CN113727520A

CN113727520A - Tower-type PCB and sewing method thereof

Info

Publication number: CN113727520A
Application number: CN202111049439.XA
Authority: CN
Inventors: 敖德彬; 韩梦鑫; 李�瑞; 刘鹏; 李治; 陈玉彬; 张腾蛟; 杨克成; 王聪
Original assignee: Ya'an Xiaohang Electronic Co ltd
Current assignee: Ya'an Xiaohang Electronic Co ltd
Priority date: 2021-09-08
Filing date: 2021-09-08
Publication date: 2021-11-30

Abstract

The invention discloses a tower-type PCB and a sewing method thereof, relating to the field of printed circuit boards and comprising a PCB body, wherein the PCB body comprises an upper layer board, a lower layer board and a square needle; the PCB body is provided with a plurality of welding suture holes and fixing suture holes, and square needles can be inserted into the welding suture holes and the fixing suture holes for sewing so as to fix the upper layer plate and the lower layer plate; the welding suture hole and the fixing suture hole are in clearance fit with the square needle, the diagonal length of the cross section of the square needle is larger than the aperture of the welding suture hole and the aperture of the fixing suture hole, and the aperture of the fixing suture hole is smaller than the aperture of the welding suture hole. This scheme of adoption can ensure effectively sewing up of PCB board, PCB board warp unfavorable condition such as dislocation about avoiding producing, can also satisfy soldering tin simultaneously and permeate to the opposite side of PCB board from sewing up the hole, ensures that the opposite side welding does not have bad phenomena such as hourglass welding, rosin joint, build-up welding.

Description

Tower-type PCB and sewing method thereof

Technical Field

The invention relates to the field of printed circuit boards, in particular to a tower type PCB and a sewing method thereof.

Background

With the rapid development of the electronic industry, the tower type circuit board has been widely used in the manufacturing industry due to the advantages of small occupied space and the like. At present, the domestic PCB tends to be standardized gradually, and how to realize effective sewing of the circuit board becomes a key for ensuring the quality of the tower-type circuit board when the quality of the tower-type circuit board is mainly limited by a sewing process.

In the traditional circuit board sewing, welded upper and lower circuit boards are overlapped together by means of tools, and then a sewing needle is inserted into a sewing hole of the circuit board, such as manual welding, dip welding or wave soldering.

However, there are a number of disadvantages with this approach:

firstly, manual welding is carried out, the circuit board is easy to seriously deform due to uneven heating during welding, a plurality of plug-in units and link units are arranged at partial positions of the circuit board, certain deformation also exists in the processing of the circuit board, a sewing process needs to be added nearby the circuit board in order to ensure the effective sewing of the circuit board, but because the gap between a sewing hole and the plug-in units is small, an electric iron cannot deeply penetrate into the position of a sewing needle during soldering, the circuit board cannot be effectively sewn, and the defects of insufficient soldering, overlaying welding, missing welding, tin bead, short circuit and the like occur, even if the soldering is finished, the defects of deformation, dislocation and the like exist among the circuit boards due to uneven heating and stress, and the like, thus the mounting process is seriously influenced,

secondly, dip-soldering, compare in manual welding, dip-soldering has great advantage, no matter be cost of labor or material cost all with manual cost low, can the various circuit boards of wicking, to original paper pin size and circuit board shape restriction basically, but its use shortcoming is also comparatively obvious on sewing up of tower circuit board:

1. the tin immersion effect can not be ensured to be consistent, and is mainly shown in three aspects:

a. in the tin immersion process, the tin immersion angle and the tin immersion time cannot be consistent, and the conditions of short circuit, cold solder and the like can be caused;

b. the elements are easy to incline and fall off in the tin immersion process, and the sewing plate is easy to deform due to uneven heating, so that the sewing effect cannot be achieved;

c. manual tin dipping enables a plurality of soldering tin to be attached to the pins, which causes waste of the soldering tin;

2. the efficiency of tin dipping is not high, and the people is not the machine, and is tired easily, and the efficiency is lower the longer the operating time is, especially will guarantee that the sewing plate is unlikely to appear serious deformation when the tin dipping, has higher demand in the operation gimmick and the lasting endurance of personnel.

3. The method has special requirements on operators, the tin immersion method is skilled, and the experience is rich, so that the operators are generally required to work stably for a long time, and the production can be influenced if the operators leave the system.

