Workpiece Holding Jig

Description

BACKGROUND

Technical Field

The present disclosure relates to a workpiece holding jig for holding a rectangular plate-shaped workpiece that is an object to be electroplated. Examples of the workpiece include printed circuit boards, wafers, and semiconductor substrates (particularly Fan-Out Panel Level Packages).

Background Art

Workpiece holding jigs for holding a rectangular plate-shaped workpiece are well known, as shown in Japanese Patent No. 5898540 and Japanese Patent Application Laid-Open Nos. 2016-180148, 2016-156084, 11-172492, 11-140694, 6-108285, 5-247692, 5-222590, 5-218048, 2020-117763, 2020-117764, and 2020-117765.

However, such conventional workpiece holding jigs have the following deficiencies.

• • (1) It is desired to more fully eliminate the possibility of plating liquid infiltrating into the connection area between the workpiece and the electrical contact terminal. When plating liquid infiltrates into the connection area, metal is deposited on the connection area, causing adhesion between the workpiece and the electrical contact terminal, to consequently make it difficult to remove the workpiece from the workpiece holding jig.
  • (2) If the rigidity of the workpiece is low, sagging occurs in the workpiece held.
  • (3) When electricity is applied for plating, heat is generated at the connection area between the workpiece and the electrical contact terminal, which increases electrical resistance, resulting in insufficient current flow for plating.

SUMMARY

An object of the present disclosure is to provide a workpiece holding jig that can eliminate the above deficiencies.

The present disclosure is characterized by a workpiece holding jig for holding a plate-shaped workpiece that is an object to be electroplated, including: a frame and a back panel, configured to hold the workpiece therebetween, and the frame is attached to the back panel so as to hold a peripheral edge of the workpiece between the frame and the back panel.

The frame includes an annular body, a conductive member disposed along an inner circumference of the body, a contact member disposed along the conductive member in electrical connection with the conductive member to allow electrical contact with the peripheral edge of the workpiece, an inner seal member disposed throughout an entire circumference of the body inside the contact member, and an outer seal member disposed throughout the entire circumference of the body outside the conductive member. The frame forms a sealed space between the inner seal member and the outer seal member in a state where the inner seal member and the contact member are in abutment against the peripheral edge of the workpiece, the sealed space accommodating the peripheral edge, the conductive member, and the contact member. The inner seal member has a column and a lip in order from outside to inside, the column protrudes toward the back panel so as to come into pressure contact with the peripheral edge of the workpiece when holding the workpiece, and the lip protrudes toward the back panel to the same extent as that of the column, with at least a tip portion of the lip inclined outward.

According to the present disclosure, it is possible to eliminate the deficiency caused by infiltration of plating liquid into the connection area between the workpiece and the electrical contact terminals and hold the workpiece without sagging even if the workpiece has low rigidity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view of a workpiece holding jig according to a first embodiment of the present disclosure;

FIG. 2 is a view of a frame of FIG. 1 seen from the direction of arrow II;

FIG. 3 is a partial view corresponding to a cross section taken along line III-III of FIG. 2, showing the state before the frame 12 is attached to the back panel 11;

FIG. 4 is a partial view corresponding to a cross section taken along line III of FIG. 2, showing the state after the frame 12 is attached to the back panel 11;

FIG. 5 is a partially enlarged view of FIG. 3;

FIG. 6 is a perspective view of the workpiece holding jig including a cooling mechanism, showing the cooling mechanism before operation;

FIG. 7 is a view seen from the direction of arrow VII in FIG. 6, with units not shown;

FIG. 8 is a schematic view seen from the direction of arrow VIII in FIG. 6;

FIG. 9 is a cross-sectional view showing the states of an inner seal member before and after it is pressed against the peripheral edge of the workpiece;

FIG. 10 is a perspective view of the workpiece holding jig including the cooling mechanism, showing the cooling mechanism after operation; and

FIG. 11 is a schematic view seen from the direction of arrow XI in FIG. 10.

DETAILED DESCRIPTION

First Embodiment

FIG. 1 is an exploded perspective view of a workpiece holding jig 1 of the present disclosure. The workpiece holding jig 1 includes a rectangular back panel 11 and a rectangular frame 12, between which a plate-shaped workpiece 10 is held. The workpiece 10 is stacked on the back panel 11. The frame 12 is attached to the back panel 11 so as to hold a peripheral edge 101 of the workpiece 10 between the back panel 11 and the frame 12. The back panel 11 and the frame 12 are made of, for example, polyvinyl chloride resin.

FIG. 2 is a view of the frame 12 of FIG. 1 seen from the direction of arrow II. The frame 12 is coupled to a carrier bar 31 via a coupling portion 32 such that the frame 12 is suspended from the carrier bar 31. FIGS. 3 and 4 are partial views corresponding to a cross section taken along line III of FIG. 2, with FIG. 3 showing the state before the frame 12 is attached to the back panel 11, FIG. 4 showing the state after the frame 12 is attached to the back panel 11. In other words, FIG. 4 shows the state in which the work holding jig 1 holds the workpiece 10. FIG. 5 is a partially enlarged view of FIG. 3.

