CH708932B1

CH708932B1 - Downholder for holding down the substrate locations of a substrate for the purpose of mounting semiconductor components.

Info

Publication number: CH708932B1
Application number: CH02035/13A
Authority: CH
Inventors: Suter Guido
Original assignee: Besi Switzerland Ag
Priority date: 2013-12-09
Filing date: 2013-12-09
Publication date: 2017-04-13
Also published as: JP6627143B2; DE102014116939A1; HK1206867A1; SG10201407399PA; JP2015115606A; KR20150067019A; CN104701220A; CN104701220B; CH708932A1

Abstract

(1) with a central recess (2), which makes at least one substrate location accessible for the bonding of "this", and with two sides adjacent to the center of the central recess. (DE). WIPO Home services World Intellectual Property Organization (12), first and second pneumatic drives, and pressure lines (9) for supplying a compressed gas to the pressure chambers of the pneumatic drives. (DE). WIPO Home services World Intellectual Property Organization Each pneumatic drive comprises a cylinder (5, 6) and a drive element, between which a pressure chamber is formed.

Description

Description: BACKGROUND OF THE INVENTION The invention relates to a holding-down device for holding the substrate locations of a substrate.

Such holding-down devices are used in assembling machines for the assembly of components, which are called "dies" in the English specialist magazine, so as to press the substrate locations of the substrate against a support during assembly. Examples of "this" are, in particular, semiconductor chips, but also capacitors, metal plates, metal covers, etc.

In the assembly of semiconductor chips, it is customary to connect the semiconductor chips, mainly power semiconductors, to the substrate by means of a solder, in order to ensure an effective dissipation of the heat loss resulting from the semiconductor chip during operation. A bonder suitable for this process is marketed by the applicant under the designation DB2009 SSI. This bonder comprises a continuous oven with a hold-down device. The holding-down device is subjected to a process temperature of 300 ° to 450 ° C.

SUMMARY OF THE INVENTION The invention is based on the object of developing a holding-down device with a simple construction and high reliability, which can be used at working temperatures of 300 ° to 450 ° C.

[0005] The stated object is achieved according to the invention by the features of claim 1. Advantageous embodiments are disclosed in the dependent claims.

[0006] The invention is explained in more detail below with reference to an exemplary embodiment and with reference to the drawing. In order to make certain aspects clearly visible, the figures are not drawn to scale.

1 shows a first exemplary embodiment of a holding-down device according to the invention with a plate and a retaining plate in a perspective view,

FIG. 2 shows the holding-down device of the first exemplary embodiment from below,

FIG. 3 shows a second exemplary embodiment of a holding-down device according to the invention from below,

FIGS. 4, 5 show the holding-down device in cross-section in two operating states, and FIG

FIG. 6 shows a second exemplary embodiment of a holding-down device according to the invention in cross-section.

[0007] FIG. 1 shows a first exemplary embodiment of a holding-down device according to the invention in perspective view. The holding-down device comprises a plate 1 with a central recess 2 and two further recesses 3 and 4 (FIGS. 4 and 5). The further recesses 3 and 4 are arranged on both sides adjacent to the central recess 2 and are advantageously essentially round, but can also have a different shape. In this exemplary embodiment, the central recess 2 is elongated and makes accessible in at least one row arranged substrate locations of a substrate for bonding the "dies".

[0008] The holding-down device further comprises a first and a second pneumatic drive. Each of the two pneumatic drives comprises a cylinder 5 or 6 and a drive element, between which a pressure chamber is formed. The drive elements are, for example, displaceable pistons 7 or 8 (FIGS. 4 and 5) or else elastically deformable and / or deflectable diaphragms 18, 19 (FIG. 6). The cylinder 5 of the first pneumatic drive is fixed on the upper side of the plate 1 above the recess 3 and the cylinder 6 of the second pneumatic drive on the upper side of the plate 1 above the recess 4. In the design with the pistons 7 and 8, they are displaceable perpendicularly to the plane which is clamped by the plate I; in the embodiment with the diaphragms 18 and 19, these are at least deformable in this direction. On the upper side of the plate 1 are arranged first pressure lines 9 for supplying a compressed gas to the pressure chambers of the two pneumatic drives. In order to prevent the substrates from oxidizing, a protective gas can be used as the compressed gas. Commonly used protective gases are nitrogen or forming gases such as N2H2.