4. In order to meet the requirements of higher conductivity, stability, corrosion resistance, tensile strength, fatigue resistance, mechanical strength, low cost and the like, lead solder is generally adopted, but lead has serious harm to human bodies due to great pollution to the living environment of human beings.

And then wave soldering is carried out, compared with the former two wave soldering, the wave soldering has more outstanding advantages, uniform soldering can be realized, but the wave soldering is mainly used for soldering the plug connector, the pre-baking temperature is 90-1000 ℃, the wave soldering temperature is 220-2400 ℃, the requirement on the high temperature resistance of the soldered PCB and the plug connector is higher, different wave soldering needs to be used according to different requirements, and the requirement on cost investment is higher.

To sum up, the welding operation of the tower type circuit board is inconvenient, the production cost is high, and the qualification rate cannot be improved.

Disclosure of Invention

The technical problem to be solved by the invention is that the welding operation of the existing tower type circuit board is inconvenient, the production cost is high, and the qualification rate cannot be improved, and the invention aims to provide the tower type PCB and the sewing method thereof.

The invention is realized by the following technical scheme:

a tower-type PCB comprises a PCB body, wherein the PCB body comprises an upper layer plate, a lower layer plate and a square needle;

the PCB body is provided with a plurality of welding suture holes and fixing suture holes, and square needles can be inserted into the welding suture holes and the fixing suture holes for sewing so as to fix the upper layer plate and the lower layer plate; the welding suture hole and the fixing suture hole are in clearance fit with the square needle, the diagonal length of the cross section of the square needle is larger than the aperture of the welding suture hole and the aperture of the fixing suture hole, and the aperture of the fixing suture hole is smaller than the aperture of the welding suture hole.

Compared with the prior art, the problems that the welding operation of the tower type circuit board is inconvenient, the production cost is high and the qualified rate cannot be improved are solved, the scheme is that the tin paste is respectively printed on the copper foils of the upper plate and the lower plate of the PCB by the printer, the PCB which is subjected to the insertion and the surface mounting is combined together, the square needle is inserted into the circuit board, the circuit board with the square needle inserted therein is subjected to reflow soldering to realize tin soldering, and finally the circuit board is sewn; specifically, the PCB body comprises an upper plate and a lower plate, tin pastes are printed on copper foils of the upper plate and the lower plate through a printer, the upper plate and the lower plate are stacked, the overlapping position of the tower-type PCB is kept constant, and on the basis, a sewing needle, namely a square needle, is inserted; the PCB body is provided with a plurality of welding suture holes and fixing suture holes, namely, the upper layer plate and the lower layer plate are both provided with suture holes, and the suture holes between the two plates are corresponding, so that a square needle can penetrate through the upper layer plate and the lower layer plate through the suture holes for suture and fixation; the fixed sewing hole and the welding sewing hole are in clearance fit with the square needle, namely a gap is reserved between the fixed sewing hole and the welding sewing hole, and when the PCB body is welded, solder paste on the upper side surfaces of the upper layer plate and the lower layer plate can be melted and effectively permeate to the other side through the gap to realize welding and fixing; furthermore, the length of the diagonal line of the cross section of the square needle is larger than the aperture of the welding suture hole and the aperture of the fixing suture hole, so that the welding suture hole and the fixing suture hole are ensured to be fixedly overlapped with the four corners of the square needle, and the square needle is prevented from falling off from a PCB (printed circuit board) due to the gravity of the square needle when the solder paste is melted in a reflow soldering machine, and the sewing failure is avoided; furthermore, the aperture of the fixing suture hole is smaller than that of the welding suture hole, so that the overlapped part between the square needle and the fixing suture hole is more, the square needle and the fixing suture hole are used for fixing the upper layer plate and the lower layer plate, the mechanical positioning is realized, the position fixation of the PCB during welding is ensured, and a smaller deformation amount is ensured; through the cooperation of the modes, the solder paste at the seaming position of the finished product can be uniformly distributed, and the phenomenon of solder accumulation does not exist; the circuit board which is well sewed can be obtained after the welding is finished, and the phenomena of solder missing, insufficient soldering, tin stacking and the like can be avoided through the mode.

Further optimizing, a plurality of welding seam holes are uniformly distributed on the periphery and the middle part of the PCB body; the stitching is used for reinforcing the circuit board.

