KR101059118B1 - Fastening method of circuit board and heat sink with excellent mounting efficiency and light efficiency - Google Patents

Abstract

According to the present invention, in the method of fastening the heat sink 400 to the substrates 100 and 110 with the screw 500, the screw 500 is inserted from the bottom of the heat sink 400 and the screw 500 to the bottom surface of the substrate 100 and 110. The end of the spiral portion 501 of the screw is screwed, but the end of the spiral portion 501 of the screw 500 is coupled so as not to be exposed to the surface of the substrate (100, 110) and the circuit board and heat sink excellent in mounting efficiency and light efficiency The present invention relates to a fastening method of the present invention, in the fastening of a circuit board to a heat dissipating part such as a heat sink, it is possible to prevent the exposure of the screw on the surface of the board to facilitate the circuit design of the board, the density of the circuit and the parts The mounting rate can be increased, and optical properties such as reflectance or absorptivity of the surface of the circuit board can be improved.

In addition, the present invention can prevent damage to the circuit board due to physical impact through the drilling work or punching work for screwing, and because the screw head is not exposed on the surface of the board, the electrical failure of the surface of the board by the metal screw It is a very useful invention that can eliminate the possibility and to ensure the reliability of the product by suppressing the inflow of foreign substances on the substrate surface.

Heat sink, case, circuit board, heat dissipation, screw fastening

Description

Joining method of circuit board and heat sink with excellent mounting efficiency and light efficiency

The present invention relates to a method for fastening a circuit board and a heat sink. In particular, when the circuit board and the heat sink are fastened, screws are fastened to the bottom surface of the circuit board, that is, in the heat sink direction, to increase the degree of integration of components on the surface of the circuit board. The present invention relates to a circuit board and a heat sink fastening method for improving optical characteristics and increasing reliability of a product.

Generally circuit boards, metal circuit boards, ceramics that require high integration or optical properties on the circuit board surface, and heat-generating components such as BLU LEDs, lighting LEDs, or high power devices where heat dissipation and temperature reliability are important. A method of fastening circuit boards, such as a board and a flexible board, or a combination of these boards to a heat sink (including a case and a jig). In the related art, a drill or punching is performed on a circuit board and a heat sink. The method of processing the screw introduction part and inserting and fastening the screw from the upper part of the circuit board has been used.

As an example, [FIG. 1] shows a fastening state between a conventional general substrate 100 and 110 and a heat sink 400, and processes a through screw hole in the substrate 100 and 110, and then processes the processed screw of the heat sink 400. FIG. In the hole, a method of fastening while inserting the screw 500 on the substrate 100 and 110 is shown.

Such conventional methods are not only limited by the difficulty of wiring the circuit due to the fastening part of the circuit board surface, the screw, etc., but also the light and short reduction due to the high density of the circuit and the decrease of the component mounting rate, and also in the drilling or punching process of the circuit board. If damage occurs to the substrate, product reliability is lowered and yield is deteriorated, and optical characteristics of the surface of the substrate are required, the characteristics of the screw insertion portion are deteriorated. There have been disadvantages that cause the possibility of electrical failures due to, and deteriorate the reliability of the product by the introduction of foreign matter from the drill groove.

The present invention facilitates the design of the circuit by preventing the screw, more specifically, the screw head from being exposed to the surface of the substrate, thereby increasing the density of the circuit and increasing the mounting rate of components, and reflecting or absorbing the surface of the circuit board. It aims at making it possible to improve an optical characteristic.

It also prevents damage to the circuit board due to physical shocks through conventional drilling or punching work, and prevents the screw from being exposed to the surface of the board, eliminating the possibility of electrical defects on the surface of the board by metallic screws. The purpose is to make it possible.

In the present invention, when a circuit board is fastened to a heat dissipation component such as a heat sink, a screw is inserted from a surface of a substrate so as to be fastened to a heat sink, and conversely, a screw is inserted into a bottom of a heat sink. It is to be inserted into the screw from the bottom of the substrate ().

As described above, in the present invention, when the circuit board is fastened to a heat dissipation component such as a heat sink, the screw may be prevented from being exposed on the surface of the substrate, thereby facilitating the circuit design of the substrate, increasing the density of the circuit and increasing the mounting rate of the component. In addition, optical characteristics such as reflectance or absorptivity of the surface of the circuit board may be improved.

In addition, the present invention can prevent damage to the circuit board due to physical impact through the drilling work or punching work for screwing, and because the screw head is not exposed on the surface of the board, the electrical failure of the surface of the board by the metal screw It is a very useful invention that can eliminate the possibility and to ensure the reliability of the product by suppressing the inflow of foreign substances on the substrate surface.

