How to solve the steel wire printing red glue drawing?
First, the basic knowledge of steel mesh SMT patch red glue: red glue squeegee is divided into manual squeegee and mechanical squeegee (machine squeegee is divided into semi-automatic squeegee and automatic squeegee). The same red glue on the same thickness steel mesh, because of the different width of the seam, the height of the red glue dots obtained is not the same.
Second, steel mesh SMT patch red plastic mesh material is mainly steel plate, in addition to plastic mesh plate, copper mesh plate. The thickness of the steel mesh plate is generally between 0.15 ~ 0.20mm, the slit width of 0603 components is 0.25 ~ 0.28mm, 0805 components are 0.30 ~ 0.33mm, and the slit length is about 10% of the length of the pad.
3. The speed of the steel mesh SMT patch red glue is set according to the different viscosity of the red glue. The higher the viscosity, the slower the speed, and the lower the viscosity, the faster the speed. 0.5cm ~ 8cm / Sec is normal , As long as it can guarantee the construction effect of red glue scraping glue. At the same time, the squeegee speed is also closely related to the condition of the circuit board. The pressure of the red glue scraper will also be adjusted according to the viscosity of the red glue. The actual operation is subject to the scraping of the red glue on the steel mesh after the scraper is scraped.
4. Analysis of common problems of steel mesh SMT patch red glue:
SMT copper mesh patch red gum prior to printing, generally stir, to reduce its viscosity, to facilitate red offset brush. During the red offset printing process, the steel mesh should be cleaned frequently.
1. Spilled glue: caused by the viscosity of the red glue being too low or the width of the steel mesh being too large.
2. When the machine is scraping, the glue can't be lowered. It may be because the surface of the blade is too rough or the specific gravity of the red rubber is too low; or the ambient temperature is too low; the thixotropic index of the red rubber is too high.
3. The amount of glue is too small: usually the seam width of the steel mesh is too small or the steel mesh is not clean, and the hole has been blocked.
4. Red gum collapse: It is due to the poor thixotropy of red gum; or the rate of moisture absorption is too fast.
1. Introduction of steel mesh SMT patch red glue:
In the red glue process, many factories have selected glue dispensers or 0.2-0.3mm steel screen printing red glue. But for products that require self-insertion and then placement and more placement points, The dispensing efficiency of the dispenser is too low and the steel screen printing cannot be completed. Of course, some factories choose to mount the component first and then insert the component, so that when inserting the component, there is the risk of stress damage and drop-out.
Second, the technical requirements of the steel mesh SMT patch red glue and the precautions for use
The process of patch red glue-wave soldering is: coating glue, patch, curing, wave soldering and cleaning. The following describes the patch red glue process in detail.
1) Steel mesh SMT patch red glue is stored before curing
The patch red gum is stored as a single component, which requires stable performance, long life, consistent quality, non-toxic and odorless, and is suitable for rapid and convenient use during production. Because the mounted components are very small, the patch red glue is often coated on the center of the two pads. It is usually coated on the PCB by screen printing, pressure dispensing, etc. Therefore, when the red glue is coated, it is not required Brushed, no tailing, the shape and size of the glue dots are consistent, smooth, full, and do not collapse.
A picture frame is a protective and decorative edging for a picture, such as a painting or photograph. It makes displaying the work safer and easier and both sets the picture apart from its surroundings and aesthetically integrates it with them.
A picture frame is a container that borders the perimeter of a picture, and is used for the protection, display, and visual appreciation of objects and imagery such as photographs, canvas paintings, drawings and prints, posters, mirrors, shadow box memorabilia, and textiles.
Traditionally picture frames have been made of wood, and it remains very popular because wood frames can provide strength, be shaped in a broad range of profiles, and allow a variety of surface treatments. Other materials include metals, e.g. silver, bronze, aluminum, and stiff plastics such as polystyrene.
A frame surface may be of any color or texture. Both genuine gilding and imitation gold remain popular, although many other surfaces are to be found in most framing establishments. Some picture frames have elaborate moldings, which may refer to the subject matter. Intricate decorations are often made of molded, then gilded plaster over a wood base.
Picture frame mouldings come in a wide variety of profiles, generally in some sort of L shape with an upward "lip" and a horizontal rabbet. The rabbet functions as a shelf to hold the frame glazing (if any is to be used), some sort of spacer or mat/matte to keep the object safely behind the inner surface of the glazing, the object itself, and backing boards to protect the object from physical damage and environmental pollutants. The lip extends a proportionate distance up from the edge of the rabbet. It restrains materials in the frame and can be used to help set off or reveal the picture aesthetically.
Wooden Photo Frame,Picture Frame,Wood Photo Frame,Wood Picture Frame,Customized Photo Frame
Jinan Tri-Tiger Technology Development Co., Ltd , https://www.tritigerwooden.com