WO2022156528A1

WO2022156528A1 - Scraper device, solder paste printing apparatus and manufacturing method for printed circuit board assembly

Info

Publication number: WO2022156528A1
Application number: PCT/CN2022/070119
Authority: WO
Inventors: 丁建国; 孙磊; 梁志刚; 陈志林; 张龙江
Original assignee: 中兴通讯股份有限公司
Priority date: 2021-01-20
Filing date: 2022-01-04
Publication date: 2022-07-28
Also published as: CN114851688A

Abstract

Disclosed are a scraper device, a solder paste printing apparatus and a manufacturing method for a printed circuit board assembly. The scraper device comprises a knife rest assembly (110) and a blade (120), wherein the blade (120) is provided with a fixed end and a free end, the fixed end of the blade (120) is connected to the knife rest assembly (110), an included angle between the free end of the blade (120) and a steel mesh (200) is any angle from 46 to 56 degrees, and the steel mesh (200) is placed on a surface of a circuit board (400) to be printed. The device avoids the situation of the filled amount of solder paste being insufficient.

Description

Squeegee device, solder paste printing equipment and manufacturing method of printed circuit board assembly

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on the Chinese patent application with the application number of 202110074164.9 and the filing date of January 20, 2021, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is incorporated herein by reference.

technical field

The present application relates to the technical field of printed circuit boards, and in particular, to a squeegee device, solder paste printing equipment and a method for manufacturing a printed circuit board assembly.

Background technique

In the related technical solution, the plug-in components are usually soldered on the circuit board by wave soldering, which inevitably increases the wave soldering equipment and the wave soldering production process, resulting in increased production costs. In the related technical solutions, reflow soldering is also used to solder the plug-in components. In the specific implementation process, tin needs to be printed in the plug-in holes of the circuit board before the plug-in components are reflowed. However, in actual production, often due to the insufficient amount of solder paste in the plug-in hole, it is necessary to repeat the tin printing process to make the amount of solder paste in the plug-in hole meet the requirements of reflow soldering. pollution, etc.

SUMMARY OF THE INVENTION

The following is an overview of the topics detailed in this article. This summary is not intended to limit the scope of protection of the claims.

The present application provides a squeegee device, a solder paste printing equipment and a manufacturing method of a printed circuit board assembly.

In a first aspect, an embodiment of the present application provides a scraper device, comprising: a knife holder assembly; a blade having a fixed end and a free end, the fixed end is connected to the knife holder assembly, and the free end is connected to the steel mesh. The included angle between them is any angle between 46 degrees and 56 degrees, and the steel mesh is placed on the surface of the circuit board to be printed.

In a second aspect, an embodiment of the present application provides a solder paste printing device, comprising: a steel mesh for placing on the surface of the circuit board, the steel mesh having openings corresponding to the plug-in holes on the surface of the circuit board one-to-one; A squeegee device for shaving solder paste on the stencil, so as to print solder paste in the plug-in hole of the circuit board through the opening of the stencil; wherein the squeegee device adopts the method described in the first aspect above. The scraper device described.

In a third aspect, an embodiment of the present application provides a method for manufacturing a printed circuit board assembly, comprising: placing a steel mesh on the surface of the circuit board, and making the position of the opening of the steel mesh to be the same as that on the surface of the circuit board The positions of the plug-in holes are aligned; the solder paste operation is performed on the stencil by the scraper device described in the first aspect, so as to print the solder paste in the plug-in holes of the circuit board through the opening of the stencil inserting plug-in components into the plug-in holes printed with the solder paste; adopting a reflow soldering process to weld the plug-in components on the circuit board through the solder paste.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification. They are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical solutions of the present application.

