CN211267300U

CN211267300U - Steel mesh and welded structure

Info

Publication number: CN211267300U
Application number: CN201922442551.4U
Authority: CN
Inventors: 汪琴; 王敏
Original assignee: Konka Group Co Ltd
Current assignee: Konka Group Co Ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-08-14
Anticipated expiration: 2029-12-26

Abstract

The utility model discloses a steel mesh and welded structure, the steel mesh includes a steel mesh body, a plurality of printing holes arranged on the steel mesh body, a baffle plate arranged in the printing holes, and a connecting rod connecting the baffle plate and the steel mesh body to form a plurality of special-shaped printing holes; the width of the connecting rod is smaller than that of the baffle; every two printing holes are arranged at intervals to form a printing hole group, and the connecting rod is connected to the steel mesh body between the two printing holes in the printing hole group to form a special-shaped printing hole group. When the solder is printed, the baffle and the connecting rod correspondingly form the through hole and the channel on the solder layer, when the chip capacitor is welded, the extruded redundant solder can overflow into the notch of the solder layer to prevent the extruded redundant solder from overflowing out of the bonding pad, so that the phenomenon that the extruded solder overflows due to more solder is avoided, the chip short circuit is caused, and the welding yield and reliability are improved.

Description

Steel mesh and welded structure

Technical Field

The utility model relates to a surface mounting technical field especially relates to a steel mesh and welded structure.

Background

Printed Circuit Boards (PCBs) are important electronic components, both as support and electrical connection carriers for electronic components. With the development of the electronic industry, the electronic products are more and more miniaturized and integrated, resulting in the specific gravity of the chip component on the printed circuit board being more and more, wherein the chip capacitor is one of the most commonly used electronic components as a component for storing electric charges.

Surface Mount Technology (SMT) is a technology in which electronic components such as chip capacitors and resistors that can be mounted on a PCB are soldered to the PCB by a machine operation. The SMT production process can be divided into the following steps: 1. manufacturing a steel mesh according to the board card, wherein printing holes are formed in the steel mesh; 2. the steel mesh is placed on the PCB, a layer of solder is brushed on the PCB through a machine, and the shape of the solder layer is the shape of the steel mesh printing hole; 3. the machine sequentially grabs the surface mount materials through the suction nozzle and places the surface mount materials on the specified bonding pads of the PCB according to a pre-programmed program; 4. and (4) passing through a furnace, and completing reflow soldering according to a set temperature curve. In the welding process of the chip capacitor, a steel mesh is an important auxiliary device. The steel mesh is primarily used to transfer solder into the steel mesh printing holes and to aid in solder deposition.

The steel mesh printing hole among the prior art is as shown in fig. 1, set up on steel mesh body 1 with correspond the printing hole 2 that the pad shape is unanimous, when adopting SMT to carry out the paster, when the solder on the pad of paster electric capacity is too much, can lead to the solder excessive, the solder excessive probably makes two pads of paster electric capacity weld even occasionally to make the electric capacity short circuit, reduced the reliability of SMT paster.

Accordingly, the prior art is yet to be improved and developed.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned prior art not enough, the utility model aims at providing a steel mesh and welded structure, aim at solving the solder and receive the extrusion overflow when welding to lead to the problem of short circuit.

The technical scheme of the utility model as follows:

a steel mesh comprises a steel mesh body, a plurality of printing holes formed in the steel mesh body, baffles arranged in the printing holes, and connecting rods for connecting the baffles and the steel mesh body to form a plurality of special-shaped printing holes; the width of the connecting rod is smaller than that of the baffle;

every two printing holes are arranged at intervals to form a printing hole group, and the connecting rod is connected to the steel mesh body between the two printing holes in the printing hole group to form a special-shaped printing hole group.

The steel mesh, wherein, the area sum of baffle and the connecting rod is 5% -20% of the printing hole area.

The steel mesh, wherein the baffle may be, but not limited to, circular or polygonal in shape.

The steel mesh, wherein, the area of connecting rod is less than the area of baffle.

The steel mesh, wherein, the one end that the connecting rod is connected with the steel mesh body is located the middle part of printing hole one side.

The steel mesh is characterized in that the thickness of the steel mesh body is 0.05-0.1 mm.

