Particle stamp for a contact-based determination of a particle contamination on a surface

Abstract

The invention relates to a transportable particle collecting device for a contact-based determination of a particle contamination on a surface, comprising a particle collecting material (3) which forms a particle collecting surface (12) on one surface, a handling element (1) which is connected to the particle collecting material (3), and a cover (2) which can be releasably connected to the handling element. According to the invention, the handling element (1) is designed as a single piece, in particular monolithically, and the particle collecting material (3) is directly connected to the handling element (1).

Description

[0001] Particle stamp for contact-based determination of particle contamination on a surface

[0002] The present invention relates to a transportable particle collecting device, in particular a particle stamp, for contact-based determination of a particle load on a surface according to the preamble of claim 1.

[0003] In modern manufacturing and production processes, technical cleanliness is a key success factor for minimizing rejects and enabling safe manufacturing processes and long-lasting, safe products. Especially in the manufacturing of electrical or electronic parts, devices, or components, even single particles or chips can be problematic and jeopardize the long-term functionality of the manufactured item.

[0004] Against this background, the quality criterion of technical cleanliness has become established in industrial manufacturing and production processes. Technical cleanliness, and thus the freedom from or absence of foreign particles or unwanted particles, is monitored and documented, and any particles found are analyzed.

[0005] For this purpose, there are different approaches to detecting the presence of particles. On the one hand, components and surfaces can be vacuumed, and the particles extracted from the surface can be collected and analyzed. While this allows for large areas to be analyzed, it has the disadvantage that it requires considerable effort to ensure that every particle extracted from the surface is also transported to a suitable collection vessel or container to enable a representative analysis.

[0006] Alternatively, it is possible to use so-called particle traps, which are placed in the production or manufacturing environment for a certain period of time and are designed to capture and hold particles. These particle traps can then be analyzed, and the individual particles can be evaluated and categorized.

[0007] The use of particle traps allows for the capture of particles from the ambient air. Accordingly, this approach is not, or not readily, suitable for directly analyzing specific surfaces, but rather represents a means of monitoring and recording general cleanliness conditions.

[0008] Another approach, which also does not aim to analyze the entire surface of a part or component but is nevertheless capable of collecting particles directly from the surface under investigation, involves the use of so-called particle stamps. These are therefore regularly used as a "spot sample" in the analysis of the technical cleanliness of a specific surface. An arbitrary or specific part of the surface is contacted with the particle stamp in such a direct and immediate manner that particles located on the surface adhere to a particle collection surface of the particle stamp or particle collection device. When the particle collection device or particle stamp is removed, they remain there and are detached from the surface.The adhesion is usually provided by chemical adhesion promoters to capture or transfer not only specific particles, as is the case with electrostatic adhesion. The particle collection surface thus loaded with particles can then also be analyzed and evaluated.

[0009] The applicant has developed an approach that combines both a particle trap and a particle stamp. This approach is described, for example, in EP 3 534 138 A1.

[0010] The disadvantage of these and similar approaches to particle collection devices designed as particle stamps has proven to be that they are relatively complex and laborious to manufacture. For example, a base or housing in the form of a bowl is used, into which a holder or base is then inserted, for example via an adhesive connection, to which the particle collection material with the corresponding particle collection surface is attached. The holder or base usually has the function of providing a certain elasticity relative to the housing or bowl, so that when the particle collection surface of the particle collection material contacts or is pressed onto the surface to be tested, an even contact pressure is achieved and limits the acting forces, also to avoid or prevent damage to the bowl or housing.

[0011] According to the state of the art, the particle collection material forming the particle collection surface is attached, for example, glued, to the base. In a further manufacturing or production step, the housing or shell is provided with a lid. The lid serves to prevent unwanted wetting of the particle collection surface with particles, such as dust particles, before use of the particle stamp or particle collection device. The lid also serves to prevent subsequent falsification of the particle collection surface after a surface has been analyzed.

[0012] Based on this prior art, the object of the present invention is to propose a portable particle collection device for contact-based determination of particle contamination of a surface, which overcomes the disadvantages of the prior art and, in particular, can be manufactured effectively and enables improved analysis of the collected or adhering particles.

[0013] This object is achieved with the features of claim 1. Advantageous embodiments of the invention are the subject of the following description, the description of the figures, the figures and the dependent claims.

[0014] All features subsequently disclosed and claimed in terms of the device shall also be deemed to be correspondingly disclosed and claimable in terms of the method, and vice versa.

