CN113013056A

CN113013056A - System and method for performing post-processing

Info

Publication number: CN113013056A
Application number: CN202011498732.XA
Authority: CN
Inventors: 丁锺才; 申允锡
Original assignee: Rokko Systems Pte Ltd
Current assignee: Rokko Systems Pte Ltd
Priority date: 2019-12-20
Filing date: 2020-12-17
Publication date: 2021-06-22
Also published as: SG10201912782SA; TW202139257A

Abstract

A deflash system for removing flash from an integrated circuit unit (IC unit), the system comprising: a shear plate having a plurality of pockets; each pocket is shaped to receive one of the IC units; wherein each pocket includes at least one dimension sized to shear flash from opposite sides of the IC unit.

Description

System and method for performing post-processing

Technical Field

The present invention relates to: electromagnetic interference (EMI) shielding is applied to Integrated Circuits (ICs) for use in compact devices to mitigate EMI.

Background

Applying EMI shielding to integrated circuits to mitigate interference between closely packed components can present various processing difficulties.

For example, placing an IC on a substrate template with an adhesive film during the application of EMI shielding requires that the adhesive strength of the IC be high. However, it can be difficult to remove the IC using a force, such as a lever, to push the IC off of the membrane. The tradeoff between maintaining consistently oriented adhesive strength and still being able to remove the IC is a quality tradeoff that affects IC placement accuracy.

Furthermore, once removed, the residual shielding material applied to the IC will inevitably spread to the peripheral area around the integrated circuit unit (IC unit). The residual material may not cleanly detach upon removal of the IC unit, leaving the shield material flash attached to the IC unit. Any unintended conductive material on the IC unit then jeopardizes the operating efficiency and utility of the IC unit, and therefore burrs must be prevented or removed before the IC unit can be used.

Disclosure of Invention

In a first aspect, the present invention provides a flash removal system for removing flash from an IC unit, the system comprising: a shear plate having a plurality of pockets; each pocket is shaped to receive one of the IC units; wherein each pocket includes at least one dimension sized to shear flash from opposite sides of the IC unit.

In a second aspect, the present invention provides a method for removing flash from an IC unit, the method comprising the steps of: inserting IC units into pockets within a shear plate, the pockets being shaped to receive one of the IC units and at least one dimension of the pockets being sized to shear flash from opposite sides of the IC unit, and; the flash is trimmed from each side of the IC unit.

In a third aspect, the present invention provides a method for removing an IC unit from an adhesive film, the method comprising the steps of: applying heat to the bottom side of the film at a predetermined temperature for a predetermined time; reducing the adhesive strength of the adhesive, thereby reducing the force required to remove the IC unit, and; removing the IC unit.

In a first aspect, reducing the adhesive strength of the film in conjunction with applying mechanical force to reduce the adhesive strength of the film facilitates removal of the IC unit; in one embodiment, a change in environmental conditions, such as a heated chamber, may provide an environmental condition that causes the adhesive force to be reduced under controlled conditions. As an alternative embodiment, the application of a hot air stream for a predetermined length of time may be sufficient to reduce the bond strength.

In the second embodiment, the shear plate into which the IC unit is inserted will shear off the burrs without damaging the IC unit. The shear plate may be procedurally placed intermediate the base template and downstream unloading of the IC units to provide limited delay in processing while addressing significant problems for subsequent use of the IC units.

Drawings

It will be convenient to further describe the invention with reference to the accompanying drawings which illustrate possible arrangements of the invention. Other arrangements of the invention are possible and consequently the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.

FIG. 1 is a schematic diagram of an IC removal system according to one embodiment of the invention;

FIG. 2 is a front view of a precision picker engaged with an IC unit according to another embodiment of the present invention;

FIG. 3 is an elevation view of a deflash process according to one embodiment of the present invention;

fig. 4A and 4B are front sequence views of a deburring process according to the embodiment of fig. 3;

FIG. 5 is a front view of a shear plate according to an embodiment of the present invention;

FIG. 6 is a front view of a polishing unit according to one embodiment of the present invention;

FIG. 7 is a front view of an inspection station according to one embodiment of the present invention; and

fig. 8A and 8B are plan views of alternative pocket shapes according to further embodiments of the present invention.

