WO2009052761A1

WO2009052761A1 - A pcb device and a method of manufacture thereof

Info

Publication number: WO2009052761A1
Application number: PCT/CN2008/072745
Authority: WO
Inventors: Songlin Li; Hongcai Li; Xiongfei Huang; Xikun Zhang; Chuanyu Wang; Jihou Li
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-10-19
Filing date: 2008-10-17
Publication date: 2009-04-30
Also published as: CN101415297B; CN101415297A

Abstract

A PCB device and a method of manufacture thereof. The PCB device includes: a first PCB (301), a second PCB (302), a power tube (305) and a heat sink (303). The second PCB (302) is a PCB of the high frequency and high power device. The SMT soldering side of the side end of the second PCB (302) is soldered with and fixed on the first PCB (301). The power tube (305) is connected with the hest sink (303) through an open window of the first PCB (301) and the second PCB (302). The pin of the power tube (305) is soldering with the second PCB (302). The heat sink (303) is connected with the lower surface of the first PCB (301).

Description

Printed board assembly and processing method thereof

The present invention relates to a circuit board, and more particularly to a high-power printed circuit board assembly having a heat dissipation function applied to a high-frequency, high-power circuit and a technology for realizing connection of power amplifier components.

Background technique

In order to solve the problem of electrical connection of electronic components, the printed circuit board (PCB) is generally used to realize electrical connection and fixing of numerous electronic components. For components with normal power and signal frequency, FR4 (Flame Retardant4) grades are used as printed circuit boards. However, with the industry's requirements for high-frequency, high-power functions, some high-frequency, high-power devices must be used. These devices, if they use common printed circuit boards (such as FR4 boards), cannot withstand high power loads and have high frequency effects. At this time, high-performance plates such as PTFE (Polytetrafluoraethylene) sheets must be used to solve the problems of matching, loss and heat dissipation of high-frequency, high-power power tubes.

At present, the printed circuit board for high frequency and power amplification functions, that is, the power amplifier board can achieve a frequency of 2G or higher, and the power of a single power tube can reach 100W or more. For low-frequency, low-power components, conventional printed boards are used to design electrical connections and fixtures for low-frequency, low-power components.

In addition, for high-power circuits under the working conditions of power amplification, it is necessary to provide sufficient heat dissipation conditions for the circuit board or components to ensure that the circuit board itself, other components on the board, and high-power components work at rated safety. Below the operating temperature, a common method is to connect a metal piece to the printed circuit here as a heat sink. Since the heat of the printed circuit mainly comes from high-power components, in order to meet the heat dissipation of the high-power components, the general high-power components are directly soldered or bonded with a conductive thermal conductive adhesive to a substrate specially designed for heat dissipation of high-power devices. The bottom is generally a metal substrate and has good thermal conductivity. This substrate is used to dissipate heat for high power devices. Of course, for some The power is very large, and the device with a large current and a large amount of heat is only insufficient for the substrate to dissipate heat at the same time. At this time, other heat dissipation measures are taken. For example, a large external heat sink is connected to the substrate. This large heat sink has a large area and volume to ensure that the heat sink is large enough. Moreover, such a heat sink often has a special heat dissipation structure, such as a multi-groove structure, to increase the heat dissipation area, and even a heat sink such as a fan, a ventilation, and the like can be installed for the heat sink. In addition, the substrate and the heat sink are generally metal parts, which can form an effective electrical connection, so in addition to effectively conducting heat, it can also provide grounding for the printed circuit board. This requirement is especially important in high frequency and RF circuit applications. The common method of grounding the printed circuit board is to design the necessary traces on the bottom surface of the printed circuit board. The rest is made of large-area copper. The copper layer on the bottom of the printed circuit board is connected to the heat sink to provide high power. The ground loop of the device.

Obviously, there are special requirements for printed circuit board design for circuits with a part of high frequency and high power. However, if high frequency plates and heat sinks are used for the entire circuit, the production cost of the printed circuit board is greatly increased. Therefore, the usual saving method is to design a special high-frequency, high-power circuit printed board for high-frequency, high-power parts of the circuit using high-frequency boards and heat sinks, here referred to as power-amplified printed boards; For circuits where the power is not very large and the frequency is not very high, conventional printed circuit boards are used to design conventional printed boards.

Thus, it is necessary to design two circuit printed boards in a circuit having high frequency and high power. One is a conventional printed board (conventional PCB board) for connecting and placing low-frequency, low-power devices; one is a power-amplified printed board (power-amplified printed board, power-amplified PCB board) for connection and placement High frequency, high power devices.

