CN111266811A

CN111266811A - Stainless steel stencil stepped template welding process

Info

Publication number: CN111266811A
Application number: CN202010194409.7A
Authority: CN
Inventors: 杨建民; 杨赫
Original assignee: Dct Tianjin Technology Development Co ltd
Current assignee: Dct Tianjin Technology Development Co ltd
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-06-12

Abstract

The invention relates to the technical field of laser precision machining, in particular to a welding process of a stainless steel screen printing stepped template, which comprises the following steps: step 1: setting data contents including position coordinates of 3 Mark points and areas needing thinning and thickening through data processing software; step 2: placing the SMT net frame in a steel net cutting machine, and cutting according to data content; and step 3: fixing the stainless steel sheet to be welded in the cut SMT screen frame by using a jig; and 4, step 4: placing the SMT net frame fixed with the stainless steel sheet into a steel net cutting machine again, introducing data content, and searching 3 Mark points by using an industrial camera to perform pattern positioning; and 5: performing laser welding on the edge of the area needing to be thinned and thickened by using a laser welding head; step 6: and taking out the SMT screen frame after welding.

Description

Stainless steel stencil stepped template welding process

Technical Field

The invention relates to the technical field of laser precision machining, in particular to a welding process of a stainless steel stencil printing step.

Background

The SMT ladder mesh is designed to meet the different tin loading requirements for all the large and small components on the same PCB. The method can be divided into the following steps: locally thickened steel mesh (i.e. large area reduction) and locally thinned steel mesh (small area reduction).

Locally thickened steel meshes are generally suitable for relatively large elements, such as: IC grounds, card sockets, modules, etc., require a large amount of solder paste.

The local thinning steel mesh is generally suitable for more precise elements, such as precise IC, 0.4-0.5-pitch BGA and the like, and the required solder paste amount is slightly less.

The traditional ladder steel mesh process at present is: etching (drawing a film splicing sheet after data is compiled, exposing and developing-corroding) is needed, and then laser cutting is needed. The process is suitable for mass production of single shaped variety. Although the produced ladder steel mesh has a clean and tidy surface, the uniformity of the etching thickness is poor for a large-width steel mesh. The etching process uses chemical liquid, has long processing time and is easy to pollute the environment. Therefore, a welding process which is simple and convenient to operate, high in efficiency, clean and tidy in the ladder steel mesh and more uniform in thickness needs to be designed.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the welding process of the stainless steel stencil with the missing printing function, which is simple and convenient to operate, higher in efficiency, clean and tidy in stepped steel mesh and more uniform in thickness.

The technical scheme adopted by the invention is as follows:

step 1: setting data contents including position coordinates of 3 Mark points and areas needing thinning and thickening through data processing software;

step 2: placing the SMT net frame in a steel net cutting machine, and cutting according to data content;

and step 3: fixing the stainless steel sheet to be welded in the cut SMT screen frame by using a jig;

and 4, step 4: placing the SMT net frame fixed with the stainless steel sheet into a steel net cutting machine again, introducing data content, and searching 3 Mark points by using an industrial camera to perform pattern positioning;

and 5: performing laser welding on the edge of the area needing to be thinned and thickened by using a laser welding head;

step 6: and taking out the SMT screen frame after welding.

Further, the data content set in step 1 includes generating a fixicialtop layer and a SolderPasteTOP layer, where the fixicialtop layer is a half-etching layer and the SolderPasteTOP layer is a cutting layer, where the fixicialtop layer has position coordinates of 3 Mark points, and the SolderPasteTOP layer has a region to be thinned and thickened.

Further, in the step 2, 3 Mark points are half engraved, and a thinned and thickened area is cut to form an opening.

Furthermore, in the step 3, the stainless steel sheet to be welded is fixed in the area of the opening of the SMT screen frame, and the used jig needs to ensure that the flatness of the stainless steel sheet to be welded and the flatness of the SMT screen frame are consistent.

Further, in the step 4, the industrial camera of the steel mesh cutting machine is used for searching the positions of 3 mark points in the SMT mesh frame, and the actual mark point positions are made to coincide with the theoretical mark point positions through the operation software of the equipment.

Furthermore, the model of the adopted fiber laser is IPG-YLR-200-AC, and the preferred laser beam power is 200W during the welding process.

The invention has the advantages and positive effects that:

according to the invention, the position coordinates of 3 Mark points are firstly determined, the area needing to be thinned or thickened is determined, then the SMT screen frame is cut according to the data, after the cutting is finished, a jig is adopted to fix the stainless steel sheet to be welded in the SMT screen frame, the stainless steel sheet is placed in a steel mesh cutting machine again for secondary positioning, and finally, the welding and fixing are carried out through a laser welding head. Compared with the etching process adopted by the prior art, the technology embodied by the patent is more environment-friendly, and the surface of the ladder steel mesh is cleaner and more tidy. In addition, because fix a position respectively in cutting and welding process, consequently, can effectively avoid when the assembly because the too big difficult problem that can't weld or weld the quality poor in clearance that equipment error, machining error and error caused, combine the advantage of the high quality of laser autogenous welding, high accuracy, high stability for whole welding process easy operation, efficient, the thickness homogeneity of whole SMT ladder steel mesh is better.

