JPH01291434A - Manufacture of resin-sealed electronic component - Google Patents

Abstract

PURPOSE:To preferably form a thin resin layer on the rear surface of a supporting plate, too, by securing the plate to a predetermined position in first and second slide molds, and suppressing sealing resin flowing to one main face side of the plate. CONSTITUTION:The thin part of the end of a supporting plate 2 at opposite side to the side from which external leads 3 are extended is interposed between a first slide mold 12, and second and third slide molds 13, 14. A gate 15 is disposed lower than the upper surface of the plate 2, and a first slide mold 12 is disposed in its whole lateral length above the gate 15. Thus, the gate 15 communicates with a region of the rear surface of the plate 2, poured sealing resin easily flows to the region of its lower side, and the flow to a region of its upper side is suppressed and weakened by the mold 12 and the plate 2. The resin can be poured in good balance to the upper and rear surface sides of the plate 2, and a favorable resin sealer can be formed on the rear surface side of the plate 3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a resin-sealed electronic component, and more specifically, a thin resin layer can be satisfactorily formed on the lower surface side of a support plate. The present invention relates to a method for manufacturing resin-sealed electronic components.

[Prior Art and Problems to be Solved by the Invention] There is a resin-sealed individual conductor device in which the entire surface of the support plate, including the bottom surface thereof, is covered with a resin sealant. This type of conductor device is not required as an insulating sheet when attaching J4!2υ to a heat sink, etc. However, since a part of the resin sealing body is also formed on the lower surface of the support plate, it is disadvantageous in terms of heat dissipation compared to a resin-sealed conductor device of the type in which the lower surface of the support plate is exposed.

Therefore, the resin sealing body on the lower surface side of the support plate has a thickness of 0.5
By making the layer as thin as about mm, this disadvantageous vibration is reduced. However, since this resin sealing body on the lower surface side is formed by pressure injecting the sealing resin into the open area where the supporting plate and the creeping surface of the molding cavity face each other with a spacing of only 0.5 mm, a good resin layer is formed. It was difficult to obtain.

As a method to solve the above problem, JP-A-60-2
No. 57529 discloses that a protrusion is provided on the upper die of the molding die so as to cross the injection direction of the resin, thereby suppressing the flow of resin on the upper surface of the support plate and relatively reducing the flow of resin on the lower surface of the support plate. A manufacturing method with enhanced flow is disclosed. However, in the above method, a bottle or lead wire for supporting the support plate is required to fix the support plate, and it is difficult to cover the entire surface of the metal maple portion other than the external lead with a resin sealant.

Therefore, Japanese Patent Application Laid-Open No. 60-30129 discloses a manufacturing method in which the bin of the support plate fixing piece is a movable bin. However, controlling movable bins was extremely difficult. That is, if the movable bottle is pulled out too early, the support plate will tilt, and if the movable bottle is pulled out too late, the sealing resin will not be injected into the void created by the movement of the movable bottle.

Therefore, the present invention provides a method for easily obtaining a resin-sealed electronic component in which a good resin layer can be formed on the lower surface side of a support plate and there is no exposed part of the metal plate other than the external lead. The purpose is to

[Means to solve the problem]

In order to achieve the above object, the present invention has an electronic element and/or a circuit board fixed to one main surface of a support plate of a lead frame, and external leads are arranged at one end vA side of the support plate. Step 11 of preparing a lead frame assembly, and molding the support plate into a shape Wj, which can be individually fixed with resin, on both one main surface side and the other main surface side. A mold with a void? The other end side of the support plate is sandwiched by first and second slide molds which are prepared and movable into and out of the molding cavity, and the other main surface of the support plate and the molding cavity opposite thereto are sandwiched between the other end side of the support plate. arranging the assembled lead frame in the molding mold such that the distance from the main surface of the support plate to the wall surface is greater than the distance between one main surface of the support plate and the nine surfaces of the molding cavity facing thereto; a step of injecting the fluidized sealing resin Y from the resin injection port located below the upper surface of the support plate into the molding cavity, and substantially half or more of the molding cavity is filled with the sealing resin. After the first and second slide molds are moved away from the support plate, the sealing molds are filled into the voids formed by the movement of the first and second slide molds. It is related to a method of manufacturing a resin-sealed electronic component, which has a step of injecting fat and features Y.

[Function] The first and second slide molds of the present invention have the function of fixing the support plate in a fixed position! The first or second slide mold has the function of suppressing the individual stopper resin flowing toward one main surface side of the support plate. Thereby, the injection of the sealing resin into the other main surface side of the support plate can be relatively strengthened. However, since the first and second slide molds are both placed on the other end side of the support plate, the sealing resin can be reliably filled into the void formed after the first and second slide molds are moved. can be injected into

〔Example〕

1 to 6, a method of manufacturing a resin-sealed semiconductor device according to an embodiment of the present invention will be described.

The lead frame 1 shown in FIG. 6 has a support plate 2 having a heat dissipation function and an external lead 3ya' arranged at one end of the support plate 2. The actual lead frame 1 is a multi-element lead frame having a plurality of support plates 2. A semiconductor chip 4 is fixed on the support plate 2 of the lead frame 1 with a lead wire (not shown), and the semiconductor chip 4 and the external leads 3 are connected to each other with a lead thin f! 5 to form a chip/lead frame assembly 6 (hereinafter referred to as lead frame assembly).