Further optimizing, the plurality of fixing sewing holes are uniformly distributed at the corners and the middle part of the PCB; the method is used for reinforcing the positions of the upper plate and the lower plate before welding.

Preferably, supporting columns are arranged at the corners of the PCB body, and the supporting columns are connected with the upper layer board and the lower layer board; the PCB board support device is used for fixing the distance between the upper board and the lower board and can support the PCB board when a square needle is inserted.

Further optimizing, the gap between the welding suture hole and the square needle contains a hollow; when the solder paste is used for welding, the solder paste can smoothly reach the other side position in a penetration mode.

Further preferably, the sewing method of the tower type PCB comprises the following steps:

the first step is as follows: uniformly distributing solder paste on the bonding pads on the upper surfaces of the upper layer plate and the lower layer plate;

the second step is that: tower-type overlapping of the upper layer plate and the lower layer plate;

the third step: after overlapping, inserting a square needle into the fixed suture hole for suturing;

the fourth step: then inserting a square needle into the welding and seaming hole for seaming;

the fifth step: and welding the PCB body to complete the fixation of the PCB body.

The front surfaces of the upper layer plate and the lower layer plate are printed with solder pastes, and the solder pastes are uniformly distributed on the welding seam holes and the welding pads for fixing the welding seam holes; the method is used for enabling solder paste to be uniformly distributed at the sewing position of the PCB finished product.

And further optimizing, and fixing the upper plate and the lower plate by adopting reflow soldering.

And further optimizing, inserting the square needle into the welding suture hole and the fixing suture hole by adopting a manual or sewing machine, and sewing.

Further optimization, before the upper plate and the lower plate are stacked in a tower type, supporting columns are required to be arranged at four corners between the upper plate and the lower plate.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the invention provides a tower type PCB and a sewing method thereof, by adopting the scheme, the effective sewing of the PCB can be ensured, the bad conditions of deformation and dislocation of the upper PCB and the lower PCB can be avoided, meanwhile, the condition that soldering tin permeates to the other side of the PCB from a sewing hole can be met, and the bad phenomena of welding leakage, insufficient welding, surfacing welding and the like on the other side can be avoided; the circuit board sewed by the mode has small deformation, small mechanical damage and small thermal deformation, no air holes are formed on the front side and the back side of the circuit board, no overlaying welding and no rosin joint exist, and solder pastes on the front side and the back side of the sewed position of the PCB are uniformly distributed.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that for those skilled in the art, other related drawings can be obtained from these drawings without inventive effort. In the drawings:

FIG. 1 is a schematic structural diagram of a tower PCB board provided by the present invention;

FIG. 2 is a side view of a tower PCB board provided by the present invention;

fig. 3 is a matching diagram of the tower type PCB board-welding seam hole, the fixing seam hole and the square needle provided by the present invention.

Reference numbers and corresponding part names in the drawings:

1-upper plate, 2-lower plate, 3-welding suture hole, 4-fixing suture hole, 5-square needle and 6-support column.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1:

the embodiment provides a tower-type PCB, as shown in fig. 1 to 3, including a PCB body, where the PCB body includes an upper board 1 and a lower board 2, and further includes a guideline 5;

the PCB body is provided with a plurality of welding seaming holes 3 and fixing seaming holes 4, and square needles 5 can be inserted into the welding seaming holes 3 and the fixing seaming holes 4 and are sewed for fixing the upper layer plate 1 and the lower layer plate 2; the welding suture hole and the fixing suture hole are in clearance fit with the square needle, the diagonal length of the cross section of the square needle is larger than the aperture of the welding suture hole and the aperture of the fixing suture hole, and the aperture of the fixing suture hole is smaller than the aperture of the welding suture hole.