Figure 1a is a schematic diagram of the state of the related technical solution before tin printing on the circuit board pads using the SMT process;

Fig. 1b is a schematic diagram of the state of the related technical solution after the SMT process is used to print tin on the circuit board pad;

Figure 2a is a schematic diagram of the state of the related technical solution before tin printing in the plug-in hole of the circuit board by using the SMT process;

Figure 2b is a schematic diagram of the state of the related technical solution after the SMT process is used to print tin in the plug-in hole of the circuit board;

3 is a schematic cross-sectional structure diagram of a solder paste printing device provided by an embodiment of the present application;

4a is a schematic diagram of the state of the solder paste printing equipment provided by the embodiment of the present application before tin printing in the plug-in hole of the circuit board;

FIG. 4b is a schematic diagram of the state of the solder paste printing equipment provided by the embodiment of the present application after tin printing in the plug-in hole of the circuit board;

5 is a schematic structural diagram of a scraper device provided in an embodiment of the present application;

6 is a schematic structural diagram of a blade holder main body of a scraper device provided in an embodiment of the present application;

7 is a schematic structural diagram of another angle of a blade holder body of a scraper device provided in an embodiment of the present application;

FIG. 8 is a schematic flowchart of a manufacturing method of a printed circuit board assembly provided by an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

It should be understood that in the description of the embodiments of the present application, multiple (or multiple) means more than two, greater than, less than, exceeding, etc. are understood as not including this number, above, below, within, etc. are understood as including this number. If there is a description of "first", "second", etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or implicitly indicating the indicated The sequence of technical characteristics.

In the following description, suffixes such as 'module', 'component' or 'unit' used to represent elements are used only to facilitate the description of the present application, and have no specific meaning per se. Thus, "module", "component" or "unit" may be used interchangeably.

For ease of understanding, the related technical solutions involved in the embodiments of the present application are first introduced.

An important process in the process of making a printed circuit board is to mount components on the printed circuit board by soldering to form a printed circuit board assembly (Printed Circle Board Assemble, PCBA) with independent functions. The components here can be resistors, capacitors, inductors, integrated circuits, etc.

In the related technical solution, the ways to realize the mounting of components on the printed circuit board include through-hole technology (Through Hole Technology, THT) and surface mount technology (Surface Mount Technology, SMT).

THT is mainly used in the installation of through-hole components (Through Hole Compment, THC). THC refers to components with pins, which can also be called plug-in components. The THT process mainly includes inserting the plug-in components into the plug-in holes of the printed circuit board, and then using wave soldering equipment and using solder alloys and fluxes to wave solder the plug-in components to solder the plug-in components on the printed circuit board.

SMT is mainly used in the installation of SMD components (Surface Mount Device, SMD). The SMT process mainly includes three processes: printing solder paste (referred to as tin printing), patch and reflow soldering. Tin printing is to use solder paste printing equipment on the pads on the surface of the circuit board or other positions where solder paste (a mixture of solder alloy powder and flux) needs to be arranged, and move the squeegee on the stencil to move the solder paste according to the required amount. The process of transferring to a circuit board. SMD is the process of placing the components that need to be soldered on the circuit board according to the specified position and angle with a special placement machine. Reflow soldering is to heat the circuit board through a special reflow furnace, so that the alloy particles in the solder paste are reflowed to form a complete solder joint, and the soldering of the chip components and the circuit board is realized.

The tin printing process of the SMT process can be referred to the schematic diagrams shown in FIG. 1a and FIG. 1b. As shown in FIG. 1a and FIG. 1b, during the tin printing process of the SMT process, the scraper 10 moves on the stencil 20 to scrape the solder paste. The mesh 20 is transferred to the pad 41 of the circuit board 40, and finally the stencil 20 is removed to complete the tin printing. In the related technical solution, the common angle between the scraper 10 and the stencil 20 is 60 degrees, and there are also a few scrapers 10 and the stencil 20 at an angle of 45 degrees.

In the actual circuit board production scenario, even if the circuit board has only a small number of plug-in components, it is still necessary to configure wave soldering equipment to wave solder the plug-in components, which will undoubtedly increase a series of costs such as equipment and labor input. Therefore, it is a development trend of printed circuit board manufacturing to complete the welding of plug-in components in the production of SMT.

