KR100675713B1 - Method for manufacturing printed circuit board for high-heating radio-device - Google Patents

Abstract

A method for manufacturing a printed circuit board for a high-heating radio-device is provided to prevent a fused solder from flowing out outside a joining surface between a printed circuit unit and a metal plate by forming a V-shaped groove on an outer periphery of a solder removing portion. A method for manufacturing a printed circuit board(10) for a high-heating radio-device includes the steps of: a metal plate forming step of forming a V-shaped groove unit on a top surface of a metal plate(110) made of a metal having high thermal conductivity; a silk screen manufacturing plate forming step of forming a lattice type pattern on a silk screen manufacturing plate having a shape equal to that of the metal plate(110) at a predetermined interval and forming an external periphery of a solder removing portion at an interval corresponding to a width of V-shaped groove unit; a solder coating step of arranging the formed silk screen manufacturing plate on a top surface of the metal plate(110) and coating the solder uniformly; and a hot press step of stacking a printed circuit unit(120) on the solder coated metal plate(110) and smoothly cooling after performing the hot press before starting oxidation.

Description

Method for manufacturing printed circuit board for high frequency high heat generating device {Method for manufacturing Printed Circuit Board for high-heating radio-device}

1 is a photograph of a printed circuit board manufactured by a method of manufacturing a printed circuit board for a high frequency high heat generating element according to the present invention.

2A and 2B are schematic cross-sectional views of a printed circuit board for explaining a method of manufacturing a printed circuit board for a high frequency high heat generating element according to the present invention;

3A and 3B are cross-sectional views (b) taken along the line x-x 'of the plan views (a) and (a) showing one example of the metal plate according to FIGS. 2a and 2b.

Figure 4 is a front view showing an example of a silk screen plate used in the method of manufacturing a printed circuit board for high frequency high heat generating element according to the present invention.

Explanation of symbols on the main parts of the drawings

10: printed circuit board for high frequency high heat generating element 110: metal plate

112 recessed portion for heating element 114 recessed portion for wiring

116: beer hole 118: rivet hole

119: V-shaped groove portion 120: printed circuit portion

130: cream solder 140: rivets

150: heating element 400: silk screen engraving

410: soldering exclusion

The present invention relates to a method for manufacturing a printed circuit board for a high frequency high heat generating element, and more particularly, in order to effectively reduce the transmission loss of a high frequency signal transmission circuit such as efficient cooling and mobile communication, broadcasting, etc. In the method of manufacturing a printed circuit board in which a printed circuit portion in which a circuit is formed is laminated on a metal plate having excellent conductivity, the hot press method which improves the structure of the metal plate and the application method of the solder cream and replaces the reflow method is used. The present invention relates to a method for manufacturing a printed circuit board for a high frequency high heat generating device capable of achieving standardization, simplification and low cost of a process.

In general, a printed circuit board (PCB) for a high frequency transmission circuit forms a signal transmission line and a path by a conductor such as copper plate or gold foil on a flat plate of a dielectric such as epoxy resin or Teflon resin. By mounting various electronic components, a predetermined function circuit is constituted.

Such printed circuit boards have various shapes and structures depending on the purpose of use and application functions. In particular, when a device that emits a large amount of heat is mounted, for example, when an amplifier is mounted, the following two conditions are required. do.

That is, a heat conductor for conducting heat to heat sinks and the like through the surface of the printed circuit board, and a function as an electrical conductor to reduce transmission loss by having a constant dielectric constant with the wiring of the printed circuit board because the ground is stable. This is required at the same time, whereby the two requirements can be achieved simultaneously by bonding the metal to the printed circuit board.

In order to achieve the requirements of thermal and electrical conduction, there are two methods of manufacturing a printed circuit board in which a metal plate is bonded. The second is to construct the circuit through additional post-processing to the printed circuit board disc with metal plate.

More specifically, the first method is a solder in which flux and lead powder are mixed on an aluminum plate copper- or tin-plated or a gold-plated aluminum plate to attach the printed circuit unit on which the circuit is first formed to the metal plate. It is a method of soldering and bonding a metal plate and a printed circuit part by applying a predetermined amount of cream using a stencil, laminating a printed circuit part on an upper surface of the metal plate, and putting the cream into a reflow soldering equipment.

