JP2925403B2 - Plating equipment for semiconductor products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus used for manufacturing a semiconductor device and for plating external leads of a resin-encapsulated semiconductor device, and more particularly to an injection plating apparatus.

[0002]

2. Description of the Related Art In general, in manufacturing a resin-encapsulated semiconductor device, it is necessary to protect the surface of external leads and to facilitate soldering during mounting of the semiconductor device after molding (resin encapsulation). Exterior plating (plating for external leads) is performed.

Conventionally, in an external plating process of a resin-encapsulated semiconductor device, a method in which a multiple lead frame after resin encapsulation is hooked on a rack and immersed in a solder plating solution or resin encapsulation is used. A method of using a barrel for a semiconductor device in a state of a multiple lead frame to be later or separated from the semiconductor device in a single state has been adopted.

In the above-described method, since the plating time (the time required for plating) is long, the number of pieces that can be processed at a time is increased (for example, several tens of frames are processed simultaneously) to increase the production capacity. Needed.

[0005] However, the quality of plating (variation in plating film thickness, etc.) is deteriorated and the size of a plating apparatus is increased, which makes it difficult to inline a semiconductor device assembly line.

On the other hand, a method is known in which silver plating (or gold plating) is applied to one surface of an island portion of a lead frame before resin sealing and one surface of inner leads around the island portion. As shown in FIG. 5, this method uses an injection plating apparatus in a state where one surface of the island portion 51 of the lead frame and one surface of the inner lead 52 around the island portion are left and the other portions are masked by the mask portion 50. A silver plating solution (or gold plating solution) 54 is sprayed from the nozzle 53 toward the island portion 51 to perform plating. In this case, the silver plating solution 5 sprayed from the nozzle 53
4 is discharged from a discharge port 55 around the nozzle 53.
Since this method requires only a short time for plating, it is conceivable that the method is applied to the above-described exterior plating process of a semiconductor device after resin sealing.

However, as described above, a flat surface such as a lead frame surface is used as a plating object for a plating object having an uneven surface as in the exterior plating process of a semiconductor device after resin sealing. When a conventional spray plating apparatus is used to perform solder plating, it is not possible to obtain a uniform plating film thickness on the entire external lead.

[0008]

As described above, if the conventional spray plating apparatus is used as it is when solder plating is applied to external leads of a semiconductor device after resin encapsulation, sufficient plating quality cannot be obtained. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides good quality solder plating in a short time to external leads of a semiconductor device after resin sealing on a multiple lead frame. It is an object of the present invention to provide a plating apparatus for a semiconductor product which enables the plating.

[0010]

SUMMARY OF THE INVENTION A semiconductor product plating apparatus according to the present invention comprises a plurality of resin-encapsulated semiconductor devices formed at predetermined intervals in a longitudinal direction on a multiple lead frame. And a convex first mask portion and a second mask portion for masking in contact with one surface of a resin package of the semiconductor device and one surface of a lead frame portion around an external lead respectively in the front surface. A first portion provided with a slit for inflow of a solder plating solution and a groove for discharging a solder plating solution in a housing portion between the two mask portions;
And a housing having a structure similar to that of the first housing at the front thereof, and being provided so as to be movable toward and away from the front of the first housing. And a second housing forming a hollow portion surrounding the external lead when holding the semiconductor product with both surfaces of the resin package of the semiconductor device and both surfaces of the lead frame portion around the external lead together with the first housing. An electrode formed on an inner wall surface of the housing that faces away from the external lead, a power supply device that applies a positive voltage to the electrode and applies a negative voltage to the external lead, A solder plating solution supply device for supplying a solder plating solution from the outside to the solder plating solution inflow slit, wherein the first mask portion has a tapered side surface that expands toward the tip end, The solder plating liquid inflow switch The opening has an opening extending along a direction crossing each base end of the external lead group of the semiconductor device and connected to a side surface of the first mask portion, and the solder plating solution discharging groove is provided in the semiconductor device. Characterized by having an opening along a direction crossing each end of the external lead group.

