JP2955954B2 - Method for manufacturing resin-encapsulated electronic component - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing a resin burr of an external lead derived from a resin-sealed body of a resin-sealed electronic component such as a diode, a transistor, and an IC. .

[Problems to be Solved by Related Art and the Invention] A resin-sealed body of a resin-sealed semiconductor device is often formed by a transfer molding method. The transfer molding method has the advantage of being excellent in mass productivity because a resin sealing body for a number of elements can be formed at one time. On the other hand, since a molding die divided into at least two parts is used, the pressure-molded sealing is used. There is a disadvantage that a part of the resin for molding flows out of the gap of the molding die and is hardened, thereby forming resin burrs (resin protrusions or layers generated at unnecessary portions). Resin burrs mainly occur on the main surface and side surfaces of the external leads and around the resin sealing body. The resin burrs formed on the side surfaces of the external leads are removed by a so-called resin cutting process, that is, a punching die is pressed against the resin burrs. However, it has been difficult to completely remove resin burrs attached to the side surfaces of the external leads.

Accordingly, an object of the present invention is to provide a novel method that can easily remove resin burrs attached to the side surfaces of external leads.

Means for Solving the Problems According to the present invention for achieving the above object, an electronic component main body, a first flat plate-shaped lead fixed to the main body,
The first lead is led out in a different direction from the first lead and
A lead-shaped portion having a lead-out portion disposed in a plane substantially the same as or parallel to a plane in which the lead-out portion of the lead is located, and fixed to the main body portion; the main body portion;
And a resin-sealed body covering a part of the second lead.
Forming a second lead by stamping a metal plate; and forming the first lead by the stamping.
Forming the assembly with the main body by arranging the first and second leads so that protrusions (burrs) at the edges of the second leads face in the same direction; and forming the assembly. Forming the resin encapsulant by injecting a fluidized encapsulation resin disposed in a mold, and forming a side surface of the first and second leads generated during the formation of the resin encapsulant. In order to remove the resin burr, the resin burr is removed by moving the resin burr removing mold in a direction from the surface where the projections of the first and second leads are formed to the opposite surface. And a method of manufacturing a resin-sealed electronic component.

[Operation] In the present invention, the main surface of the punched first lead, on which the projection (burr) at the edge of the second lead is formed, is oriented in the same direction as the resin. Therefore, the resin burrs formed on the side surfaces of the first and second leads can be easily removed by pressing from the side where the protrusion (burr) is formed. That is, since the projections (burrs) of the first and second leads have the same directionality, resin burrs on the side surfaces of the first and second leads can be simultaneously and easily removed.

Embodiment Next, a method of manufacturing a resin-sealed diode according to an embodiment of the present invention will be described with reference to FIGS.

First, a pair of flat plate-shaped first and second lead frames 1 and 2 shown in FIG. 5 are prepared. The first lead frame 1 and the second lead frame 2 are respectively composed of a plurality of narrow lead portions (lead-out portions) 1a, 2a and supporting plate portions (element mounting portions) 1b, 2b connected thereto and the lead portions 1a, 2a. Are connected to each other (see FIG. 7). Lead portion 1 of first and second lead frames 1 and 2
A bent portion 1d, 2d is formed between the support plate portions 1b, 2b and the support plate portions 1b, 2b, and the support plate portions 1b, 2b are respectively provided with lead portions 1a, 2a.
It is deviated from the extension of. Protrusions 1e and 2e are provided on the support plate portions 1b and 2b as shown in FIG. 5 for fixing the element. In the present specification, for convenience of explanation, the surfaces of the lead frames 1 and 2 on the element fixing side are referred to as one main surface, and the main surface on the opposite side is referred to as the other main surface.

The first lead frame 1 and the second lead frame 2 are substantially the same as a whole, but differ in details. This slight difference is caused by a difference in the method of forming the first and second lead frames 1 and 2. When forming the first lead frame 1, the first lead frame 1 has a first metal plate corresponding to one main surface thereof,
Move the punching die. As a result, at the cutting edge of the first lead frame 1, a sag (a portion having a curvature) falling on one main surface side is generated, and burrs (metal burrs, ie, mountain-like) are formed on the other main surface side. A raised protrusion 4) results.

On the other hand, when forming the second lead frame 2, the second punching die is moved from the front side to the back side of the metal plate corresponding to the other main surface of the second lead frame 2. As a result, sagging 3 occurs on the other main surface side at the cutting edge of the second lead frame 2, and burrs 4 are formed on one main surface side.
Occurs.

Next, the above-mentioned lead frames 1 and 2 are
b, 2b arranged so that the element fixing surfaces face each other,
A diode chip element 6 as an electronic component main body is fixed between the two convex parts 1e and 2e via a solder 5. Thus, the element / lead frame assembly 7 is completed. Since the element / lead frame assembly 7 is arranged with one main surface of the lead frames 1 and 2 facing each other, the directions in which the sag 3 and the burrs 4 are formed are the same as shown in FIG. That is, the sag 3 of the first and second lead frames 1 and 2 is disposed on the lower surface side of the element / lead frame assembly 7, and the burrs 4 are disposed on the upper surface side of the lead frame assembly 7, respectively.