Figure la is a schematic diagram of a current main power amplifying printed board and its connection, including: a power tube 101, a high frequency board 102, a substrate 105, a heat sink 106, and a solder 104.

In the high frequency board 102 there is a circuit connection specifically designed for high frequency, high power circuits.

The power tube 101 passes through the high frequency sheet 102, and its lead 103 is soldered to the high frequency sheet 102 for providing electrical connection and fixing of the power tube 101.

The high frequency sheet 102 and the substrate 105 are soldered by solder 104. The substrate 105 is generally metal lining bottom.

The substrate 105 is connected to the heat sink 106 for heat dissipation.

In the prior art, in order to simplify the design of the circuit printed board, the power amplifying printed board is generally modularized to form a power amplifying printed board module. The power-amplified printed board module integrates a power-amplified printed board, as well as high-power devices soldered onto it, as well as a substrate or heat sink to which high-power devices are connected.

In the overall circuit design, by using the power amplifying printed circuit board module, the repeated design of the high power part circuit can be saved, and the power amplifying printed circuit board module can be directly embedded into the conventional printed circuit board, thereby further improving the system integrated design and returning. A design.

As shown in FIG. 1b, a schematic diagram of a design of an embedded power amplifying printed circuit board module embedded in a conventional printed board is shown, which includes: a conventional printed board 121, a power amplifying printed board 122, a heat sink 123, a solder 124, Power tube 125, power tube pin 126, substrate 127, jumper 128.

The power tube 125 is in contact with the substrate 127 through the fenestration of the power amplifying printed board 122 for heat dissipation. The substrate 127 is generally a metal substrate, and functions such as heat dissipation and grounding of the power tube.

The power tube pin 126 is soldered to the power amplifying printed board 122 to electrically connect the power tube 125 to the power amplification board 122.

The power tube 125, the power amplifying printed board 122 and the substrate 127 are integrally formed, and the power is amplified by the printed board module. After the power-amplified printed board module is modularized, it will be modularized, and the repeated design will be avoided in the future. For similar applications, the module can be regarded as a component for use. From the perspective of a conventional printed board, the power amplifying printed circuit board module is equivalent to a large electrical component connected thereto.

A window is opened on the conventional printed board 121, and the power amplifying printed board module is entirely placed in the window of the conventional printed board 121.

The power amplifying printed board 122 placed in the window is connected to the conventional printed board 121 via a jumper 128 to electrically connect the power amplifying printed board 122 to the conventional printed board 121.

The power amplifying printed board 122 is connected to the substrate 127 to form a whole through the fenestration of the conventional printed board 121 to contact the heat sink 123, and the power amplifying printed board 122, the power tube 125 and the substrate 127 are both It is embedded in the window opened by the conventional printed board 121.

The conventional printed board 121 and the heat sink 123 are soldered by the solder 124.

As can be seen from the above technology, the embedded power amplifying printed circuit board module does save the steps of designing the power to amplify the printed circuit board circuit, but the embedded power amplifying printed circuit board module is connected with the conventional printed circuit board.釆 Connect with a jumper.

In the process of realizing the above-mentioned printed board connection, the inventors found that at least the following problems exist in the prior art: In the actual production process, the soldering of the jumper cannot be used in the automatic soldering process, and the jumper must be manually prepared. Then - solder these jumpers to the power-amplified printed board and the conventional printed board. This complicates the welding process and results in inefficient production of the entire board. At the same time, the quality of the welding cannot be completely guaranteed due to the manual use of the welding, and the consistency of the welding cannot be guaranteed. Summary of the invention

Embodiments of the present invention provide a printed board assembly and a method of connecting the same to achieve a more efficient and reliable electrical connection between a power amplifying printed board and a conventional printed board.

A printed board assembly comprising:

a first printed board and a second printed board, wherein the second printed board is a printed board of the first printed board connected to the high frequency, high power device, and the first end of the surface is soldered to the first end The printed board is fixed by welding; the power tube and the heat sink, and the power tube is connected to the heat sink through the opening window of the first printed board and the second printed board;

The pins of the power tube are soldered to the second printed board;

The heat sink is coupled to a lower surface of the first printed board.