In the second method, the circuit pattern is formed on the integrated metal PCB original plate to which the printed circuit part and the metal plate which are not formed of the circuit are soldered and attached by using an electrically conductive resin, the via hole drill processing, the machining and the via hole of the outer part and the device mounting part. It is a method of forming a printed circuit board by additional post processing such as forming.

However, the manufacturing method of the above-described printed circuit board has a problem in that the bonding process is difficult in the first method, and the circuit processing process in the second method.

More specifically, as in the first method described above, the joining method by the reflow soldering equipment has a problem that the temperature conditions of the soldering should vary depending on the shape and size of the metal plate and the printed circuit.

Because the metal plate must be heated to a certain temperature, the solder cream applied to the metal plate can be melted and bonded to the printed circuit part. However, in general, the reflow soldering equipment heats using heat by convection of heated nitrogen, so that the heat efficiency decreases. It is difficult to standardize the working conditions according to the type and size of the metal plate, the spacing of the metal plate to be loaded into the reflow soldering equipment, and the size and shape of the jig for fixing the metal plate and the printed circuit part.

In this case, the solder cream is applied using a stencil, which is very difficult to finely adjust the amount of the solder cream, and when the amount of the solder cream is large, there is a possibility that molten lead is released to the outside of the joint, If the amount of solder cream is small, the joint is not adequately achieved, and manufacturing costs are expensive.

On the other hand, as in the second method described above, the circuit forming method by an additional post-processing using an integrated metal printed circuit board is a relatively strong strength and heavy processing object because the PCB must be processed in a state where the metal plate is bonded to the existing Teflon And compared to the printed circuit board of the epoxy material there is a problem that the processing is quite difficult.

In particular, the process of processing and plating via holes in a printed circuit board is difficult and may damage the circuit formed in the process of cutting to a desired shape, and moreover, such a method is also expensive to manufacture.

The present invention has been proposed to solve the above problems, it is possible to constantly manage the amount of lead and the bonding conditions for the bonding of the printed circuit portion and the metal plate on which the circuit is formed, and to prevent the outflow of molten lead to improve the quality of the product An object of the present invention is to provide a method for manufacturing a printed circuit board for a high frequency high heat generating element.

The present invention for achieving the above object is a method for manufacturing a printed circuit board for a high frequency high heat generating element in which a printed circuit portion formed of a circuit is formed on the upper surface of the metal plate, the printing on the upper surface of the metal plate made of a high thermal conductivity metal, A metal plate forming step of forming a V-shaped groove portion on the outside of the solder exclusion portion where the circuit portions are not laminated; A silkscreen plate is formed on the silkscreen plate having the same shape as that of the metal plate at regular intervals with a lattice pattern having a predetermined width, and the outer edge of the solder exclusion portion is formed at intervals corresponding to the width of the V-shaped groove portion. Forming step; A lead coating step of disposing the formed silkscreen plate on the upper surface of the metal plate and applying a pressurized lead constantly; The printed circuit part is laminated on the lead-coated metal plate, and the hot press is hot pressed before melting starts after oxidation of the lead at a constant pressure according to the material of the printed circuit part and the metal plate at a temperature higher than the melting point of the coated lead. Characterized in that it comprises a step.

Preferably, the forming of the metal plate further includes a soldering affinity plating step of plating a metal having a high affinity for lead on the surface of the printed circuit unit when the metal plate is made of a metal other than a soldering affinity material. can do.

Preferably, the silkscreen plate forming step may adjust the amount of lead to be applied to the metal plate according to the line width or lattice spacing of the grid pattern.

The present invention may further include a rivet fixing step of stacking the printed circuit unit on the lead-coated metal plate and riveting the metal plate and the printed circuit unit through the rivet hole formed in the metal plate and the printed circuit unit. .

Preferably, the hot pressing step may be maintained for 10 to 20 minutes at a pressure of 30 ~ 100psi at a temperature of 197 ~ 217 ° C lead is applied to the metal plate is a general cream solder.