A welded structure, comprising: the circuit comprises a base layer, a first bonding pad and a second bonding pad which are arranged on the base layer at intervals, a first welding material layer arranged on the first bonding pad and a second welding material layer arranged on the second bonding pad; the first solder layer and/or the second solder layer are provided with a notch, the notch comprises: the solder comprises a first solder layer, a second solder layer and a channel, wherein the first solder layer is arranged on the first surface of the first substrate, the second solder layer is arranged on the second surface of the second substrate, the channel is communicated with a spacing region between the first solder layer and the second solder layer, and the channel is connected with a through hole connected with the channel, and the width of the channel is.

The welding structure, wherein an insulating oil layer is arranged between the first bonding pad and the second bonding pad.

The welding structure, wherein the first pad is rectangular or triangular.

The soldering structure, wherein the area of the first solder layer is smaller than that of the first pad; the area of the channel is smaller than that of the through hole.

Has the advantages that: the utility model provides a steel mesh, which comprises a steel mesh body, a printing hole arranged on the steel mesh body, a baffle arranged in the printing hole, and a connecting rod for connecting the baffle and the steel mesh body, wherein the width of the connecting rod is less than that of the baffle; the baffle and the connecting rod are used for enabling the printing hole to form a special-shaped printing hole, and the special-shaped printing hole is used for printing a solder layer. When the solder is printed, the baffle and the connecting rod correspondingly form the through hole and the channel on the solder layer, when the chip capacitor is welded, the extruded redundant solder can overflow into the notch of the solder layer to prevent the extruded redundant solder from overflowing out of the bonding pad, so that the phenomenon that the extruded solder overflows due to more solder is avoided, the short circuit of the chip capacitor is caused, and the yield and the reliability of the chip capacitor welding are improved.

Drawings

FIG. 1 is a schematic diagram of a prior art steel mesh printing hole design.

Fig. 2 is the utility model provides a steel mesh dysmorphism printing hole design sketch map.

Fig. 3 is a schematic view of the welding structure provided by the present invention.

Reference numerals:

1. a steel mesh body; 2. printing holes; 3. a baffle plate; 4. a connecting rod; 5. printing holes in a special shape; 6. a substrate; 7. a first pad; 8. a second pad; 9. a first solder layer; 10. a second solder layer; 11. a channel; 12. a through hole; 13. and an insulating oil layer.

Detailed Description

The utility model provides a steel mesh and welded structure, for making the utility model discloses a purpose, technical scheme and effect are clearer, clear and definite, following right the utility model discloses further detailed description. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

Referring to fig. 2 and fig. 3, fig. 2 is a schematic view of a steel mesh profile printing hole design provided by the present invention. Fig. 3 is a schematic view of the welding structure provided by the present invention.

As shown in fig. 2, the embodiment provides a steel mesh, which includes a steel mesh body 1, a plurality of printing holes disposed on the steel mesh body 1, baffles 3 disposed in the printing holes, and connecting rods 4 connecting the baffles 3 and the steel mesh body 1, wherein the width of the connecting rods 4 is smaller than the width of the baffles 3, so as to form a plurality of profile prints 5; every two printing holes are arranged at intervals to form a printing hole group, and the connecting rod 4 is connected to the steel mesh body 1 between the two printing holes in the printing hole group to form a special-shaped printing hole group.

Because the printing hole is the dysmorphism printing hole, when printing the solder layer through the steel mesh, usually earlier put the steel mesh on the pad corresponds the position, then print the solder on the steel mesh, the solder can fill in dysmorphism printing hole 5 to form the solder layer with dysmorphism printing hole 5 the same shape, size, that is to say, the solder layer is also special-shaped, baffle 3 and connecting rod 4 correspond the position and can not print the solder, therefore correspond respectively and form passageway 12 and passageway 11. During soldering, the solder can overflow into the channels 12 and 11 preferentially, but not overflow to the periphery of the solder layer, thereby avoiding short circuit caused by the connection of the solder with other solders or pins of other chip capacitors.

In the embodiment, the width of the connecting rod 4 is smaller than that of the baffle 3, on one hand, even if the solder overflows, the solder overflows preferentially to the corresponding area of the baffle 3 on the solder layer; on the other hand, when the connecting rod 4 is of a smaller width, the solder overflows and fills the corresponding area of the connecting rod 4 on the solder layer, so that the solder is formed on the pad, and the pins of the chip capacitor are fully connected with the pad.

