vibration generated by the piezoelectric element 146 is transmitted to the chamber 143 through the diaphragm 145, pressure is applied to the chamber 143, and the nozzle 154 may spray the thermally conductive adhesive ink by the pressure. Will be.

Meanwhile, in the present embodiment, the piezoelectric inkjet head 140 is provided as described above, but not only the piezoelectric inkjet head 140 but also the electrostatic inkjet head 140 may be varied according to the needs of a designer or a user. Of course you can change it.

The thermally conductive adhesive ink 148 may be in a form in which an adhesive medium mainly performing an adhesive function and thermally conductive particles mainly performing a heat transfer function are mixed. In this case, the adhesive medium may be formed of a silicon-based material or an epoxy-based material, and the thermally conductive particles may be formed of a metal material such as silver (Ag), copper (Cu), or nickel (Ni) when the electrical conductivity is required. If the electrical conductivity is not required, it is based on ceramic material such as alumina. In addition, as long as the material having excellent thermal conductivity can be changed and applied as necessary.

The thermally conductive adhesive ink 148 is applied through the inkjet head 140. That is, by applying a heat conductive adhesive ink 148 to the upper surface of the electronic device 130 to be coupled to the heat dissipation unit 150, by using the inkjet head 140, the process is simplified, automated and mass production To make it possible. In addition, the use of a release paper and a treatment problem inevitably generated when using a film type or a pad type adhesive material may be solved, and high reliability may be provided.

In the application process as described above, the process of checking whether an error occurs and processing the same may increase the reliability. That is, it is possible to check whether or not an error has occurred by driving an image program for checking in real time whether the thermally conductive adhesive ink is applied without error through the inkjet head 140, and if it is determined that an error has occurred The reliability of the product can be increased by avoiding the subsequent process for the product.

On the other hand, prior to spraying the thermally conductive adhesive ink 148 by the inkjet method, it is preferable to go through an appropriate filtration process to remove large particles that can block the nozzle of the inkjet head 140.

By applying the thermally conductive adhesive ink 148 through the inkjet head 140 as described above, the thermally conductive layer 149 can be formed.

Next, as illustrated in FIG. 3E, the heat dissipation part 150 is coupled to the electronic device 130 on which the heat conductive layer 149 is formed (S13). The electronic package may be manufactured by coupling the heat dissipation part 150 to the electronic device 130 to which the thermally conductive adhesive ink 148 is applied through step s12 described above.

On the other hand, in order to increase the bonding force between the electronic device 130 and the heat dissipation unit 150, in coupling the heat dissipation unit 150 to the electronic device 130, a method of supplying heat and compressing, that is, a thermal compression method It is available. In addition, it is a matter of course that after the heat dissipation unit is coupled to the electronic device can be completely cured adhesive using a curing oven or the like.

The heat dissipation unit 150 serves to receive and store heat from the electronic device 130 or to discharge the received heat to the outside. In this embodiment, the heat conduction layer 149 is formed as the heat dissipation unit 150. A heat sink 152 coupled to the electronic device 130 and a plurality of heat sinks 154 formed on the heat sink 152 are provided.

The heat sink 152 receives and stores heat generated from the electronic device 130 through the heat conductive layer 149, and discharges heat through contact with external air. The heat sink 152 may be made of a metal having good thermal conductivity, and examples thereof include copper and aluminum.

The heat dissipation wing 154 may be formed on the heat dissipation plate 152 as a means for dissipating heat efficiently by increasing the contact area between the heat dissipation unit and the outside air. Like the heat sink 152, the heat dissipation wing 154 may be made of a metal material having good thermal conductivity, such as copper and aluminum.

The heat dissipation wing 154 may be manufactured separately from the heat dissipation plate 152 and coupled to the heat dissipation plate 152, but may be integrally formed with the heat dissipation plate 152 by processing one surface of the heat dissipation plate 152. In addition, the size, material, number, etc. of the heat dissipation plate 152 and the heat dissipation wing 154 may be variously changed according to design needs.

Next, an electronic package manufacturing method according to a second embodiment of the present invention will be described. 5 is a flowchart illustrating a method of manufacturing an electronic package according to a second embodiment of the present invention, and FIG. 6 is a flowchart illustrating a method of manufacturing an electronic package according to a second embodiment of the present invention. Referring to FIG. 6, the substrate 110, the pad 112, the adhesive film 120, the conductive ball 122, the electronic device 130, the electrode 132, the inkjet head 140, the thermal conductive adhesive ink 148. The heat dissipation part 250, the heat dissipation plate 152, the heat dissipation wing 154, the lid 260, and the lead seal 262 are illustrated.

In the method for manufacturing an electronic package according to the present embodiment, steps s21 and s22 are the same as steps s11 and s12 of the first embodiment described above, and thus a detailed description thereof will be omitted and reference to the same components as in the first embodiment is referred to. Keep the numbers the same.

