阅读说明：本技术 一种辐射单元的焊接方法 (Welding method of radiation unit ) 是由 龚奎 马红智 于 2019-09-23 设计创作，主要内容包括：本发明提供一种辐射单元的焊接方法,解决了回流焊接连不上锡的问题,所述辐射单元的焊接方法包括如下步骤：提供辐射PCB、功分PCB和交叉巴伦；在辐射PCB和功分PCB的对应位置开设供交叉巴伦插接的槽孔,并利用钢网分别在两个PCB上的槽孔两侧涂刷锡膏以形成第一焊盘；在交叉巴伦的引脚上设置第二焊盘,并将交叉巴伦的引脚插接于辐射PCB和功分对应的槽孔中；利用回流焊将辐射PCB和功分PCB上的第一焊盘处的锡膏依次经预热、回流焊接、冷却固定,使辐射PCB、功分PCB和交叉巴伦三者焊接固定。通过规范焊盘结构的设计工艺,确保辐射单元的PCB间的有效连接,保证垂直焊盘间焊点质量,解决辐射单元回流焊接连不上锡的问题,有效提高生产效率。(The invention provides a welding method of a radiation unit, which solves the problem that solder reflow is not carried out on the radiation unit, and comprises the following steps: providing a radiation PCB, a power division PCB and a cross balun; forming slotted holes for splicing the crossed balun in corresponding positions of the radiation PCB and the power division PCB, and respectively coating solder paste on two sides of the slotted holes on the two PCBs by utilizing a steel mesh to form a first bonding pad; arranging a second bonding pad on the pin of the cross balun, and inserting the pin of the cross balun into the slot holes corresponding to the radiation PCB and the power divider; solder paste on the radiation PCB and the first bonding pad on the power division PCB is sequentially preheated, reflowed, cooled and fixed by reflow soldering, so that the radiation PCB, the power division PCB and the cross balun are welded and fixed. Through the design technology of standardizing the pad structure, the effective connection between PCBs of the radiation units is ensured, the quality of welding spots between the vertical pads is ensured, the problem that tin is not applied to reflow soldering of the radiation units is solved, and the production efficiency is effectively improved.)

1. A method of welding a radiating element, comprising the steps of:

providing a radiation PCB used as a radiation plate, a power division PCB used as a power division plate and a cross balun;

forming slotted holes for splicing cross baluns at corresponding positions of the radiation PCB and the power division PCB, and respectively coating solder paste on two sides of the slotted holes on the two PCBs by utilizing a steel mesh to form a first bonding pad;

arranging a second bonding pad on the pin of the cross balun, and inserting the pin of the cross balun into the corresponding slot holes of the radiation PCB and the power division PCB;

solder paste at the first bonding pads on the radiation PCB and the power distribution PCB is sequentially preheated, reflow-welded and cooled and fixed by reflow welding, wherein the solder paste at the molten state at the first bonding pads flows onto the second bonding pads at a high temperature state, and the radiation PCB, the power distribution PCB and the cross balun are welded and fixed after cooling.

2. The method of claim 1, wherein the slot has a width of 1.0-1.1mm, and the pin has a thickness that is 0.05-0.1mm less than the width of the slot.

3. The method for soldering a radiation unit according to claim 1, further comprising the step of forming solder leaking holes in the steel mesh, wherein the solder leaking holes are formed in the steel mesh corresponding to positions of the slots in the radiation PCB and the power division PCB, and the solder leaking holes are formed in both sides of each of the slots.

4. The method for soldering a radiating element according to claim 3, wherein the distance between two solder-leaking holes corresponding to a same slot is smaller than the width of the slot.

5. The method of claim 3, wherein the length of the solder-leaking hole is equal to the length of the slot, and the width of the solder-leaking hole is greater than the width of the slot.

6. The method of welding a radiating element according to claim 1, further comprising the step of forming a cross balun, said step comprising: providing a positive polarized balun plate and a negative polarized balun plate with the same size; connecting grooves which can be mutually clamped so as to enable the positive polarization balun plate and the negative polarization balun to be orthogonally arranged in a cross shape are respectively arranged on the positive polarization balun plate and the negative polarization balun; the pins which can be inserted into the slotted holes on the PCB are formed on the upper side and the lower side of the positive polarization balun plate and the negative polarization balun plate.