The present invention for achieving the above objects and effects will be described in detail.

Prior to the description, the terms or words used in the specification and claims, etc. should not be construed as limited to conventional or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical characteristics of the present invention, and accordingly the present invention and the specification. The described embodiments and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents and modifications that may be substituted for them at the time of filing the present invention. It should be understood that there may be examples, and the embodiments described herein are illustrative only and do not have a limiting meaning, and the scope of the present invention is defined in the appended claims and all that can be understood therefrom. It is to be understood that the modification includes the embodiments.

The present invention is to allow a screw to be fastened to a bottom surface of a substrate by inserting a screw from the bottom of the heat sink in fastening the circuit board to a heat dissipation component such as a heat sink.

This method can be applied to general rigid circuit boards, ceramic circuit boards, metal circuit boards, and the like, and can also be applied to the combined use of rigid circuit boards, ceramic circuit boards, metal circuit boards, and flexible circuit boards.

In case of general rigid circuit board, it can be applied to all rigid circuit boards such as FR-4, FR-1, CEM-1, CEM-3, in this case, after lamination process, copper clad laminate (CCL; Cu clad laminate) state If the substrate is hardened, such as after PCB processing, screw hole processing is possible. At this time, the screw hole is processed to a depth directly below the upper circuit metal, leaving no holes or traces on the upper portion of the circuit board.

In the case where the rigid circuit board is a multilayer circuit board, the above-described method can be used, and screw holes can be processed below the final upper circuit layer.

In the case of a multi-layer circuit board, alternatively, through threaded holes are machined before laminating the final upper circuit metal or a portion of the upper circuit layer, and the final upper circuit layer or the portion of the upper circuit layer is semi-radiated and insulated. The lamination and pressure forming method may be used to cover the perforated screw hole using a layer, and the semi-cured insulating layer may be made of a material having low or little flowability during curing. It can flow into the hole and prevent it from hardening while filling the hole unnecessarily.

In the case of ceramic circuit boards, the method of the rigid circuit board may be applied. Alternatively, after drilling through-holes in the ceramic plate, a semi-hardened insulating layer and a circuit metal or semi-cured RCC (Resin) may be used. Laminated by using a coated Cu coil, and by pressing a ceramic plate having a through hole for a screw hole in the step of manufacturing a ceramic substrate, and produced a semi-insulated insulating layer and a circuit metal or semi-cured RCC ( You can use lamination method using Resin coated Cu coil).

In addition, in the case of a metal circuit board, a method similar to that of a rigid circuit board may be applied. As shown in FIG. 4, after processing the through-hole for screwing in the metal, the insulating layer and the circuit metal or the semi-hardened layer thereon Laminated by using Resin coated Cu coil (RCC) (The semi-hardened insulating layer uses a material with low or little flowability when hardened. The insulating layer flows into the screw hole to harden the holes unnecessarily. It can be used to process the screw holes that do not penetrate the metal, as shown in FIG. 5, and then apply a semi-cured insulating layer and circuit metal or semi-cured resin coated Cu coil (RCC). Lamination using a method (not affected by the flowability of the insulating layer in this case), and a method for processing screw holes that do not penetrate after lamination or after PCB processing as shown in FIG. Law can be used.

In addition, when a multilayer circuit board is formed using a metal circuit board, the above schemes may be used or combined and modified.

In using the above-mentioned boards and boards composed of a combination of boards for LED lighting and LED BLU, the light efficiency of the board surface is important and the manufacturing cost and the product are not important if the mounting efficiency is not important. In consideration of the yield, it is possible to process the hole through punching or drilling to the upper surface of the circuit board and fasten the screw from the heat sink to the circuit board. The length of the screw is lower than the height of the upper circuit. Using the length that can be fastened and the concave remainder on the upper screw hole, the optical properties such as reflectivity, thermal conductivity and insulation properties, which are excellent in optical properties such as reflectivity, alone or in combination of silicone, epoxy, acrylic and other resins, etc. By applying, inserting or capping materials containing additives to increase the Can. Additives used in the material to be applied and inserted can be used alone or combined inorganic fillers such as Al2O3, Al (OH) 3, TiO2, SiO2, AlN, BN, MgO, flame retardants, hardeners, etc. Rubber-based resins and polymer resins may be used to give adequate elasticity, and the cap may be manufactured in various shapes such as cylindrical, wedge-shaped, mushroom-shaped, and hat-shaped.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Example 1

2 is a screw is inserted from the bottom of the heat sink to fasten the circuit board (100,110) to the heat sink 400 so that the spiral end of the screw is screwed to the bottom surface of the substrate, but It shows a method of joining such that the spiral end of the screw is not exposed to the surface of the substrate.