Detailed Description

Fig. 1 and 2 illustrate one embodiment of an IC removal system arranged to facilitate removal of IC units from adhesive film 15. The adhesive strength is affected by variations in the environmental conditions used to remove the IC units. The system 5 in this case comprises a hot gas source 25, which hot gas source 25 injects hot gas 30 to the bottom side of the substrate template 10 for a predetermined time. The template 10 includes an adhesive film 15, and the IC unit 20 is placed on the adhesive film 15. In this arrangement, the EMI shielding material has been placed over the IC unit.

The application of hot gas 30 is provided for a predetermined time, wherein the hot gas has a specific temperature. The actual time and temperature will vary with the type of adhesive used. As an example of a typical adhesive for such application, a time of 5 seconds to 10 seconds at a temperature of 35 ℃ may be sufficient. This may vary greatly from application to application. By way of non-limiting example, the heating time may be 5 seconds to 10 seconds, after which mechanical force is applied, such as by a ram, to push the ICs and continue blowing until all the ICs are removed. The temperature may be in the range of 50 ℃ to 150 ℃, but this depends on the different IC.

The applied heat reduces the adhesive strength of the film 15 so that a removal force (not shown) is applied sufficient to overcome the adhesive bond.

The picker 35 then freely engages the IC unit 40 via the picker head 40, thereby applying a vacuum sufficient to pull the IC unit disengaged from the affected adhesive film 15. In this embodiment, the pickup is a precision pickup capable of at least 4 degrees of freedom, i.e., movement in the horizontal plane (X, Y) and vertical direction (Z) and rotation about the vertical axis (θ). Each of these movements can have a very high precision (+ -3 microns). While such precision is not necessary for an IC removal system, the use of a high precision picker will become apparent when the removal system is used with a deflash system.

In another embodiment, the IC unit 45 of the vacuum head 40 bonded to the pickup is observed in fig. 3. Then, a shear plate 50 having a plurality of

pockets

55, 60, 65 is provided, so that IC units 45 having burrs 80 as shown in fig. 4A and 4B are inserted 85 into the pockets 55. The sharp edge 90 of the shear plate 50 then shears through the flash 80, leaving the deflashed IC unit 45 that has overcome the significant processing deficiencies previously mentioned.

As shown in fig. 3, the debris 70, which is the removed flash, is drawn downward by the extractor 72 under a vacuum suction effect 75 to maintain a clean environment.

It should be noted that different IC units 45 may have different tolerance requirements. Thus, shear plate 50 may have

different pockets

60, 65 with different tolerances to match different IC units. Thus, in another embodiment, shear plate 50 may have

pockets

55, 60, 65 of different sizes or tolerances to more broadly accommodate a range of different units. In view of the high level of tolerance required to remove the flash 80, the precision picker is well suited to accurately lower and raise the IC unit, as well as to orient the IC unit by rotating it about a vertical axis to accommodate any misalignment during removal from the adhesive film, before inserting it into the corresponding pocket.

After removing the IC units 45, in order to maintain the cleanliness of the shear plate 50, the adhesive roller 90 may pass 95 through the top surface of the shear plate 50. This will perform a double operation to engage and remove any flash that may remain on the top surface of shear plate 50. In addition, any flash not picked up by the roller may be pushed through the

pockets

55, 60, 65 by the extractor 72 for removal 100.

Fig. 6 shows another embodiment whereby final removal of flash, including detached flash that may adhere to IC units that may be placed into a polishing station by a picker, is ensured. The polishing station may have twin rotating brushes 110. In this embodiment, the two brushes counter-rotate with respect to each other to engage the IC unit and sweep debris 120 downward so that the debris is removed by the extractor 72.

As mentioned, the precision picker that may be employed in the process may also be rotatable 105, such that the brush acts on a first pair of opposing sides in a first action, with the picker rotating the IC unit 105 such that the brush then engages a second pair of opposing sides. Thus, for such final burr removal, the IC unit may be placed first between the brushes, then rotated, and placed again between the brushes to remove any debris from the periphery of the IC unit.