7. The method for welding the radiation unit according to claim 6, wherein a first connecting groove is formed at a center line of the positive polarization balun plate from bottom to top, a second connecting groove is formed at a center line of the negative polarization balun from top to bottom and can be matched and plugged with the first connecting groove, and the sum of the groove depths of the first connecting groove and the second connecting groove is equal to the plate length of the cross balun.

8. The method of welding a radiating element according to claim 7, wherein the width of the first connecting slot and the width of the second connecting slot are adapted to the plate thickness of the crossed balun.

9. The method of welding a radiating element according to claim 6, wherein the pin thicknesses of the crossed baluns are each less than the width of the slot.

10. The method of soldering the radiating element according to claim 6, wherein the pins of the cross-balun pass through the PCB from the corresponding slots, and part of the pins are exposed out of the surface of the PCB.

11. The method of welding a radiant element as claimed in claim 1 wherein the steel mesh has a thickness of 0.6 mm.

Technical Field

The invention relates to the technical field of antenna manufacturing, in particular to a welding method of a radiating unit.

Background

In a base station antenna, a PCB is widely used as the most basic connection device. Firstly, the antenna radiation unit of the 5G base station needs to use a PCB as a connection; secondly, components such as a filter of the 5G base station and the like are greatly increased, and a single PCB is needed to be used for connecting the components; the CU/DU parts of the last 5G base station also need to use PCBs. At present, the pads of the PCB radiating units of the 5G antenna are designed with different sizes and shapes, and the problems that the solder reflow of the crossed PCB radiating units is not soldered and the manual soldering efficiency is low in the actual production process are caused by the characteristics.

Disclosure of Invention

The invention aims to provide a welding method of a radiation unit, which has high soldering tin quality and high production efficiency.

In order to achieve the purpose, the invention provides the following technical scheme:

a welding method process of a radiation unit comprises the following steps:

providing a radiation PCB used as a radiation plate, a power division PCB used as a power division plate and a cross balun;

forming slotted holes for splicing cross baluns at corresponding positions of the radiation PCB and the power division PCB, and respectively coating solder paste on two sides of the slotted holes on the two PCBs by utilizing a steel mesh to form a first bonding pad;

arranging a second bonding pad on the pin of the cross balun, and inserting the pin of the cross balun into the corresponding slot holes of the radiation PCB and the power division PCB;

solder paste at the first bonding pads on the radiation PCB and the power distribution PCB is sequentially preheated, reflow-welded and cooled and fixed by reflow welding, wherein the solder paste at the molten state at the first bonding pads flows onto the second bonding pads at a high temperature state, and the radiation PCB, the power distribution PCB and the cross balun are welded and fixed after cooling.

Further setting: the method also comprises a step of manufacturing tin leakage holes on the steel mesh, wherein the tin leakage holes are arranged on the steel mesh corresponding to the positions of the slotted holes on the radiation PCB and the power division PCB, and the tin leakage holes are respectively arranged on two sides of each slotted hole corresponding to each slotted hole.

Further setting: the distance between the two tin leakage holes corresponding to the two sides of the same slotted hole is smaller than the width of the slotted hole.

Further setting: the length of the tin leakage hole is equal to that of the slotted hole, and the width of the tin leakage hole is larger than that of the slotted hole.

Further setting: further comprising the step of forming a cross balun, said step comprising: providing the cross balun with equal size, wherein the cross balun comprises a positive polarized balun plate and a negative polarized balun plate; connecting grooves which can be mutually clamped so as to enable the positive polarization balun plate and the negative polarization balun to be orthogonally arranged in a cross shape are respectively arranged on the positive polarization balun plate and the negative polarization balun; the pins which can be inserted into the slotted holes on the PCB are formed on the upper side and the lower side of the positive polarization balun plate and the negative polarization balun plate.