Preferably, the hot pressing step may be maintained for 10 to 20 minutes at a pressure of 30 ~ 100psi at a temperature of 222 ~ 242 ℃ lead is applied to the metal plate is lead-free.

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

1 is a photograph of a printed circuit board manufactured by a method for manufacturing a printed circuit board for a high frequency high heat generating device according to the present invention, and FIGS. 2a and 2b illustrate a method for manufacturing a printed circuit board for a high frequency high heat generating device according to the present invention. It is a schematic sectional drawing of a printed circuit board.

The printed circuit board 10 for a high frequency high heat generating element is composed of a metal plate 110 made of a metal having high thermal conductivity and a metal plate 110 and a printed circuit unit 120 having a corresponding circuit.

Here, the metal plate 110 is, for example, aluminum, copper, gold in order to provide effective cooling of the heat generating element 150 that dissipates a large amount of heat and to provide stable grounding for the high frequency circuit formed in the printed circuit unit 120. And metals having high thermal and electrical conductivity such as silver and alloys thereof.

The printed circuit unit 120 may have a pattern of a high frequency circuit or a power circuit, and the metal plate 110 may be used to effectively cool the heat generated from the heating element 150 in a portion except for the corresponding electrode among the portions in which the heating element 150 is disposed. It is formed to be exposed.

As shown in FIG. 2, the metal plate 110 and the printed circuit unit 120 are bonded by a cream solder 130 applied therebetween, and such bonding is achieved by a hot press as described later.

Here, the metal plate 110 and the printed circuit unit 120 is a rivet fixing part 140 through a rivet hole (not shown) formed in the metal plate 110 and the printed circuit unit 120 before the hot press to accurately match the stacking position. It is fixed by).

Hereinafter, a method of manufacturing a printed circuit board for a high frequency high heat generating element according to the present invention will be described with reference to FIGS. 3A to 4.

3a and 3b are cross-sectional views (b) taken along the line x-x 'of the plan views (a) and (a) showing an example of the metal plate according to Figures 2a and 2b, Figure 4 is a high frequency in accordance with the present invention It is a front view which shows an example of the silkscreen making used for the manufacturing method of the printed circuit board for high heat generating elements.

First, a printed circuit unit 120 in which a circuit including the heating element 150 is formed is manufactured. In this case, a pattern is not formed to expose the metal plate 110 at a position where the heating element 150 is disposed.

Next, the fabrication of the metal plate 110 uses a metal having high thermal conductivity and electrical conductivity, and the heating element is positioned at the position where the heating element 150 is disposed on the upper surface of the metal plate 110 for effective cooling of the heating element 150. The dragon recess 112 is formed. The recess 112 for the heating element is a solder excluding portion 410, which will be described later, and the lead is not applied to the portion.

Here, when the metal plate 110 is made of a metal that is not a solder affinity material, for example, a copper alloy such as aluminum, bronze, or brass, the printed circuit unit 120 may be stacked on the surface of the metal plate 110 on which lead is formed. Metals, such as affinity tin, silver, and gold, are plated.

For example, when the metal plate 110 is aluminum, electro-tin plating after electroless nickel plating, and when the metal plate 110 is a cobalt and copper alloy, gold is plated to improve soldering affinity of the metal plate 110. .

In addition, in the manufacture of the metal plate 110, as shown in Figure 3a, the wiring recess 114 for forming the wiring between the via hole 116, and the upper surface of the metal plate 110 for wiring the circuit and A via hole 116 penetrating the lower surface and a rivet hole 118 for fixing to the printed circuit unit 120 are formed.

Here, the heat generating element recesses 112 and the wiring recess portions 114 are formed on different surfaces of the metal plate 110. For example, as shown in FIG. 3A, the heat generating element recesses 112 are formed on the metal plate. On the upper surface (or the front surface) of the 110, the wiring recess 114 is formed on the lower surface (or the rear surface) of the metal plate 110.