The frame 12 includes a rectangular annular body 13, a conductive member 15 (FIG. 5), a contact member 16, an inner seal member 17, and an outer seal member 18. The conductive member 15 is disposed along two vertically extending opposite sides among the four sides of the inner circumference of the body 13. The conductive member 15 is a metal member disposed inside a wiring 191 in electrical connection with the wiring 191. The wiring 191 extends along the conductive member 15 through the carrier bar 31 and connects to an external power source (not shown). The contact member 16 is disposed along the conductive member 15 in electrical connection with the conductive member 15 to ensure electrical contact with the peripheral edge 101 of the workpiece 10. The contact member 16 is secured to the conductive member 15 from the inside with bolts 162. The inner seal member 17 is disposed over the entire circumference of the body 13 inside the contact member 16. The outer seal member 18 is disposed over the entire circumference of the body 13 outside the conductive member 15. Note that a wiring cover 192 is disposed on the back panel 11 side of the conductive member 15 to cover the wiring 191 from the back panel 11 side.

The frame 12 forms a sealed space 5 between the inner seal member 17 and the outer seal member 18 (within a range W in FIG. 4) in the state of FIG. 4, i.e., the state where the inner seal member 17 and the contact member 16 are in abutment against the peripheral edge 101 of the workpiece 10, the sealed space 5 accommodating the peripheral edge 101, the conductive member 15, and the contact member 16. The inner seal member 17 is made of, for example, silicone rubber. The inner seal member 17 adheres tightly to the peripheral edge 101 of the workpiece 10 in a compressed manner. In FIG. 4, the frame 12 is attached to the back panel 11 by being fixed via bolts 131 to the peripheral edge 119 of the back panel 11.

The contact member 16 is a comb-shaped contact member having a large number of parallel plate-spring-like contact terminals 161 for electrical contact with the peripheral edge 101 of the workpiece 10. Note that the contact member 16 is replaced when the restoring force of the contact terminal 161 becomes weak. The contact terminal 161 is made of, for example, copper coated with gold.

(Inner Seal Member 17)

As shown in FIG. 5, the inner seal member 17 has a column 171 and a lip 172 in the mentioned order from the outside. Preferably, the inner seal member 17 further has a seat 173 and an outer plate 174. The column 171 protrudes toward the back panel 11 by a height H so as to come into pressure contact with the peripheral edge 101 of the workpiece 10 when holding the workpiece 10. The lip 172 protrudes toward the back panel 11 to the same extent as the column 171 does. The lip 172 has an inclined surface 1721 on the inside of at least the tip portion, so that at least the tip portion is inclined outward. The seat 173 extends inward from the end of the column 171 to a position overlapping the lip 172. In this case, the lip 172 protrudes toward the back panel 11 until it comes into contact with the seat 173. The outer plate 174 is disposed outside the column 171, with the contact terminals 161 of the contact member 16 abutting against the surface of the outer plate 174.

(Cooling Mechanism 2)

The workpiece holding jig 1 includes a cooling mechanism 2, as shown in FIGS. 6 and 7. That is, the frame 12 includes the cooling mechanism 2 that cools the contact member 16 by causing liquid to continuously flow into the sealed space 5. As shown in FIG. 7, the cooling mechanism 2 has a liquid inlet port 21, an inflow passage 22 allowing the liquid inlet port 21 and the sealed space 5 to communicate with each other, a liquid outlet port 23, and an outflow passage 24 allowing the liquid outlet port 23 and the sealed space to communicate with each other. The cooling mechanism 2 further has an inlet connection unit 26 for connecting a supply line 25 from a liquid supply source (not shown) to the liquid inlet port 21, and an outlet connection unit 28 for connecting the liquid outlet port 23 to a drain line 27. FIG. 6 is a perspective view of the workpiece holding jig 1 including the cooling mechanism 2. In FIG. 6, the cooling mechanism 2 is in a pre-operation state. FIG. 7 is a view seen from the direction of arrow VII in FIG. 6, with the units 26 and 28 not shown. FIG. 8 is a schematic view seen from the direction of arrow VIII in FIG. 6. The inlet connection unit 26 has an inlet portion 262 connected to the liquid inlet port 21 via a packing 261, and a cylinder actuator 263 pressing or drawing the inlet portion 262 against or away from the liquid inlet port 21. The outlet connection unit 28 has an outlet portion 282 connected to the liquid outlet port 23 via a packing 281, and a cylinder actuator 283 pressing or drawing the outlet portion 282 against or away from the liquid outlet port 23.

According to the workpiece holding jig 1 of this embodiment, the following functions and effects can be achieved.

• • (1) When the frame 12 is attached to the back panel 11 to hold the workpiece 10, the inner seal member 17 is pressed against the peripheral edge 101 of the workpiece 10, as shown in FIG. 9, exerting the functions and effects below.
  • (1-1) Since the lip 172 bends outward, the lip 172 exerts an outward force on the workpiece 10. Hence, even if the workpiece 10 has low rigidity, the workpiece 10 can be held without sagging.
  • (1-2) Since the seat 173 also bends outward together with the lip 172, the seat 173 also exerts an outward force on the workpiece 10. In particular, the seat 173 has a larger contact area with the workpiece 10 than the lip 172 has, so that the outward force exerted by the seat 173 greatly reinforces the outward force exerted by the lip 172. Accordingly, the workpiece 10 can be held without sagging even when the surface of the workpiece 10 is extremely smooth or when the surface of the workpiece 10 has minute irregularities, not to mention when the workpiece 10 has low rigidity.