Compared with the prior art, the problems that the welding operation of the tower type circuit board is inconvenient, the production cost is high and the qualified rate cannot be improved are solved, the scheme is that the tin paste is respectively printed on the copper foils of the upper plate and the lower plate of the PCB by the printer, the PCB which is subjected to insertion and mounting is combined together, the square needle is inserted into the circuit board, the circuit board with the square needle inserted therein is welded by reflow soldering, and finally the circuit board is sewn; specifically, the PCB body comprises an upper plate and a lower plate, tin pastes are printed on copper foils of the upper plate and the lower plate through a printer, the upper plate and the lower plate are stacked, the overlapping position of the tower-type PCB is kept constant, and on the basis, a sewing needle, namely a square needle, is inserted; the PCB body is provided with a plurality of welding suture holes and fixing suture holes, namely, the upper layer plate and the lower layer plate are both provided with suture holes, and the suture holes between the two plates are corresponding, so that a square needle can penetrate through the upper layer plate and the lower layer plate through the suture holes for suture and fixation; the fixed sewing hole and the welding sewing hole are in clearance fit with the square needle, namely a gap is reserved between the fixed sewing hole and the welding sewing hole, and when the PCB body is welded, solder paste on the upper side surfaces of the upper layer plate and the lower layer plate can be melted and effectively permeate to the other side through the gap to realize welding and fixing; furthermore, the length of the diagonal line of the cross section of the square needle is larger than the aperture of the welding suture hole and the aperture of the fixing suture hole, so that the welding suture hole and the fixing suture hole are ensured to be fixedly overlapped with the four corners of the square needle, and the square needle is prevented from falling off from a PCB (printed circuit board) due to the gravity of the square needle when the solder paste is melted in a reflow soldering machine, and the sewing failure is avoided; furthermore, the aperture of the fixing suture hole is smaller than that of the welding suture hole, so that the overlapped part between the square needle and the fixing suture hole is more, the square needle and the fixing suture hole are used for fixing the upper layer plate and the lower layer plate, the mechanical positioning is realized, the position fixation of the PCB during welding is ensured, and a smaller deformation amount is ensured; through the cooperation of the modes, the solder paste at the seaming position of the finished product can be uniformly distributed, and the phenomenon of solder accumulation does not exist; the circuit board which is well sewed can be obtained after the welding is finished, and the phenomena of solder missing, insufficient soldering, tin stacking and the like can be avoided through the mode.

In this embodiment, the plurality of welding seam holes 3 are uniformly distributed on the periphery and the middle part of the PCB body; for the sewing up of reinforcing circuit board, in this scheme, because PCB board peripheral position atress is more, and

welding seam hole

3 and 5 coincidence parts of square needle are less, and is little to the injury of PCB board, but consequently has a plurality of welding seam holes 3 at the periphery of PCB board body and middle part equipartition, sews up through square needle 5, realizes the sewing up of PCB board periphery and middle part position and consolidates. Further preferably, the plurality of solder stitching holes 3 disposed at the periphery of the PCB body should be used for stitching of the reinforced circuit board in the form of an array square 5, wherein the array square 5 is in various forms, such as rectangular array, path array, etc.

In this embodiment, the plurality of fixing suture holes 4 are uniformly distributed at the corners and the middle part of the PCB; for before the welding PCB board, consolidate the position of upper plate 1 and lower floor's board 2, in this scheme, because the coincidence part of fixed suture hole 4 and square needle 5 is more, nevertheless the injury to the PCB board is bigger, consequently, fixed suture hole 4 only need be in four corners and five positions altogether in the middle part, set up in the corner and the middle part position of PCB board by 5 fixed suture holes 4, lean on fixed suture hole 4 to maintain assembling of going up the hypoplastron, the realization is fixed PCB board four corners and central point.

In the embodiment, supporting columns 6 are arranged at the corners of the PCB body, and the supporting columns 6 are connected with an upper layer plate 1 and a lower layer plate 2; for the effect of interval between fixed upper plate 1 and the lower floor plate 2, when inserting square needle 5, can support the PCB board, in this scheme, all be equipped with support column 6 at PCB board body edge, wherein support column 6 plays the effect of supporting upper plate 1 and lower floor plate 2, when inserting square needle 5, can support the PCB board, further reduces the deformation volume, wherein has the buckle on the support column 6, can fix on the mounting hole of lower floor plate 2.

In this embodiment, the gap between the welding seam hole 3 and the square needle 5 contains a hollow; when the welding, for making the tin cream can reach the opposite side position through the infiltration mode smoothly, in this scheme, contain certain sky in the gap between welding seam hole 3 and square needle 5, wherein the clearance between welding seam hole 3 and the square needle 5 is difficult too big, otherwise can lead to the soldering to leak the PCB board opposite side, forms the condition of leaking welding or rosin joint at PCB board opposite side.