On the other hand, outside the solder exclusion portion where lead is not applied, such as the outermost portion of the heat generating element recess 112, the via hole 116, the rivet hole 118, and the metal plate 110 formed in the metal plate 110, As shown in FIG. 3B, the V-shaped groove 119 may be formed to prevent the molten lead from flowing out of the bonding surface of the metal plate 110 and the printed circuit unit 120 by hot pressing.

In order to manufacture the silkscreen plate 400 for applying lead to the metal plate 110, first, the silkscreen plate 400 having the same shape as that of the metal plate 110 is prepared, and then the surface of the silkscreen plate 400 is fixed. A grid pattern having a line width of a size is formed at regular intervals (a), but the outer edge of the solder excluding portion 410 not to apply lead corresponds to the width of the V-shaped groove portion 119 of the metal plate 110. It forms in the space | interval b.

Here, the amount of lead to be applied to the metal plate 110 can be adjusted according to the spacing a and the line width of the lattice pattern. For example, the line width of the lattice pattern is 0.1 mm and the pattern spacing is 1 mm. .

In addition, the outer edge of the solder exclusion portion 410 forms a lattice pattern at intervals of 0.5 mm, which is the width of the V-shaped groove portion 119 to prevent lead from being applied to the V-shaped groove portion 119 of the metal plate 110. Form a grid at intervals of magnitude.

The silk screen plate 400 manufactured as described above is disposed on the upper surface of the metal plate 110 and the lead is uniformly pressed to include lead for bonding the metal plate 110 and the printed circuit unit 120.

At this time, the lead is applied to the metal plate 110 along the line of the grid pattern formed on the silk screen plate 400, as shown in Figure 4, the recess 112, the via hole 116, rivets for the heating element The solder exclusion portion 410 corresponding to the dragon hole 118 and the outermost portion of the metal plate 110 is not applied.

The application of lead using the silk screen platen is easier to control the amount of lead to be applied than when using a stencil as in the prior art, and the application of lead according to the circuit pattern of the metal plate 110 or the printed circuit unit 120. Various shapes for the purpose can be easily provided.

Next, as illustrated in FIG. 2, the printed circuit unit 120 is laminated on the lead-applied metal plate 110, where the metal plate 110 and the printed circuit unit 120 are fixed to each other at an accurate position. The metal plate 110 and the printed circuit unit 120 are fixed by the rivet fixing part 140 through the rivet hole 118 formed in the plate.

The rivet fixing may be selectively used in order to achieve an effective bonding by maintaining the exact position of the metal plate 110 and the printed circuit unit 120 in the hot pressing process as described later.

As described above, the metal plate 110 and the printed circuit unit 120, which are riveted or fixed, are bonded to each other using a hot press.

More specifically, after the melting of the lead applied at a constant pressure according to the material of the metal plate 110 and the printed circuit unit 120 at a temperature higher than the melting point of the lead applied to the metal plate 110, hot pressing before the start of oxidation and then is cooled slowly.

Here, the temperature of the hot press is set to a temperature higher than the melting point so that the applied lead can be sufficiently melted. For example, the general cream solder has a melting point of about 187 ° C. and the lead-free lead is 212 ° C. When using a solder, it is set to 197-217 degreeC, and in the case of lead-free, it is set to 222-242 degreeC.

In addition, the pressure of the hot press is set to a pressure such that the metal plate 110 and the printed circuit unit 120 can be sufficiently bonded, in particular, depending on the material of the printed circuit unit 120, for example, 30 ~ Set to a pressure of 100 psi.

In addition, the holding time of the hot press is set to the time before the start of oxidation after the applied heat source reaches the temperature condition, the lead applied to the metal plate 110 is sufficiently melted and distributed throughout the metal plate 110. The holding time of the hot press is determined according to the type of lead to be applied and the material of the metal plate 110 and the printed circuit unit 120. For example, the holding time is maintained for 10 to 20 minutes.

At this time, the molten lead by the hot press may flow out of the bonding surface of the metal plate 110 and the printed circuit unit 120 by the pressure of the hot press, the recess 112, the via hole 116, The V-shaped groove portion 119 formed in the riveting hole 118 and the solder excluding portion 410 corresponding to the outermost portion of the metal plate 110 may be accommodated therein, thereby improving the quality of the bonding.

