KR101215451B1 - A manufacturing method of Heat-pressed micro heat spreader based metal substrate - Google Patents

Abstract

The present invention relates to a method of manufacturing a heat pressurized heat spreader-based metal substrate in which a printed circuit layer is integrally formed on a plate surface of the heat pressurized heat spreader and a heat pressurized heat spreader having a channel into which a heat medium is vacuum-injected. To prepare the upper plate and the lower plate of the plate-shaped metal material and to process the concave surface of the lower plate to form a channel for receiving the heat medium and the injection needle receiving recess connected to the channel, the channel formed on the lower plate is in the center of the lower plate It is formed by etching the plate surface of the lower plate to be composed of a concave center groove and a radial groove which is arranged radially around the center groove as a center groove connected to the central groove, the injection needle accommodating recesses recess the plate surface of the lower plate Pressing to form; Forming a thermally pressurized heat spreader by placing a tubular injection needle having an injection flow path formed therein into the injection needle accommodating recess of the lower plate and then thermally pressing the upper plate and the lower plate to combine the upper and lower plates; Cleaning and drying the plate surface of the heat pressurized heat spreader; Forming an insulating layer on the plate surface of the cleaned and dried heat pressurized heat spreader; Forming a copper foil layer on the insulating layer; Forming a photosensitive material layer on the copper foil layer and then forming a printed circuit pattern through an exposure, development, and etching process; Forming a solder mask layer using solder resist ink on the printed circuit pattern to protect the printed circuit pattern; Vacuum injection of the heat medium through an injection needle connected to the inside of the heat pressurized heat spreader; And heat pressurizing the injection needle to seal and close the injection flow path therein, thereby providing a method of manufacturing a metal substrate based on a heat pressurized heat spreader.

Description

A manufacturing method of heat-pressed micro heat spreader based metal substrate}

The present invention relates to a heat pressurized heat spreader-based manufacturing method and a metal substrate manufactured by the same, and is formed by integrating a heat press heat spreader having a heat medium moving channel and a printed circuit pattern formed therein, and a specially designed heat dissipation frame In combination with the present invention relates to a method for rapidly and efficiently cooling a substrate in which a plurality of high heat generating elements such as high brightness LEDs are integrated, and to manufacture such a metal substrate efficiently and reliably.

A heat spreader is a kind of heat transfer mechanism manufactured by molding a metal material having excellent thermal conductivity such as aluminum by extrusion or mold, and has a plurality of channels separated and partitioned in the longitudinal direction, and includes liquid-vapor as in acetone. It is easy to change the phase of the phase and during the phase change, a vacuum medium is injected with a large amount of latent heat.

When the heat spreader is mounted on a heat generating electronic component such as a semiconductor chip or a CPU, the parts are cooled by latent heat due to the phase change of the heat medium while the inside thereof is maintained in a vacuum state, thereby providing excellent cooling performance.

The heat spreader is flexible, so that it can be freely applied to complex electric and electronic circuit components, can be easily installed in a narrow place, and the cooling performance is excellent.

Such a heat spreader is disclosed in Korean Patent No. 631050 "Flat Plate Heat Pipe," and in Applicant's Utility Model No. 439429, "Flat Surface Heating Mechanism," the inner wall of the channel formed inside the heat pipe is corrugated. Disclosed is a heat spreader in which the contact area with the heat medium is increased to maximize the capillary phenomenon.

Among the heat spreaders as described above, micro groove spreaders are formed to maximize the capillary force of the heat medium by forming minute grooves (grooves) on the wall of the inner channel.

Various electronic components such as mobile phones, video cameras, computers, LCD TVs, PDP TVs, and the like are embedded in printed circuit boards in which various electronic components are mounted. In recent years, these electronic components have become increasingly smaller, more integrated, smaller, and lighter. Therefore, how to effectively release the high heat generated in the integrated printed circuit board is emerging as an important issue.