2A illustrates a fastening method in the case of a general rigid circuit board 110, and FIG. 2B illustrates a fastening method in the case of a metal circuit board or a ceramic substrate 100.

[Example 2]

3 is a diagram illustrating a method for fastening a general rigid circuit board 110 to the heat sink 400.

Accordingly, the fastening method according to the present embodiment,

1) a lamination step of the general rigid circuit board 110 (FIG. 3A);

2) after the press molding of the circuit board 110, a drilling step and a screw hole 700 processing step for fastening the screw 500 to a height below the upper circuit metal (Fig. 3b);

3) PCB process step and module manufacturing step for circuit processing (Fig. 3c);

4) fastening of the circuit board 110 and the heat sink 400 (FIG. 3D);

At this time, the processing of the screw hole 700 can be performed at any stage after lamination, after PCB processing, and before and after module processing. However, in general, PCB processing is completed after circuit processing for the efficiency of process management and damage caused by chemicals during PCB processing. It is advantageous to do after the process.

In addition, the embodiment according to the case of the multi-layer circuit board and the board combining the composite material substrate has been described in detail in the problem solving means, and the present embodiment because it will be similarly described in the other embodiments and the like [Example 1] Omit from.

Example 3

FIG. 4 illustrates one method for fastening the metal circuit board 100 or the ceramic substrate 110 to the heat sink 400.

Accordingly, the fastening method according to the present embodiment,

1) a step of machining the through type screw hole 700 of the bottom metal of the metal circuit board 100 (FIG. 4A);

2) laminating and pressure forming the processed bottom metal, the insulating layer and the top circuit metal (FIG. 4B);

3) PCB process step and module manufacturing step for circuit processing (Fig. 4c);

4) fastening of the metal circuit board 100 and the heat sink 400 (Fig. 4- (d));

At this time, the processing of the through screw hole 700 of the metal circuit board 100 sets a reference point before the lamination, and processing at the required position, the insulating layer used is a thermal conductivity of the entire substrate using a high thermal conductivity It is preferable to increase the value, and it is preferable to use the one in which the unnecessary filling phenomenon of the screw hole 700 does not occur by using a low or almost no flow of the insulating layer in the curing step.

Example 4

FIG. 5 illustrates another method for fastening the metal circuit board 100 or the ceramic substrate 110 to the heat sink 400.

Accordingly, the fastening method according to the present embodiment,

1) the step of processing the unperforated screw hole 700 of the bottom metal of the metal circuit board 100 (FIG. 5A);

2) pressing and laminating the processed bottom metal, the insulating layer and the upper circuit metal after lamination (FIG. 5B);

3) PCB processing step and module manufacturing step for circuit processing (Fig. 5c);

4) a fastening step of the metal circuit board 100 and the heat sink 400 (Fig. 5-d);

At this time, the processing of the non-through threaded hole 700 of the metal circuit board 100 sets a reference point before lamination, and processes it at a necessary position. In this case, the insulating layer used is a thermal conductivity of the entire substrate using a high thermal conductivity. It is preferable that the degree is high, and the insulating layer may be used without any general insulating layer.

Example 5

FIG. 6 illustrates another method for fastening the metal circuit board 100 or the ceramic substrate 110 to a heat sink.

Accordingly, the fastening method according to the present embodiment,

1) laminating the upper metal and the insulating layer and the bottom metal (Fig. 6a);

2) pressing the metal circuit board 100 by pressing (FIG. 6B);

3) PCB processing step and module manufacturing step (FIG. 6C) for the bottom through-hole screw hole 700 processing step of the bottom metal of the metal circuit board 100 and circuit processing;

4) fastening of the metal circuit board 100 and the heat sink 400 (Fig. 6-D);

In this case, the processing of the non-through threaded hole 700 of the metal circuit board 100 may be performed at any stage after lamination and pressure forming, after the PCB process and before and after the module process, but is generally damaged by chemicals during PCB processing. It is advantageous to do this after the PCB process is finished, for efficiency and process control.

Example 6

FIG. 7 illustrates the through screw hole 700 in the circuit board 100 and fastening the screw 500 from the heat sink 400 to the circuit board 100, wherein the remaining screw hole 700 in the upper portion of the circuit is shown. Is a view showing a method of coating or inserting the cap 900 with a material having excellent reflectivity, thermal conductivity, insulation properties, and the like, or covering the concave portion of the concave portion.