[0011]

When the semiconductor product is sandwiched between the housings from both sides during the plating process, both sides of the resin package of the semiconductor device and the lead frame around the external leads are masked. Then, while applying a positive voltage to the electrode and applying a negative voltage to the external lead, the solder plating liquid is jetted into the hollow portion from the slit for flowing the solder plating liquid into the hollow portion, so that the solder plating liquid It flows through the gap and is discharged out of the housing via the solder plating solution discharge groove.
In this process, both surfaces of the external lead are electroplated in a short time. In this case, since the solder plating solution is sprayed from both sides of the external lead, the variation in plating film thickness on both sides of the external lead is reduced.

Further, the slit for inflow of the solder plating solution is
Since the semiconductor device has an opening extending along the direction crossing each base end of the external lead group of the semiconductor device and connected to the side surface of the first mask portion, the solder plating solution is applied along the tapered side surface of the first mask portion. By spraying toward each base end of the lead group, it becomes possible to flow the solder plating solution so as to uniformly contact the external lead surface, so that good quality solder plating can be performed.

Although the number of semiconductor devices that can be plated simultaneously is small compared to the conventional method of immersing the entire semiconductor product in a solder plating solution, the plating section is downsized and the plating apparatus is downsized. It is easy to make the assembly line of the semiconductor device in-line.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows a configuration of a sparger type injection plating apparatus used in an exterior plating process of a semiconductor device according to one embodiment of the present invention. FIG. 2 shows FIG.
FIG. 4 is a top view schematically showing a cross-sectional structure in a plating state of the plating apparatus of FIG. FIG. 3 (a) and FIG. 3 (b)
FIGS. 3A and 3B are a front view and a top view illustrating an example of a semiconductor product to be plated in FIG. 2;

The semiconductor product 30 has a plurality of resin-sealed semiconductor devices 32 formed at predetermined intervals in a length direction on a multiple lead frame 31. For example, the length direction is horizontal. The exterior plating of the semiconductor device 32 is performed in a state where the width direction is vertical. The above semiconductor device 3
Reference numeral 2 denotes a dual-in-line type in which the external leads 34 protrude from both sides of the resin package 33 in this example.

In FIG. 1 and FIG.
Are convex first mask portions 11 for contacting and masking one surface of the resin package 33 of the semiconductor device, and convex projections for contacting and masking one surface of a lead frame portion around the external leads 34. A second mask section 12 is provided on the front. The casing 13 between the two masks is provided with a solder plating solution inflow slit 14 and a solder plating solution discharge groove 15 continuous with the concave space between the masks. . Further, an electrode 16 is formed on a part of the inner wall surface of the housing 13 (a surface facing away from the external lead surface), and an electrode terminal (for applying a voltage to the electrode 16 from outside the housing). (Not shown)
Is provided.

The second casing 2 has a structure similar to that of the first casing 1, and is provided with an arrow in the figure so that the semiconductor product 30 can be sandwiched together with the first casing 1 from both sides. As shown by A, the first housing 1 is provided so as to be movable toward and away from the front of the first housing 1. Then, the second housing 2 approaches the first housing 1, and the semiconductor products 30 are sandwiched by the mask portions 11 and 12 on both sides of the resin package 33 and both sides of the lead frame around the external leads 34. Is held, both surfaces of the resin package 33 and the lead frame around the external leads 34 are respectively masked, and a hollow structure (cavity) having the hollow portion 17 surrounding the external leads 34 is formed. In this case, the facing distance d1 between the electrode surface and the external lead surface is, for example, 10 mm.

The first housing 1 and the second housing 2 are
Although provided corresponding to each semiconductor device 32 in the semiconductor product 30, only one is typically shown. And each hollow part 1 corresponding to each semiconductor device 32
7, the slit 14 for inflow of the solder plating solution and the groove 1 for discharging the solder plating solution are connected to the hollow portions, respectively.
5 are provided.

