JPH072611Y2 - Press plate for plating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement of a plating pressing plate applied when partial plating is performed on a short lead frame for an IC, for example.

[Prior Art] With recent advances in semiconductor technology, the capacitance of semiconductor elements,
Eventually, it is necessary to increase the size and shape, but on the other hand, there is a demand for size and weight reduction of this type of electronic component. Therefore, while the size of the semiconductor element itself is large, the package itself The dimensions tend to remain the same.

Therefore, in such a case, it is necessary to expand the range of the area of the partial plating occupying on the surface of the lead frame, and from this requirement, at the time of plating, to obtain high plating area accuracy, It is essential to reduce the allowance for back leakage.

Conventionally, for example, there is known a method of using a pressing plate made of a soft and adhesive material as a backside mask for a lead frame to be plated.

Here, FIG. 8 shows the structure of a conventional pressing plate device used in a partial plating device for a short lead frame of this type.

That is, in the apparatus configuration of FIG. 8, the pressing plate body 1 is composed of the support plate 2 and the back surface mask 3 adhered to the lower surface thereof. As shown in the figure, a plurality of power supply lines 4 are stretched so as to pass through the lower surface of the backside mask 3, and these power supply lines 4 are connected to each other by a conductive wire 5 via a tap 6. ing.

Here, the back surface mask 3 is used by being pressed against the back surface (upper surface) of the lead frame to be plated, as will be described later, but is generated by the intrusion of the plating solution between the contact surfaces of these two. As described above, in order to prevent back leakage of plating, the backside mask 3 formed of an insulating material made of a soft material and the pressing plate body 1 are made of a soft material so as to secure the rigidity and prevent the deformation thereof. The support plate 2 thus formed is joined to each other by a double-sided adhesive tape or an adhesive.

On the other hand, the power supply line 4 is used as a bare wire in order to directly contact with the lead frame to form a required current-carrying circuit. When the mask 3 is pressed against the lead frame,
The lead frame is stretched so as to be arranged corresponding to the intermediate position between the adjacent plated portions.

Further, FIG. 9 shows a main part of a partial plating apparatus for a short lead frame using the pressing plate shown in FIG.

In the figure, 7 is a plating mask which is installed horizontally and has a through hole 7a for defining a plating region, and 8 is arranged in parallel with the plating mask 7 and below it. Is a nozzle attached to the anode 8 so that the plating solution injection port 9a faces the through hole 7a, and 10 is the plating mask 7 and the anode 8 through the conductive wire 5 '. It is a power supply that applies a voltage between them.

In such a plating apparatus, first, in a lead frame L for which a pretreatment process for plating has been completed, a surface La to be partially plated (hereinafter, referred to as a plating surface) is made to face a plating mask 7 surface, and each plating area is formed. And the through holes 7a are aligned with each other and set on the plating mask 7. Next, the pressing plate 1 is lowered, and the lead frame L is pressed by the back surface mask 3, whereby the plating mask 7 is set in a close contact state with respect to the lead frame L.

Then, in such a state, the plating liquid is ejected from the ejection port 9a of the nozzle 9 toward the through hole 7a of the plating mask 7, so that the plating layer is formed only in the plating region through the through hole 7a.
Moreover, after a lapse of the required time, the injection of the plating liquid from the nozzle 9 is completed, the partial plating of the lead frame L is completed, the pressing plate is lifted after this completion, and the plated lead frame L is It is being sent to the processing process of.

[Problems to be solved by the device]

As described above, in this type of plating, a high plating area precision is required as the finished state of the plating, but in the case of the conventional plating apparatus, when the lead frame L and the plating mask 7 are in close contact with each other. , Especially the lead frame L
Since the power supply line 4 is interposed between the back surface of the lead frame and the bottom surface of the mask 3 for the back surface, it is difficult to ensure the close contact of the lead frame L. Therefore, it is impossible to eliminate the back leakage at all. It is possible that the desired plating area accuracy cannot be obtained, and the back plate mask 3 is formed of a soft material as described above, or the back plate mask 3 is formed of a soft material as described above. There is a problem that the lead frame L sticks to the lower surface of the backside mask 3 when the metal plate rises, and thus the lead frame L is set at a predetermined position on the plating mask 7 after plating. The point that cannot be maintained is a big obstacle especially for automation.

In view of such circumstances, an object of the present invention is to provide a plating pressing plate capable of completely preventing back leakage of a plating solution and solving problems such as sticking of a lead frame.