[0015] The inventive, portable particle collection device, in particular a particle stamp, for contact-based determination of particle contamination on a surface comprises a particle collection material that forms a particle collection surface on a surface. Furthermore, the particle collection device comprises a handling body connected to the particle collection material, in particular for manual operation of the particle collection device. Furthermore, the particle collection device comprises a cover that can be detachably connected to the handling body.

[0016] According to the invention, it is also provided that the handling body is formed in one piece, in particular monolithic, and that the particle collecting material is directly connected to the handling body.

[0017] This significantly simplifies and facilitates the production or manufacturing process for the particle collection device according to the invention. Thus, the handling body only needs to be manufactured in a first process step, the handling body needs to be connected to the particle collection material in a second step, and the handling body needs to be closed with the lid in a final, third process step.

[0018] In particular, in the inventive development of the prior art, a base or holder within a base of a housing or in a shell is completely dispensed with, so that the need for a connection between the holder and the housing or the shell is also eliminated.

[0019] Particularly advantageously, the particle collection material can be a flat, preferably sheet-shaped material provided with two adhesive coatings on opposite sides or on opposite base surfaces. The adhesive layers can, for example, comprise or consist of chemical adhesives. This allows one, lower, adhesive coating to be used for connection to the handling body, and the opposite, upper, adhesive coating to form the particle collection surface. The adhesive coating of the particle collection material should also be understood as a direct connection to the handling body.In other words, the direct connection between the particle collection material and the handling body is to be understood according to the invention in such a way that only those means are provided in addition to the particle collection material and the handling body which establish the connection between the two parts, for example the adhesive coating of the particle collection material itself or alternatively an additional adhesion promoter, such as an adhesive.

[0020] The particle collection device according to the invention ensures that only a one-piece handling body and the particle collection material need to be connected to each other, and the lid needs to be connected to the handling body. No further manufacturing or production steps are necessary.

[0021] In a first, particularly advantageous embodiment of the particle collection device, it can be provided that the handling body and / or the lid is / are designed as a monolithic layered component, which can be produced using an additive manufacturing process, preferably a printing process. This particularly advantageously ensures that the handling body and / or the lid can be manufactured simply and monolithically, with no or fewer restrictions regarding the shape, such as those that exist, for example, with molded components, in particular injection-molded components. Furthermore, the particle collection device can be particularly easily adapted to specific customer specifications or wishes, even in small or medium quantities. Finally, little or no storage of the individual components is necessary.Instead, it is sufficient to keep the materials for carrying out the additive manufacturing process and the production machines, for example, a 3D printer, in stock or store them. In a further, particularly preferred embodiment of the particle collection device, it can be provided that the particle collection material is enclosed or framed on the outside or at the edge by a standardized edge of the handling body. Such a standardized edge has the particular advantage that it can serve as a reference in optical analysis methods of the particle collection surface and the particles adhering thereto, both with regard to the imaging properties, such as distortion, warping, and the like, as well as with regard to the measurement of the adhering particles.

[0022] For example, it is possible to image the particle collection device using a portable electronic device, such as a smartphone or other device with an imaging unit or camera, whereby the edge framing or enclosing the particle collection surface is used to create a projection of the image in a standardized, for example orthogonal, viewing direction onto the particle collection surface and to measure the individual particles according to their size.

[0023] It can also be particularly advantageous for the handling body to be designed in a single color. While it is fundamentally possible to change the material being fed or printed, and thus alter the color, even with additive manufacturing processes such as a printing process, this is associated with increased manufacturing effort. Alternatively, part of the handling body could be subsequently colored, for example, by painting. A two-color design could potentially facilitate the detection and measurement of the edge of the handling body and thus facilitate downstream image processing and image analysis.However, it has surprisingly been found that a single-coloured handling body, which is accordingly easy to manufacture, can be used with appropriate image processing algorithms to create a standardised edge for the detection and for the rectification and / or correction of the image and for the measurement of the particles if the edge does not have a colour highlight but is instead monolithic and in the same colour as the rest of the handling body.