The number of the baffle plates 3 and the tie bars 4 may be set as desired, for example, 1 or more, and when a plurality of baffle plates 3 and tie bars 4 are provided, the solder layer can more sufficiently flow to the corresponding areas of the baffle plates 3 and the tie bars 4.

Further, the sum of the areas of the baffle 3 and the connecting rod 4 is 5% -20% of the area of the printing hole. The overlarge area sum of the baffle 3 and the connecting rod 4 can lead the solder of the solder layer to be too little, so that the welding strength of the pin and the pad of the chip capacitor is reduced, and the overlarge area sum of the baffle 3 and the connecting rod 4 can lead the gap on the solder layer not to contain too much solder, so that the solder overflows and is connected and welded.

Further, the shape of the baffle 3 may be, but is not limited to, circular or polygonal.

For example, the baffle 3 is shaped as a star to increase the length of the edge of the channel 12, so that the solder can more easily overflow the channel 12 and cannot overflow the periphery of the solder layer.

Further, the area of the connecting rod 4 is smaller than that of the baffle 3.

Since the area of the connecting rods 4 is smaller than the area of the baffle 3, the area of the passage 11 is smaller than the area of the passage 12. When the solder overflows, the solder overflows preferentially to the channel 12 with a large area, that is, the solder overflows preferentially to the center of the solder layer rather than to the periphery, and the channel 12 with a large area can also contain more solder.

Furthermore, one end of the connecting rod 4 connected with the steel mesh body 1 is positioned in the middle of one side of the printing hole, so that redundant solder on two sides of the gap can uniformly overflow into the gap. If the solder on the notch side of the solder layer is too much, there is a risk that the solder will overflow because the solder will not flow into the channel 12 from the channel 11 in time.

Further, the thickness of the steel mesh body 1 is 0.05-0.1 mm.

Based on the steel mesh of any one above-mentioned embodiment, as shown in fig. 3, the utility model also provides a welded structure wherein, include: a base layer 6, a first pad 7 and a second pad 8 which are arranged on the base layer 6 at intervals, a first solder layer 9 arranged on the first pad 7 and a second solder layer 10 arranged on the second pad 8; the first solder layer 9 and/or the second solder layer 10 are provided with indentations comprising: a channel 11 communicated with the interval area between the first solder layer 9 and the second solder layer 10, and a through hole 12 connected with the channel 11, wherein the width of the channel 11 is less than the width 12 of the channel 12.

A notch may be provided in both the first solder layer 9 and the second solder layer 10, and both the notch (referred to as a first notch) of the first solder layer 9 and the notch (referred to as a second notch) of the second solder layer 10 communicate with the spaced area between the first solder layer 9 and the second solder layer 10. The first notch and the second notch are symmetrically arranged or staggered. When the first notch and the second notch are arranged in a staggered mode, because one solder layer corresponds to the notch, the probability of overflow of the solder in one solder layer is low, and the situation that the overflow probability of the solder in two solder layers is high, so that overflow of the same position is caused and the solder is connected in the interval area is avoided. When the device is arranged in a staggered manner, the possibility of short circuit can be greatly reduced.

Of course, when a plurality of notches are provided in the solder layer, the middle position of the solder layer is more likely to overflow, and therefore, more notches are provided in the middle position of the solder layer, and fewer notches are provided in the positions on both sides of the solder layer.

In the present embodiment, the shape and size of the irregular printing hole 5 are the same as those of the first solder layer 9 and the second solder layer 10, the shape and size of the tie bar 4 are the same as those of the channel 11, and the shape and size of the baffle 3 are the same as those of the through hole 12.

Through set up baffle 3 and connecting rod 4 on the basis of prior art's printing hole, form special-shaped printing hole 5, when welding paster electric capacity, receive extruded unnecessary solder can be toward in the breach on the excessive solder that overflows the solder layer, prevent that it from overflowing outside the pad to avoided because the solder is more and make and receive extruded solder overflow, thereby leaded to the phenomenon of paster electric capacity short circuit, improved paster electric capacity welded yield and reliability.