The power supply device 3 is for applying a positive voltage to the electrode 16 via the electrode terminal and for applying a negative voltage from the end of the multiple lead frame 31 to the external lead 34.

Further, there is provided a solder plating liquid supply device for supplying a solder plating liquid 18 from the outside of each of the housings 1 and 2 to the respective solder plating liquid inflow slits 14 at a predetermined pressure. .

This solder plating solution supply apparatus includes a solder plating solution tank 5, a solder plating solution supply pump 6, a plurality of solder plating solution supply pipes 7, and a solder plating solution supplied from the pipes 7, It comprises pressure boxes 81 and 82 for supplying a solder plating solution, the inside of which is divided into a plurality of sections corresponding to the pipes 7. And the pressure box 8
Each of the semiconductor devices 32 corresponding to each of the sections (rooms) 1 and 82
The solder plating solution is supplied to each hollow portion 17 corresponding to. In this case, the pressure box 81 and the first housing 1 are integrally formed, and the pressure box 82 and the second housing 2 are also integrally formed.

The first mask portion 11 has a tapered side surface 11a which expands toward the tip, and when one surface of the resin package 33 is masked, the tapered side surface 33a of the resin package The tapered side surface 11a is formed so as to be located on the same surface.
The inclination angle θ of the tapered side surface 11a of the first mask portion 11 is, for example, approximately 80 degrees.

The slit 14 for inflow of the solder plating solution is
When the semiconductor product 30 is sandwiched between the housings 1 and 2 from both sides, the semiconductor product 30 extends along the direction crossing each base end of the group of external leads 34 of the semiconductor device 32 and the tapered side surface 11 a of the first mask portion 11. It has a continuous opening and is provided so as to penetrate the housing 13. The length of the opening of the slit 14 is a length crossing each base end of the external lead group, and the opening width w1 of the slit 14 is, for example, 2 mm.
It is.

The solder plating solution discharging groove 15 is
When the semiconductor product 30 is sandwiched between the housings 1 and 2 from both sides, the semiconductor device 30 has an opening along a direction crossing each end of the external leads 34 of the semiconductor device 32. It is provided on the housing 13 at a parallel position. The width w2 of the opening of the solder plating solution discharge groove 15 is equal to or less than the opening width w1 of the solder plating solution inflow slit 14. Further, the solder plating solution discharge groove 15 has an aperture structure in which the width of the opening is smaller than the width of the inside of the groove. Next, an example of a case where a plating process is performed on the semiconductor product 30 using the above-described injection plating apparatus will be described. FIG. 4 is a plan view showing a state where the semiconductor product 30 is masked by the casings 1 and 2 during the plating process, and the masked portion is indicated by oblique lines.

When the semiconductor product 30 is sandwiched between the housings 1 and 2 from both sides during the plating process, both surfaces of the resin package 33 of the semiconductor device 32 and the lead frame portions around the external leads 34 are masked. Then, while applying a positive voltage to the electrode 16 and applying a negative voltage to the external lead 34, the solder plating liquid 18 is jetted from the slit 14 into the hollow portion 17. Thereby, the solder plating liquid 18 flows between the electrode 16 and the external lead 34,
It is discharged out of the housing via the solder plating solution discharge groove 15.
In this process, electroplating is performed on both surfaces of the external lead 34 in a short time. At this time, the flow rate of the solder plating solution 18 is, for example, 20 liters / minute, and the current density of the solder plating solution 18 flowing in the hollow portion 17 is controlled by the power supply device 3.

According to the injection plating apparatus of the above embodiment, by injecting the solder plating solution 18 into the hollow portion 17,
Electroplating can be performed on both surfaces of the external lead 34 in a short time. In this case, since the solder plating solution 18 is sprayed from both sides of the external leads 34, the plating film thickness does not vary on both sides of the external leads 34.