[Means for Solving the Problems]

The plating pressing plate according to the present invention has a lower surface on which a back surface mask is superposed, at least one insertion hole penetrating the lower surface mask, a mount mounted on the support plate, and a vertical movement on the mount. And a power feeding rod which is capable of being locked with the lower end projecting from the lower surface of the backside mask through the insertion hole, and biasing the power feeding rod into the projecting state. And a suppression means.

Therefore, by lowering the pressing plate with respect to the lead frame set on the plating mask, when the lead frame and the back surface mask come into close contact with each other, the lower end of the power feeding rod is pressed against the back surface of the lead frame. At this time, since nothing is interposed between the back surface of the lead frame and the bottom surface of the mask for the back surface, the contact between these contact surfaces is uniform at a predetermined pressure. Even when the plating surface and the upper surface of the plating mask are in contact with each other, a uniform and constant contact pressure is applied, and the invasion of the plating solution into this contact surface is hindered.

That is, the back leakage of the plating solution can be completely eliminated in this way, and further, when the pressing plate rises after the plating is completed, the tip of the power feeding rod represses the back surface of the lead frame. The lead frame can be easily separated from the backside mask.

〔Example〕

Hereinafter, with reference to FIGS. 1 to 3, a first embodiment of a plating pressing plate of the present invention will be described by using the same reference numerals for the same members as in the conventional example.

In the figure, 1 is a pressing plate body composed of a supporting plate 2 and a backside mask 3. Further, 11 is a proper place of the pressing plate body 1, that is,
Here, a power feed rod, which will be described later, is formed so as to penetrate through both the support plate 2 and the backside mask 3 in at least one location selected so as to be optimum for the lead frame L to be plated. It is a hole.

Further, 12 is a guide hole 12 formed in the upper arm 12a and the lower arm 12b.
a ₁ and 12b ₁ are mounts (see FIG. 2) mounted on the support plate 2 so that they can be aligned with the insertion holes 11, respectively, and 13 is the insertion holes 13a, 13a so that the insertion portions 13a, 13a can move up and down. 11 and the guide holes 12a ₁ and 12b ₁ and the locking portion 13b is attached to the gantry 1.
2 shows a power supply rod (see FIG. 3) which is in contact with the upper surface of the lower arm 12b of the lower arm 12b, and the lower end of the insertion portion 13a projects from the lower surface of the backside mask 3 to be locked. Is a compression coil spring as an elastic means interposed between the upper arm 12a of the gantry 12 and the locking portion 13b of the power feeding rod 13 and interposed in the insertion portion 13a of the power feeding rod 13.

In the case of the above configuration, the pedestal 12 is connected to the power source 10 (see FIG. 9) through the conductive wire 5'and the tap 6, and the conductive wire 5'is connected to, for example, the upper end of the power supply line 13. May be done.

Since the pressing plate for plating according to the first embodiment is configured as described above, when the lead frame L (see FIG. 9) set on the plating mask 7 is lowered from above, power is first fed. Since the locking portion 13b is elastically pressed downward by the compression coil spring 14, the lower end portion of the rod 13 is
It is in a state of protruding from the lower surface of the back surface mask 3,
The lower end of the insertion portion 13a is brought into contact with the back surface of the lead frame L.

Further, when the pressing plate body 1 descends, the feeding line 13 relatively rises in the insertion hole 11 against the elasticity of the compression coil spring 14 due to the contact with the lead frame L, and the backside mask 3 When the lead frame L and the lead frame L come into pressure contact with each other, the lower end of the power feeding rod 13 comes into contact with the back surface of the lead frame L with an appropriate pressure.

Then, in this state, a result of the lower surface of the backside mask 3 is pressed against the back surface of the lead frame L in the whole surface uniform force, the upper surface of the plated surface L _a and plating mask 7 of the lead frame L with uniform contact pressure It will be in close contact, and by this,
Intrusion of the plating solution between these contact surfaces is prevented, and back leakage can be prevented.

Thus, the lower surface of the backside mask 3 and the lead frame L
The lead frame L
By making contact between the back surface of the power supply rod and the power feeding rod 13, back leakage as in the conventional case is prevented, and a voltage for plating is applied through the power feeding rod 13 at the most suitable position for this type of lead frame. Therefore, the precision of the plating area is significantly improved.

