JPH0461131A - Manufacture of resin-sealed electronic component - Google Patents

Abstract

PURPOSE:To provide an electronic component, having support plates covered entirely with packaging mold, by using upper and lower molding dies between which outer leads and an insulating member installed between adjacent support plates are placed. CONSTITUTION:A positioning member 11 is provided between adjacent support plates 5 for supporting a lead frame assembly 1. The assembly is placed in a mold 13 consisting of separable upper and lower dies 14 and 15. The lower die 15 has a groove 22 and a recess 17 to accommodate outer leads 6 and connecting wires 8 and 9. The outer leads are engaged with the grooves 22, and the lower die is closed with the upper die, so that the mold 13 is furnished with a molding cavity 25 corresponding to the profile of an electronic component. Molding resin is forced into the cavity through a runner 23 and a gate 24. The positioning member 11 acts to connect and fix the adjacent support plates 5 and to control the amount of resin. In this manner, a resin seal 26 with uniform thickness can be formed on the reverse sides of a plurality of support plates.

Description

[Detailed Description of the Invention] l↓Ichirozuki - Field The present invention relates to a method of manufacturing a resin-sealed electronic component, and in particular, a structure in which two or more support plates are covered with one envelope. In a semiconductor device for power charging, a part of a resin encapsulation body is formed thinly on the back side of a support plate which also serves as a heat sink. Certain types of semiconductor devices have the advantage of being directly attached to an external heat sink without using an insulating member such as a mica plate. As a method for manufacturing the semiconductor device described in L, Japanese Patent Laid-Open No. 61-5
Publication No. 6420 discloses a method of resin molding by sandwiching a support lead connected to one end of a support plate and a support lead connected to the other end of the support plate between molds. .

According to this manufacturing method, the support plate can be resin-sealed at a desired distance from the bottom surface of the molding cavity, so that a thin resin layer can be formed on the back side of the support plate in a relatively good manner. However, this manufacturing method has the drawback that the support lead must be broken after resin molding, and the cut surface of the support lead is exposed on the surface of the resin sealing body, making it impossible to obtain a sufficiently large dielectric strength voltage. Therefore, JP-A-60-1.301
In Publication No. 29, during resin molding, a support plate is fixed with a movable bottle, sealing resin is injected into the molding cavity, and just before the end of resin molding, the movable bottle is separated from the support plate, and the movable bottle is moved. A method is disclosed for injecting further sealing resin into the subsequently formed void. According to this manufacturing method, a semiconductor device having a high dielectric strength and having a support plate whose entire surface is covered with a resin sealant can be obtained.

Nowadays, it is desired to realize a complex semiconductor device even in this type of power semiconductor device. Therefore, the present inventor attempted to manufacture a semiconductor device in which two support plates were covered with one resin sealant.

As a result, the above-mentioned Japanese Patent Application Laid-Open No. 60-130
It was found that the manufacturing method of Publication No. 129 could not be put into practical use. This is because in the case of two support plates, it is more difficult to determine the timing for pulling out the plurality of III moving pins than in the case of one support plate.

That is, if the movable pin is pulled out too early, the support plate will be molded in an inclined state within the molding cavity, making it impossible to form a resin layer of uniform thickness on the back side of the support plate.

Furthermore, if the movable bottle is pulled out too late, the resin in the molding cavity will progress to harden, making it impossible to inject the resin into the cavity formed after the movable pin is moved. As a result, holes are formed in the resin sealing body, resulting in a decrease in dielectric strength.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a method that can satisfactorily manufacture an electronic component having a structure in which a plurality of support plates are entirely covered with one envelope.

tm 蟇deci''!L-ru=fS　/)　(7) 1st stage.

The method for manufacturing a resin-sealed electronic component according to the present invention includes a plurality of support plates, an external lead connected to one end of the support plate, an N, which is placed on one main surface of the support plate, an f-element,
an insulating member disposed between at least one set of adjacent support plates; and a first mold and a second mold forming a mold cavity; A set of support plates and an insulating member are arranged in the molding cavity of a molding mold in which a resin injection port is formed along the side surface of the molding cavity, and the external lead and the insulating member are placed between the first mold and the second mold. By holding the set of support plates between the molds, the other main surface of the set of support plates was separated from the creeping surface of the molding cavity, and movement of the set of support plates in the thickness direction within the molding cavity was prevented by the insulating member. In this state, a set is formed by injecting a sealing resin into the molding cavity from the resin injection port, and an outer envelope and an insulating member formed by curing the sealing resin injected into the molding cavity. After substantially the entire surface of the support plate is coated, the lead frame assembly is taken out from the mold.