Referring to FIGS. 2a and 2b, when the circuit board has plug-in holes, during the tin printing process of SMT, the squeegee 10 and the stencil 20 are at 60 degrees to squeegee the solder paste to pass through the plug-in holes of the circuit board 40. The opening 22 corresponding to 42 transfers the solder paste 30 to the plug-in hole 42, however, in actual production, the situation that the amount of solder paste in the plug-in hole 42 is insufficient as shown in FIG. 2b often occurs. In view of the insufficient amount of solder paste in the plug-in hole 42 , multiple stencils 20 are often used to print tin in multiple times, so that the plug-in hole 42 is filled with a sufficient amount of solder paste. However, multiple times of tin printing will bring about a sharp increase in cost (investment of stencil 20 and equipment, manpower, etc.), and multiple times of tin printing is also prone to the problem that the circuit board 40 is contaminated with solder paste. For the situation that the amount of solder paste in the plug-in hole 42 is insufficient, the method of expanding the hole can also be used to increase the area of the window on the steel mesh 20 to increase the amount of the solder paste. Hole way to solve the problem.

Based on this, the embodiments of the present application provide a squeegee device, a solder paste printing device, and a manufacturing method of a printed circuit board assembly, which can increase the amount of solder paste applied to the plug-in hole in one tin printing process.

Referring to FIG. 3 , FIG. 3 shows a solder paste printing device provided by an embodiment of the present application. The solder paste printing apparatus of the embodiment of the present application includes a stencil 200 and a squeegee device 100 .

4a and 4b, the stencil 200 is used to be placed on the surface of the circuit board 400, and the stencil 200 has openings 220 corresponding to the insertion holes 420 on the surface of the circuit board 400; A solder paste scraping operation is performed on the stencil 200 to print solder paste in the insertion holes 420 of the circuit board 400 through the openings 220 of the stencil 200 .

It can be understood that, in the process of tin printing by the solder paste printing equipment, the circuit board 400 is fixed on the platform of the solder paste printing equipment, the stencil 200 is fixed on the surface of the circuit board 400 to be printed, and the stencil 200 is fixed on the surface of the circuit board 400 to be printed. The window 220 is aligned with the position of the plug-in hole 420 on the surface of the circuit board 400; the scraper device 100 can move on the steel mesh 200 under the driving of the driving device, from the first side of the steel mesh 200 to the second side of the steel mesh 200; When the scraper device 100 moves on the stencil 200, the operation of scraping the solder paste 300 is performed on the stencil 200. The blade of the scraper device 100 is in contact with the stencil 200, and the solder paste 300 located between the blade and the stencil 200 is passed through the stencil The openings 220 of the circuit board 400 are missed to be printed on the corresponding plug-in holes 420 , so that the solder paste 300 is filled in the plug-in holes 420 , so that the solder paste can be printed in the plug-in holes 420 of the circuit board 400 .

It can be understood that the driving device involved in the embodiment of the present application belongs to the content that should be known by a person of ordinary skill in the art, which is not repeated in the embodiment of the present application.

It can be understood that the stencil 200 also has windows corresponding to the pads (not shown in the figure) on the surface of the circuit board 400. When the scraper device 100 performs the operation of scraping the solder paste on the stencil 200, the stencil also passes through the stencil 200. The opening of the window 200 allows the solder paste to be leaked on the corresponding pad, so that the scraper device 100 simultaneously prints the solder paste in the insertion hole 420 and the pad of the circuit board 400 in one solder printing process.

Referring to FIGS. 4a and 4b , compared with the angle between the blade and the stencil 200 in the conventional scraper device 100 , the angle between the blade and the stencil 200 is mostly 60 degrees (45 degrees are used in a small part), and the angle between the blade and the stencil 200 in the scraper device 100 of the embodiment of the present application is 60 degrees. The included angle α adopts any angle between 46 degrees and 56 degrees. This angle range enables the blade to apply proper pressure to the solder paste when the blade is shaving the solder paste on the stencil 200, so as to ensure the filling in the plug hole 420. The amount of solder paste is appropriate to avoid the situation that the amount of solder paste filling in the plug-in hole 420 is insufficient, so that the amount of solder paste in the plug-in hole 420 can meet the requirements of reflow soldering, and overcome the traditional scraper device 100 that cannot complete the plug-in hole 420 through one-time tin printing Solder paste filling problem.

