Device and Method for Detecting and Removing Contaminants on a Mould for Encapsulating Electronic Components

Abstract

The invention relates to a cleaning device for detecting and removing contaminants on a mould for encapsulating electronic components, especially semiconductors, including a light source for irradiating a mould surface; an optical detector for detecting irradiated contaminants on the mould surface; a moveable cleaner for removing the contaminants; and a controller for the cleaner. The invention also relates to a cleaning method for such a mould.

Claims

1. A cleaning device for detecting and removing contaminants on a mould for encapsulating electronic components, especially semiconductors, comprising: at least one light source for irradiating a mould surface with at least one light beam; at least one optical detector for detecting the location of at least one irradiated contaminant on the mould surface; a relative moveable cleaner for removing contaminants from the mould surface; and a controller for driving the relative moveable cleaner to the detected location.

2. The cleaning device according to claim 1, wherein the at least one light source is a laser.

3. The cleaning device according to claim 1, wherein the at least one light beam is a flat light beam.

4. The cleaning device according to claim 1, wherein the light beam strokes the surface of the mould surface.

5. The cleaning device according to claim 1, wherein the light beam is a relative moveable light beam.

6. The cleaning device according to claim 1, wherein the at least one light source is positioned to irradiate the mould surface with a light beam at an acute angle.

7. The cleaning device according to claim 6, wherein the acute angle is smaller than 30 degrees, preferably smaller than 20 degrees, more preferably smaller than 10 degrees, most preferably smaller than 5 degrees.

8. The cleaning device according to claim 1, wherein the controller comprises a memory to store the locations of the detected contaminants.

9. The cleaning device according to claim 1, wherein the relative moveable cleaner is moveable along the surface of the mould surface.

10. The cleaning device according to claim 1, wherein the relative moveable cleaner is provided with a blower head, a suction head, a brush head, a laser head and/or a scraping head.

11. The cleaning device according to claim 10, wherein a brush head, a laser head and/or a scraping head of the relative moveable cleaner is moveable along a suction head.

12. The cleaning method for detecting and removing contaminants on a mould for encapsulating electronic components, especially semiconductors, comprising the method steps: A) irradiating a mould surface of a mould for encapsulating electronic components with at least one light beam; B) detecting the locations of irradiated contaminants on the mould surface; and C) steering a relative moveable cleaner to remove the detected contaminants.

13. The cleaning method according to claim 12, wherein the mould surface is irradiated with a laser beam.

14. The cleaning method according to claim 12, wherein the light beam moveable irradiates the mould surface.

15. The cleaning method according to claim 12, wherein the light beam irradiates the mould surface at an acute angle.

16. The cleaning method according to claim 15, wherein the acute angle is smaller than 30 degrees, preferably smaller than 20 degrees, more preferably smaller than 10 degrees, most preferably smaller than 5 degrees.

17. The cleaning method according to claim 12, wherein the locations of the detected contaminants are stored.

18. The cleaning method according to claim 12, wherein the relative moveable cleaner is moved along the surface of the mould surface to the locations of the detected contaminants.

19. The cleaning method according to claim 12, wherein the relative moveable cleaner removes the detected contaminants by suction, blowing, brushing and/or mechanical engagement.

20. The cleaning method according to claim 12, wherein in performing the method use is made of a cleaning device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The terms Fig., Figs., Figure, and Figures are used interchangeably to refer to the corresponding figures in the drawings.

[0024] The invention will be further elucidated on the basis of the non-limitative exemplary embodiments shown in the following figures. Corresponding elements are designated in the figures with corresponding reference numerals. Herein shows:

[0025] FIG. 1 a schematic view on a first part of the cleaning device according to the present invention;

[0026] FIG. 2 a schematic view on a second part of the he cleaning device according to the present invention, together with the first part as shown in FIG. 1 making the complete cleaning device according to the present invention;

[0027] FIG. 3 a cross-sectional side-view on an optional scraper head part of the cleaning device according to the present invention;

[0028] FIG. 4 a schematic view on a scraper during a cleaning operation; and

[0029] FIG. 5 a schematic overview of the process steps of the cleaning method for detecting and removing contaminants according to the present invention.

DESCRIPTION OF THE INVENTION

[0030] FIG. 1 shows a schematic view on a first part of the cleaning device 1 according to the present invention wherein a mould surface 2 is irradiated by four light sources 3, here laser lights. Due to the laser rays of light 4 shining against contaminations 5 sidewards (seen from the surface of the mould surface 2) laser light is deflected which deflected light 6 enables a camera 7 relatively simple to detect the contaminations 5 on the mould surface 2 (when compared to a situation without the use of the sideward lighting of the contaminations 5). After detections of the locations (e.g. X, Y coordinates) of the contaminations 5 on the mould surface 2 these locations (X.sub.1, Y.sub.1; X.sub.2, Y.sub.2, . . . ) are stored in a database 8.

[0031] FIG. 2 shows the second part of the he cleaning device 1 according to the present invention, together with the first part as shown in FIG. 1 making the complete cleaning device 1. Herein the mould surface 2 with the allocated contaminations 5 is cleaned by a cleaner 9 that is relative moveable to the mould surface 2. A computer 10 is fed with the allocations of the detected contaminations 5 from the database 8. The computer (controller) 10 steers a controller 11 making the cleaner to be moved in X, Y directions (see arrows) relative to the mould surface 2. In this FIG. 2 the mould surface is stationary but as an alternative the mould surface may also controllable moved by the computer 10. With the cleaner (here a brush or broom) the contaminations 5 may be moved outwards (see arrows P.sub.1) away from the operative part of the mould surface 2.

[0032] FIG. 3 shows a a cross-sectional side-view on a cleaner embodied as a scraper head 12. Here a central scraping element 13 is surround by an air passage 14 through which an air flow can be supplied. Such a scraper head 12 combines two cleaning techniques; scraping and blowing.

[0033] In FIG. 4 a schematic a scraper 15 is shown during a cleaning operation wherein a contamination 5 on mould surface 2 is slided away (see arrow P.sub.2) with a skew scraper 15 providing a sharp contact edge 16.

[0034] FIG. 5 is showing a schematic overview 20 of the process steps of the cleaning method for detecting and removing contaminants 5 on a mould surface 2 according to the present invention. In a process step A a mould surface 2 of a mould for encapsulating electronic components is irradiated with at least one light beam. In a subsequent process step B the locations of irradiated contaminants on the mould surface is detected and the locations of the contaminations are stored in a database 8. In the next process step C the relative moveable cleaner is steered based on location information retrieved from the database 8 to remove the detected contaminants 5 from the mould surface 2. Additionally to the here described process also an initial detection of the mould surface may be included to enable the deletion of background information from the information gathered during the second (irradiated) detection step.