One support plate of the adjacent support plates is fitted into a groove formed on one side of the insulating member, and the other support plate of the adjacent support frame plate is formed on the other side of the insulating member. It is fitted into the groove.

The distance between one main surface of the insulating member and the groove is larger than the distance between the other main surface of the insulating member and the groove. The resin injection port of the molding mold is adjacent to a first resin injection port that has a portion that extends toward the first support plate side from the insulating member corresponding to one of the adjacent support plates. and a second resin injection port having a portion corresponding to the other support plate and extending closer to the other support plate than the insulating member.

According to the invention set forth in claim (1) of the present application, the insulating member and the external lead provided between adjacent support plates are sandwiched between the upper mold and the lower mold. Therefore, a plurality of support plates can be effectively positioned within a small molding cavity. Since the insulating member constitutes a part of the envelope, it is possible to realize an electronic component in which the support plate is not exposed. In addition, the insulating member sandwiched between the first mold and the second mold can suppress the movement of the plurality of support plates in the thickness direction l\ until the injection of the sealing resin is completed. The support plate does not tilt in the molding cavity during injection. Therefore, a resin layer having a desired thickness can be formed on the other main surface side of the support plate.

According to invention 1.3 of claim (2), since the adjacent support plates fit into the grooves of the insulating member and are connected,
The support plate can be reliably fixed during resin molding. Therefore, during the injection of the sealing resin 5, the effect of preventing the support plate from tilting increases.

According to the invention described in claim (3), the insulating member acts to divide the forming spaces corresponding to adjacent support plates. Therefore, it is impossible that the sealing resin injected from the first resin injection port flows into one main surface side of the other support plate and that the sealing resin injected from the second resin injection port The sealing resin is suppressed from flowing into one main surface side of one support plate.

Further, the insulating member passes between adjacent support plates and flows from the other main surface side to the one main surface side of the support plates.

It also has the effect of suppressing the amount of sealing resin produced. Therefore, the desired amount of sealing resin can be injected into one support plate side and the other support plate side of the molding cavity, and the sealing resin can be well injected into the other main surface side of the support plate. can do.

Big...! li! .

The resin-sealed transistor device shown in FIG. 1 is a composite transistor device in which two transistors are packaged in one envelope (27).

To form this transistor device, first, a lead frame assembly (1) shown in FIG. 2 is prepared.

The lead frame assembly (1) is composed of a lead frame (2), a plurality of transistor chips (3), and a plurality of thin lead wires (4). The lead frame (2) includes a plurality of support plates (5), a plurality of external leads (6) disposed on one end side of the plurality of support plates (5), and the other of the plurality of support plates (5). Multiple support leads (
7). To prevent bending or distortion of the lead frame (2), multiple external leads (6) and support leads (
7) are respectively connected in a ladder shape by external lead connecting strips (8) (ri) and supporting lead connecting strips (10).

The transistor chip (3) is fixed to one main surface of the support plate (5) through solder (not shown) by the well-known die bonding method.The 6-lead thin wire (4) is fixed to the transistor chip by the well-known wire bonding method. (3)
(not shown) and an external lead (6).

Next, the positioning member (insulating member) (11
). As shown in the figure, the positioning member (11) has grooves (12) formed on one side and the other side of the positioning member (11) and extending over the entire length of the positioning member (11). The grooves (12) are formed on both side surfaces of the positioning member (11) at the same height from the lower surface (the other main surface). Further, since the groove (12) is located on the lower surface side of the positioning member (11), the groove (12) of the positioning member (11)
) and the upper surface (one main surface) is larger than the distance between the groove (12) and the lower surface (the other principal surface). In this specification, the groove (12) of the positioning member (11)
) is the first main surface side part (1], a), and the do side part of the groove (12) is the second main surface side part (1], b),
The first main surface side portion (lla) and the second main surface side portion (l
lb) is called a connecting portion (llc). First main surface side portion (Ila) on one end side of the positioning member (11)
An inclined surface (], 1d) is formed as shown in FIG. 3.