In one embodiment, an insulating oil layer 13 is arranged between the first pad 7 and the second pad 8. The insulating oil layer 13 is arranged between the first bonding pad 7 and the second bonding pad 8 as a solder resist, the isolation between the first bonding pad 7 and the second bonding pad 8 is increased, and therefore the phenomenon of continuous welding when reflow soldering is passed is further avoided, and the welding quality is improved.

In one embodiment, the first pad 7 may be, but is not limited to, rectangular or triangular. Specifically, the first pad 7 of an appropriate shape may be selected according to the pin shape of the patch capacitor.

In one embodiment, the area of the first solder layer 9 is smaller than the area of the first pad 7, so that the amount of solder on the pad is not excessive, and when reflow soldering is performed, because a part of space on the pad is not coated with solder, the excessive solder can fill the part of space preferentially, so that the risk of solder overflow from the pad to cause solder connection is reduced; the area of the channel 11 is smaller than that of the channel 12, when the solder overflows, the solder overflows preferentially to the channel 12 with a large area, but does not overflow to the periphery, and the channel 12 with a large area can also contain more solder.

In one embodiment, the solder of the first solder layer 9 and/or the second solder layer 10 further contains flux, when the chip capacitor is subjected to reflow soldering, the pins of the chip capacitor can be effectively combined with the solder, so that the pins of the chip capacitor can be firmly soldered on the pads; the solder of the first solder layer 9 and/or the second solder layer 10 may be a solder paste.

To sum up, the utility model provides a steel mesh, which comprises a steel mesh body, printing holes arranged on the steel mesh body, a baffle plate arranged in the printing holes, and a connecting rod for connecting the baffle plate and the steel mesh body, wherein a plurality of special-shaped printing holes are formed, and the width of the connecting rod is smaller than that of the baffle plate; every two printing holes are arranged at intervals to form a printing hole group, and the connecting rod is connected to the steel mesh body between the two printing holes in the printing hole group to form a special-shaped printing hole group. When the solder is printed, the baffle and the connecting rod correspondingly form the through hole and the channel on the solder layer, when the chip capacitor is welded, the extruded redundant solder can overflow into the notch of the solder layer to prevent the extruded redundant solder from overflowing out of the bonding pad, so that the phenomenon that the extruded solder overflows due to more solder is avoided, the short circuit of the chip capacitor is caused, and the yield and the reliability of the chip capacitor welding are improved.

It is to be understood that the invention is not limited to the above-described embodiments, and that modifications and variations may be made by those skilled in the art in light of the above teachings, and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.

Claims

1. A steel mesh is characterized by comprising a steel mesh body, a plurality of printing holes arranged on the steel mesh body, baffles arranged in the printing holes, and connecting rods for connecting the baffles and the steel mesh body to form a plurality of special-shaped printing holes; the width of the connecting rod is smaller than that of the baffle;

2. The steel net according to claim 1, wherein the sum of the areas of the baffles and the connecting bars is 5-20% of the area of the printing holes.

3. The steel net according to claim 1, wherein the shape of the baffle is circular or polygonal.

4. The steel net according to claim 1, wherein the area of the connecting rod is smaller than the area of the baffle.

5. The steel net according to claim 1, wherein the end of the connecting rod connected to the steel net body is located in the middle of one side of the printing hole.

6. The steel net according to claim 1, wherein the thickness of the steel net body is 0.05-0.1 mm.

7. A welded structure, comprising: the circuit comprises a base layer, a first bonding pad and a second bonding pad which are arranged on the base layer at intervals, a first welding material layer arranged on the first bonding pad and a second welding material layer arranged on the second bonding pad; the first solder layer and/or the second solder layer are provided with a notch, the notch comprises: the channel is communicated with the interval area between the first solder layer and the second solder layer, and the through hole is connected with the channel; the width of the channel is smaller than the width of the through hole.

8. The bonding structure according to claim 7, wherein an insulating oil layer is provided between the first pad and the second pad.

9. The bonding structure of claim 7, wherein the first bonding pad is rectangular or triangular.

10. The solder structure according to claim 7, wherein the first solder layer has an area smaller than that of the first land; the area of the channel is smaller than that of the through hole.