On the other hand, the hot press can manufacture a plurality of high-frequency high-heating element printed circuit board 10 at a time by using a hot press device for multilayer PCB bonding, in this case, 0.1T aluminum plate for each layer of the hot press device Are superimposed on top and bottom of the printed circuit board 10 for high frequency high heat generating elements, and several are arranged at regular intervals, and then hot press is performed to remove the lead from the molten state of lead that can flow out of the printed circuit board 10 for high frequency high heat generating elements. The press apparatus can be protected.

As described above, the method of manufacturing a printed circuit board for a high frequency high heat generating element according to the present invention is a silkscreen having a lattice pattern in a method of manufacturing a metal laminated printed circuit board for high heat generating element cooling and stable grounding of a high frequency circuit. By controlling the amount of lead applied to the metal plate using the plate making, it is possible to manage the amount of lead and the bonding conditions more consistently than the conventional manufacturing method by reflow soldering, thereby achieving the standardization and simplification of the process.

In addition, according to the present invention, by forming a V-shaped groove portion outside the solder exclusion portion of the metal plate, it is possible to prevent the lead in the molten state to flow out of the bonding surface of the printed circuit portion and the metal plate, thereby improving the quality of the product.

In addition, the present invention uses a hot press for multi-layer PCB bonding when bonding the printed circuit portion and the metal plate formed circuit, it is possible to manufacture a large amount of products at the same time for a short time, because the lead coated on the metal plate is heated by a heat conduction method Since the high thermal efficiency can reduce the production cost, there is an effect that can achieve a low cost of the process.

Claims (6)

In the manufacturing method of a printed circuit board for a high frequency high heat generating element in which a printed circuit portion having a circuit formed on the upper surface of a metal plate is laminated, A metal plate forming step of forming a V-shaped groove on an upper surface of a metal plate made of a metal having high thermal conductivity, on an outer side of a solder exclusion portion in which the printed circuit portion is not laminated; A silkscreen plate is formed on the silkscreen plate having the same shape as that of the metal plate at regular intervals with a lattice pattern having a predetermined width, and the outer edge of the solder exclusion portion is formed at intervals corresponding to the width of the V-shaped groove portion. Forming step; A lead coating step of disposing the formed silkscreen plate on the upper surface of the metal plate and applying a pressurized lead constantly; The printed circuit part is laminated on the lead-coated metal plate, and the hot press is hot pressed before melting starts after the melting of the lead at a constant pressure according to the material of the printed circuit part and the metal plate at a temperature higher than the melting point of the coated lead. Method of manufacturing a printed circuit board for high frequency high heat generating element comprising the step. The method according to claim 1, The forming of the metal plate may further include a solder affinity plating step of plating a metal having high affinity for lead on the surface of the printed circuit unit when the metal plate is made of a metal other than a solder affinity material. The manufacturing method of the printed circuit board for high frequency high heat generating elements. The method according to claim 1, The silk screen plate forming step is a method of manufacturing a printed circuit board for a high frequency high heating element, characterized in that for controlling the amount of lead to be applied to the metal plate according to the line width or the grid spacing of the grid pattern. The method according to claim 1, And a rivet fixing step of laminating the printed circuit part on the lead-coated metal plate and riveting the metal plate and the printed circuit part through rivet holes formed in the metal plate and the printed circuit part. Method of manufacturing a printed circuit board for a high heat generating element. The method according to claim 1, The hot pressing step is a method of manufacturing a printed circuit board for a high frequency high heating element, characterized in that the lead is applied to the metal plate is a general cream solder for 10 to 20 minutes at a pressure of 30 ~ 100psi at a temperature of 197 ~ 217 ℃. . The method according to claim 1, The hot pressing step is a method of manufacturing a printed circuit board for a high frequency high heat generating element, characterized in that when the lead applied to the metal plate is lead-free, it is maintained for 10 to 20 minutes at a pressure of 30 ~ 100psi at a temperature of 222 ~ 242 ℃ .

Images