Next, the positioning member (11) is attached to the lead frame assembly (
1), the support leads (7) of the lead frame assembly (1) are cut at the boundary with the support plate (5) (the part indicated by the broken line in FIG. 2).

In this example, a hole (
7a) is formed and the cross-sectional area of the area to be cut is smaller than other parts, so the support lead (7) can be easily cut. After cutting the support leads (7), a positioning member (11) is attached between adjacent support plates (5). Positioning member (11) Support plate (5) arranged at an odd number from the left side of the beamed frame assembly (1) and its support plate (
-) between a pair of support plates (5) which are intended to be covered by an identical envelope (27). Another adjacent enclosure (2
The positioning member (]1) is not placed between the support plates (5) that are scheduled to be covered by step 7). Positioning member (11
) The width of the groove (12) formed on both sides of the support plate (5
) is the same or slightly larger.

Therefore, a set of support plates (5) are connected to each other by fitting adjacent support plates (5) into the grooves (12) of the positioning member (11).

is fixed. Incidentally, since the positioning member (11) is formed with an inclined surface (+, ld) as shown in , the other end of the support plate (5) is connected from one end side to the inclined surface (lld). It can be easily placed by sliding it and pushing it in.

After attaching the positioning member (11), the lead frame assembly (1) is placed in a mold in order to form a resin sealing body covering the support plate (5) by a well-known transfer mold. The molding mold (13) used in this example consists of a pair of molds (13) that are separably installed on one side as shown in Fig. 4.
14) and a lower mold (15). Type (1
4) and one main surface of the do type (15) have four parts (1
6) (17) has been formed. The four parts (16) L: of the J-shape (14) are formed with a step part (18), with a first plane (19) on one side of the step part (18) + a second plane (on the other side). 20) is formed. Two pins (21) extending downward are formed on the first plane (19). The mold (15) has a groove (2) in which the external lead (6) and the external lead connecting strips (8) and (9) are accommodated.
Runner (23) and Game 1 leading to Part 2) and Part 4 (17)
- (24) is formed. Lead frame assembly (1) such that the external lead (6) fits into the groove (22)
is placed on the lower mold (15), and the old mold (14) and lower mold (15)
When the mold is closed, a recess (16) is formed in the mold (13).
A molding cavity (25) matching the shape of the outer envelope (27) is formed based on the recess (17) and the recess (17). Identical enclosure (2
a set of two adjacent support plates (5) covered with 7);
Positioning part 1 (11,) arranged between support plates (5)
are accommodated in each molding cavity (25). The support plate (5) is placed in the molding cavity (25) such that one end side of the support plate (5) is located on the second plane (20) side and the other end side is located on the first plane (19) side. placed within. Positioning member (11
) and the bottom surface of the molding cavity (25), respectively.
When the upper mold (14) and lower mold (15) that contact the first plane (19) and the bottom of the molding cavity (25) are closed, the positioning member (11) and the bottom lead (6 ) is the upper die (
14) and the lower mold (15), and the support plate (5)
is fixed floating in the molding cavity (25). Note that the distance between the upper surface of the support plate (5) and the upper surface of the molding cavity (25) is the thickness of the first main surface side portion (lla) of the positioning member (11), and the distance between the lower surface of the support plate (5) and The distance from the bottom of the molding cavity (25) corresponds to the thickness of the second main surface side portion (+, 1b) of the positioning member (11). The second plane (20) of the upper die (14) is closer to the support plate (5) than the first plane (19).
Since it is offset in the direction away from the two surfaces, the support plate (5
) and the second plane (20) is the support plate (5).
It is larger than the distance between the upper surface of and the first plane (19).

The two pins (21) provided on the upper mold (14) are connected to the holes (5).
It is housed inside a). Since the pin (21) is arranged apart from the inner surface of the hole (5d), a part of the resin sealing body 26) is formed inside the hole (5a).

Next, the sealing resin softened by high-frequency heating is put into a pot (resin inlet) (not shown) of the mold (13). Next, the sealing resin is pressed with a plunger (push mold) that can be moved downwards in the pot, and the runner (
23) and into the molding cavity (25) through the gate (24). One support plate (5) as shown in Figure 5
The gates (24) are arranged so that one gate (24) faces the
4) each molding cavity (25) connected to the first plane (19)
There are two on each side of the. In this embodiment, the gate (24) is placed below the -F surface of the support plate (5), and the sealing resin injected from the gate (24) is relatively placed on the bottom side of the support plate (5). It flows easily.