[0024] A further, particularly advantageous embodiment of the particle stamp or particle collection device can provide that the handling body has a receiving surface that is set back from the edge in a height direction of the handling body such that the particle collection surface protrudes minimally beyond the edge in the height direction. It has been shown that this can both improve the correct arrangement of the particle collection material in the set-back receiving surface and, at the same time, minimize disruptive or unwanted image artifacts during the optical evaluation of the particle collection surface after contact with a surface to be inspected, for example due to shadows cast at an offset between the handling body, in particular the edge of the handling body, and the particle collection material. In this way, incorrect, particularly automated, evaluations of the optical image of the particle collection surface can be prevented or minimized.

[0025] In a further, particularly advantageous variant of the particle collection device, the handling body can be provided with one, preferably two, straight and / or flat side walls arranged perpendicular to the vertical direction. This can, for example, improve the edge or corner accessibility of the handling body and thus also of the particle collection area compared to a round or rounded contour of the handling body. Since particle deposition is particularly likely in corners, this allows for particularly accurate analysis even of potentially more contamination-prone and less easily accessible areas.

[0026] Furthermore, this particularly advantageously ensures that the correct relative position between the handling body and the lid is easily visible to the user. For this purpose, it can be particularly advantageously provided that the lid also has one or two straight and / or flat side walls arranged at right angles to one another perpendicular to a vertical direction.

[0027] In a further, particularly preferred variant of the particle collection device, the handling body can be provided with a bevel, particularly preferably a circumferential chamfer, on a bottom-side section in the vertical direction, preferably on the outside. It has been found that such a bottom-side, externally extending bevel allows for improved manufacture or production of the handling body, particularly when it is printed. This is because the handling body can then be more easily removed from a production substrate, for example, a print bed.

[0028] Similarly, it can be advantageously provided, alternatively or additionally, that the lid has a bevel, preferably a circumferential bevel, on an upper edge section in a vertical direction. The lid can usually be manufactured or produced, in particular printed, upside down. The upper edge section in the vertical direction of the lid then forms the transition between the edge of the lid and the printing substrate. Due to the bevel, in particular due to the circumferential bevel, the lid can also be removed from the printing substrate particularly easily and preferably automatically. This can be achieved, for example, using a slider.

[0029] In a further, particularly advantageous embodiment of the particle collection device, it can be provided that the cover has an internal locking groove, formed at least in sections, and the handling body has a locking lug, preferably a plurality of locking lugs, on an outer side for locking into the locking groove. This ensures that the cover and handling body are securely connected to one another and yet can be detached from one another, so that during the manufacture and production of the particle collection device, the particle collection surface can be securely covered and closed. Even after the cover has been removed and the particle collection device opened, the particle collection surface wetted with any particles can be securely covered and closed again by replacing the cover and re-establishing the engagement between the locking lugs and locking groove or locking lug and locking groove.Advantageously, both the locking groove and the locking lug are part of the monolithic handling body and / or the monolithic cover.

[0030] In a further, particularly advantageous embodiment of the particle collection device, in particular the particle stamp, it can be provided that the handling body comprises an elastically deformable spring part to which the particle collection material is fastened. Accordingly, according to the invention, both the elastically deformable spring part and the remaining handling body are designed and manufactured monolithically. This ensures that, on the one hand, elastic deformation and thus a particularly advantageous pressing of the particle collection material and its particle collection surface against a surface to be tested is possible, while, at the same time, the manufacture or production of the particle collection device, in particular the handling body, is kept very simple and effective.Surprisingly, it has been shown that a deformable spring part, for example by forming leaf spring sections, can also be manufactured additively and monolithically together with the rest of the handling body, for example using a 3D printing process.

[0031] In a particularly desirable embodiment of the particle collection device, it can be provided that a recess is formed in the handling body, preferably on an underside facing away from the particle collection material, in order to accommodate and / or fasten a holding device, preferably comprised by the particle collection device. Particularly advantageously, the holding device can be reversibly fastened to or in the recess. This makes it possible to provide a very small and compact particle collection device without the holding device if the application requires it. However, if, alternatively, difficult-to-access surfaces are to be tested, this can also be achieved by means of a holding device. The holding device can preferably have a handpiece or a handle and a spacer element connected to the handpiece or handle.The spacer element can advantageously be designed as a telescopic rod and / or angled rod to enable access to locations remote from the operator's hand, even if this requires traveling a complex path. Alternatively or additionally, the spacer element can also be designed as a deformable rod in the manner of a gooseneck, which remains in a deformed geometry as long as no external forces act on the spacer element. The present invention will be explained below with reference to purely schematic drawings showing advantageous embodiments.