Referring to FIG. 5 , FIG. 5 shows a scraper device 100 provided by an embodiment of the present application, where the scraper device 100 is used in a solder paste printing device. As shown in FIG. 5 , the scraper device 100 of the embodiment of the present application includes a blade holder assembly 110 and a blade 120 , wherein the blade 120 has a fixed end and a free end, the fixed end of the blade 120 is connected with the blade holder assembly 110 , and the free end of the blade 120 is The included angle α between the end and the steel mesh 200 is any angle from 46 degrees to 56 degrees, and the steel mesh is set on the to-be-printed circuit board 400 .

It can be understood that the squeegee device 100 shown in FIG. 5 is used in the solder paste printing equipment. When the squeegee device 100 performs the solder paste squeegee operation on the stencil 200, the free end of the blade 120 is in contact with the squeegee on the circuit board 400 to be printed. The steel mesh 200 is in contact and forms an included angle α with the steel mesh 200 , and the angle of the included angle α is any angle from 46 degrees to 56 degrees. This angle range enables the blade 120 to apply proper pressure to the solder paste when the blade 120 performs the solder paste shaving operation on the stencil 200 , thereby ensuring an appropriate amount of solder paste filled in the plug-in hole 420 and avoiding insufficient filling amount of the solder paste in the plug-in hole 420 In this case, the amount of solder paste in the plug-in hole 420 can meet the requirements of reflow soldering, which overcomes the problem that the traditional scraper device 100 cannot complete the filling of the solder paste in the plug-in hole 420 by one-time tin printing.

Referring to FIG. 5 , the tool holder assembly 110 according to the embodiment of the present application includes a tool holder body 111 and a fixing structure, wherein the fixing structure is used to fix the fixing end of the blade 120 on the tool holder body 111 .

It can be understood that the main body 111 of the blade holder is used for connecting with the driving device of the solder paste printing equipment, and connecting the fixed end of the blade 120 through the fixed structure, so as to provide support for the blade 120 and drive the blade 120 to move together on the steel under the driving of the driving device. Web 200 on mobile.

It can be understood that, the fixing structure is used for fixing the connection between the blade 120 and the main body 111 of the blade holder, and for fixing the included angle between the blade 120 and the steel mesh 200 .

As shown in FIG. 5 , it can be understood that the tool holder main body 111 is provided with an abutting portion 1111 , and the first surface of the blade 120 abuts on the abutting portion 1111 , and the abutting portion 1111 provides support for the blade 120 . The fixing structure includes a pressure strip 113 and a fastener. The pressure strip 113 is used to press the second surface of the blade 120 , and the fastener is used to lock the pressure strip 113 so that the pressure strip 113 fixes the blade 120 on the abutting portion 1111 .

Referring to FIG. 5 and FIG. 7 , in this example, the fasteners may be bolts, the tool holder body 111 is provided with bolt holes 112 , and the bolts pass through the bolt holes 112 to lock the bead 113 . In specific implementation, the first surface of the blade 120 can be pressed against the abutting portion 1111 of the main body 111 of the blade holder, and then the bead 113 on the second surface side of the blade 120 can be brought close to the blade 120, and the The bolts on the bolt holes 112 are tightened, so that the pressing bar 113 presses the blade 120 against the abutting part 1111 of the tool holder main body 111 , so that the pressing bar 113 locks and fixes the blade 120 on the tool holder main body 111 .

Referring to FIG. 5 , it can be understood that the abutting portion 1111 has an abutting surface. In order to meet the requirement that the angle between the blade 120 and the steel mesh 200 is 46 degrees to 56 degrees, the angle between the abutting surface and the horizontal plane is 46 degrees to 56 degrees. any angle. For example, the angle between the abutting surface and the horizontal plane is 51 degrees, the fixed end of the blade 120 is attached to the abutting surface of the main body 111 of the tool holder, and the position is locked by the fastener, so that the angle between the blade 120 and the steel mesh 200 is made Keep it at 51 degrees.