Conventionally, as a material of a substrate on which a printed circuit for forming such electric and electronic components functions, a heat resistant resin such as epoxy or phenol resin or glass substrate is mainly used. Recently, various materials have been developed. .

13 and 14 illustrate a heat pipe integrated printed circuit board, the former of which is disclosed in Korean Patent No. 0791982, "The Heat Pipe Integrated Printed Circuit Board and Manufacturing Method thereof," The latter of which is registered in Patent No. 0862203, "Heat Pipe." Integrated printed circuit board and a method of manufacturing the same.

The former patent is to form a heat pipe and a printed circuit board integrally, the heat source is arranged in the first direction, and the working fluid movement path is formed inside the heat pipe to correspond one-to-one to the heat source in a second direction perpendicular thereto, The movement paths of a plurality of working fluids are used as the heat source, and the other end is the end of the heat pipe or forms a bellows.

In the case of this patent, it is meaningful in that the printed circuit board is integrally formed on the heat pipe, but in practice, it is necessary to form the heat transfer path in a direction perpendicular to the arrangement direction of the heat source or to form a closed loop to correspond one-to-one to the heat source. Not only is it very difficult, there is a problem that mass production is not easy because the heat pipe itself cannot be formed by extrusion or the like.

In addition, in the manufacturing process of the registered patent, a printed circuit board is formed on a heat pipe in which a heat medium is vacuum-injected through lamination, exposure / development, peeling, and etching processes. There is a problem that the temperature and pressure of the heat medium therein is rapidly increased to cause deformation or explosion of the aluminum heat pipe or printed circuit board.

In the case of the latter patent, a plurality of heat pipes are fixed to a jig, and then a copper foil layer is formed, a printed circuit pattern is formed, and a protective tape is attached to exposed portions at both ends of the copper foil layer. However, the latter patent has the same problems as the above-described process, and if the printed circuit pattern is formed on the entire panel having a plurality of unit heat pipes and then routed for each unit heat pipe, the aluminum layer is in process. Since this is not exposed, there is a problem that the protective tape attaching step is unnecessary.

Therefore, the cooling efficiency is excellent due to the collection and dissipation of heat generated from the high heat generating element, and the manufacturing process is simple and suitable for mass production, compared to the case of the conventional heat-resistant resin or glass substrate, suitable for mass production, and various designs of electric and electronic parts It is required to develop an improved metal substrate for universal application to patterns.

Patent 631050 "Flat plate heat pipe" Utility Model Registration No. 439429 "Plane heating device" Patent No. 0791982 "Heatpipe integrated printed circuit board and its manufacturing method" Patent No. 0862203 "Heat pipe integrated printed circuit board and its manufacturing method" Patent No. 0414860 "Flat Plate Cooling Device" Korean Patent Publication No. 10-2005-0117482 "Printed Circuit Board with Cooling Device and Manufacturing Method thereof" Korean Patent No. 0989518 "Heat Spreader Manufacturing Apparatus, Manufacturing Method and Heat Spreader Produced thereby"

An object of the present invention is to improve the process of forming a printed circuit pattern layer on the heat spreader to prevent the deterioration of heat transfer efficiency due to the capillary force attenuation of the heat medium by the foreign matter flows into the channel of the heat spreader in the process of forming the printed circuit pattern, In addition, the substrate is not deformed or exploded due to the expansion of the heat medium due to high heat even during the process of forming a printed circuit pattern in a high temperature and high pressure environment.

Another object of the present invention is to provide an improved metal substrate module to maximize the cooling capacity by heat collection and heat dissipation of the metal substrate manufactured by the safe and reliable manufacturing method described above.