The holding-down device further comprises a holding-down plate 10 with a recess 11. FIG. 2 shows the holding-down device of the first exemplary embodiment from below. In this exemplary embodiment, the recess II is elongated and accordingly the holding-down plate 10 is cross-shaped. On its underside, ie, on its side facing away from the plate 1, the holding plate 10 has a plurality of depressions 12 arranged in the recess 11. The lower edge portions 12 are arranged here along the two longitudinal side edges of the recess 11. If required, the retaining webs 12 can extend transversely across the recess 11. The hold-down plate 10 is arranged on the underside of the plate 1 and is supported on the plate 1, That the oblong recess 11 of the holding plate 10 is aligned with the central recess 2 of the plate 1 which is also elongated in this exemplary embodiment. The holding plate 10 is articulated to the plate 1 so that it can adapt to the alignment of the substrate when the pneumatic drives are pressurized. The hold-down plate 10 is fastened, for example, to the plate 1 by means of four screws 13. The screws 13 are guided into the plate 1 by means of resetting springs 14 (FIG. 1) and by means of threaded bores and are screwed into the holding plate 10, the restoring springs 14 arranged between the screw heads of the screws 13 and the upper side of the plate 1 being prestressed. The return springs 14 therefore push the screw heads away from the plate 1,

The hold-down plate 10 has on its upper side two depressions 15 and 16 arranged on both sides of the center of the recess 11, the position of which in FIG. 2, which shows the underside of the holding plate 10, is indicated by dashed lines. The recess 15 is spherical. The depression 16 is elongated, it consists of two approximately hemispherical end regions and a central portion with a circular cross-section. The longitudinal direction of the recess 16 extends orthogonally to the longitudinal direction of the recess 11, which is elongated in this exemplary embodiment.

[0011] FIG. 3 shows a second exemplary embodiment of the holding-down device from below. In this exemplary embodiment, the central recess 2 of the plate 1 as well as the recess 11 of the hold-down plate 10 are square or rectangular / elongated, in order, for example, to make the substrate location of a single-place substrate accessible. Accordingly, the hold-down plate 10 is wide and narrow. The longitudinal direction of the depression 16 of the holding plate 10 extends parallel to the longitudinal direction of the holding plate 10 in this embodiment.

[0012] The further recesses 3 and 4 are preferably arranged symmetrically with respect to the central recess 2 in both exemplary embodiments. Symmetric means on both sides of the center of the and at the same distance from the central recess 2.

4 and 5 show the holding-down device in the embodiment with the pistons 7, 8 as drive elements in the cross-section, FIG. 4 in the first operating state when the pressure chambers of the two pneumatic drives are relieved, FIG. 5 in the second Operating condition when the pressure chambers of the two pneumatic drives are pressurized with the pressurized gas so that the pistons 7, 8 press the hold-down plate 10 away from the plate 1 and against the substrate. The upper edge of the pistons 7, 8 has a lowered shoulder, so that the pistons 7, 8 never completely cover the mouth openings of the first pressure lines 9.

FIG. 6 shows the holding-down device in the embodiment with the diaphragms 18 and 19 as drive elements in the cross-section. The pressure chamber, which can be pressurized, is formed between the cylinders 5 and 6 and the diaphragms 18 and 19. The diaphragms 18 and 19 are elastically deformable in the perpendicular direction to the plane stretched by the plate 1. In this exemplary embodiment, the cylinders 5 and 6 can also be designed as an integral component of the plate 1 as depressions, which then form the pressure chambers.

The drive elements, ie the pistons 7, 8 or diaphragms 18, 19, of the pneumatic drives have a spherical projection 17 or a component with a spherical projection 17 is attached to the diaphragms 18 and 19. The spherical projection 17 of the piston 7 or of the diaphragm 18 of the first pneumatic drive engages in the spherical depression 15 of the holding plate 10. The spherical projection 17 of the piston 7 or the diaphragm 18 of the first pneumatic drive and the spherical depression 15 of the holding plate have the same radius. Thanks to this design, the holding plate 10 can tilt in any direction but can not displace it against the plate 1. The spherical projection 17 of the piston 8 or Of the diaphragm 19 of the second pneumatic drive engages in the oblong recess 16 of the holding plate 10. The radius of the spherical projection 17 of the piston 8 or of the diaphragm 19 of the second pneumatic drive is equal to the radius of the circular cross-section of the central portion of the oblong recess 16 of the holding plate 10. This formation of the articulated bearing allows displacement of the holding plate 10 relative to the plate 1, thus enabling the precise alignment and adjustment of the lower edge 12 with respect to the substrate locations of the substrates and during the assembly operation, the tilting of the holding plate 10 in any direction and thus the adaptation of the holding plate 10 to the substrate,

The plate 1 and the two cylinders 5 and 6 can be manufactured from a single piece or they can be designed in such a way that the cylinders 5 and 6 can be slidably fastened to the plate 1. [0016] In the second case, the diameter of the recesses 3 and 4 is so large that the cylinders 5 and 6 can be displaced in a certain region without the pistons 7, 8 touching the recess 3 or 4. The cylinders 5 and 6 are fastened to the plate 1, for example by means of two screws 20 (FIG. 1), the cylinders 5 and 6 being displaceable relative to the screws 20. This embodiment offers the advantage that the position and orientation of the two pneumatic drives can be adjusted in a simple manner.