Referring to FIG. 6, it can be understood that the tool holder assembly 110 further includes a first shielding portion 114a and a second shielding portion 114b, the first shielding portion 114a is provided on the first side of the tool holder body 111, and the second shielding portion 114b is provided On the second side of the tool holder body 111 , the first shielding portion 114 a and the second shielding portion 114 b are located opposite to each other, for preventing solder paste from overflowing from the first side and the second side of the tool holder body 111 .

As shown in FIG. 6 , it can be understood that the first shielding portion 114a is inclined away from the first side of the tool holder main body 111 , and the second shielding portion 114b is inclined away from the second side of the tool holder main body 111 . In this way, the first shielding portion 114 a and the second shielding portion 114 b expand outward relative to the frame body to increase the coverage of shielding solder paste overflow and reduce the overflow of the solder paste to both sides of the tool holder body 111 .

It can be understood that the first shielding portion 114a and the second shielding portion 114b are components installed on the tool holder main body 111 . side. Alternatively, the first shielding portion 114a and the second shielding portion 114b are integrally connected with the tool holder main body 111 .

In addition, the embodiments of the present application also provide a method for manufacturing a printed circuit board assembly. Referring to FIG. 8 , FIG. 8 shows a schematic flowchart of a manufacturing method of a printed circuit board assembly according to an embodiment of the present application. As shown in FIG. 8 , the method of an embodiment of the present application includes the following method steps.

S10, place the steel mesh on the surface of the circuit board, and align the position of the opening of the steel mesh with the position of the plug-in hole on the surface of the circuit board.

4a and 4b, in the specific implementation process, the circuit board 400 can be fixed on the platform of the solder paste printing equipment first, and then the steel mesh 200 is placed on the surface of the circuit board 400 to be printed; The plug-in holes 420 on the surface of the board 400 correspond to the openings 220 one-to-one. When the stencil 200 is placed on the surface of the circuit board 400 to be printed, the openings 220 of the stencil 200 are aligned with the plug-in holes 420 on the surface of the circuit board 400 position; then fix the circuit board 400 and the stencil 200 together.

S20, the operation of scraping solder paste is performed on the steel mesh through the scraper device, so as to print the solder paste in the plug-in hole of the circuit board through the opening of the steel mesh, wherein the angle between the free end of the blade of the scraper device and the steel mesh is Any angle from 46 degrees to 56 degrees.

In a specific implementation process, the squeegee device 100 as shown in FIG. 5 can be used to scrape the solder paste on the steel mesh. Referring to FIGS. 4a and 4b, when the squeegee device 100 performs a solder paste shaving operation on the stencil 200, the free end of the blade 120 of the squeegee device 100 is in contact with the stencil 200 on the to-be-printed circuit board, and is formed with the stencil 200. The included angle is any angle from 46 degrees to 56 degrees. This angle range enables the blade 120 to apply proper pressure to the solder paste 300 when the blade 120 performs the solder paste shaving operation on the stencil 200 , thereby ensuring the proper amount of solder paste filled in the insertion hole 420 and avoiding the filling amount of the solder paste in the insertion hole 420 Insufficient situation occurs, so that the amount of solder paste in the plug-in hole 420 can meet the requirements of reflow soldering, and overcome the problem that the traditional scraper device 100 cannot complete the filling of the solder paste in the plug-in hole by one-time tin printing.

S30, inserting plug-in components into the plug-in holes printed with solder paste.

It can be understood that, after the solder paste is printed on the interposer hole, the interposer component is inserted into the interposer hole printed with the solder paste.

S40, the reflow soldering process is used to solder the plug-in components on the circuit board through solder paste.

In the specific implementation, the circuit board after the plug-in can be put into a reflow furnace, and the solder paste printed on the circuit board can be melted through the reflow furnace to realize the soldering between the pins of the plug-in components and the plug-in holes, so as to achieve The purpose of reflow soldering plug-in components on the circuit board.

In the solution of the embodiment of the present application, the angle between the blade of the scraper device and the steel mesh adopts any angle from 46 degrees to 56 degrees. Compared with the angle between the blade of the traditional scraper device and the steel mesh, the angle is mostly 60 degrees. The pressure applied by the blade to the solder paste during the solder paste shaving operation is more appropriate, so that the correct amount of solder paste can be filled into the plug-in hole in one solder printing process, avoiding the increased cost and contamination of the circuit board caused by multiple solder printing. And other issues.