In order to achieve the above object, according to the present invention, a heat pressurized heat spreader-based metal in which a printed circuit layer is integrally formed on a plate surface of the heat pressurized heat spreader and a heat pressurized heat spreader in which a channel through which a heat medium is vacuum-injected is formed. A method of manufacturing a substrate, comprising: preparing a plate-shaped metal upper plate and a lower plate, and processing the plate surface of the lower plate to concave to form a channel for accommodating a heat medium and an injection needle accommodating portion connected to the channel, wherein the lower plate is formed on the lower plate. The channel is formed by etching the plate surface of the lower plate to be composed of a central groove formed concave in the center of the lower plate and a plurality of radial grooves disposed radially around the central groove, and receiving the injection nozzle The depression is formed by pressing the plate surface of the lower plate concave; Forming a thermally pressurized heat spreader by placing a tubular injection needle having an injection flow path formed therein into the injection needle accommodating recess of the lower plate and then thermally pressing the upper plate and the lower plate to combine the upper and lower plates; Cleaning and drying the plate surface of the heat pressurized heat spreader; Forming an insulating layer on the plate surface of the cleaned and dried heat pressurized heat spreader; Forming a copper foil layer on the insulating layer; Forming a photosensitive material layer on the copper foil layer and then forming a printed circuit pattern through an exposure, development, and etching process; Forming a solder mask layer using solder resist ink on the printed circuit pattern to protect the printed circuit pattern; Vacuum injection of the heat medium through an injection needle connected to the inside of the heat pressurized heat spreader; And heat pressurizing the injection needle to seal and close the injection flow path therein, thereby providing a method of manufacturing a metal substrate based on a heat pressurized heat spreader.

According to the manufacturing method of the present invention, during the process of forming the printed circuit pattern on the plate surface of the heat spreader, it is possible to prevent the deterioration of the heat transfer performance caused by foreign matter flowing into the channel of the heat spreader. Even if exposed to a high temperature and high pressure environment, there is no fear of deformation of the substrate and product defects due to the expansion of the heat medium.

In addition, in the case of the metal substrate of the present invention and the metal substrate module using the same, the cooling efficiency by collecting and dissipating heat transmitted from a plurality of heat generating elements is very excellent, and thus does not require a separate cooling fan. In addition to the advantages, there is an advantage that the manufacturing cost is low.

1 is an external perspective view and a front view of a heat pressurized heat spreader according to a first embodiment of the present invention;
Figure 2 is an external perspective view showing the structure of the upper plate and the lower plate of Figure 1;
3 is a cross-sectional view taken along the cutting line of FIGS. 1 and 2;
4 is an external perspective view of a heat pressurized heat spreader according to a second embodiment of the present invention;
5 is an external perspective view and a top view of a bottom plate of a heat pressurized heat spreader according to a third embodiment of the present invention;
FIG. 6 is a cross-sectional view of the radial groove taken along the line VI-VI of FIG. 5; FIG.
Figure 7 is a schematic external perspective view of the metal substrate of the present invention.
FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 7; FIG.
9 is a cross-sectional perspective view of the metal substrate module according to the present invention.
10 is a cross-sectional view taken along the line XX of FIG. 9.
11 is a flow chart of a metal substrate manufacturing process according to the present invention.
12 is a thermal analysis result of the metal substrate module applying the metal substrate of the present invention.
13 and 14 show a conventional heat pipe integrated printed circuit board.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the configuration and operation of the present invention.

1 is an external perspective view and a front view of a heat pressurized heat spreader according to a first embodiment of the present invention, Figure 2 is an external perspective view showing the structure of the upper plate and the lower plate of Figure 1, Figure 3 is a cut of Figures 1 and 2 Sectional view along the line.

The heat pressurized heat spreader 100 of the present invention is formed by attaching a plate-like upper plate 110 and a lower plate 120 made of metal such as copper or aluminum to face each other, and a channel for accommodating a heat medium to be vacuum-injected therein. Is formed.

In this embodiment, the channel in which the heat medium is injected and stored is formed in a concave recessed shape on the lower plate. Specifically, the channel is pressed by pressing a predetermined portion of the central portion of the lower plate 120 which is plate-shaped to concave the plate surface. .