Next, as shown in FIG. 6, the element / leadframe assembly 7 is formed into a molding for transfer molding in order to form a resin sealing body 8 indicated by a broken line in FIG. Placed on mold 9. As shown in FIG. 6, the molding die 9 is composed of an upper die 10 and a lower die 11, and when the upper die 10 and the lower die 11 are closed, the resin sealing body 8 is placed in the molding die 9. Is formed.

As shown in FIG. 6, the element / lead frame assembly is such that the lead portions 1a and 2a are respectively accommodated in the grooves 13 and 14 of the lower mold 11, and the support plate portions 1b and 2b and the diode chip 6 are accommodated in the molding cavity 12. 7 is placed in a molding die 9, and a fluidized sealing resin is pressed and injected through a resin injection port 15 communicating with the molding cavity 12.
The sealing resin fills the molding space 12 to cover the support plates 1b and 2b of the leads 1a and 2a, the support plates 1b and 2b, and the diode chip 6. At this time, a part of the sealing resin is formed at the interface between the lead portions 1a and 2a and the molding die 9 and at the upper die 10 and the lower die 11.
Flows into the interface with

When the sealing resin injected into the molding cavity 12 is cured, the element / lead frame assembly 7 is removed from the molding die 9. FIGS. 3 and 7 show the element / lead frame assembly 7 on which the resin sealing body 8 formed by curing the sealing resin is formed.
Adjacent lead portions 1a and 2a of element / lead frame assembly 7
3 and 7, resin burrs 16 are formed in the region between the resin sealing bodies 8 as shown by hatching in FIGS.
As shown in FIG. 1, the resin burrs 16 are relatively thick burrs on the lead portions 1a and 2a, the connecting strips 1c and 2c and the resin sealing body 8, and the lead burrs 1a and 2a and the connecting strip 1c are formed. , 2c and the portion separated from the resin sealing body 8 are relatively thin burrs. Further, resin burrs also occur on the main surfaces of the lead portions 1a, 2a and the connecting strips 1c, 2c, but since the resin burrs are extremely thin compared to the resin burrs 16 formed in the above-described region,
This is omitted in the drawings.

Next, the above-described element / lead frame assembly 7 on which the formation of the resin sealing body 8 has been completed is firstly removed to remove the resin burr 16 thereof.
Place it on the deburring device as shown. The deburring device is a mounting table 17 for mounting the element / lead frame assembly 7.
And a punching die 18 for punching resin burrs 16.
The mounting table 17 is connected to the leads 1a, 2a and the connecting strip as shown in FIG.
A first mounting portion 17a on which 1c and 2c are mounted, and a second mounting portion 17b on which a resin sealing body 8 formed in a concave shape recessed below the mounting portion 17a is mounted. A hole 17c corresponding to a region between adjacent lead portions 1a and 2a of the element / lead frame assembly 7 and between adjacent resin sealing members 8 is formed. The punching die 18 is located in the above-mentioned area, that is, the hole 17c of the mounting table 17.
. The punching die 18 is moved up and down by a driving device 19 so as to be able to advance and retreat into a hole 17c of the mounting table 17.

The punching die 18 is kept on standby, and the element / lead frame assembly 7 is connected to the lead portions 1a, 2a and the connecting strips 1c, 2c.
The resin sealing body 8 is located above the second placement part 17b, the resin burr 16 is located above the hole 17c, and the element / lead frame assembly 7 is located above the placement part 17a. Is set on the mounting table 17 so that the upper surface (the side on which burrs are formed) faces the punching die 18 based on the present invention. Subsequently, the punching die 18 is moved downward until it is fitted into the hole 17c of the mounting table 17. As a result, the lead portions 1a of the element / lead frame assembly 7,
The resin burrs 16 formed between 2a and between the resin sealing bodies 8 are pushed by a punching die 18, and as shown in FIG.
2a and the resin sealing body 8 are peeled off.

The element / lead frame assembly 7 from which the resin burr 16 has been removed is subjected to a lead portion by a well-known liquid honing process or the like.
After removing the ultra-thin resin burrs formed on the main surfaces of 1a and 2a, the connecting strips 1c and 2c are cut and removed to complete a resin-sealed diode. The liquid honing step may be performed before the resin cutting step.

According to the present embodiment, the resin burr 16 is hit from the main surface of the lead portions 1a and 2a where the burrs are formed, so that the resin burr 16 can be easily removed. Also, since the main surfaces on which the burrs of the lead portions 1a and 2a are formed face in the same direction,
The resin burr 16 formed on the first lead portion 1a and the resin burr 16 formed on the second lead portion 2a can be easily and simultaneously removed without inverting the element / lead frame assembly 7. . The resin burrs 16 are connected to the lead portions 1a and 2a.
From the main surface on which the sag 3 is formed.
And the resin burr 16 tends to remain on the portion.