Since the solder plating solution inflow slit 14 and the solder plating solution discharge groove 15 are provided so as to be continuous with the same hollow portion 17, the solder plating solution 18 in the hollow portion 17 contacts the external lead surface. It is possible to flow.

In this case, the slit 1 for inflow of the solder plating solution is used.
4 has an opening extending along the direction crossing each base end of the external leads 34 of the semiconductor device and connected to the tapered side surface 11a of the first mask portion 11, so that the solder plating liquid 18 The external leads 34 are sprayed along the tapered side surface 11a of the mask portion 11 toward each base end of the group, so that the solder plating liquid 18 can be caused to flow so as to uniformly contact the external lead surfaces. And good quality solder plating.

The solder plating solution inflow slit 14 faces the base end of the external lead, and the solder plating solution discharge groove 15 is formed.
Opposes the tip of the external lead, and the slit 14 and the groove 1
5 are provided in parallel with each other, so that the solder plating solution 18 can be flowed so as to almost uniformly contact the external lead surface, so that good quality solder plating can be performed.

Further, since the solder plating liquid discharge groove 15 has a throttle structure, the solder plating liquid 18 in the hollow portion 17 is prevented from easily flowing into the solder plating liquid discharge groove 15, and the solder plating liquid 18 is formed. It is possible to generate a flow that almost uniformly touches the external lead surface.

When the plating process is actually performed on the semiconductor product 30 using the injection plating apparatus of the above embodiment,
When the average film thickness was 10 μm, the standard deviation σ of the variation in the plating film thickness was 0.3 to 0.5. This result shows that the variation in the plating film thickness was ２〜 = 1.0 to 1.5 when the average film thickness was 10 μm, and the variation was reduced to ２〜 to ５. I have.

Further, according to the injection plating apparatus of the above embodiment, as compared with the conventional method of immersing the entire semiconductor product in a solder plating solution, even if the number of semiconductor devices that can be plated simultaneously is small, the plating section Since the size of the semiconductor device is reduced and the size of the plating apparatus is reduced, it is easy to inline a semiconductor device assembly line.

By applying solder plating to the external lead surface as described above, it is possible to protect the surface of the external lead and to facilitate the soldering at the time of mounting. Can be performed by thermocompression bonding. The present invention is not limited to the package of the semiconductor device described in the above embodiment, but can be implemented by appropriately modifying various packages of the resin-encapsulated semiconductor device.

[0034]

As described above, according to the present invention, good quality solder plating can be applied in a short time to external leads of a semiconductor device after resin sealing on a multiple lead frame. Semiconductor device plating apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a plating apparatus for semiconductor products according to a first embodiment of the present invention.

FIG. 2 is a top view schematically showing a cross-sectional structure of the plating apparatus of FIG. 1 in a plating state.

FIG. 3 is a front view and a top view showing an example of a semiconductor product to be plated in FIG. 2;

FIG. 4 is a plan view showing a state where the semiconductor product of FIG. 3 is masked during plating.

FIG. 5 is a cross-sectional view showing a plating process on one surface of an island portion of a lead frame and one surface of inner leads around the island portion by a conventional injection plating apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st housing | casing, 2 ... 2nd housing | casing, 3 ... Power supply device, 5 ...
Solder plating solution tank, 6 ... Solder plating solution supply pump, 7 ... Solder plating solution supply pipe, 81, 82 ... Pressure box, 1
DESCRIPTION OF SYMBOLS 1 ... 1st mask part, 11a ... Tapered side surface of 1st mask part, 12 ... 2nd mask part, 13 ... Case part, 14
... Slit for solder plating solution inflow, 15 ... Slot for solder plating solution discharge, 16 ... Electrode, 17 ... Hollow part, 18 ... Solder plating solution, 30 ... Semiconductor product, 31 ... Multiple lead frame, 3
2 semiconductor device, 33 resin package, 33a tapered side surface of resin package, 34 external leads.