FIG. 1 illustrates that the upper and lower plates 110 and 120 are reversed for convenience of explanation, and the injection needles 130 such as injection needles are coupled between the upper and lower plates 110 and 120.

In addition to the heat medium accommodating portion 121, which is a kind of channel formed concave in the center portion, the lower plate 120 is formed with an injection needle accommodating portion 122 connected to the heat medium accommodating portion 121 in a straight line. The injection needle accommodating portion 122 may be formed at the same time when the heat medium accommodating depression 121 is formed by pressing the press, and the injection needle 130 is accommodated therein.

The injection needle accommodating portion 122 and the injection needle 130 form a printed circuit pattern on the surface of the heat pressurized heat spreader 100 coupled by heat pressurizing the upper plate 110 and the lower plate 120 and then heating the channel. It serves as a means for securing an injection hole for vacuum injection.

That is, in the present invention, after the process of forming the printed circuit pattern on the surface of the heat pressurized heat spreader 100 is not filled with the heat medium, the heat medium 10 such as acetone is shown in FIG. Injection through the injection device 160 as described above, the injection needle 130 is for this purpose. Therefore, an injection passage 130a is formed inside the injection needle 130 like a syringe needle. The injection device 160 may be a manual type such as a syringe, and may be selected from an automatic injection device in which the piston 161 of the injection device 160 is driven by a pneumatic cylinder or a linear actuator.

In the drawing, reference numeral 123 denotes an edge portion of the lower plate 120 and is a portion of the plate surface of the lower plate 120 which is not recessed.

Figure 4 is an external perspective view of a heat pressurized heat spreader 200 according to a second embodiment of the present invention, unlike the first embodiment described above, the upper plate 210 and the lower plate 220 has a rectangular shape as a whole. The heat medium receiving recess 221 formed on the lower plate 220 also has a square shape. Except for this point, the rest of the configuration is the same as that of the above-described first embodiment, and thus redundant description is omitted.

5 is a perspective view of an external perspective view and a bottom plate of a heat pressurized heat spreader according to a third exemplary embodiment of the present invention, and FIG. 6 is a cross-sectional view of the radial groove along the cutting line VI-VI of FIG. 5. FIG. 5A is an external perspective view of the heat pressurized heat spreader 300, and FIG. 5B is a plan view of the lower plate 320.

The heat pressurized heat spreader 300 of the present embodiment is also composed of a plate-shaped upper plate 310 and a lower plate 320, and the shape and structure of the channel, which is a storage and movement path of the heat medium, are different from the above-described embodiments.

In the present embodiment, the central groove 321a is circularly concave in a predetermined area of the center of the lower plate 320, and a plurality of radial grooves 321b extending radially from the central groove 321a are formed concave. . That is, the channel for the movement of the heat medium of the present embodiment is composed of a central groove 321a and a plurality of linear radial grooves 321b radially disposed about the central groove 321a.

The center groove 321a and the spinning groove 321b may also be concave by pressing the plate surface of the lower plate 320 by a mold or a press, but in this embodiment, an etching process is used to corrode the lower plate 320 which is a metal plate. It was supposed to be formed using. If the center groove 321a and the spinning groove 321b are formed by an etching process, there is an advantage in that the channel can be finely formed on a fine scale. Therefore, the heat medium channel formed by the etching process has a feature that the depth or width of the groove is smaller than the channel formed by the above-described pressing process, and the amount of the heat medium to be injected will be very small.

Thus, the heat pressurized heat spreader 300 having the central groove 321a and the radial groove 321b formed by the etching process is advantageous when it is mounted inside small and sophisticated electric and electronic products.

An injection needle accommodating portion 322 is also formed in the lower plate 320 of the present embodiment. An inner end of the injection needle accommodating portion 322 is connected to the central groove 321a and an outer end of the lower plate 320 is formed. It extends to the circumference. Other methods of forming the injection needle receiving recess 322 and coupling with the injection needle 330 are the same as those of the above-described embodiments.