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible.

(1) The width W1 of the first mounting portion 17a on which the leads 1a and 2a of the mounting table 17 are mounted is smaller than the width W2 of the leads 1a and 2a, and the resin formed on the sag 3 is formed. Burr 16 is receiver 17a
It is desirable that the resin burrs 16 are not located on the upper surface of the resin for good and easy removal of the resin burrs 16. However, the mounting portion 17a may slightly protrude from the resin burr 16 formed in the sag 3 portion.

(2) Using a plurality of punching dies 18 at multiple locations
16 may be removed at the same time.

(3) The resin burr 16 may be completely removed by the punching die 18 after the resin burr 16 is easily peeled off in combination with another deburring means such as a honing step. Further, after the resin burr 16 is almost completely removed by the punching die 18, air or the like may be further blown to finish.

(4) In the embodiment, the width of the stamping die 18 is
Although the distance between a and 2a is substantially the same, it may be smaller. In this case, the width of the punching die 18 is preferably set to be equal to or greater than the interval between the opposing thick burrs (the width of the thin burr) so that the punching die 18 can press the thick burr portion of the resin burr 16.

(5) In order to reliably prevent the leads 1a and 2a from being bent due to the removal of the resin burr 16, a mold for removing the resin burr 16 of the lead 1a and the lead 2a is separately provided, and the mold is connected to the lead 1a.
And the timing of contact with the resin burr 16 attached to the lead portion 2a may be shifted.

(6) The shape of the mounting table 17 can be variously modified. For example, only the connecting strips 1c and 2c may be placed.

[Effects of the Invention] As described above, according to the present invention, resin burrs of an electronic component can be satisfactorily removed.

[Brief description of the drawings]

1 is a cross-sectional view showing a lead having a resin burr on a side surface and a resin burr removing device, FIG. 2 is a cross-sectional view showing removal of a resin burr by the device of FIG. 1, and FIG. 3 is an element / lead frame assembly. FIG. 4 is a plan view showing a mounting table for removing resin burrs, FIG. 5 is a cross-sectional view showing an assembly of a chip and first and second leads, FIG. 6 is a sectional view showing an assembly and a molding die, and FIG. 7 is a plan view showing an element / lead frame assembly after molding having resin burrs. 1... First lead frame, 2... Second lead frame, 4... Burrs (projections), 6... Chips, 16.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-26671 (JP, A) JP-A-54-121062 (JP, A) JP-A-63-124426 (JP, A) JP-A-2- 66964 (JP, A) JP-A-2-214629 (JP, A) JP-A-3-248817 (JP, A) JP-A-58-105134 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/00-45/17 B29C 37/02 H01L 21/56

Claims (2)

(57) [Claims] An electronic component main body, a flat first lead fixed to the main body, and a lead-out part which is led out in a direction different from that of the first lead and is located at the lead part. A plate-shaped second lead having a lead-out portion disposed in a plane substantially the same as or parallel to a plane and fixed to the main body; and a part of the main body and the first and second leads. A method for manufacturing a resin-sealed electronic component comprising: a resin-sealed body covering the first and second leads; a step of forming the first and second leads by punching a metal plate; Forming the assembly with the main body by arranging the first and second leads so that protrusions (burrs) at the edges of the first and second leads face in the same direction; Place the assembly in the mold and inject the fluidized sealing resin Forming the resin encapsulant, and removing the resin burrs on the side surfaces of the first and second leads generated during the formation of the resin encapsulant. Removing the resin burr by moving a resin burr removal mold in a direction from the surface where the protrusions are formed to the opposite surface. The method of manufacturing the part. 2. A chip of an electronic component, a first flat lead having one end fixed to one main surface of the chip, and one end fixed to the other main surface of the chip, 1
A second lead in the form of a flat plate, which is led out in a direction different from that of the lead and has a lead-out portion disposed on a plane substantially the same as or parallel to a plane where the lead-out portion of the first lead is located; A method for manufacturing a resin-encapsulated electronic component, comprising: a resin-encapsulated body that covers a part of first and second leads, wherein the first lead corresponds to a main surface of the side on which the chip is fixed. Forming a first lead by relatively moving a punching die from a front surface to a back surface of a metal plate; and a main surface of the second lead opposite to a main surface on which the chip is fixed. Forming a second lead by relatively moving a punching die from a front surface to a rear surface of a metal plate corresponding to the step, and edges of the first and second leads generated by the punching process. The first and second projections (burrs) are oriented in the same direction. Arranging a lead to form an assembly with the chip; arranging the assembly in a molding die and injecting fluidized sealing resin to form the resin sealing body; In order to remove resin burrs on the side surfaces of the first and second leads generated at the time of forming the resin sealing body, the first and second leads are removed from the surface where the protrusions are formed in the opposite direction. Removing the resin burr by moving the resin burr removal mold in a direction toward the surface to remove the resin burr.