JP3163743B2 - Resin molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding apparatus, and more particularly, to a long hoop-shaped lead frame having a molded exterior resin portion used in the manufacture of a semiconductor device and attached to an end in the width direction. The present invention relates to a resin molding device that separates and removes unwanted cured resin.

[0002]

2. Description of the Related Art For example, mini-mold type semiconductor devices are generally manufactured collectively by using a long hoop-shaped metal lead frame. The main manufacturing process of this type of semiconductor device includes a pellet mounting process of mounting a semiconductor pellet on a lead frame, a wire bonding process of electrically connecting the semiconductor pellet and the lead with a thin metal wire, and a main portion including the semiconductor pellet. And a resin molding step of molding with an exterior resin such as an epoxy resin.

In the resin molding step, the lead frame after wire bonding is clamped by upper and lower molds, and molten resin injected into the cavity from the pots and culls of the upper and lower molds via the runners and gates.
The main part including the semiconductor pellet on the lead frame is resin-molded. After this resin mold,
As shown in FIGS. 7 (a) and 7 (b), in addition to the exterior resin portion (2) of the lead frame (1), the runner and the exterior resin portion (2) are attached to the width direction end of the lead frame (1). Since the cured resin (hereinafter, referred to as runner (3) and gate (4)) is attached to an undesired portion corresponding to the gate which is a connecting portion, the runner (3) and gate (4) are separated and removed. There is a need.

Therefore, conventionally, as shown in FIG. 8, the hoop-shaped lead frame (1) is transported in a fixed direction (the direction of the arrow in the figure) by a feed mechanism (not shown) in a state of being stretched at a constant tension. Meanwhile, the first to third rollers (5) to (7) are arranged during the transfer, and the lead frame (1) to be transferred is moved to the first to third rollers (5) to (7). Inflection and turn direction along the circumference of.

[0005] In the first roller (5), FIG. 9 and FIG.
As shown in FIG. 0, the lead frame (1) is bent along the peripheral surface (9) and changes direction, and is transferred obliquely upward in the figure, while the runner (3) is connected to the lead frame (1). Because it is long, thick and hard along the width direction end of
The runner (3) attempts to go straight without going along the peripheral surface (9) of the first roller (5). as a result,
Outer resin part (2) of runner (3) and lead frame (1)
Since the gate (4), which is a connecting portion with the gate, is very small, the gate (4) tears off the runner (3) and the gate (4) from the lead frame (1). After that, the lead frame (1)
It is transferred to a subsequent process via the second and third rollers (6) and (7). Incidentally, (8) shown in FIG. 10 is formed on the peripheral surface of each of the first to third rollers (5) to (7), and is a concave groove for accommodating the exterior resin portion (2) of the lead frame (1). It is.

[0006]

By the way, conventionally,
As described above, the runner (3) and the gate (4) are separated and removed from the lead frame (1) by bending and changing the direction of the lead frame (1) with the first roller (5). ing.

However, in the first roller (5), when the lead frame (1) moving along the peripheral surface (9) bends obliquely upward, the runner (3) tries to go straight. On the other hand, the gate (4) connecting the runner (3) to the lead frame (1) is
Is pulled obliquely upward to move, and an undesired stress is applied to the exterior resin portion (2) through the gate (4), so that the exterior resin portion (2) of the lead frame (1). However, there is a problem that the lead is bent with respect to the lead frame (1), and the lead derived from the exterior resin portion (2) is bent, or, in extreme cases, the exterior resin portion (2) is chipped. Was.

In view of the above, the present invention has been proposed in view of the above-mentioned problems, and an object of the present invention is to smoothly remove runners and gates attached to a lead frame from a lead frame without applying undesired stress to the lead frame. Another object of the present invention is to provide a resin mold device that can be separated and removed.

[0009]

SUMMARY OF THE INVENTION As a technical means for achieving the above object, the present invention provides a long hoop-shaped lead in which a semiconductor pellet is mounted and a main part including the semiconductor pellet is molded with an exterior resin. The frame is transferred in a fixed direction, and the unnecessary resin separating means disposed in the middle of the transfer is used to separate the undesired cured resin adhered to the end in the width direction of the lead frame. It is characterized by comprising a pair of rollers for sandwiching a lead frame conveyed in a straight line from the front and back surfaces thereof, and forming a flange protruding from the end of the lead frame at the end of the one of the rollers in the width direction of the lead frame. .

It is also possible to form a tapered portion on the outer peripheral edge of the flange of the one roller, the tapered surface gradually increasing in the circumferential direction.

[0011]

In the resin molding apparatus according to the present invention, of the rollers sandwiching the lead frame to be transferred, the flange protruding from the lead frame of one of the rollers leads to the undesired cured resin at the end in the lead frame width direction. Press in the direction perpendicular to the frame transfer direction. As described above, since the lead frame is transported in a straight line, and the pressing by the flange is orthogonal to the lead frame transport direction, undesired stress is not applied by the pressing force by the flange, and the undesired cured resin is lead. Can be separated and removed smoothly from the frame.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a resin molding apparatus according to the present invention will be described with reference to FIGS. The following embodiment shows a case where the present invention is applied to the lead frame (1) shown in FIG.