The radiation groove 321b is a fine linear groove formed by etching the surface of the lower plate 320, but may be finely formed by itself. Further, the radiation groove 321b may be formed as shown in FIG. 6. Another microcapillary groove 321c may be formed therein to maximize capillary force due to the heating medium.

7 is a schematic external perspective view of the metal substrate of the present invention, and FIG. 8 is a cross-sectional view taken along the cutting line VIII-VIII of FIG.

The metal substrate 400 of the present invention is manufactured by using the heat pressurized heat spreaders 100, 200, and 300 according to the above-described embodiments, and basically a column in which a plurality of heat medium moving paths 121, 221, 321a, and 321b are formed. Pressurized heat spreader (micro heat spreader, 100, 200, 300) and a printed circuit layer 410 formed through a plurality of steps of the printed circuit pattern manufacturing process thereon. In the present embodiment, the metal substrate 400 is formed based on the structure of the heat pressurized heat spreader 100 according to the first embodiment, but the present invention is not limited thereto.

The heat pressurized heat spreader 100 formed of the upper plate 110 and the lower plate 120 is formed of a metal which is light in weight and excellent in heat transfer efficiency such as copper or aluminum.

The heat pressurized heat spreader (hereinafter, simply abbreviated as heat spreader for convenience of description) is formed of a plate-shaped circular or polygonal casing whose upper and lower thicknesses are relatively small compared to the diameter of the plate surface. It has a heat medium accommodating depression 121 that functions as a channel that is a moving passage. Until the process of forming the printed circuit layer 410 on the plate surface of the heat spreader 100 is completed, the inside of the heat medium accommodating recess 121 maintains a hollow state in which the heat medium is not filled.

The heat spreader 100 forms a lower layer of the metal substrate 400 of the present invention and collects and dissipates high heat transmitted from a plurality of heating elements 420 mounted on the printed circuit layer 410 formed on the upper layer. do.

The printed circuit layer 410 is an insulating layer 411 is formed on the upper surface of the heat spreader 100 of the metal material, as shown in the printed circuit pattern layer 412 of copper foil formed on the insulating layer 411 And a solder mask layer 413 formed on the printed circuit pattern layer 412. Details of the configuration and the formation method of the respective layers will be described later.

According to the metal substrate 400 of the present invention having the configuration as described above, the heat spreader 100 at the lower side can quickly absorb and cool the heat generated from a plurality of heat sources with high heat generation, such as a high-brightness LED. Therefore, in order to cool the printed circuit board, there is no need to install a separate cooling fan or a complicated heat sink fin structure.

9 is a cross-sectional perspective view of the metal substrate module according to the present invention, and FIG. 10 is a cross-sectional view taken along the cutting line X-X of FIG.

The metal substrate 400 has an excellent efficiency of collecting heat transferred from the heating element 420 by using latent heat due to the phase change of the heat medium vacuum-injected therein. There is a limit. Therefore, in the present invention, the metal substrate 400 is coupled to the heat dissipation frame 510 in which the plurality of heat dissipation fins 513 are formed to form the metal substrate module 500.

As illustrated, the metal substrate 400 having the printed circuit layer 410 having the printed circuit pattern is fixedly attached to the upper portion of the block-shaped heat dissipation frame 510. The heat dissipation frame 510 includes a plurality of heat dissipation fins 513 formed on one surface of the body part 511, coupling parts 512a and 512b formed on both sides of the body part 511, and the body part 511. )

In the illustrated embodiment, the metal substrate 400 is fixedly attached to the top surface of the heat dissipation frame 510 by the coupling parts 512a and 512b, and the heat dissipation fins 513 are formed on the bottom of the body part 511. It is not limited.