A method of processing a printed board assembly, comprising:

Soldering the surface mount solder end of the second printed board side end to the first printed board, wherein the second printed board is a printed board of the first printed board connected to the high frequency, high power device;

Opening the first printed board and the second printed board at a position where the power tube is placed;

Passing the power tube through the window, and soldering the pins of the power tube to the second printed board; Connecting the power tube to a heat sink;

The heat sink is coupled to a lower surface of the first printed board. Another printed board assembly includes:

a first printed board and a second printed board, wherein the first printed board and the second printed board are each provided with a signal path, and the second printed board is mounted on the second printed board a signal path on the first printed circuit board and a signal path on the second printed circuit board are connected to the mounting portions of the first printed board and the second printed board;

A power tube is carried on the second printed board and communicates with a signal path on the second printed board. The surface mount connection, the surface mount assembly efficiency is much higher than the manual soldering, which reduces the assembly cost, has high assembly efficiency, and ensures the consistency of processing.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

Figure la is a prior art power amplifying printed board and its connection mode intention;

FIG. 3b is a schematic diagram of a prior art embedded power amplifying printed board; FIG. 3a is a schematic structural view of a printed board assembly according to Embodiment 1 of the present invention;

3b is a flow chart of a method for processing a printed board assembly according to Embodiment 1 of the present invention;

4a is a schematic structural view of a printed circuit board assembly according to Embodiment 2 of the present invention;

4b is a flow chart of a method for processing a power amplifying printed circuit board assembly according to Embodiment 2 of the present invention. detailed description The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Embodiments of the present invention provide a modular surface-mount power amplifying printed board, which is applied with a power tube and a substrate or a heat sink to form a surface-mount power amplifying printed board. The module realizes the connection method of high-frequency, high-power devices with low cost and high assembly efficiency. Embodiment 1 is a structure of a printed board assembly with a substrate and a processing method thereof; Embodiment 2 is a structure of a printed board assembly without a substrate and a processing method thereof.

A surface-mount power amplifying printed board is shown in Fig. 2, and a surface-mounted soldering end is provided at a side end of the power amplifying printed board. The castle-type welded end is a typical surface-mounted solder joint. The structure of the castle-type soldering end includes three parts, namely, a pad 201 disposed on the upper surface edge of the power amplifying printed board 200, a pad 203 on the lower surface edge, and a plating plate electrically connecting the pad 201 and the pad 203. The groove 202 of the metal film.

The method of forming the metal film recess 202 is as follows:

A groove connecting the upper and lower pads is drilled on the side of the power amplifying printed board 200. The structure of the groove can be diversified, and the cross section can be processed into a semicircular, square or triangular shape or other shapes according to a processing technique. The iHJ tank is then plated on the inner wall of the IHJ tank to form a metal film.

In addition to being directly used for soldering and fixing with conventional printed boards, the soldered end can also bear certain electrical connections, such as grounding, reflow, etc., as required, so the position and number of soldered ends are based on the circuit board and the circuit on the conventional printed board. Depending on the specific function.

Through the soldering end, the power amplifying printed board can be easily realized by electrical connection with a conventional printed board and fixed functions.

Obviously, in order to facilitate the surface mount soldering, the surface mount power amplifying printed board can also use other types of solder joints which are easy to surface mount. For example, a through-hole solder joint can be used. The via-type soldering end includes: a pad for upper surface edge of the power amplifying printed board 200, a pad of a lower surface edge, a via hole penetrating the upper surface edge pad and the lower surface edge pad, and plating A metal film on the via. The electrical connection between the upper surface edge pad and the lower surface edge pad is achieved by a via hole plated with a metal film. A power amplifying printed board can be soldered to a conventional printed board by this via.

Obviously, the above-mentioned surface-mount power amplifying printed boards can also be modularized, and modularized after designing a printed board of a certain type of high-frequency, high-power circuit.

Embodiment 1

As shown in FIG. 3a, the printed circuit board assembly of the embodiment of the present invention includes: a conventional printed board 301, a surface-mounted power amplifying printed board 302, a heat sink 303, a solder 304, a power tube 305, and a power tube pin 306. Substrate 307, surface mount solder tail 308.

The power amplifying printed board 302 is soldered to the conventional printed board 301 through the side surface solder joints 308. The power amplifying printed board 302 is electrically connected to the conventional printed board 301 by a plurality of soldering ends soldered on the conventional printed board 301, such as a power supply on the conventional printed board 301, and the RF signal is passed through the power amplifying printed board 302. The top surface solder terminal 308 is soldered to the pad on the conventional printed board 301 and transferred to the power amplifying printed board 302. And the power amplifying printed board 302 can be firmly fixed to the conventional printed board 301.

In the position where the power tube 305 needs to be placed, the conventional printed board 301 and the power amplifying printed board 302 are opened with windows; the power tube 305 passes through the conventional printed board 301 and the window of the power amplifying printed board 302, and its pin Soldering on the power amplifying printed board 302 realizes electrical connection between the power tube 305 and the resistive container member on the power amplifying printed board 302, and constitutes a power amplifying module. The RF signal is amplified by the power tube 305 and then amplified by the power tube 305 to become a high power signal, which is again transmitted from the power amplifying printed board 302 to the conventional printed board 301 through the surface mount solder terminal 308. Power Amplification Printed board 302 consumes much less RF signal than conventional printed board 301 to ensure high quality RF signals.