Drawings

FIG. 1 is a schematic flow diagram of the present invention;

FIG. 2 is a schematic diagram of a process for setting data;

FIG. 3 is a schematic diagram of a cutting process according to data;

FIG. 4 is a schematic structural view of a stainless steel sheet in a fixed state;

FIG. 5 is a schematic structural view of a flux and additives applied before soldering;

fig. 6 is a schematic structural view of a welded state.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.

The invention discloses a stainless steel stencil welding process, which is characterized by comprising the following steps of:

step 1: setting data contents including position coordinates of 3 Mark points 1 and an area 2 needing thinning and thickening through data processing software;

step 2: placing the SMT net frame 3 in a steel net cutting machine, and cutting according to data content;

and step 3: fixing the stainless steel sheet 5 to be welded in the cut SMT screen frame by using a jig;

and 5: laser welding is carried out on the edge of the area needing to be thinned and thickened by using a laser welding head 7;

step 6: and taking out the SMT screen frame after welding.

In this embodiment, the data content set in step 1 includes generating a fiducialotop layer and a solder pastetop layer, where the fiducialotop layer is a half-etching layer and the solder pastetop layer is a cutting layer, where the fiducialotop layer is internally provided with position coordinates of 3 Mark points, and the solder pastetop layer is internally provided with an area that needs thinning and thickening.

In this embodiment, in step 2, 3 Mark points are half engraved and thinned and thickened regions are cut to form openings.

In this embodiment, the stainless steel sheets to be welded and the holes made by the SMT frame are preferably made by using the same steel mesh cutting machine.

In this embodiment, in step 3, the stainless steel sheet to be welded is fixed in the area where the hole of the stainless steel sheet 4 in the SMT frame screen is formed, and the jig needs to ensure that the flatness of the jig is consistent with that of the stainless steel sheet to be welded and the flatness of the SMT frame screen.

In this embodiment, in step 4, the industrial camera of the steel mesh cutting machine is used to find the positions of 3 mark points in the SMT frame, and the actual mark point position coincides with the theoretical mark point position through the operation software of the device.

In the embodiment, the welding flux is smeared on the outer edge 6 of the stainless steel sheet and the inner edge of the opening of the SMT screen frame before welding, and a mixture of a thermoplastic binder and metal powder is also smeared, so that the thermoplastic binder is easily heated and melted, and the welding strength of the stainless steel sheet is improved.

In this embodiment, the thicknesses of the SMT stepped steel meshes are mostly 0.1mm, 0.12mm,0.15mm,0.2mm, etc., and the thicknesses are all less than 0.3mm, which belongs to ultra-thin stainless steel sheet welding. Therefore, the following fiber laser is adopted and corresponding parameters are set to ensure the welding quality in the welding process. The model of the adopted fiber laser is IPG-YLR-200-AC, and in the welding process, the preferred laser beam power is 200W, the pulse width is 0.1 microsecond, the frequency is 20Hz, and the welding speed is 8 mm/s-16 mm/s.

In this embodiment, after the soldering is completed, it is preferable to perform polishing on both the front and back surfaces of the SMT frame.

Claims

1. A stainless steel stencil welding process is characterized in that: the method comprises the following steps:

step 6: and taking out the SMT screen frame after welding.

2. The stainless steel stencil welding process of claim 1, wherein: the data content set in the step 1 comprises that a FiducialTop layer and a SolderPasteTOP layer are generated, wherein the FiducialTop layer is a half-etching layer, the SolderPasteTOP layer is a cutting layer, the position coordinates of 3 Mark points are set in the FiducialTop layer, and an area needing thinning and thickening is set in the SolderPasteTOP layer.

3. The stainless steel stencil welding process of claim 2, wherein: and in the step 2, half engraving 3 Mark points and cutting out thinned and thickened areas to form openings.

4. The stainless steel stencil welding process of claim 1, wherein: in the step 3, the stainless steel sheet to be welded is fixed in the area of the opening of the SMT screen frame, and the used jig needs to ensure that the flatness of the stainless steel sheet to be welded is consistent with that of the SMT screen frame.

5. The stainless steel stencil welding process of claim 1, wherein: in the step 4, the industrial camera of the steel mesh cutting machine is used for searching the positions of 3 mark points in the SMT screen frame, and the actual mark point position is overlapped with the theoretical mark point position through the operation software of the equipment.

6. The stainless steel stencil welding process of claim 1, wherein: the model of the adopted fiber laser is IPG-YLR-200-AC, and the power of the laser beam is 200W preferably in the welding process.