A separate heat spreader may be installed in the body portion 511, which is distinguished from the heat spreader 100 described above and is referred to as a built-in heat spreader 520. Unlike the heat spreader 100 of the metal substrate 400, the internal snow spreader 520 may be formed by extrusion using an aluminum material, and a plurality of channels 523 are formed therein, and the channel 523. A plurality of fine grooves 524a and 524b are formed on the inner wall surface of the. The grooves 524a and 524b of the internal snow spreader 520 are for maximizing the capillary force of the heat medium, and a plurality of grooves 524a and 524b are formed side by side in the longitudinal direction of the channel 523 of the internal snow spreader 520.

The internal snow spreader 520 may be inserted into the body portion 511 of the heat dissipation frame 510 and then interpolated thereto or integrally formed in the body portion 511.

The high heat transmitted from the plurality of heat generating elements 420 mounted on the metal substrate 400 is transferred to the heat spreader 100 of the metal substrate 400 and collected. The collected heat is collected on the metal substrate 400. ) Is transferred to and cooled by the heat dissipation frame 510. Heat transferred to the heat dissipation frame 510 may be more effectively cooled by the heat dissipation fins 513.

The built-in snow heat spreader 520 embedded in the heat dissipation frame 510 further doubles the heat transfer effect and the cooling effect. In the present embodiment, but the internal snow spreader 520 is one, in some cases, the number and shape of the internal snow spreader 520 may be different.

The heat dissipation fin 513 is not limited to the illustrated example and may be formed on one or more sides of the heat dissipation frame 510 or the like, which is disposed inside the electrical and electronic product on which the metal substrate 400 is mounted. The structure may vary.

11 is a flow chart of a metal substrate manufacturing process according to the present invention. In the metal substrate 400 of the present invention, a process of forming the heat spreader 100 using the upper plate 110 and the lower plate 120 and a process of forming the printed circuit layer 410 on the heat spreader 100 are performed. Is done.

First, an artwork film is formed by outputting a wiring pattern using a photoplotter, a laser plotter, or the like according to a customer's order (ST1).

Next, a plate-shaped metal upper plate 110 and a lower plate 120 are prepared, and the plate surface of the lower plate is concave to process the heat medium accommodating portion 121 and the heat medium accommodating portion 121, which are channels for accommodating the heat medium. The injection needle receiving recess 122 is connected (ST2).

Subsequently, the injection needle 130 having a tubular shape in which an injection passage 130a is formed is positioned at the injection needle receiving recess 122 of the lower plate 120, and then the upper plate 110 and the lower plate 120 are opened. By pressurizing and combining, the heat pressurization heat spreader 100 is formed (ST3).

At this time, the heat medium receiving recess 121 of the heat spreader 100 maintains a hollow state in which the heat medium is not vacuum injected. As such, the reason why the subsequent printed circuit pattern process is performed without vacuum injecting the heat medium into the heat medium accommodating recess 121 which is a channel inside the heat spreader 100 is that the heat medium vacuum-injected into the heat spreader 100 is This is because the heat spreader 100 is deformed or exploded due to thermal expansion during the heating and pressing process.

In addition, the heat spreader 100 of the present invention has an advantage that it is difficult to introduce foreign substances into the heat spreader 100 during the printed circuit pattern forming process except that the slope is closed except for the injection needle 130. When foreign matter penetrates into the inner space of the heat spreader 100, the function of the heat medium which is vacuum-injected afterwards is impeded, thereby rapidly degrading the performance of the heat spreader 100.

Since impurities may exist on the surface of the sealed heat spreader 100, the surface (plate surface) of the heat spreader 100 is cleaned and dried (ST4) in order to smoothly perform the insulating layer forming process.

Next, an insulating layer 411 is formed on the surface of the heat spreader 100 by using a prepreg-treated epoxy resin or the like (ST5). Specifically, a film or thin film sheet prepreg treated with a synthetic resin such as epoxy is attached to the surface of the heat spreader 100 and then thermally compressed at a temperature of about 280 ° C.