Accordingly, the method according to the present embodiment,

1) PCB processing step of the circuit board 100;

2) a machining step and a module process of the screw hole 700 passing through the circuit board 100;

3) fastening of the heat sink 400 and the module;

4) applying a filling material 800 to the upper screw hole 700 and curing step (FIG. 7A);

5) capping the cap 900 in the upper screw hole 700 (FIG. 7B);

The through screw hole 700 is processed by punching or drilling, and the process of applying the filling material 800 is preferably performed after the circuit board 100 and the heat sink 400 are fastened. The process of covering the cap 900 may be performed first after the module process.

In addition, the shape of the cap 900 may be manufactured and used in a variety of shapes, such as cylindrical, wedge, mushroom, hatshade, etc., the diameter of the cap 900 is the same as the through screw hole 700 or several to tens of micro It is preferable not to be removed after inserting using a large enough, and the height of the cap 900 is adjusted to the length of the screw 500, after protruding to the upper portion of the circuit board 100 after the screw 500 is fastened. It is desirable to avoid.

At this time, the material to be applied and inserted into the material 800 and the cap 900 is a resin and a composite material such as epoxy, silicone, acrylic, urethane, and the additives are Al2O3, Al (OH) 3, TiO2, SiO2, Inorganic fillers such as AlN, BN, MgO, or a combination of inorganic fillers, flame retardants, hardeners, and the like may be used, and rubber-based resins and polymer resins may be used together to give proper elasticity so that the inserted cap does not fall out.

1 is a view showing a fastening method of a conventional general circuit board and the heat sink.

2 is a view showing a fastening method of a general circuit board, a metal circuit board and a heat sink according to the present invention.

3 is a view showing a fastening method of a general circuit board and a heat sink according to the present invention, showing a method of processing a screw hole below the upper circuit metal before, during and after the PCB process.

4 is a view showing a fastening method between a metal circuit board and a heat sink according to the present invention, and before lamination process, the process of screw hole through the bottom metal completely and then lamination process, pressure forming, PCB process and module process A diagram showing progress.

5 is a view showing a fastening method between a metal circuit board and a heat sink according to the present invention, in which a screw hole not penetrating the bottom metal is processed before the lamination process, and then the lamination process, the PCB process, and the module process are performed. Shown.

FIG. 6 is a view showing a method of fastening a metal circuit board and a heat sink according to the present invention, and showing a method of processing a screw hole not penetrating a bottom metal before, during and after a PCB process. FIG.

7-In the present invention, the through-hole is processed in the circuit board and the screw is fastened to the circuit board in the heat sink, wherein the concave portion of the remaining screw grooves in the upper part of the circuit is coated with a material having excellent reflectance, thermal conductivity, insulation properties, and the like. Or a drawing showing how to insert or cap.

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

100: metal circuit board 110: general circuit board or ceramic board

200: substrate circuit portion 300: component or element

400: heat sink 500: screw for fastening

600: thermal pad, thermal tape, thermal grease adhesive, plain tape or grease

700: screw hole 800: material for application and filling

900: cap

Claims (4)

delete In the method for fastening the heat sink 400 to the substrate (100,110) with a screw 500, Machining a screw hole 700 in the substrate (100,110), but drilling the screw hole (700) only to a portion directly under the upper circuit metal; PCB processing and module mounting using the screw hole perforated substrate; And processing the screw hole 700 in the heat sink 400 to be screwed to the substrate. The fastening method of the circuit board and the heat sink excellent in mounting efficiency and light efficiency. In the method for fastening the heat sink 400 to the substrate (100,110) with a screw 500, When the substrate 100 is a metal substrate, the screw hole 700 is processed in the bottom metal for the metal substrate, and the screw hole 700 passes through the bottom metal, or the depth of the screw hole 700 is lower than the bottom metal. Processing smaller than the thickness; Manufacturing a metal substrate by laminating a metal plate, an insulating layer, and a metal part constituting a circuit; PCB processing and module mounting using the manufactured metal substrate; Process for fastening the screw hole (700) in the heat sink 400 using a screw to the substrate; fastening method of the circuit board and heat sink excellent in mounting efficiency and light efficiency, characterized in that it comprises a. In the method for fastening the heat sink 400 to the substrate (100,110) with a screw 500, The screw hole 700 is formed to penetrate the circuit boards 100 and 110, and the spiral part 501 is fastened to the screw hole 700, and the remaining part is filled with a material for coating and filling 800 so that the screw is formed on the substrate. Fastening method of circuit board and heat sink excellent in mounting efficiency and light efficiency, characterized in that not to be exposed to the surface.

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