[0032] Showing:

[0033] Fig. 1: a sectional view through a particle collecting device according to the invention in a first embodiment;

[0034] Fig. 2: an enlarged view of section B of Figure 1;

[0035] Fig. 3: a plan view of a particle collecting device according to the invention according to the embodiment of Fig. 1;

[0036] Fig. 4: an exploded view of a particle collecting device according to the invention according to the embodiment of Fig. 1;

[0037] Fig. 5: an alternative embodiment of a particle collecting device according to the invention in a sectional view;

[0038] Fig. 6: a sectional view through an inventive

[0039] Particle collection device in a third embodiment;

[0040] Fig. 7: a sectional view through an inventive

[0041] Particle collection device in a further embodiment; Fig. 8 is a plan view of a particle collection device according to the invention according to an alternative embodiment.

[0042] Fig. 1 shows a sectional view of a particle collection device 10 according to the invention, in particular a particle stamp. The particle collection device comprises a handling body 1, a cover 2 detachably attached to the handling body 1, and a particle collection material 3. The cover 2 and the handling body 1 can each be designed as one-piece, preferably monolithic, components or layered components, particularly preferably manufactured using an additive manufacturing process.

[0043] The particle collection material 3 can, for example, comprise an adhesive pad that has an adhesive coating on both opposing surfaces 11, wherein the underlying adhesive coating on surface 11 can serve to establish the connection between the particle collection material and the handling body 1. It can be provided that the adhesive force for connecting to the handling body is significantly greater than the adhesive force of the particle collection surface 12.

[0044] The sectional view shows that the particle collection material 3 is enclosed by an edge 5 or a standardized edge 5. Automated image processing and measurement of particles adhering to the surface 11 of the particle collection material 3 can be performed via the edge 5.

[0045] Furthermore, Fig. 1 shows that a receiving surface 6 of the handling body 1 is set back from the edge 5 in a height direction H such that the particle collection surface protrudes minimally beyond the edge 5 in the height direction H. The cover 2 is shown secured or attached to the handling body 1 in the illustration in Fig. 1. However, the cover 2 can also be removed to expose the particle collection material and the particle collection surface.

[0046] Fig. 2 shows the enlarged section B of Fig. 1. It can be seen therein that on the inside of the cover 2 there is formed a locking groove 8 which is formed at least in sections and into which a locking lug 7 of the opposite handling body 2 engages.

[0047] In Fig. 1, it can also be seen that both the handling body 1 and the cover 2 have a bevel 9, preferably a circumferential chamfer. The bevel of the handling body 2 is formed in a bottom section in the vertical direction, and for the cover, the bevel is formed in an upper edge section. The bevel 9 allows for improved automated production, in particular the automatic printing and removal of the printed component.

[0048] The top view of Fig. 3 shows that the handling body 1 as well as the lid 2 have a straight and / or flat side wall 4. The flat and / or straight side wall 4 makes it easy to identify the correct arrangement of the lid 2 with respect to the handling body 1, for which purpose the lid also has a flat or flat side wall 4. Furthermore, the side wall 4 can be used to improve the edge or corner accessibility of the particle collection device 10.

[0049] The exploded view in Fig. 4 once again shows that the particle collection device essentially consists of just three individual parts. The particle collection material 3 is attached or fastened to the one-piece handling body 1. The direct connection can be established, for example, via an adhesive coating of the particle collection material 3. Alternatively, a direct connection can be established via an adhesion promoter. The arrangement of the cover 2 on or at the handling body 1 is intuitive due to the flat side wall 4, both in the area of ​​the handling body and in the area of ​​the cover 2. The locking lugs 7 shown engage in the locking grooves not shown in the exploded view.

[0050] After removing the cover 2, the particle stamp or particle collection device 10 with the particle collection surface 12 can be pressed onto a substrate, in particular onto a surface to be analyzed. Particles can be picked up by the particle collection surface and adhere to it. For this purpose, the particle collection surface 12 preferably has an adhesive coating. Before and after pressing the particle collection surface 12 onto the surface to be analyzed, the cover 2 can ensure that the particle collection surface 12 is not further contaminated or wetted with particles. The edge 5 can advantageously be used to rectify or distort an image of the particle collection surface and to measure the particles adhering to the particle collection surface 12.