[0017] In the embodiment, when the pressure chambers of the pneumatic drives are pressurized with pressurized gas, the diaphragms 18, 19 are elastically deformed, thereby deflecting the projections 17 (downward). When the pressure chambers are vented, the hold-down plate 10 pulled by the return springs 14 to the underside of the plate 1 presses against the projections 17 so that the diaphragms 18, 19 are deformed in the opposite direction. The height of the cylinders 5, 6 is advantageously such that the diaphragms 18, 19 come to rest against the cylinder cover in this case.

Claims

The pistons 7, 8 as well as the diaphragms 18, 19 can assume two positions, namely a retracted position when the pressure chambers are not pressurized with compressed gas, and an extended position when the pressure chambers are pressurized. In order to be able to check whether the pistons 7, 8 or diaphragms 18, 19 return to their retracted position when the pressurized gas is removed, second pressure lines 21, which lead to the pressure chambers of the two pneumatic drives, are preferably provided (Not shown) are provided. In operation, at the end of the pressurizing of the pressure chambers with compressed gas or permanently a gas with low pressure is fed into the second pressure lines 21. When the pistons 7, 8 or diaphragms 18, 19 return to their retracted position, Then the pistons 7, 8 or diaphragms 18, 19 close the end of the assigned second pressure line 21 so that the pressure in the pressure lines 21 rises and the gas flow stops. If the pistons 7, 8 or diaphragms 18, 19 do not return to their retracted position, the gas supplied via the pressure lines 21 flows via the first pressure lines 9 and / or, if appropriate, via the gap between the pistons 7, 8 and the associated cylinder 5 and 6, respectively, and the pressure does not rise. The sensors are, for example, pressure sensors which monitor the pressure in the pressure lines 21, or flow sensors which monitor the gas flow. claims If the pistons 7, 8 or diaphragms 18, 19 do not return to their retracted position, the gas supplied via the pressure lines 21 flows via the first pressure lines 9 and / or, if appropriate, via the gap between the pistons 7, 8 and the associated cylinder 5 and 6, respectively, and the pressure does not rise. The sensors are, for example, pressure sensors which monitor the pressure in the pressure lines 21, or flow sensors which monitor the gas flow. claims If the pistons 7, 8 or diaphragms 18, 19 do not return to their retracted position, the gas supplied via the pressure lines 21 flows via the first pressure lines 9 and / or, if appropriate, via the gap between the pistons 7, 8 and the associated cylinder 5 and 6, respectively, and the pressure does not rise. The sensors are, for example, pressure sensors which monitor the pressure in the pressure lines 21, or flow sensors which monitor the gas flow. claims Which monitor the pressure in the pressure lines 21, or flow sensors that monitor the gas flow. claims Which monitor the pressure in the pressure lines 21, or flow sensors that monitor the gas flow. claims

(DE). (EN) The invention relates to a holding device for holding down the substrate locations of a substrate, comprising a plate (1) with a central recess (2), and two further recesses (3, 4) arranged on both sides adjacent to the central recess (2) (10) is mounted on the underside of the plate (1) in such a way that the recess (11) of the hold-down plate (10) is arranged on the underside of the plate (1) in the recess (11) and on the underside at the recess (11) 10) is aligned with the central recess (2) of the plate (1), a first and a second pneumatic drive, each of the two pneumatic drives comprising a cylinder (5, 6) and a drive element between which a pressure chamber is formed,Wherein the cylinder (5) of the first drive is arranged on the upper side of the plate (1) above the first of the further recesses (3) and the cylinder (6) 4), and first pressure lines (9) for supplying a pressurized gas to the pressure chambers of the two pneumatic drives.
2. The holding device according to claim 1, characterized in that the drive element of the first pneumatic drive has a spherical projection (17), which engages into a spherical depression (15) of the hold-down plate (10), and that the drive element of the second pneumatic drive has a ball- (17) of the driving element of the first pneumatic drive and the ball-shaped recess (15) of the holding device (17), which projection (17) engages in an oblong recess (16) of the retaining plate (10) ) Of the holding plate (10) have a same radius,And wherein the radius of the spherical projection (17) of the drive member of the second pneumatic drive is equal to the radius of the cross-section of the central portion of the elongated recess (16) of the hold-down plate (10).
3. The hold-down device according to claim 1, wherein the drive element of the pneumatic drives is a piston.
4. The hold-down device according to claim 1, wherein the drive element of the pneumatic drives is a diaphragm.
5. The hold-down device as claimed in claim 3, further comprising second pressure lines for supplying a gas to the pressure chambers of the two pneumatic drives and sensors for monitoring the pressure or gas flow in the second pressure lines in order to check whether or not The pistons (7, 8) or diaphragms (18, 19) return to a retracted position when the pressurized gas is removed.