Thus, according to the workpiece holding jig 1 of this embodiment, even a workpiece 10 difficult to hold can be held without sagging.

• • (1-3) Since the lip 172 is pressed against the periphery 101 of the workpiece 10, plating liquid can be prevented from entering the sealing space 5.
  • (1-4) Since the seat 173 is also pressed against the peripheral edge portion 101 of the workpiece 10, plating liquid can effectively be prevented from entering the sealing space 5.
  • (1-5) Since the column 171 is also pressed against the peripheral edge 101 of the workpiece 10, plating liquid can reliably be prevented from entering the sealed space 5.
  • (1-6) Since the contact terminals 161 of the contact member 16 abut against the surface of the outer plate 174, the outer plate 174 can bring the contact terminals 161 into intimate close contact with the peripheral edge portion 101 of the workpiece 10, as shown in FIG. 9. Hence, even though the plating liquid were to infiltrate, the plating liquid can be prevented from touching the contact terminal 161. FIG. 9 shows the state of the inner sealing member 17 before and after it is pressed against the peripheral edge 101 of the workpiece 10.

Thus, according to the work holding jig 1 of this embodiment, since the plating liquid can sufficiently be prevented from entering the sealed space 5, metal arising from the plating liquid can be prevented from depositing on the peripheral edge 101 of the workpiece 10 and the contact member 16. As a result, when the workpiece 10 is removed from the workpiece holding jig 1 after the plating process, damage to the workpiece 10 and the contact member 16 can be prevented.

• • (2) Since the contact terminals 161 of the contact member 16 abut against the surface of the outer plate 174, the outer plate 174 can bring the contact terminals 161 into intimate close contact with the peripheral edge portion 101 of the workpiece 10, as shown in FIG. 9. Hence, the reliability of the electrical connection between the contact terminals 161 and the workpiece 10 can be improved.
  • (3) FIG. 10 is a perspective view of the workpiece holding jig 1 including the cooling mechanism 2, showing the cooling mechanism 2 after operation. FIG. 11 is a schematic view seen from the direction of arrow XI in FIG. 10. As shown in FIGS. 10 and 11, when the cooling mechanism 2 is activated, water continues to flow through the interior of the sealed space 5. That is, the cylinder actuator 263 is activated to press the inlet portion 262 against the liquid inlet port 21, while the cylinder actuator 283 is activated to press the outlet portion 282 against the liquid outlet port 23. In this state, when water is supplied from the liquid supply source through the supply line 25, water flows in through the liquid inlet port 21, fills the sealed space 5, flows out through the liquid outlet port 23, and is discharged through the drain line 27. As a result, water continues to flow through the interior of the sealed space 5. This enables fresh water to constantly cool the connection area between the peripheral edge 101 of the workpiece 10 and the contact member 16. Thus, heat generation in the connection area can sufficiently be prevented, and as a result, the problem of insufficient current flow for the plating process can be eliminated.

Another Embodiment

• • (1) The workpiece holding jig may not have the inlet connection unit 26 and the outlet connection unit 28, and the sealed space need only be filled with water.
  • (2) The left-right arrangement of the inlet connection unit 26 and the outlet connection unit 28 may be reversed.
  • (3) The inner seal member 17 may not have the seat 173 and/or the outer plate 174.
  • (4) The conductive member 15 is preferably disposed along all the four sides of the inner circumference of the body 13.
  • (5) The plate-shaped workpiece 10 may have a circular shape, a polygonal shape, or another shape instead of a rectangular shape. In such a case, the back panel 11 and the frame 12 also correspondingly have a circular, polygonal, or other shape instead of a rectangle.

The workpiece holding jig of the present disclosure has a high industrial utility value because it can eliminate the deficiency caused by infiltration of plating liquid into the connection area between the workpiece and the electrical contact terminals and hold the workpiece without sagging even if the workpiece has low rigidity.

• • 1 workpiece holding jig
  • 10 workpiece
  • 101 peripheral edge
  • 11 back panel
  • 12 frame
  • 13 body
  • 15 conductive member
  • 16 contact member
  • 161 contact terminal
  • 17 inner seal member
  • 171 column
  • 172 lip
  • 173 seat
  • 174 outer plate
  • 18 outer seal member
  • 2 cooling mechanism
  • 21 liquid inlet port
  • 22 inflow passage
  • 23 liquid outlet port
  • 24 outflow passage
  • 25 supply line
  • 26 inlet connection unit
  • 261 packing
  • 262 inlet portion
  • 263 cylinder actuator
  • 27 drain line
  • 28 outlet connection unit
  • 281 packing
  • 282 outlet portion
  • 283 cylinder actuator