Moreover, the support plate (5) passes between the adjacent support plates (5).
Since the flow of the sealing resin toward the top surface of the support plate (5) is suppressed by the positioning member (11), the flow of the sealing resin toward the top surface of the support plate (5) is relatively strengthened. therefore,
The sealing resin can be smoothly injected into the narrow space between the lower surface of the support plate (5) and the bottom surface of the molding cavity (25). Also, as is clear from FIG. 6, when viewed from the gate (24), the forming cavity (25) is separated by the positioning member (11) from the side where the force support plate (5) is accommodated and the side where the force support plate (5) is accommodated. (5
) is separated from the side where the housing is accommodated. Therefore, the molding cavity (25) on the negative support plate (5) side and the other support plate (5)
) side molding cavity (25) respectively corresponds to the gate (
24), the sealing resin can be injected in approximately equal amounts. Therefore, the entire wide molding cavity (25) can be sufficiently and uniformly filled with the sealing resin.

After the sealing resin filled in the entire molding cavity (25) has hardened, the lead frame assembly (1) is placed in the molding die (13).
) When using the same epoxy-based sealing resin as the positioning member (11) taken out from 6, the resin sealing body (26) formed by solidifying the sealing resin will adhere well to the positioning member (11). and integrate. An envelope (27) composed of a positioning member (]l) and a resin sealing body (26) covers the entire surface of the two support plates (5) and the end sides of the six external reams (6). . Since the first main surface side portion (1, 1, a) is sufficiently thick, there is no problem with moisture intrusion or low dielectric strength F.

In addition, although the first main surface side portion (llb) is thin, as shown in the figure, a step is formed on the bottom surface and the length of the interface with the resin sealing body (26) is increased, which prevents moisture from entering. Low dielectric strength does not occur. (27a) is the hole (5a) of the support plate (5)
This is a hole for screw insertion formed correspondingly.

As described above, according to the method for manufacturing a composite transistor device of the present embodiment, the positioning member (11) functions as a connecting part and a fixing part for the adjacent support plates (5).9 Furthermore, the positioning member (11) also functions as a flow suppressing part that controls the amount of sealing resin injected onto one main surface side and the other main surface side of the support plate (5). Since the positioning member (11) constitutes a part of the outer enclosure (27), the support plate (5) is not exposed from the outer enclosure (27) and can be attached to the other main surface side of the plurality of support plates (5). A resin sealing body (26) having a uniform thickness can be formed. Therefore, a composite transistor device with high dielectric strength can be provided.

Crushed knee i - example - The above embodiments of the present invention can be modified in various ways.

(1) The other end of the positioning member (11) may be brought into contact with one side of the molding cavity (25).

Moreover, the positioning member (11) is extended from the - side of the molding cavity (25) to the other side, and the adjacent support plate (
5), the molding cavity (25) containing the positioning member (11
) may be used to completely separate them. In addition, in order to suppress the sealing resin flowing from the other main surface side of the support plate (5) toward one main surface side through the area between adjacent support plates (5), it is necessary to The first plane (
It is preferable that the positioning member (11) extends to 173 or more, preferably 172 or more of the length of 19). In addition, when there is no step part (I8), the length from one side of the molding cavity (25) to the other side is 1/6 or more, preferably 1/6 of the length between one side and the other side. It is better to extend it to /4 or more. In this case, the first of the five positioning members (11)
Only the main surface side portion (lla) may be extended.

(2) As shown in Fig. 7, the upper mold (14) has a convex portion (
Ha) is provided, and the positioning member (1
1) may be sandwiched. In this case, if the convex part (14a) is formed by extending in the direction in which the positioning member (11) extends, the convex part (14a) is formed on the first main surface side portion (+, Together with 1.a), it functions as a flow suppressor for soil-related resin.

(3) The first main surface side portion (11, a), the second main surface side portion (llb), and the connecting portion (11, e) may be formed separately.

(4) As shown in Figure 8, the second main surface side portion (l
lb) may be formed so as to face substantially the entire surface of the other main surface of the adjacent support plate (5).