In the technical solution of the embodiment of the present application, the scraper device includes a knife holder assembly and a blade, the blade has a fixed end and a free end, the fixed end of the blade is connected to the knife holder assembly, and the angle between the free end and the steel mesh is Any angle from 46 degrees to 56 degrees, the stencil is placed on the surface of the circuit board to be printed. The squeegee device of the embodiment of the present application can be used for shaving solder paste on the circuit board to be printed. During the process of shaving the solder paste, the angle between the blade of the squeegee device and the steel mesh is any one of 46 degrees to 56 degrees. The angle of the included angle can ensure that when the blade passes through the plug-in hole of the circuit board, a sufficient amount of solder paste can be scraped into the plug-in hole, so as to ensure that the amount of solder paste in the plug-in hole can meet the reflow in one tin printing process welding requirements.

The above is a specific description of some implementations of the present application, but the present application is not limited to the above-mentioned embodiments, and those skilled in the art can make various equivalent deformations or replacements under the shared conditions that do not violate the scope of the present disclosure. Equivalent modifications or substitutions are included within the scope defined by the claims of the present application.

Claims

A scraper device, comprising:

Tool holder assembly;

The blade has a fixed end and a free end, the fixed end is connected with the tool holder assembly, the angle between the free end and the steel mesh is any angle between 46 degrees and 56 degrees, and the steel mesh is placed on the surface of the circuit board to be printed.
The doctor blade assembly of claim 1, wherein the blade holder assembly comprises:

Tool holder body;

The fixing structure is used for fixing the fixed end of the blade on the main body of the tool holder.
The scraper device according to claim 2, wherein the blade holder body is provided with an abutting portion, and the first surface of the blade abuts on the abutting portion;

The fixing structure includes a pressure strip and a fastener, the pressure strip is used to press the second surface of the blade, and the fastener is used to lock the pressure strip, so that the pressure strip can fix the blade in the place. on the abutting part.
The scraper device according to claim 3, wherein the abutting portion has an abutting surface, and an included angle between the abutting surface and the horizontal plane is any angle between 46 degrees and 56 degrees.
The scraper device according to claim 3, wherein the fasteners are bolts, the tool holder body is provided with screw holes, and the bolts pass through the screw holes to lock the bead.
The doctor blade device of claim 2, wherein the blade holder assembly further comprises:

a first shielding part and a second shielding part, the first shielding part is arranged on the first side of the tool holder body, the second shielding part is arranged on the second side of the tool holder body, the first shielding part is arranged on the second side of the tool holder body The shielding portion and the second shielding portion are located opposite to each other, and are used to prevent solder paste from overflowing from the first side and the second side of the tool holder body.
The scraper device according to claim 6, wherein the first shielding portion is disposed obliquely away from the first side of the blade holder main body, and the second shielding portion is disposed obliquely away from the second side of the blade holder main body.
The scraper device according to claim 6, wherein the first shielding portion and the second shielding portion are members mounted on the blade holder body, or the first shielding portion and the second shielding portion are The part is integrally connected with the main body of the tool holder.
A solder paste printing equipment, comprising:

The steel mesh is used to be placed on the surface of the circuit board, and the steel mesh has openings corresponding to the plug-in holes on the surface of the circuit board one-to-one;

a scraper device, used for scraping solder paste on the stencil, so as to print solder paste in the plug-in hole of the circuit board through the opening of the stencil;

Wherein, the scraper device adopts the scraper device according to any one of claims 1 to 8.
A manufacturing method of a printed circuit board assembly, comprising:

placing the stencil on the surface of the circuit board, and aligning the position of the opening of the stencil with the position of the plug-in hole on the surface of the circuit board;

The squeegee device according to any one of claims 1 to 8 performs a solder paste shaving operation on the stencil, so as to print solder paste in the plug-in hole of the circuit board through the opening of the stencil;

inserting plug-in components into the plug-in holes printed with the solder paste;

Using a reflow soldering process, the plug-in components are soldered on the circuit board through solder paste.