The electronic package manufacturing method according to the present embodiment includes a lead 260 covering the electronic device 130, a heat sink 152, and a heat conductive layer 249 interposed between the lead 260 and the heat sink 152. It is characterized by presenting the heat dissipation unit 250. That is, in the first embodiment, the heat dissipation plate 152 and the heat dissipation wing 154 are provided as the heat dissipation part 150, whereas in the present embodiment, the lead 260, the heat dissipation plate 152, and the heat conduction are used as the heat dissipation part 250. Layer 249 is presented. Of course, the heat dissipation blade 154 may be formed on the heat sink 152. FIG. 6G illustrates an example in which the heat dissipation blade 154 is formed on the heat dissipation plate 152.

The leads lid 260 covering the electronic device 130 are coupled to the electronic device 130 to which the thermally conductive adhesive ink 148 is applied through steps s21 and s22 as shown in FIG. (s23). The lead 260 is a means for protecting the electronic device 130 which is vulnerable to external environment such as fine dust and moisture. The lead 260 covers the electronic device 130, and the electronic device 130 is externally exposed through the lead seal 262. To isolate it from the environment.

In addition, since the lead 260 also receives heat from the electronic device 130, it is also possible to perform some heat dissipation function.

On the other hand, in order to efficiently discharge the heat generated from the electronic device 130, as shown in Figure 6 (f) to form a thermal conductive layer 249 in the lead 260 (s24), Figure 6 (g As shown in FIG. 2, the heat sink 152 having the heat dissipation wings 154 is coupled to the heat conductive layer 249 (S25). That is, the heat generated from the electronic device 130 reaches the heat dissipation plate 152 via the lead 260, thereby protecting the electronic device 130 from the external environment and performing a heat dissipation function.

The thermally conductive layer 249 formed on the lead 260 may be formed by applying the thermally conductive adhesive ink 148 through an inkjet method as in step s22 of the first embodiment described above. The use of the inkjet method enables the process to be simplified, automated and mass produced, and the reliability of the process can be improved as described above.

However, the thermal conductive layer 249 may also be formed through a tape-shaped thermal interface material (TIM) or a TIM applied through dispensing.

The heat dissipation plate 152 having the heat dissipation blades 154 formed thereon may be coupled to the heat conductive layer 249 so that heat dissipation from the electronic device 130 may be efficiently performed. Such coupling may be performed through thermocompression bonding. .

Since the description of the heat sink 152 and the heat dissipation wing 154 is the same as described through the first embodiment, detailed description thereof will be omitted. On the other hand, the size, thickness, number, etc. of the heat sink 152 and the heat dissipation wing 154 can be changed in various ways as described above.

The electronic package manufacturing method according to the first and second embodiments of the present invention has been described above, and many embodiments other than the above-described embodiments exist within the claims of the present invention.

As described above, according to the preferred embodiment of the present invention, by forming the thermal conductive layer using the inkjet method, it is possible to simplify the process, automate the process and mass production, and provide high reliability.

Claims (10)

A method of manufacturing an electronic package including an electronic device coupled to a substrate, (a) providing the electronic device; (b) applying a thermally conductive adhesive ink to one surface of the electronic device using an inkjet method; And (c) a method of manufacturing an electronic package comprising coupling a heat dissipation unit to one surface of the electronic device to which a heat conductive adhesive ink is applied. The method of claim 1, The method of claim 1, further comprising filtering the thermally conductive adhesive ink. The method of claim 1, The step (c) is an electronic package manufacturing method characterized in that it is carried out by thermal compression. The method of claim 1, The heat dissipation unit, A heat sink coupled to one surface of the electronic device; Electronic package manufacturing method comprising a heat dissipation wing formed on the heat sink. The method of claim 1, The heat dissipation unit includes a lid for covering the electronic device and a heat dissipation plate receiving heat from the lead, Step (c) is, (c1) coupling a lid covering the electronic device to the electronic device; (c2) forming a thermal conductive layer on the lead; And and (c3) coupling the lead and the heat sink having the heat conductive layer formed thereon. The method of claim 5, The step (c2) is, the electronic package manufacturing method characterized in that is carried out by applying a thermally conductive adhesive ink in an inkjet method. The method of claim 1, The thermally conductive adhesive ink comprises an adhesive medium and thermally conductive particles. The method of claim 7, wherein The adhesive medium is an electronic package manufacturing method comprising a silicon-based material or an epoxy-based material. The method of claim 7, wherein The thermally conductive particle comprises an alumina manufacturing method of the electronic package. The method of claim 7, wherein The thermally conductive particles include any one or more selected from the group consisting of silver (Ag), copper (Cu) and nickel (Ni).

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