The power tube 305 is connected to the substrate 307 through the other end of the window to contact the heat dissipation. The substrate 307 is generally a metal substrate, and functions to dissipate heat and ground the power tube. The connection between the power tube 305 and the substrate 307 may be by soldering or by bonding with a conductive paste.

The substrate 307 is connected to the heat sink 303 to contact heat dissipation to achieve better heat dissipation of the power tube. Substrate The connection between the 307 and the heat sink 303 may be by soldering or by bonding with a conductive paste.

The lower surface of the conventional printed board 301 is connected to the heat sink 303 to achieve heat dissipation and fixation of the PCB. On the lower surface of the conventional printed board 301, there is generally a large area of copper, and the connection of the copper to the heat sink 303 may be by soldering or by bonding with a conductive paste.

The processing method of the printed circuit board assembly of the first embodiment, as shown in FIG. 3b, specifically includes the following steps:

Step S321: Opening a window on the power amplifying printed board and the conventional printed board.

The window is opened at the position where the power amplifying printed board and the conventional printed board are placed with the power tube 305. The window size of the window should be adapted to the size of the power tube 305 to be connected, and its size should be larger than the power tube.

The 305 is slightly larger and allows the power tube 305 to pass through its window.

Step S322: soldering the surface mount solder end of the power amplifying printed board to the conventional printed board. At the side end of the power amplifying printed board 302, there is a surface-mounted soldering end, and a typical surface-mounted soldering end is a castle-shaped soldering end. The soldering end facilitates automatic surface mount welding, and the soldering end can be used to efficiently and reliably solder and fix the power amplifying printed board 302 to the conventional printed board 301.

Step S323: Connect the power tube to the substrate through the window, and solder the power tube pins to the power amplification printed board.

The power tube 305 is passed through the opened window, and the pins of the power tube 305 are soldered to the power amplifying printed board 302 to electrically connect and fix the power tube 305.

At the other end of the power tube 305 through the window, it is connected to the substrate 307 for dissipating heat from the power tube 305. The connection can be either by soldering or by bonding with a conductive paste.

Step S324: connecting the substrate to the heat sink.

In order to achieve better heat dissipation of the power tube 305, the substrate 307 can also be connected to the heat sink 303. The connection can be either by soldering or by bonding with a conductive paste.

Step S325: Connect the heat sink to the lower surface of the conventional printed board.

In order to fix the heat sink 303 and at the same time better heat dissipation for the entire printed board assembly, the heat sink 303 It is connected to the lower surface of the conventional printed board 301. On the lower surface of the conventional printed board 301, there is generally a large area of copper that is grounded and dissipated, and the heat sink 303 is connected to the copper to form a better ground loop and dissipate heat. The connection can be either by soldering or by bonding with a conductive paste.

Since the embodiment of the present invention uses the method in which the surface-mount power amplifying printed board is soldered to the conventional printed board through the side surface soldering end, the steps of soldering the jumper in the prior art are eliminated, achieving a higher level. Assembly efficiency, high assembly quality.

Embodiment 2

As shown in FIG. 4a, the printed circuit board assembly of the embodiment of the present invention includes: a conventional printed board 401, a surface-mounted power amplifying printed board 402, a heat sink 403, a solder 404, a power tube 405, and a power tube pin 406. Surface mount solder tail 408.

The power amplifying printed board 402 is soldered to the conventional printed board 401 through the side surface solder joints 408. The power amplifying printed board 402 is electrically connected to the conventional printed board 401 by a plurality of soldering ends soldered on the conventional printed board 401, and is firmly fixed to the conventional printed board 401.

In the position where the power tube 405 needs to be placed, the conventional printed board 401 and the power amplifying printed board 402 are opened with windows; the power tube 405 passes through the conventional printed board 401 and the window of the power amplifying printed board 402, and its pin Soldering on the power amplifying printed board 402 realizes electrical connection between the power tube 405 and the power amplifying printed board 402.

The power tube 405 is connected to the heat sink 403 through the other end of the window to contact the heat sink. The connection of the power tube 405 to the heat sink 403 may be by soldering or by bonding with a conductive paste.

The lower surface of the conventional printed board 401 is connected to the heat sink 403 to achieve heat dissipation and fixation of the PCB. The lower surface of the conventional printed board 401 generally has a large area of copper, and the connection of the copper to the heat sink 403 may be soldered or bonded by a conductive paste.