[0051] In the sectional view of the alternative embodiment in Fig. 5, it can be seen that the handling body comprises an elastically deformable spring part 13, which allows a resilient deflection of the particle collection material 3 relative to the lower and outer part of the handling body 1. Particularly advantageously, the elastically deformable spring part 13 is also formed as a single piece, preferably monolithically, with the rest of the handling body 1, preferably printed. This allows the contact force on a surface to be examined to be particularly advantageously limited or restricted.

[0052] Fig. 6 shows an embodiment similar to that of Fig. 1. The sectional view of Fig. 6 shows that a recess 15 is arranged in the handling body 1 on a bottom side 14 facing away from the particle collection material 3. The recess 15 serves to accommodate a holding device. With a holding device secured in the recess and encompassed by the particle collection device 10, the particle collection device 10 can be more easily guided into largely enclosed spaces, such as tanks or corners, in order to check for the presence of particles there.

[0053] Similarly, Fig. 7 shows a modified embodiment of the particle collection device 1 of Fig. 5. Here, too, a recess 15 is formed in the underside 14 to accommodate and / or fasten a holding device. Particularly advantageously, as also shown in Fig. 6, the holding device can be reversibly fastened to or in the recess 15. This allows a very small and compact particle collection device to be provided without the holding device if the application requires it. However, if, alternatively, hard-to-reach surfaces are to be tested, this can also be achieved using a holding device.

[0054] Fig. 8 shows a modified embodiment of the particle stamp or the particle collecting device 10. In this case, two side walls 4 of the handling body are arranged at right angles to one another and are straight and / or flat. This allows the particle collecting device 10 to reach into corners particularly well and collect particles there or check for their presence. The embodiment of Fig. 8 can also be combined with the embodiments of Figs. 1, 2 and 5 to 7. For example, section AA of Fig. 8 is designed according to Fig. 6 or according to Fig. 1. Thus, depending on the area of ​​application or intended use, either a flat and / or straight side wall 4 can be provided - as shown in connection with Figs. 3 and 4 - or two side walls 4 arranged at right angles to one another can be provided.

[0055] Reference symbol

[0056] 1 handling body

[0057] 2 Lid 3 Particle collection material

[0058] 4 side wall

[0059] 5 Edge

[0060] 6 Recording area

[0061] 7 locking lug 8 locking groove

[0062] 9 Bevel

[0063] 10 Particle collection device

[0064] 11 Surface

[0065] 12 Particle collection surface 13 Spring part

[0066] 14 Bottom

[0067] 15 Recess

Claims

Patent claims 1. Portable particle collection device for the contact-based determination of a particle load on a surface, with a particle collection material (3) forming a particle collection surface (12) on a surface, a handling body (1) connected to the particle collection material (3) and a cover (2) detachably connectable to the handling body, characterized in that the handling body (1) is designed in one piece, in particular monolithic, and the particle collection material (3) is connected directly to the handling body (1).

2. Particle collecting device according to claim 1, characterized in that the handling body (1) and / or the cover (2) is / are designed as a monolithic layered component which can be produced in an additive manufacturing process, preferably a printing process.

3. Particle collecting device according to claim 1 or 2, characterized in that the particle collecting material (3) is enclosed on the outside by a standardized edge (5) of the handling body (1).

4. Particle collecting device according to one of the preceding claims, characterized in that the handling body (1) is of single-color design.

5. Particle collecting device according to claim 3 or 4, characterized in that the handling body (1) has a receiving surface (6) which is set back from the edge (5) in a height direction (H) of the handling body (1) such that the particle collecting surface (12) projects minimally beyond the edge (5) in the height direction (H).

6. Particle collecting device according to one of the preceding claims, characterized in that the handling body (1) has one, preferably two, rectilinear and / or flat side walls (4) arranged perpendicular to the height direction (H) and arranged at right angles to one another.

7. Particle collecting device according to one of the preceding claims, characterized in that the cover (2) has an internal locking groove (8) formed at least in sections and the handling body (1) has on an outer side a locking lug (7), preferably a plurality of locking lugs (7), for locking with the locking groove (8).

8. Particle collecting device according to one of the preceding claims, characterized in that the handling body (1) has a bevel (9), preferably a circumferential chamfer, on a bottom-side section in the height direction.

9. Particle collecting device according to one of the preceding claims, characterized in that the cover (2) has a bevel (9), preferably a circumferential chamfer, on an upper edge section in a height direction.

10. Particle collecting device according to one of the preceding claims, characterized in that the handling body (1) comprises an elastically deformable spring part (13) on which the particle collecting material (3) is attached.

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