Claims (6)

(57) [Claims] 1. A semiconductor product in which a plurality of resin-encapsulated semiconductor devices are formed at predetermined intervals in a length direction on a multiple lead frame, on one surface of a resin package of the semiconductor device and around an external lead. A first mask portion and a second mask portion having a convex shape on the front surface for masking in contact with one surface of the lead frame portion, respectively;
A first housing in which a slit for inflow of a solder plating solution and a groove for discharging a solder plating solution are provided in a housing portion between the two mask portions, and a structure similar to the first housing is viewed from the front. And the first housing is provided so as to be movable toward and away from the front surface of the first housing. Forming a hollow portion surrounding the external lead when the semiconductor product is held across both sides of the lead frame portion around the lead;
A case, an electrode formed on an inner wall surface of the case that faces away from the external lead of each case, a power supply device that applies a positive voltage to the electrode and applies a negative voltage to the external lead, A solder plating liquid supply device for supplying a solder plating liquid from the outside of each housing to the solder plating liquid inflow slit, wherein the first mask portion has a tapered side surface that expands toward the front end. The solder plating solution inflow slit has an opening extending along a direction crossing each base end of the external lead group of the semiconductor device and continuing to a side surface of the first mask portion. A plating apparatus for a semiconductor product, wherein the discharge groove has an opening along a direction crossing each end of the external lead group of the semiconductor device. 2. A semiconductor product in which a plurality of resin-encapsulated semiconductor devices are formed at predetermined intervals in a length direction on a multiple lead frame, the mask being in contact with one surface of a resin package of the semiconductor device. And a convex second mask portion for contacting and masking one side of a lead frame portion around the external lead in front of the two mask portions. A first casing in which a solder plating solution inflow slit and a solder plating solution discharging groove are provided in a casing portion between the first casing and a first casing having a structure similar to that of the first casing on the front surface; The semiconductor device is provided so as to be movable toward and away from the front of the body. Semiconductor on both sides Second to form a hollow portion surrounding the outer lead when a product was kept
A case, an electrode formed on an inner wall surface of the case that faces away from the external lead of each case, a power supply device that applies a positive voltage to the electrode and applies a negative voltage to the external lead, A solder plating solution supply device for supplying a solder plating solution from outside the housing to the solder plating solution inflow slit, wherein the solder plating solution inflow slit is provided for each of the external lead groups of the semiconductor device. The semiconductor device has an opening along a direction crossing the base end, and the solder plating solution discharge groove has an opening along a direction crossing each end of the external lead group of the semiconductor device, and has a width of the opening. A plating apparatus for semiconductor products, wherein the plating apparatus has a drawing structure smaller than the width of the inside of the groove. 3. The plating apparatus for a semiconductor product according to claim 2, wherein the first mask portion has a tapered side surface that expands toward a tip, and an opening of the solder plating solution inflow slit includes: The first
A plating apparatus for a semiconductor product, wherein the plating apparatus is connected to a side surface of the mask portion. 4. The plating apparatus for a semiconductor product according to claim 1, wherein the tapered side surface of the first mask portion has a tapered shape when the first mask portion masks the resin package. A plating apparatus for a semiconductor product, wherein the plating apparatus is formed so as to be located on the same plane as a side surface of the semiconductor product. 5. The plating apparatus for a semiconductor product according to claim 1, wherein the slit for flowing in the solder plating solution and the groove for discharging the solder plating solution are provided in parallel. Characteristic plating equipment for semiconductor products. 6. The plating apparatus for a semiconductor product according to claim 1, wherein the width of the opening of the groove for discharging the solder plating liquid is equal to the width of the slit for inflow of the solder plating liquid. A plating apparatus for semiconductor products, which is equal to or less than the above.