Further setting: and a first connecting groove from bottom to top is formed in the center line of the positive polarization balun plate, a second connecting groove which is from top to bottom and can be matched and spliced with the first connecting groove is formed in the center line of the negative polarization balun, and the sum of the groove depths of the first connecting groove and the second connecting groove is equal to the plate length of the crossed balun.

Further setting: the width of the first connecting groove and the width of the second connecting groove are matched with the plate thickness of the crossed balun.

Further setting: the pin thicknesses of the positive polarized balun plate and the negative polarized balun plate of the crossed balun are smaller than the width of the slot hole.

Further setting: the pins of the cross balun penetrate through the PCB from the corresponding slotted holes, and parts of the pins are exposed out of the surface of the PCB.

Further setting: the thickness of the steel mesh is 0.6 mm.

Compared with the prior art, the scheme of the invention has the following advantages:

1. the welding method of the radiation unit can ensure the effective connection between the PCBs of the radiation unit and the quality of welding spots between the vertical welding pads by standardizing the design process of the welding pad structure and the relation of the matching sizes between the PCBs, thereby solving the problem that the solder reflow of the radiation unit is not soldered, effectively improving the production efficiency and being widely applied to 5G antennas.

2. In the welding method of the radiation unit, the thickness of the pins on the crossed balun is set to be 0.05-0.1mm smaller than the width of the slotted hole, and the small distance is beneficial to flowing solder paste in a molten state on the first bonding pad to the second bonding pad in a high-temperature state, so that the radiation PCB, the power division PCB and the crossed balun can be welded and fixed after cooling.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a process flow diagram of a method of welding a radiant element according to the present invention;

FIG. 2 is a schematic structural diagram of an embodiment of a radiating element of the present invention;

fig. 3 is a schematic structural diagram of a radiating PCB of the radiating unit of the present invention;

fig. 4 is a schematic structural diagram of a power division PCB of the radiation unit of the present invention;

fig. 5(a) is a schematic structural diagram of a negative polarized balun plate of a cross balun in a radiating element of the present invention;

fig. 5(b) is a schematic structural diagram of a positive polarization balun plate of the cross balun in the radiation unit of the present invention.

In the figure, 1, radiating PCB; 2. a power division PCB; 3. a cross balun; 31. positively polarizing the balun plate; 311. a first connecting groove; 32. a negative polarized balun plate; 321. a second connecting groove; 33. a pin; 331. a second pad; 100. a slot; 101. a first bonding pad.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.

The invention relates to a method for welding a radiation unit, which is shown in figure 1, and ensures the quality of welding spots by standardizing the relation between the structural design process of a PCB (printed circuit board) welding disc and the matching size of PCBs (printed circuit boards), so as to solve the problem that the solder reflow of crossed PCB radiation units is not soldered, and has high production efficiency and stable electrical property of the produced radiation unit.

The welding method of the radiation unit specifically comprises the following steps:

s1, providing a radiating PCB1 serving as an upper radiating plate, a power dividing PCB2 serving as a lower power dividing plate, and a cross balun 3 for connecting the radiating PCB1 and the power dividing PCB 2.

Referring to fig. 2 to 5(b), the thicknesses of the radiation PCB1 and the power dividing PCB2 are both designed to be 0.9-1.1mm, and the cross balun 3 also adopts a PCB as a material, so that the radiation unit of the present invention has the effects of portability, stable performance and strong operability.

The steps of providing the cross balun 3 are as follows:

firstly, please refer to fig. 5(a) and 5(b), two PCBs with the same size are provided to be the positive polarized balun plate 31 and the negative polarized balun plate 32, and then the connection slots are formed on the positive polarized balun plate 31 and the negative polarized balun plate 32, and the connection slots are mated with each other so that the positive polarized balun plate 31 and the negative polarized balun plate 32 are disposed orthogonally in a cross shape. Specifically, the positive polarization balun plate 31 is provided with a first connection groove 311, the first connection groove 311 is provided at a center line of the positive polarization balun plate 31 and extends upward from the bottom of the positive polarization balun plate 31, the negative polarization balun plate 32 is provided at a center line thereof with a second connection groove 321 from top to bottom and in insertion fit with the first connection groove 311, and a sum of groove depths of the first connection groove 311 and the second connection groove 321 is equal to a plate length of the cross balun 3. Meanwhile, the groove widths of the first connecting groove 311 and the second connecting groove 321 are both adapted to the plate thickness of the crossed balun 3, so that the structural connection of the positive polarized balun plate 31 and the negative polarized balun plate 32 is reliable, and the installation is convenient.

