Mould Half and Mould Method for Transfer Moulding Encapsulating Electronic Components Mounted on a Carrier Including a Dual Support Surface and a Method for Using Such

Abstract

The present invention relates to a mould half for a mould for transfer moulding encapsulating electronic components mounted on a carrier, where the mould part to support the carrier has a contact surface that includes a primary carrier support surface and a the primary carrier support surface surrounding secondary surface, which surrounding secondary surface is supported by a drive for height adjustment of the secondary surface relative to the height of the primary carrier support surface. Such mould half may be used for transfer moulding of electronic components while relatively easy providing a levelled support for the carrier and compensating for any thickness variations in the carrier. The invention also provides a mould with at least two mould parts and a method for transfer moulding encapsulating electronic components mounted on a carrier using such a mould.

Claims

1. A mould half for a mould for transfer moulding encapsulating electronic components mounted on a carrier, wherein the mould part to support the carrier has a contact surface that comprises a primary carrier support surface and a the primary carrier support surface surrounding secondary surface, which surrounding secondary surface is supported by a drive for height adjustment of the secondary surface relative to the height of the primary carrier support surface.

2. The mould half according to claim 1, wherein the mould half comprises a mould half base that is stationary connected to the primary carrier support surface and that is adjustable connected with the surrounding secondary surface through the drive for height adjustment.

3. The mould half according to claim 1, wherein the drive for height adjustment of the secondary surface relative to the height of the primary carrier support surface is pressure or position controlled.

4. The mould half according to claim 1, wherein the drive for height adjustment of the secondary surface comprises at least one moveable wedge.

5. The mould half according to claim 1, wherein the drive for height adjustment of the secondary surface comprises at least one pneumatic or hydraulic cylinder.

6. The mould half according to claim 1, wherein the secondary surface also carries at least one guide for encapsulating material.

7. The mould half according to claim 1, wherein the primary and secondary surface are at least moveable between a position wherein the primary and secondary surface are on the same level and a position wherein the secondary surface is equal or more than the thickness of a carrier higher than the primary surface.

8. The mould half according to claim 1, wherein between the primary and secondary surface a gasket is located.

9. The mould half according to claim 8, wherein the gasket between primary and secondary surface is an operable gasket.

10. The mould half according to claim 1, wherein the mould half comprises a measurement sensor for measuring the relative position of the primary and secondary surfaces.

11. The mould for transfer moulding encapsulating electronic components mounted on a carrier, comprising at least two mould parts which are displaceable relative to each other, comprising a mould half according claim 1 and an opposite clamping mould part.

12. The mould for transfer moulding encapsulating electronic components according to claim 11, wherein at least the opposite clamping mould part is provided with at least one mould cavity recessed in a contact side, with the contact side of the opposite clamping mould part with the at least one mould cavity being configured to engage on the carrier around the electronic components to be encapsulated.

13. The mould for transfer moulding encapsulating electronic components according to claim 11, wherein the contact side of the opposite clamping mould part is also provided with a feed channel for moulding material.

14. The mould for transfer moulding encapsulating electronic components according to claim 11, wherein a moulding material feed (top edge) is provided between the opposite clamping mould parts and at least one of the clamping mould parts is provided with an aperture to hold the moulding material feed in a clamped position of the opposite clamping mould parts.

15. A method for transfer moulding encapsulating electronic components mounted on a carrier using a mould according to claim 11, comprising the processing steps of: a) positioning a carrier onto the primary surface of the carrier supporting mould half such that the electronic components face a mould cavity, wherein the secondary support surface is located on the same side of the electronic components carrying surface of the carrier as the primary support surface; b) moving the mould parts towards each other, such that the mould parts are clamping the carrier between the primary support surface and the mould cavity recessed contact side, while the mould cavity is enclosing the electronic components to be encapsulated; c) moving the secondary support surface towards the mould cavity recessed contact side of the opposite clamping mould part; d) transferring a liquid moulding material via a feed channel in the mould cavity recessed contact side into the mould cavity; e) at least partially curing the moulding material; f) moving the mould parts apart from each other; and removing the carrier with moulded electronic components from the primary support surface of the carrier supporting mould half.

16. An encapsulation method according to claim 15, wherein after moving the mould parts apart the secondary support surface is moved further away from the opposite mould part than the electronic components carrying surface of the carrier.

17. The encapsulation method according to claim 15, wherein during processing step c) the secondary support surface is moved towards the mould cavity recessed contact side of the opposite mould part until a specific closing pressure level of the secondary support surface is reached.

18. The method for transfer moulding encapsulating electronic components mounted on a carrier using a mould half according to claim 15, wherein the position of the secondary support surface relative to the primary support surface is registered and for instance fed back to an automatic process control.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further elucidated on the basis of the non-limitative exemplary embodiments shown in the following figures. Herein shows:

[0018] FIG. 1 a schematic perspective exploded view on a mould part according the present invention;

[0019] FIG. 2 a schematic perspective exploded view on an alternative embodiment of a mould part according the present invention;

[0020] FIGS. 3A-3G schematic represented subsequent steps of a moulding method according the present invention;

[0021] FIG. 4 a cross section of a schematic represented mould according the present invention; and

[0022] FIG. 5 a schematic view on a step in an alternative (top edge) moulding method according the present invention.