Since the insulating layer 411 is formed for electrical insulation between the heat spreader 100 of copper or aluminum and the printed circuit pattern of copper foil to be formed later, the insulating layer 411 may be formed by coating or coating an insulating resin material. It may also be carried out by attaching an insulating film.

A copper foil layer is formed on the insulating layer 411 of the heat spreader 100, which is to be a printed circuit pattern layer 412 (ST6). The copper foil layer is preferably formed by attaching a copper foil sheet on the insulating layer, but is not limited thereto.

After the copper foil layer is attached, the heat spreader 100 having the copper foil layer is heated and pressurized to secure the adhesive force between the copper foil layer and the insulating layer (ST7). That is, when the copper foil layer portion is heated and pressurized, the copper foil layer is well bonded with the insulating layer which is partially melted.

In the present invention, since the heat medium is not vacuum-injected into the heat spreader 100 unlike the conventional insulation layer forming process and the copper foil layer forming process, the heat spreader 100 is subjected to thermal expansion of the heat medium during the heating and pressing process. There is no risk of deformation or explosion by means of safety and product defects do not occur.

After the bonding of the copper foil layer is completed, via holes, various bolt fastening holes, and the like can be processed in the heat spreader 100 including the copper foil layer (ST8). Such a hole processing step can be arranged later than this if necessary, and may be omitted in some cases.

The hole processing is performed by thermal compression and punching method. Specifically, the hole processing position is pressed by using a thermopressing press, and the upper plate 110 and the lower plate 120 of the heat spreader are brought into contact with each other to be thermally fused to punch the corresponding parts. Is done in a manner.

Next, the printed circuit pattern is transferred onto the copper foil layer by using known processes such as photosensitive material layer formation, exposure, and development. The image forming process proceeds in the order of Lamination-> Exposure-> Development, in which the photosensitive material is applied onto the copper foil layer, and through the development, the desired wiring pattern is transferred onto the copper foil layer (ST9). ).

The photoresist and Mylar film and cover film for imparting elasticity are called dry films. The dry film is attached onto the copper foil layer to form a photoresist layer. do. At this time, in order to further secure the adhesion between the dry film and the copper foil layer, the dry film is thermocompressed with a hot roller. In this case, of course, the cover film is excluded.

Exposure and development processes using a photoresist as a photosensitive material are already known techniques, and thus detailed description thereof will be omitted.

After the development process is completed, the wiring pattern of the copper foil is formed using the corrosion solution, which is called etching (ST10). After the etching process is completed, the remaining corrosion resist (resistive photoresist layer remaining after development) is removed using a stripping solution.

After the etching process is completed, a solder mask layer is formed to protect the printed circuit pattern (ST11). The solder mask refers to a film that protects the substrate from unwanted connection by soldering when the component is mounted. The solder mask is formed on the entire surface of the printed circuit pattern except for an exposed part that is connected to a component such as a heating element. The resist ink for solder mask formation is called PSR (Photo imageable Solder Resist ink), and is formed of a heat resistant resin that can sufficiently withstand the melting temperature of solder.

Next, the heat medium is vacuum-injected through the injection needle 130 coupled to the heat spreader 100 of the metal substrate 400 formed up to the solder mask layer (ST12). Specifically, the tip portion of the above-described manual or automatic injection device in the form of a syringe may be coupled to the injection needle 130, and then the piston 161 may be pushed to inject a heat medium such as acetone.

In the case of vacuum injecting the heat medium, a vacuum state can be formed in the same manner as in the heat spreader manufacturing apparatus disclosed in the Applicant Patent No. 0989518, "Heat spreader manufacturing apparatus, a manufacturing method, and a heat spreader manufactured thereby", which is incorporated in the present invention. It may be.

When the vacuum injection of the heat medium is completed, the injection needle is finally thermally pressurized to seal and close the injection flow path therein and then cut. When the injection of the heat medium is completed, the heat medium injected therein must be sealed so that it does not leak. Therefore, the injection needle 130 is pressed while applying heat with a press or the like to seal the injection flow path 130a. Thereafter, the injection needle 130 protruding sharply to the outside is cut and removed.