In addition, pins 33 which can be respectively in plug-in fit with the radiation PCB1 and the power division PCB2 are formed on the upper side and the lower side of the positive polarization balun plate 31 and the negative polarization balun plate 32, the radiation PCB1 is connected to the top of the cross balun 3, and the power division PCB2 is connected to the bottom of the cross balun 3.

In a preferred embodiment, the two pins 33 are respectively disposed at the upper side and the lower side of one balun plate, and the two pins 33 located at the same side are respectively located at two ends of the width direction of the balun plate, so that the top and the bottom of the cross balun 3 both have four pins 33 capable of being respectively in plug-in fit with the radiation PCB1 and the power division PCB2, and when the pins 33 are welded with the radiation PCB1 and the power division PCB2, the pins are electrically connected with the radiation PCB1 and the power division PCB2, so that the power division PCB2 can feed the radiation PCB 1. Meanwhile, the pins 33 and the correspondingly connected PCB are integrally formed, so that the stability is high.

S2, forming a slot 100 for inserting the cross balun 3 at a corresponding position of the radiation PCB1 and the power division PCB2, and respectively painting solder paste on two sides of the slot 100 on the radiation PCB1 and the power division PCB2 by using a steel mesh to form a first pad 101.

Referring to fig. 3 and 4, the radiating PCB1 has four slots 100 corresponding to the four pins 33 on the top of the cross balun 3, and the slot 100 on the radiating PCB1 has a length of 2.8-3.0mm and a width of 1.0-1.1 mm.

The power distribution PCB2 is provided with four slots 100 corresponding to the four pins 33 at the bottom of the cross balun 3, and the length of the slot 100 on the power distribution PCB2 is 5.0-6.0mm, and the width thereof is 1.0-1.1 mm.

And the thickness of the pins 33 on the cross balun 3 is slightly smaller than the width of the corresponding plugged slot holes 100 by 0.05-0.1 mm. The length of the pins 33 of the cross balun 3 correspondingly connected with the radiating PCB1 and the power dividing PCB2 is different, so that different assembly requirements can be met.

Then the steel mesh is fixed with the radiation PCB1 and the power division PCB2 respectively, and then the uniformly stirred solder paste is uniformly coated on the PCB by a scraper according to the positions of solder leaking holes on the steel mesh to form the first solder pad 101.

The long side of the first pad 101 formed on the radiation PCB1 is flush with the long side of the slot 100, and the length and the width of the first pad are 2.8-3.0mm and 1.8-2.2mm, respectively. The first pad 101 formed on the power distribution PCB2 is flush with the long side of the slot 100, and has a length of 5.0-6.0mm and a width of 1.8-2.2 mm.

Before the solder paste is coated on the steel mesh, solder leakage holes are required to be arranged on the steel mesh at positions corresponding to the slots 100 on the radiation PCB1 and the power division PCB 2. The radiation PCB1 has a long edge enlarged by 0.2-0.3mm relative to the outer edge of the first pad 101, and a specific opening size of 0.1-0.15mm relative to the inner edge of the first pad 101 facing the slot 100, wherein the long edge of the tin leakage hole of the steel mesh is as follows: the length is 2.8-3.0mm, the width is 2.1-2.6mm, the width is larger than the width of the slot 100, and the distance between two tin leakage holes corresponding to the same slot 100 is smaller than the width of the slot 100, specifically 0.7-0.9mm, so that the long side of the first pad 101 painted on the radiation PCB1 can ensure that the distance between the long side and the edge of the slot 100 is infinitely close to 0. The design structure of the tin leakage hole of the power distribution PCB2 corresponding to the steel mesh is the same, and the size of the tin leakage hole is as follows: the length is 5.0-6.0mm, the width is 2.1-2.6mm, and the distance between two tin leakage holes corresponding to the same slot hole 100 is 0.7-0.9 mm.