On the other hand, after the plating of the lead frame LII is completed, the pressing plate body 1 rises again, but at that time, the feed rod 13 is elastically pressed by the compression coil spring 14 as described above, and the lower end of the insertion portion 13a leads. Since the back surface of the frame L is pressed downward, the lower surface of the back surface mask 3 and the back surface of the lead frame L are automatically separated as the pressing plate body 1 rises. Thus, the lead frame L after plating is very easily and automatically separated from the back surface mask 3 and can be kept in a state of being placed at a predetermined position on the plating mask 7.

Therefore, it is possible to completely eliminate the sticking of the lead frame L on which the plating process has been completed to the back surface mask 7, and at the same time, to automate the transfer of the lead frame L to the next processing step after removing it from the plating position. Etc. are advantageous.

Next, FIG. 4 shows a second embodiment of the plating plate for plating according to the present invention.

That is, in this example, two guide holes 12a ₁ and 12b ₁ are formed in the upper arm 12a and the lower arm 12b of the gantry 12, and two pairs of power feeding rods 13 configured in the same manner as in the first embodiment are mounted. It has become so.

The pedestal 12 can be attached to two corners of the pressing plate body 1 as shown in FIG. 1, for example.

Therefore, in the case of this second embodiment, since two power supply rods 13 are provided for one gantry 12, a sufficient and appropriate plating voltage can be applied to the lead frame L, and plating can be performed. After the completion, the lead frame L can be smoothly separated from the back surface mask 3.

In this example, as shown in FIG.
The mount 12 provided with only the upper arm 12a may be mounted on the support plate 2, and the locking portion 13b of the power feeding rod 13 may be brought into contact with the upper surface of the support plate 2 to be locked.

Next, FIG. 6 shows a third embodiment of the plating plate for plating according to the present invention.

That is, in this example, the gantry 12 has two upper arms 12a, 12a 'and two lower arms 12b, 12b' so that a total of four sets of power supply rods 13 can be mounted. By providing a plurality of rods 13, it is possible to more effectively perform the action such as detachment of the lead frame L.

Also in this example, the pedestal 12 may be provided with only the upper arms 12a and 12a 'as shown in FIG.

Thus, the gantry 12 in each of the above-described embodiments can be installed in an appropriate number on the support plate 2 in an appropriate number, while each gantry 12 has at least one or more power feeding rods. 13 is attached, but the locking portion 13b of the power supply rod 13
Instead of the compression coil spring 14 that should be pressed downward,
Another elastic body formed of a material such as rubber, for example, a hollow cylindrical elastic body, is used to connect the locking portion 13b and the upper arm 12a (12
The power supply rod 13 may be elastically pressed downward by mounting it between the lower surface of a ').

Further, it is necessary that the material of the power feeding rod 13 has electric conductivity, but the insertion portion 13a and the locking portion 13b of the power feeding rod 13 are formed separately and are coupled to each other. Alternatively, it may be machined as a single piece.

Furthermore, the gantry 12 and the compression coil spring 14 themselves do not necessarily need to have electrical conductivity.

[Effect of device]

As described above, according to the plating plate for plating of the present invention, the lead frame attached to the backside mask can be forcibly peeled off when the pressing plate rises after the plating is completed, so that it can be compared with the conventional method. As a result, the range of the partial plating area can be made large, and in addition, there is an advantage that it is possible to eliminate a trouble in transportation in the lead frame which has been plated in the automatic partial plating apparatus.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a plating pressing plate according to the present invention, FIG. 2 is a perspective view showing a mount attached to the pressing plate, and FIG. 3 is a power supply rod for supplying power to a lead frame. 4 is a perspective view showing a mount according to the second embodiment, FIG. 5 is a perspective view showing a modification of the mount of FIG. 4, and FIG. 6 is a perspective view showing the mount according to the third embodiment. FIG. 7 and FIG. 7 are perspective views showing a modified example of the gantry of FIG. 6, FIG. 8 is a perspective view showing a conventional plating pressing plate, and FIG. 9 is a portion using a conventional plating pressing plate. It is a longitudinal cross-sectional view showing a main part configuration of a plating apparatus.

Claims (1)

[Scope of utility model registration request] 1. A support plate on which a back surface mask is superposed on the lower surface, at least one insertion hole penetrating these, a pedestal mounted on the support plate, and a movably supported vertically on the pedestal. At the same time, a power supply rod that can be locked with the lower end portion protruding from the lower surface of the backside mask through the insertion hole, and an elastic pressure means that urges the power supply rod to the protruding state. A pressing plate for plating having.