Example 2:

the embodiment is further optimized on the basis of embodiment 1, and provides a sewing method for a tower-type PCB, which includes the following steps:

the first step is as follows: uniformly distributing solder paste on the bonding pads on the upper surfaces of the upper plate 1 and the lower plate 2;

the second step is that: overlapping the upper plate 1 and the lower plate 2 in a tower manner;

the third step: after overlapping, inserting a square needle 5 into the fixed suture hole 4 for suturing;

the fourth step: then inserting a square needle 5 into the welding and sewing hole 3 for sewing;

the fifth step: and (3) soldering the PCB body by using reflow soldering to complete the fixation of the PCB body.

In the embodiment, solder pastes are printed on the front surfaces of the upper plate 1 and the lower plate 2 and are uniformly distributed on the welding pads of the welding and sewing holes 3 and the fixing and sewing holes 4; the method is used for enabling solder paste to be uniformly distributed at the sewing position of the PCB finished product.

In the embodiment, the upper plate 1 and the lower plate 2 are fixed by reflow soldering;

in this embodiment, a manual or sewing machine is used to insert the square needle 5 into the welding and sewing hole 3 and the fixing and sewing hole 4, and sewing is performed; in this scheme, can be through putting into the sewing machine automatic insertion square needle 5 of the PCB board that will make up, or place and insert square needle 5 on the frock of square needle 5 manually, will accomplish the 5 male PCB boards of square needle and put into reflow soldering and realize the welding, treat to weld and can obtain the circuit board of sewing up after accomplishing.

In the embodiment, before the upper plate 1 and the lower plate 2 are stacked in a tower type, support columns 6 need to be arranged at four corners between the upper plate 1 and the lower plate 2; wherein support column 6 plays the effect of supporting upper plate 1 and lower floor plate 2, when inserting square needle 5, can support the PCB board, further reduces the deformation volume, wherein has the buckle on the support column 6, can fix on the mounting hole of lower floor plate 2.

The specific working principle of the scheme is as follows: firstly, printing by a printer, wherein solder paste is uniformly distributed on a pad of a front stitching hole of a PCB (printed Circuit Board), then a support column 6 is arranged on an upper plate 1, the support column 6 is provided with a buckle and can be fixed on a mounting hole of a lower plate 2 for supporting the upper plate 1 and the lower plate 2, and plug-in components and patches are respectively arranged on the upper plate 1 and the lower plate 2, wherein the plug-in components of the lower plate 2 can play a role in fixing the relative position by penetrating the upper plate 1, then the PCB is stacked, the upper plate 1 and the lower plate 2 are stacked, and the overlapping position of the tower type PCB is kept constant, which is a prerequisite condition for ensuring the effective stitching of the tower type PCB except for the requirements on the size and precision of the PCB; then, inserting a sewing needle, inserting a square needle 5 into the fixed sewing hole 4 through a manual or sewing machine, sewing, ensuring the position of the PCB to be fixed during welding, ensuring smaller deformation and realizing mechanical positioning; then inserting a square needle 5 into the welding seaming hole 3, and seaming, wherein the welding seaming hole 3 and the square needle 5 are in interference fit, and a gap is reserved, so that soldering tin can conveniently permeate to the other side, and the soldering tin is uniformly distributed; and then placing the PCB board into which the guideline 5 is inserted into reflow soldering to realize soldering, and obtaining the sewn circuit board after the soldering is finished.

Example 3:

the embodiment is further optimized on the basis of the embodiment 2, and provides a specific implementation manner.

The process before sewing comprises the following steps:

firstly, printing by a printer, uniformly distributing solder paste on a welding disc of a front sewing hole of the PCB, wherein the thickness of the solder paste is as follows: 0.5 mm; and completing the insertion and the surface mounting of the PCB, completing the overlapping combination of the upper PCB and the lower PCB, fixing the PCB, and waiting for subsequent sewing.

The sewing process comprises the following steps:

the first step is as follows: firstly, the PCB boards are stacked, and the overlapping position of the tower type PCB boards is kept fixed, which is a prerequisite for ensuring the effective sewing of the tower type PCB boards except for the requirements on the size and the precision of the PCB boards.

The second step is that: the insertion of the sewing needle, manual or machine insertion of the square 5, should follow the following:

materials: 1.5 by 1.5mm square needle 5, the unanimous upper and lower floor PCB board of thickness 1.6 mm. In order to ensure that the PCB is fixed in position during welding and ensure small deformation, a machine is firstly neededMechanical positioning (the four corners and the middle part of the lower plate are provided with

The fixing suture holes are 45, and a plurality

Welding seam holes 3 are arranged on the front and back surfaces of the PCB

A pad).