The processing method of the printed circuit board assembly of the second embodiment, as shown in FIG. 4b, specifically includes the following steps:

Step S421: Opening a window on the power amplifying printed board and the conventional printed board.

Opening at the position where the power amplifying printed board 402 and the conventional printed board 401 are placed with the power tube 405 window. The window size of the window should be adapted to the size of the power tube 405 to be connected, and should be slightly larger than the power tube 405 to allow the power tube 405 to pass through its window.

Step S422: soldering the surface mount solder end of the power amplifying printed board to the conventional printed board. At the side end of the power amplifying printed board 402, there is a surface-mounted soldering end, and a typical surface-mounted soldering end is a castle-shaped soldering end. The soldered end facilitates surface mount soldering, and the soldered end is used to solder and secure the power amplifying printed board 402 to the conventional printed board 401 efficiently and reliably.

Step S423: Connect the power tube to the heat sink through the window, and solder the power tube pin to the power amplification printed board.

The power tube 405 is passed through the opened window, and the pin of the power tube 405 is soldered to the power amplifying printed board 402 to realize electrical connection and fixing of the power tube 405.

In order to achieve better heat dissipation of the power tube 405, the rate tube 405 can be connected to the heat sink 403. The connection can be either by soldering or by bonding with a conductive paste.

Step S424: Connect the heat sink to the lower surface of the conventional printed board.

In order to fix the heat sink 403 while providing better heat dissipation for the entire printed board assembly, the heat sink 403 is attached to the lower surface of the conventional printed board 401. On the lower surface of the conventional printed board 401, there is generally a large area of copper that is grounded and dissipated, and the heat sink 403 is connected to the copper to form a better ground loop and dissipate heat. The connection can be either by soldering or by bonding with a conductive paste.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. In execution, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

The above description is only a preferred embodiment of the present invention, and it should be noted that Many modifications and refinements can be made by those skilled in the art without departing from the principles of the invention. These modifications and modifications are also considered to be within the scope of the invention.

Claims

Claim

A printed board assembly, comprising:

a first printed board and a second printed board, wherein the second printed board is soldered and fixed to the first printed board through the surface-mounted soldering end of the side end;

a power tube and a heat sink, wherein the power tube is connected to the heat sink through a window of the first printed board and the second printed board; the pin of the power tube and the second printed board Phase soldering; the heat sink is coupled to a lower surface of the first printed board.

2. The component of claim 1 further comprising:

a substrate, the substrate being located between the power tube and the heat sink, and connected to the power tube and the heat sink.

3. The assembly of claim 1 wherein said surface mount weld end comprises a castellated weld end.

4. The assembly of claim 3, wherein the castle solder tail comprises: a first pad (201) and a second pad (203) electrically connected, the first pad ( 201) and a second pad (203) respectively disposed on an upper surface edge and a lower surface edge of the second printed board;

A groove (202) coated with a metal film, the groove (202) coated with the metal film simultaneously passes through the first pad (201) and the second pad (203).

The assembly according to claim 1, wherein the connection between the power tube and the heat sink may be soldering or bonding with an electrically and thermally conductive adhesive.

The assembly of claim 1, wherein the connection of the heat sink to the lower surface of the first printed board may be soldering or bonding with an electrically and thermally conductive adhesive.

7. A method of processing a printed board assembly, comprising:

Welding the surface-mounted soldering end of the second printed board side end to the first printed board, wherein the second printed board is a printed board of the first printed board connecting the high-frequency, high-power device;

Connecting the power tube to the heat sink through the window, and soldering the pins of the power tube to the Second printed board;

The heat sink is coupled to a lower surface of the first printed board.

8. The method of claim 7 further comprising: connecting the power tube to the heat sink through the substrate.

9. The method of claim 7, wherein the method of connecting the power tube to a heat sink comprises:

Connected by welding; or,

Bonded by a conductive thermally conductive adhesive.

10. The method of claim 7, wherein the method of connecting the heat sink to a lower surface of the first printed board comprises:

Connected by welding; or,

Bonded by a conductive thermally conductive adhesive.

11. A printed board assembly, comprising:

The power tube is carried on the second printed board and communicates with a signal path on the second printed board.

12. The printed circuit board assembly of claim 11, wherein the first printed board and the second printed board are each provided with a window opening, and the power tube passes the first printing The windows and the fenestration on the second printed board conduct heat to the heat dissipating component.

13. The printed board assembly of claim 12 wherein the fenestration on the first printed board is opposite the fenestration on the second printed board.