Squeegees
Pre-Placement Printing Process Solutions
The modern manufacturing environment is continually developing, subject to advances in technology, legislative requirements and end user demand. However, consistency remains a valuable commodity, particularly in the field of pre-placement print process control. That’s why DEK has extended its range of squeegee products, guaranteed to deliver the continual optimisation of pre-placement solutions.
The new range features tougher durometer polyurethane, metal and composite material types. Plus, further options in squeegee mounting and angle of attack are also available. Like all products from DEK, the new additions are available from eEnquiry. If you have not yet registered, please click here.
Lead Free Chrome
The changing paste properties associated with lead-free raise significant implications for the whole print process. Going lead-free is so much more than merely substituting lead-rich paste for different alloys. For example, lead-free alloys will react differently with fluxes, affecting reflow profiles, residue characteristics, wetting performance, cleaning methods and processing time.
As a consequence, it is imperative that manufacturers are equipped not only to optimise paste transfer and alignment, but also to eliminate the prospect of contamination with lead-rich paste. Following extensive application test trials by our Lead-Free project team, DEK has developed a new range of chrome coated stainless steel squeegee blades and ProFlow® wipers to achieve exactly this.
The chrome material encourages improved lead-free paste rolling characteristics, preventing paste sticking to blades and wipers. For manufacturers, this means improved transfer efficiency, effective alignment and lower paste wastage for a superior, cost-effective lead-free performance.
All DEK chrome coated squeegee blades are identifiable by an engraved DEK Lead-Free logo, enabling easy distinction from regular squeegee blades.
The introduction of engraved part numbers on the new blades facilitates easy re-order.
A green anodized squeegee assembly is also available, further enhancing manufacturers’ ability to identify lead-free printing lines.
Polyurethane
Polyurethane material delivers exceptional print quality
High durability, exhibiting no stencil abrasion
Able to be easily re-ground in order to maintain its edge
Current hardness ranges from 70 to 120 shore with harder durometers - typically 94-97 through to 120 shore – being better suited to solder paste applications using single stencil thickness stencils. Generally, step stencil applications use a softer approach, at between 75-80 and 94-97 shore
Metal
Increasingly popular solution, particularly for environments mixing larger and fine-pitch components on a single board
Viable low cost alternative to polyurethane, offering wider pressure window, consistent performance and minimal wear effects
Excellent performance when boards are not flat
Composite
Incorporates benefits of polyurethane and metal by supporting exceptional print definition and even print volume for horizontal and vertical pads in fine pitch applications
Excellent performance with very large apertures
For more information on any of the above solutions, please contact DEK.
Squeegee Mounting Options
DEK customers can currently choose between two types of squeegee mounting options:
Bonded
Although the need for an ultra-straight printing edge is widely acknowledged, it is particularly difficult to achieve with higher durometer polyurethane blades. To address this, DEK’s bonded squeegee assembly has been designed to guarantee a straight printing edge while reducing set-up time.
In comparison with traditional mounting methods, the lower overall material distortion of polyurethane allows easy set-up and a significant increase in cycle life.
Further advantages of this product include its accommodation of a greater paste bead through a large blade face and its ground printing edge, which allows lower pressure settings to be used.
Clamped
The traditional method of mounting the pre-drilled squeegee blade to the holder by securing it with a matching clamp plate is illustrated in Figure 1. Particularly suited to for use with metal blades, the clamping mechanism enables multiple blade width storage and durometer interchangeability. Two spacers are available, allowing the blades to be set up in either a very rigid or more common flexible configuration.
Optimum Printing Angles
To complement the options of squeegee materials and types, a choice of angles is also available, allowing users to select the best squeegee type for each specific 
application. For flexibility, both 45º and 60º angles of attack, as shown in Figure 2, are offered.
All available combinations have been qualified for use in both large and ultra-fine pitch printing. This ensures that current programs may be continued using existing materials and angles, renders process design changes more efficient and effective, as well as allowing new stencil and process designs to be optimized from the start.