The specific sewing process comprises the following steps: and (3) placing the combined PCB into a sewing machine to automatically insert the square needle 5, or placing the combined PCB on a tool for inserting the square needle 5 to manually insert the square needle 5, and inserting the fixed seaming hole 4 and then welding the seaming hole 3. And (3) placing the PCB into which the guideline 5 is inserted into a reflow soldering machine to realize soldering, and obtaining the sewn circuit board after the soldering is finished.

In the fixed suture hole 4 near the support column 6, a suture needle is first inserted.

The square needle 5 is fixed on the PCB board, and there is certain fretwork between square needle 5 and the suture hole simultaneously, is in PCB board upside tin cream like this and can permeate the opposite side effectively after melting, and does not have the accumulational phenomenon of soldering tin, and specific dimensional selection sees the following table:

the commonly used (copper) guideline is matched with the rigid PCB (copper foil thickness is 0.3) and the aperture parameter table unit: mm is

Meanwhile, the stitching of the circuit board is reinforced by adopting the mode of the array square needle 5 at the position with more stress outside the circuit board, the stitched circuit board has small deformation, small mechanical damage and small thermal deformation, and the solder paste at the stitching position of the finished product can be uniformly distributed without the defects of solder leakage, insufficient soldering and solder piling. When reflow soldering is passed, the gap between the stitching aperture and the square needle 5 is too large, which easily causes solder to leak to one side of the PCB, and the condition of solder leakage or cold solder is formed on one side of the PCB. Both the front and back surfaces of the circuit board have no air holes, no overlaying welding and no insufficient soldering, and the soldering tin is uniformly distributed.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A tower-type PCB comprises a PCB body, wherein the PCB body comprises an upper layer plate (1) and a lower layer plate (2), and is characterized by further comprising a square needle (5);

the PCB body is provided with a plurality of welding suture holes (3) and fixing suture holes (4), and square needles (5) can be inserted into the welding suture holes (3) and the fixing suture holes (4) for sewing so as to fix the upper layer plate (1) and the lower layer plate (2); the welding suture holes (3) and the fixing suture holes (4) are in clearance fit with the square needles (5), the diagonal lengths of the cross sections of the square needles (5) are larger than the aperture of the welding suture holes (3) and the aperture of the fixing suture holes (4), and the aperture of the fixing suture holes (4) is smaller than the aperture of the welding suture holes (3).

2. The tower-type PCB board as claimed in claim 1, wherein the plurality of welding seam holes (3) are uniformly distributed at the periphery and the middle of the PCB board body.

3. The tower-type PCB of claim 1, wherein a plurality of the fixing suture holes (4) are uniformly distributed at the corners and the middle of the PCB.

4. The tower-type PCB board of claim 3, wherein supporting columns (6) are arranged at corners of the PCB board body, and the supporting columns (6) are connected with the upper layer board (1) and the lower layer board (2).

5. The tower-type PCB board as claimed in claim 1, wherein the gap between the welding seam hole (3) and the square needle (5) contains a hollow.

6. The sewing method for the tower-type PCB board as claimed in any one of claims 1 to 5, characterized in that the method comprises the following steps:

the first step is as follows: uniformly distributing solder paste on the bonding pads on the upper surfaces of the upper layer plate (1) and the lower layer plate (2);

the second step is that: overlapping the upper plate (1) and the lower plate (2) in a tower type;

the third step: after overlapping, inserting a square needle into the fixed suture hole (4) for suturing;

the fourth step: then inserting a square needle into the welding suture hole (3) for suturing;

7. The method for sewing the tower-type PCB board as claimed in claim 6, wherein the front surfaces of the upper board (1) and the lower board (2) are printed with solder paste which is uniformly distributed on the welding seam holes (3) and the pads for fixing the seam holes (4).

8. The sewing method for the tower-type PCB board as claimed in claim 6, wherein the upper board (1) and the lower board (2) are fixed by reflow soldering.

9. The sewing method of the tower-type PCB board according to claim 6, wherein the square needle (5) is inserted into the welding sewing hole (3) and the fixing sewing hole (4) and sewed by a manual or sewing machine.

10. The method for sewing the tower-type PCB board according to claim 6, wherein the support columns (6) are installed at four corners between the upper board (1) and the lower board (2) before the upper board (1) and the lower board (2) are stacked in the tower type.