In addition, the thickness of the steel net used in the present embodiment is 0.6mm, so that the thickness of the first pad 101 painted on the PCB can be 0.59-0.66 mm.

S3, providing a second pad 331 on the pin 33 of the cross balun 3, and plugging the pin 33 of the cross balun 3 into the corresponding slots 100 of the radiating PCB1 and the power dividing PCB 2.

The second pad 331 is electrically connected to the cross balun 3, and the second pad 331 in this embodiment may be a rectangular pad made of copper foil.

Since the sizes of the slots 100 on the radiating PCB1 and the power dividing PCB2 are different, and the sizes of the leads 33 corresponding to the top and bottom of the cross balun 3 are also different, the length of the second pad 331 at the lead 33 on the top of the cross balun 3 is 2.4-2.7mm, and the width thereof is 1.8-2.0 mm. The second pad 331 at the lead 33 at the bottom of the cross balun 3 has a length of 4.6-5.6mm and a width of 1.8-2.0 mm. In addition, the distance between the second bonding pad 331 and each edge of the corresponding lead 33 is 0.15-0.2mm, so that the joint of the cross balun 3 and the radiation PCB1 and the power division PCB2 has enough tin storage space, and the phenomenon that the tin paste at the first bonding pad 101 overflows to other positions of the radiation PCB1 and the power division PCB2 to affect the electrical performance of the radiation unit is avoided.

The pins 33 of the cross balun 3 pass through the PCB through the slots 100 and partially extend out of the PCB. Specifically, the pin 33 at the top of the cross balun 3 passes through the radiating PCB1, and the length of the protruding part is 2.0-2.2 mm; the pin 33 at the bottom of the cross balun 3 passes through the power dividing PCB2, and the length of the protruding part is 2.0-2.2 mm. The lead 33 can be exposed 2.0-2.2mm outside the radiation PCB and the power division PCB to ensure that there is enough tin storage space at the joint of the radiation PCB1 and the power division PCB 2. In addition, the pin 33 of the cross balun 3 partially extends out of the radiation PCB1 and the power division PCB2, so that the connection of the three is reliable, and the reduction of the welding quality caused by the displacement in the reflow soldering process can be avoided.

S4, placing a radiation unit formed by connecting a radiation PCB1, a power division PCB2 and a cross balun 3 in a reflow soldering furnace, and sequentially preheating, reflow soldering, cooling and curing solder paste at a first pad 101 on the radiation PCB1 and the power division PCB2 through a temperature rising area, a constant temperature area, a soldering area and a cooling area in the reflow soldering furnace, so that the radiation PCB1, the power division PCB2 and the cross balun 3 are fixedly soldered, and the radiation PCB1, the power division PCB2 and the cross balun 3 are electrically connected to meet the feeding requirement of the radiation unit.

The invention can ensure the effective connection between the PCBs of the radiation unit by standardizing the design process of the pad structure and the relation of the matching sizes of the PCBs, and can ensure that in the reflow soldering process, because the distance between the pin 33 and the long side of the slot 100 which is correspondingly connected is small, the solder paste flows to the second pad 331 from the first pad 101 after being melted, and meanwhile, the second pad 331 is heated to a high temperature state in the reflow soldering process, which is beneficial to absorbing the solder paste in a molten state on the first pad 101 to flow to the second pad 331, so that the gap between the long side of the slot 100 and the pin 33 is filled with the solder, thereby realizing the effective soldering between the first pad 101 and the second pad 331 which are vertical to each other, having high solder joint quality, solving the problem that the solder of the radiation unit is not soldered, and having high solder joint quality between the vertical pads, the subsequent repair welding of workers is not needed, the production efficiency is improved, and the antenna can be generally applied to 5G antennas.

The foregoing is only a partial embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.