DESCRIPTION OF THE INVENTION

[0023] FIG. 1 shows a mould part 1 for carrying a carrier with electronic components (not represented in this figure) having a primary carrier support surface 2 that is solid integrated with a mould half base 3. The primary carrier support surface 2 is surrounded by a secondary surface 4, which secondary surface 4 is supported by wedges 5. By moving the wedges 5 according arrows P.sub.1 (in a direction parallel to the primary carrier support surface 2 and the secondary surface 4) the height of the secondary surface 4 relative to the primary carrier support surface 2 is adjustable. The side of the secondary surface 2 directed towards the wedges 5 is chamfered 6 for collaboration with the wedges 5

[0024] In FIG. 2 an alternative mould part 10 is shown having a primary carrier support surface 11 that again is solid integrated with a mould half base 12. The primary carrier support surface 11 is surrounded by a secondary surface 13, which secondary surface 13 is supported by cylinders 14, which cylinders (for instance hydraulic or pneumatic cylinders) are integrated in the mould half base 12. By actuating the cylinders 14 according arrows P.sub.2 (in a direction perpendicular to the primary carrier support surface 2 and the secondary surface 4) the height of the secondary surface 13 relative to the primary carrier support surface 11 is adjustable.

[0025] FIG. 3A shows a mould half 20 with a primary carrier support surface 21 that is solidly integrated with a mould half base 22. The primary carrier support surface 21 is surrounded by a secondary surface 23, which secondary surface 23 is supported by wedges 24 that are displaceable by electric driven spindles 25. The secondary surface 23 is levelled with the primary carrier support surface 21 enabling e.g. easy access to the primary carrier support surface 21 for cleaning and/or inspection purposes.

[0026] In FIG. 3B the mould half 20 from FIG. 3A is shown again now with a carrier 26 of electronic components 27 placed onto the primary carrier support surface 21. The secondary surface 23 is still in the lower position as shown in FIG. 3A.

[0027] In FIG. 3C a second mould part 28 (here upper mould part) is closed according arrow P.sub.3 onto the carrier 26 such that a moulding cavity 29 recessed in a contact side 30 of the second mould 30 encloses the electronic components 27 to be encapsulated.

[0028] In FIG. 3D the secondary surface 23 is moved according arrow P.sub.4 against the contact surface 30 of the second mould part 28 thus further confining the carrier 26 with electronic components 27. In subsequent FIG. 3E a moulding material 31 is fed to the moulding cavity 29. After curing as shown in FIG. 3F the second mould part 28 may be removed (moved away from the a mould half 20 with the primary carrier support surface 21) thus loosening the moulded electronic components 32 on the carrier 26 from the second mould part 28.

[0029] In FIG. 3G is shown that the secondary surface 23 is moved downwards with the spindle 25 driven wedges 24 according arrows P.sub.5 so enabling access to the sides of the carrier 26, for instance to allow grippers 33 to come in (see arrows P.sub.6) and to remove the moulded electronic components 32 on the carrier 26 from the primary carrier support surface 21.

[0030] FIG. 4 shows a cross section of a further alternative mould 40 with a mould base 41 and integrated primary carrier support surface 42, the integrated primary carrier support surface 42 being surrounded by a secondary surface 43. The height of the secondary surface 43 is adjustable (see arrows P.sub.7) by moving wedges 44, 45 (see arrows P.sub.8, P.sub.9). In between a base 46 of the secondary surface 43 and a base 47 of the primary carrier support surface 42 a gasket 48 is located to prevent passage of dirt, to enable to establish an under pressure above the carrier 49 and even to prevent any unexpected leakage of moulding material. As also shown in this figure a rim 50 of the carrier 49 is rounded and in the embodiment shown here the rim 50 is on some distance of the secondary surface 43 making is possible for a gripper to grasp the carrier 49 even with the secondary surface 43 in a higher position.

[0031] FIG. 5 shows a step in a moulding process wherein the bottom mould half 20 with the primary carrier support surface 21 corresponds with the disclosure of the bottom mould part as shown in the FIGS. 3A-3G. As the bottom half 20 corresponds also the same reference numbers have been used for this part of the mould. Different is a second mould part 50 that is now provided with a aperture 51 for holding an individual moveable moulding material feed 52. Such moulding material feed 52 is also referred to as a “top edge”. The moulding material feed 52 is used to transfer the moulding material to the carrier 26 passing the side of the carrier 26 without problems of leakage while keeping the edge of the carrier 26 free of moulding material. For a correct positioning the moulding material feed 52 is to be brought in contact with the carrier 26 by moving it towards the carrier 26 (see arrow P.sub.10). A problem in this contact could be that the carrier 26 becoming gets damaged (cracked). An important advantage of the present invention is that the secondary surface 23 may be moved upward (here by moving the wedges 24 as explained in relation to FIG. 3A) so that the secondary surface 23 is more or less level with the upper side of the carrier 26. The secondary surface 23 is then used as a support for the moulding material feed 52 thus chance of damaging the carrier 26 due to the contact with the moulding material feed 52 is now very limited.