(5) The groove (12) may be shaped to open on the side surface and the upper or lower surface of the positioning member (11).

(6) If the first main surface side portion (lla) is formed across adjacent support plates (5) and is fixed to these, the second main Ii side portion (llb) and the connecting portion (+, 1
．． c) can be omitted.

(7) The first main surface side portion (lla) may be formed wide and a circuit board may be formed on the child main surface. in this case,
The mold (]4) presses the portion of the first main surface side portion (11.l) where the circuit board is not formed.

(8) Positioning member (1) with a support bin or slide mold that constitutes a part of the upper mold (14) or the negative part of the upper mold (15)
) may be sandwiched.

(9) Three or more adjacent support plates (5) may be formed into groups and covered with one envelope (27).

(10) When attaching the positioning member (11) to the lead frame assembly (1), use the common outer enclosure (27)
The support lead connecting strips (10) connecting a set of support plates (5) covered with
Adjacent support plates (5) not covered by connecting strips (1)
0) may be used.

In this case, after the adjacent support plates (5) have been fixed by means of the 5 positioning elements (11), the remaining connecting strips (10) are removed together with the support leads (7).

Moreover, according to the present invention, it is possible to satisfactorily provide a resin-sealed electronic component in which the entire surfaces of two or more support plates are covered with one envelope, as described above by 1° or more. can.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a composite resin-sealed transistor device manufactured according to an embodiment of the present invention, and a plan view of a lead frame assembly used in manufacturing the first composite resin-sealed transistor device. Figure 3 is a perspective view of the positioning member;
Figure 4 is a cross-sectional view taken along the line ■-IV in Figure 5, Figure 5 is a cross-sectional view showing the lead frame assembly mounted on the mold, and Figure 6 is a cross-sectional view taken along the line VI-VI in Figure 4. FIG. 7 is a sectional view showing a modification of the upper die, and FIG. 8 is a sectional view showing a modification of the positioning member. (1) , Lead frame assembly, (3) ,
, Transistor chip (electronic element), (5), Support plate, (6), , External lead, (11), , Positioning member (insulating member), (13), , Molding mold, (14) 0 .1: type (first type), (1,5),
, Upper mold (second mold), (24), , Gate (resin injection 11), (25). , Molding cavity, (27) , , Enveloping body, Patent applicant: Sanken Electric Co., Ltd. Agent Yo Shimizu - ``(- and 1 other person) Fig. Fig. ＼ Fig.

Claims (3)

[Claims] (1) A plurality of support plates, an external lead connected to one end of the support plate, an electronic element placed on one main surface of the support plate, and at least one set of adjacent external leads connected to one end of the support plate. providing a lead frame assembly having an insulating member disposed between support plates; and a first mold and a second mold forming a molding cavity, the lead frame assembly having a first mold and a second mold forming a molding cavity; The pair of support plates and the insulating member are arranged in the molding cavity of the molding mold in which the resin injection port is formed, and the external lead and the insulating member are connected to the first
and a second mold, the other main surface of the set of support plates is separated from the creeping surface of the molding cavity and in the thickness direction of the set of support plates within the molding cavity. a step of injecting a sealing resin into the molding cavity from the resin injection port while the movement of the molding cavity is prevented by the insulating member; and curing the sealing resin injected into the molding cavity. After substantially the entire surface of the set of support plates is covered with the formed outer envelope and the insulating member, the lead frame assembly is taken out from the mold. A method for manufacturing resin-sealed electronic components. (2) One of the adjacent support plates is fitted into a groove formed on one side of the insulating member, and the other of the adjacent support plates is fitted into the other side of the insulating member. The method for manufacturing a resin-sealed electronic component according to claim 1, wherein the resin-sealed electronic component is fitted into a groove formed on a side surface of the resin-sealed electronic component. (3) The distance between one main surface of the insulating member and the groove is larger than the distance between the other main surface of the insulating member and the groove, and the resin injection port of the mold is a first resin injection port having a portion corresponding to one of the adjacent support plates and extending closer to the one support plate than the insulating member; and support for the other of the adjacent support plates. Claim (2) further comprising: a second resin injection port having a portion corresponding to the plate and extending closer to the other support plate than the insulating member.
A method for manufacturing a resin-sealed electronic component as described in .