CN212649807U

CN212649807U - LED solder paste printing screen

Info

Publication number: CN212649807U
Application number: CN202021745965.0U
Authority: CN
Inventors: 李燕华
Original assignee: Changzhou Keruis Lighting Appliance Co ltd
Current assignee: Changzhou Keruis Lighting Appliance Co ltd
Priority date: 2020-08-20
Filing date: 2020-08-20
Publication date: 2021-03-02
Anticipated expiration: 2030-08-20

Abstract

The utility model discloses a LED tin cream printing screen board, including frame, silk screen, central net, frame thickness is 38cm, and the material is the aluminium material, the silk screen bonds in the frame bottom, and central net bonds all around in the silk screen inboard, it has the printing mouth to correspond the radium-shine PCB board printing position on the central net, the printing mouth comprises the opening dish, and a PCB pad correspondence is equipped with four opening dishes, opening dish middle part is semi-circular, is equipped with the clearance in the middle of the adjacent opening dish, the clearance distance is 2mm, the opening dish outside is equipped with the hypotenuse. The utility model discloses an opening dish shape design, the effectual LED printing short circuit problem of avoiing.

Description

LED solder paste printing screen

Technical Field

The utility model relates to a PCB printing screen technical field especially relates to a LED tin cream printing screen.

Background

With the rapid development of electronic industry and integrated circuits, the electronic Surface Mount Technology (SMT) is the mainstream PCB mounting method, before mounting, solder paste needs to be printed on a PCB bare board, the solder paste needs to be printed by a printer, a screen plate is one of the special tools for printed circuit boards, openings on the screen plate correspond to pads of the PCB bare board one by one, under normal conditions, the size of the openings of the screen plate is smaller than that of the pads of the PCB bare board, but because of the physical change of the solder paste caused by the temperature in a reflow furnace, the solder paste which is used as the "tin climbing action of the solder paste" in the industry generally reaches the melting point of the solder paste after passing through a welding area of the reflow furnace, the melting point of the general alloy solder paste is between 180 and 230, the solder paste can be greatly gathered towards part pins of the PCB pad after being dissolved, the gap between the element pins is large, the problem of short circuit can not occur, but when the pin range between the elements is small, the root of the pin of the element can gather tin balls to cause short circuit, so that poor printing is caused, the improved scheme is that the amount of tin paste printing is controlled through the opening of the steel plate, and the opening of the steel plate is designed under the condition that the tin absorption of the welding plate is enough.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the shortcoming that exists among the prior art, through design steel sheet printing opening, the effectual problem of mentioning in avoiding appearing above-mentioned technical background.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a LED tin cream printing screen board, is including frame, silk screen, central net, frame thickness is 38cm, and the material is the aluminium material, the silk screen bonds in the frame bottom all around, and central net bonds in the silk screen inboard all around, it has the printing mouth to correspond the radium-shine of PCB board printing position on the central net, the printing mouth comprises the opening dish.

According to the further technical scheme, four opening discs are correspondingly arranged on one PCB bonding pad.

According to the further technical scheme, the middle of each opening disc is semicircular, a gap is formed between every two adjacent opening discs, the gap distance is 2mm, and the outer side of each opening disc is provided with a bevel edge.

Compared with the prior art, the beneficial effects of the utility model are that:

the printing screen frame is made of aluminum, the center screen is bonded on the screen, the tension of the center screen printing is ensured, the solder paste is better separated from the center screen during printing, the printing quality is ensured, the center screen is provided with an opening disc through laser, 4 opening discs are correspondingly arranged on one bonding pad corresponding to a PCB bare board bonding pad, the middle parts of the opening discs are semicircular, gaps are arranged between adjacent opening discs, the gap distance is 2mm, and inclined edges are arranged on the outer sides of the opening discs, the design is to reduce the amount of the printed solder paste, when the printed solder paste reaches a melting point in a reflow furnace, the solder paste changes from a solid state to a liquid state, the original printing range is expanded and diffuses outwards, the gaps of the solder paste are arranged in the middle parts of the opening discs to leave space for the solder paste to diffuse to the positions of element pins, short circuit is caused, the middle parts of the opening discs are designed to be semicircular, and the short circuit is also caused by the fact that the solder paste, leaving a gap that spreads towards the middle. The utility model discloses the effectual printing tin cream that has prevented causes the inside short circuit problem that takes place of LED lamp.

Drawings

FIG. 1 is a schematic view of a structure of a LED solder paste printing stencil according to the present invention;

fig. 2 is the utility model provides a LED tin cream printing screen center net opening dish structure sketch map.

In the figure: 1 frame, 2 wire mesh, 3 center mesh, 4 semicircle, 5 bevel, 6 gap, 7 open disc, 8 pad.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.

Referring to fig. 1-2, one of them LED tin cream printing screen board, including frame 1, silk screen 2, central net 3, frame 1 thickness is 38cm, and the material is the aluminium material, silk screen 2 bonds in frame 1 bottom all around, and central net 3 bonds in silk screen 2 inboard all around, and central net 3 adopts stainless steel material preparation, it has the printing mouth to correspond PCB board printing position radium-shine on the central net 3, the printing mouth comprises opening dish 7.

In this embodiment, four opening plates 7 are correspondingly disposed on one PCB pad.

In this embodiment, the middle of each opening disc 7 is semicircular 4, a gap 6 is arranged between every two adjacent opening discs 7, the distance between every two adjacent opening discs 7 is 2mm, the outer side of each opening disc 7 is provided with a bevel edge 5, and the number of the opening discs 7 is determined according to the number of the PCB pads.

In summary, the following steps: the printing screen frame 1 is made of aluminum materials, the central screen 3 is bonded on the silk screen, so that the printing tension of the central screen 3 is ensured, the central screen 3 is better separated during solder paste printing, and the printing quality is ensured;

the central net 3 is provided with an opening disc 7 through laser, a pad corresponding to a PCB bare board pad is correspondingly provided with 4 opening discs 7, the middle part of each opening disc 7 is semicircular 4, a gap 6 is arranged in the middle of the adjacent opening disc 7, the distance of the gap 6 is 2mm, the outer side of each opening disc 7 is provided with a bevel edge 5, the design is to reduce the amount of printed solder paste, when the printed solder paste reaches a melting point in a reflow furnace, the solder paste is changed from a solid state to a liquid state, the original printing range is expanded, the solder paste diffuses outwards, the gap 3 is arranged in the middle of each opening disc 7, a space is reserved for the diffusion of the molten solder paste, the solder paste cannot climb to the pin position of an element to cause short circuit, the semicircular 4 in the middle part of each opening disc 7 is also designed to cause short circuit for the solder paste to dissolve and diffuse to the element pad. The utility model discloses the effectual printing tin cream that has prevented causes the inside short circuit problem that takes place of LED lamp.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims

1. The utility model provides a LED tin cream printing screen, is including frame, silk screen, central net, its characterized in that, frame thickness is 38cm, and the material is the aluminium material, the silk screen is through bonding in the frame bottom, and central net bonds all around at the silk screen inboard, it has the printing mouth to correspond the radium-shine of PCB board printing position on the central net, the printing mouth comprises the opening dish.

2. The LED solder paste printing screen plate of claim 1, wherein four opening plates are correspondingly arranged on one PCB pad.

3. The LED solder paste printing screen plate according to claim 1, wherein the middle part of the opening plate is semicircular, a gap is arranged between the adjacent opening plates, the gap distance is 2mm, and the outer side of the opening plate is provided with a bevel edge.