Through this process, the metal substrate 400 in which the printed circuit layer 410 and the heat spreader 100 are integrated is obtained. The metal substrate 400 may be produced through each of the above-described processes for each unit metal substrate, but preferably, one panel including a plurality of unit metal substrates 400 is subjected to the above-described process. In the post-routing process, it is preferable to manufacture in a manner of cutting and dividing along a V-cutting portion (V-cut) formed at the boundary between each unit metal substrate 400.

12 is a thermal analysis result of the metal substrate module to which the metal substrate of the present invention is applied. Figure 12 (a) is a result of analyzing the case of applying the metal substrate module of the present invention, (b) shows an analysis result applying the case of using only a typical aluminum heat dissipation frame. In the case of using a general aluminum heat dissipation frame as shown in (b), heat is concentrated only at the center portion where the heat source is located, so that heat is not transmitted and dissipated to the surroundings, whereas in case of (a), heat is evenly transmitted and dissipated to the surroundings. It can be seen that.

According to the present invention, since the thermally pressurized heat spreader with a relatively small volume and a printed circuit pattern are formed integrally with each other, the cooling efficiency of the heating element is very excellent compared to the conventional printed circuit board, It will be possible to prevent product malfunction or breakdown. Therefore, when the present invention is applied to various electric and electronic parts such as LCD TVs, LED TVs, PDP TVs, various computers, audio devices, lighting devices, etc., the heating and cooling problems of the devices will be easily solved without the addition of additional cooling means.

100: heat pressurized heat spreader 110: top plate
120: lower plate 121: heat medium accommodating depression
122: injection needle accommodating depression 123: edge portion
130: injection needle 160: injection device
200,300: Heat spreader 310: Top plate
320: lower plate 321a: center groove
321b: spinning groove 400: metal substrate
410: printed circuit layer 411: insulating layer
412: printed circuit pattern layer 413: solder mask layer
420: heating element 500: metal substrate module
510: heat dissipation frame 511: body portion
512a, 512b: coupling portion 513: heat radiation fin
523: channels 524a, 524b: grooves

Claims (1)

The present invention relates to a method of manufacturing a heat pressurized heat spreader-based metal substrate having a heat pressurized heat spreader having a channel into which a heat medium is vacuum-injected and a printed circuit layer integrally formed on a plate surface of the heat pressurized heat spreader.
The upper plate and the lower plate of the plate-shaped metal are prepared and the plate surface of the lower plate is recessed to form a channel for accommodating the heating medium and an injection needle receiving recess connected to the channel, wherein the channel formed on the lower plate is recessed in the center of the lower plate. It is formed by etching the plate surface of the lower plate so as to be connected to the central groove and the central groove is formed so as to consist of a plurality of radial grooves disposed radially around the central groove, the injection needle receiving recessed portion to concave the plate surface of the lower plate Forming by pressing;
Forming a thermally pressurized heat spreader by placing a tubular injection needle having an injection flow path formed therein into the injection needle accommodating recess of the lower plate and then thermally pressing the upper plate and the lower plate to combine the upper and lower plates;
Cleaning and drying the plate surface of the heat pressurized heat spreader;
Forming an insulating layer on the plate surface of the cleaned and dried heat pressurized heat spreader;
Forming a copper foil layer on the insulating layer;
Forming a photosensitive material layer on the copper foil layer and then forming a printed circuit pattern through an exposure, development, and etching process;
Forming a solder mask layer using solder resist ink on the printed circuit pattern to protect the printed circuit pattern;
Vacuum injection of the heat medium through an injection needle connected to the inside of the heat pressurized heat spreader; And
Heat-pressing the injection needle to seal and close the injection flow path therein;
Method of manufacturing a metal substrate based on heat pressurized heat spreader comprising a.

Images