As shown in FIGS. 1 and 2, the unnecessary resin separating means of the present invention comprises a pair of rollers (11) (1) which sandwich a lead frame (1) conveyed in a straight line from its front and back surfaces.
2) The upper roller (1
A flange (13) protruding from the lead frame (1) is formed at both ends in the lead frame width direction of (1).

Specifically, the lead frame (1)
As in the prior art, the sheet is transferred in a fixed direction (the direction of the arrow in the figure) by a feed mechanism (not shown) while being stretched at a constant tension. The difference is that the sheet is transferred in a straight line.

The upper roller (11) is provided with a roller body (1).
A groove (15) for accommodating the exterior resin portion (2) of the lead frame (1) is formed in a part of 4) over the entire circumference, and the groove (15) is formed at both ends of the roller body (14) as described later. As described above, the flanges (13) for pressing the runners (3) attached to both ends of the lead frame (1) are integrally formed.

Further, similarly to the above-mentioned upper roller (11), the lower roller (12) has a concave groove () in which the exterior resin portion (2) is housed in a part of the roller body (16) over the entire circumference. 17), and a recess (18) for accommodating a gate (4) protruding from the lower surface of the lead frame (1) is formed in a peripheral edge at both ends of the roller body (16). Are formed at regular intervals corresponding to the pitch of

In the apparatus according to the present invention, as shown in FIGS. 3 and 4, when the lead frame (1), which has been completed with resin molding, is transferred in a straight line, the lead frame (1) passes between the upper and lower rollers (11) and (12). Undesired runners (3) and gates (4) are separated and removed.

That is, the exterior resin portion (2) of the lead frame (1) is made up of the roller body (14) (1) of the upper and lower rollers (11) and (12).
The lead frame (1) is sandwiched between the roller bodies (14) and (16) while being housed in the concave grooves (15) and (17) of 6). On the other hand, the gate (4) is housed in the recess (18) of the lower roller (12), and the gate (4) is accommodated in the recess (18).
Is locked, and the lead frame (1) is sent out together with the runner (3). At this time, the flange (13) of the upper roller (11)
Pushes the runner (3) at its end face in a direction perpendicular to the direction of transport of the lead frame (1), that is, downward in the figure.
As described above, since the transfer of the lead frame (1) is linear, and the pressing by the flange (13) is orthogonal to the transfer direction of the lead frame, the pressing force by the flange (13) is applied to the exterior resin portion (2). The runner (3) together with the gate (4) is quickly separated from the exterior resin part (2) without applying undesired stress.

The shape of the end surface of the flange (13) of the upper roller (11) described above is not limited to those shown in FIGS. 1 and 2, and for example, FIGS. 5 and 6 (a) to (c). As shown in (1), a tapered portion (20) in which the tapered surface (19) gradually increases along the circumferential direction may be formed on the outer peripheral edge of the flange (13). That is, at the initial stage of pressing the runner (3), the pressing amount is increased by the small tapered surface (19). If the pressing amount is large at this initial stage,
Although the subsequent pressing amount is small, the gate (4) is easily separated under the influence of the initial large pressing amount, so that the pressing amount after the initial stage may be small, and the tapered surface thereafter. (19) should be gradually increased.

[0020]

According to the resin molding apparatus of the present invention, the undesired cured resin adhering to the lead frame on which the resin molding has been completed can be quickly separated and removed without applying stress to the lead frame. As a result, the yield of products is greatly improved, and a highly reliable and high-quality semiconductor device can be provided, which has a great practical value.

[Brief description of the drawings]

FIG. 1 is a front view showing upper and lower rollers according to an embodiment of the present invention.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is an enlarged partial front view showing a state in which a runner is separated by upper and lower rollers in FIG. 1;

FIG. 4 is a partial side view of FIG. 3;

FIG. 5 is a front view showing a modification of the flange of the upper roller.

6 (a) is a side view at point A, FIG. 6 (b) is a side view at point B, and FIG. 6 (c) is a side view at point C in the flange of FIG.

7A is a plan view showing a lead frame after resin molding, and FIG. 7B is a side view of the lead frame.

FIG. 8 is a front view showing a conventional example of a resin molding apparatus.

FIG. 9 is an enlarged front view showing the first roller of FIG. 8;

10 is a side view including a part omitted in FIG. 9.

[Explanation of symbols]

 1 Lead frame 2 Exterior resin part 3 Undesired cured resin [runner] 4 Undesired cured resin [gate] 11 Roller [upper roller] 12 Roller [lower roller] 13 Flange 19 Tapered surface 20 Tapered part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/56 B29C 45 / 02,45 / 14

Claims (2)

(57) [Claims] 1. A long hoop-shaped lead frame in which a semiconductor pellet is mounted and a main part including the semiconductor pellet is molded with an exterior resin is transferred in a fixed direction, and unnecessary resin separating means arranged in the middle of the transfer is used. In separating the undesired cured resin adhered to the width direction end of the lead frame, the unnecessary resin separating means includes a pair of rollers for sandwiching the lead frame conveyed in a straight line from the front and back surfaces, Slightly wider than the lead frame width at both ends of one roller
A resin molding apparatus wherein flanges having a diameter larger than the diameter of the roller are formed at wide intervals . 2. The resin molding apparatus according to claim 1, wherein a tapered portion whose tapered surface gradually increases along the circumferential direction is formed at a peripheral edge of an outer end of a flange of one of the rollers.