Fig. 7 shows the final step whereby the picker 130 places the IC unit over an inspection station with a camera 140 to ensure that all burrs have been removed. Since the burrs are created by residual EMI shielding material, inspection from below is required to ensure that no material protrudes beyond the planar view of the IC unit.

It will be appreciated that the pockets may be shaped to shear two or four sides of the IC unit at a time, depending on the arrangement of the shear plates.

Fig. 8A and 8B show an alternative arrangement for trimming flash from the

IC units

155, 170. In the first embodiment of fig. 8A, shear plate 145 may have pockets 150 shaped to receive IC units 155. The dimensions of the pocket are such that each peripheral edge 157 is a sheared edge. Thus, once the IC unit is inserted into the pocket 150, burrs are cut from each side of the IC unit 155 by the peripheral edge.

In the alternative arrangement of fig. 8B, the pocket 165 is again shaped to receive an IC unit 170. However, in this embodiment, only two opposing peripheral sides or edges 175 have a sufficiently high tolerance to act as shearing edges, and thus the pocket is sized in only one dimension to shear opposing sides of the IC unit. The other side portions 180 are sized further apart so that they do not contact the IC unit 170 when the IC unit 170 is inserted. It will be appreciated that the dimension separating the non-sheared side portions 180 may be very large, and may be a slot, such that two IC units may be inserted side-by-side while shearing respective sides of the IC units. Once the first pair of sides is sheared, the IC unit can then be rotated and reinserted using a precision picker to complete the process.

Although the embodiment of fig. 8A has the advantage of a single insertion step, the embodiment of fig. 8B requires only two high tolerance sheared edges, thereby reducing manufacturing costs. Further, the embodiment of fig. 8B may adapt to an advantage of being able to eliminate burrs on a pair of side portions in the EMI shielding process. Therefore, both embodiments have an advantage that selection can be made according to the process.

Further, although the pocket and IC unit shapes are shown as rectangular, other shapes of IC units having two or more shearing edges are possible within the scope of the invention.

Claims

1. A deburring system for deburring integrated circuit units, said system comprising:

a shear plate having a plurality of pockets;

each pocket is shaped to receive one of the integrated circuit units;

wherein each pocket includes at least one dimension sized to shear flash from opposite sides of the integrated circuit unit.

2. The system of claim 1, wherein each peripheral edge of the pocket is arranged to trim flash from each side of the integrated circuit unit.

3. The system of claim 1, wherein only two opposing peripheral edges of the pocket are arranged to shear flash from each side of the integrated circuit unit.

4. The system of any of claims 1 to 3, further comprising: a precision picker arranged to engage and insert the integrated circuit unit into the pocket, the precision picker having at least 4 degrees of freedom, one of the degrees of freedom being rotation about a vertical axis.

5. The system of any one of claims 1 to 4, further comprising an extractor arranged to remove debris resulting from the removed flash.

6. The system of any one of claims 1 to 5, further comprising a roller arranged to pass over a top surface of the shear plate, the roller arranged to remove debris from the top surface.

7. The system of any of claims 1 to 6, further comprising: a polishing station comprising brushes of opposite rotational directions, the brushes being arranged to remove debris adhering to the integrated circuit unit when the integrated circuit unit is placed in contact with the brushes.

8. A method for removing flash from an integrated circuit cell, the method comprising:

inserting the integrated circuit cells into a pocket within a shear plate, the pocket shaped to receive one of the integrated circuit cells and sized in at least one dimension to shear flash from opposing sides of the integrated circuit cell, and;

the flash is trimmed from each side of the integrated circuit cell.

9. The method of claim 8, wherein each peripheral edge of the pocket is arranged to trim flash from each side of the integrated circuit unit.

10. A method for removing integrated circuit units from an adhesive film, the method comprising the steps of:

applying heat to the bottom side of the film at a predetermined temperature for a predetermined time;

reducing the adhesive strength of the adhesive, thereby reducing the force required to remove the integrated circuit unit; and

the integrated circuit unit is removed.

11. The method of claim 10, wherein the removing step comprises the steps of: engaging the integrated circuit unit with a pick and lifting the integrated circuit unit from the film.

12. The method according to claim 10 or 11, further comprising the steps of: applying a force to the integrated circuit cell to assist in removing the integrated circuit cell.