When forming the resin sealing body 7 on the I-node frame assembly 6 as shown by the dotted line in FIG. Place in mold 8. The mold 8 shown in FIG. 1 consists of an upper mold 9 and a lower mold 10, and the upper mold 9 has a cylindrical convex portion 11 formed therein.

The convex portion 11 is fully inserted into the mounting hole 2a formed in the support plate 2. However, the convex portion 11 is spaced apart from the inner peripheral surface of the attachment hole 2a. Therefore, the inner circumferential surface of the mounting hole 2a is covered with a portion of the resin sealing body 7 without being exposed. A groove is formed in which the F type 1 type 0 pressure external lead 3 is accommodated.The main structure described above is no different from the conventional one.The features of this embodiment are as shown in Figs. 1 and 2. goldffi+8
In addition to the upper mold 9 and the lower mold 10, there are also a first slide mold 12 and a second slide mold 12.
and a sixth slide mold 14, and a gate 15 serving as a resin injection port is located below the bottom surface of the first slide mold 12. The first slide mold 12 is provided so as to be movable up and down relative to the upper mold 94C.
．． 14 is provided so as to be movable up and down relative to the lower mold 10. Next to these slide molds 12, 13, and 14!
W,,W,,W.

is the width %I of the first slide mold 12 as shown in FIG.
, is large (the widths l1IIW2, W3 of the second and third slide molds 13 and 14 are smaller than that. In this embodiment, the width w1 of the slide mold 12 of Ml is also larger than the width of the gate 15. The gate 15 and the runner 16 connected thereto are formed at the interface between the lower mold 1o and the upper mold 9.By closing the upper mold 9 and the lower mold 1°, the convex portion formed on the upper mold 9 is removed. A molding cavity 19 corresponding to the resin sealing body 7 is formed in the mold 8 by the recess 18 formed in the lower m10.

When the lead frame assembly 6 is placed, the outer portion 3 is fitted into a groove provided in the lower mold 10 and is held between the upper mold 9 and the lower mold 10. Further, the thin portion of the end of the support plate 2 opposite to the side from which the external leads 3 are led out is connected to the first slide mold 12.
and the second and third slide molds 13 and 14. Therefore, the lower surface of the support plate 2 is lifted from the bottom surface of the molding space 19 by a small distance L1 of about 0.5 mm! 4, both sides are supported. After the lead frame assembly 6 was placed, the first, second and third slide molds 12, 13 and 14 were lowered and raised to sandwich the support plate 2. but,
Slide mold 12.1 in advance before closing upper mold 9 and lower mold 10
3.14 protrudes from the upper mold 9 and lower mold 10 into the molding cavity 19? You can leave it alone.

Next, as shown in FIG. 1, a cylindrical resin block 20y
! -Bot) (resin inlet) 21.

The bot 21 and the mold 8 are heated to about 160° C. in advance, and the resin block 20 is melted and fluidized. bot 2
1 is formed air PIr1 through the runner 16 and gate 15
Connected to 9, resin block 20 is Granja (
By being suppressed by the press mold 22, it flows into the molding cavity P9r19. In this embodiment, since the bot 21 connects the two moldings symmetrically arranged around the bot 21 to the FFr 19, the resin block 20 also corresponds to the resin sealing bodies 8 of the two resin-sealing type cow conductor devices. In this embodiment, the gate 15 is located below the upper surface of the support plate 2, and the first slide mold 12 is arranged above the gate 15 over its entire width. Therefore, the gate 15 communicates with the region on the lower side of the support plate 2, and the injected sealing resin easily flows to the lower region, and the inflow to the upper region is limited to the first slide mold 12.
The paddy is restrained and husked on the support plate 2. However, the first slide mold 12 functions as the protrusion of the upper mold of the conventional example.

However, since the slide mold 12 of @1 is provided near the gate 15, the effect of suppressing the flow of the sealing resin to the upper surface of the support plate 2 is much improved compared to the protrusion of the conventional example. In addition, as shown in FIG. 3, the support &2 gate 151
There is a protrusion on the end of 411! 2b is provided, and the distance between the other end of the support plate 2 and the wall surface of the molding cavity 19 facing it is narrowed.

This further improves the effect of suppressing the flow of the sealing resin toward the upper surface side.

In Figure 1, the upper and lower surfaces of the support plate 2 are completely separated, and it seems that the #2 sealing resin is not injected into the upper surface of the support plate 2. In reality, the upper and lower regions of the support plate 2 are connected on the sides of the first slide mold 12 and on the sides of the support plate 2, so the sealing resin is applied to the support plate 2. Injected in a well-balanced manner on the upper and lower sides.

When almost the entire molding cavity 19 is filled with the sealing resin, the first slide mold 12 and the second and third slide molds 1 are removed.
3.14 Move away from the support plate 2. As a result, the other end of the support fj2 is released, and the support plate 2
becomes cantilevered.

However, as shown in FIG. 4, the molding cavity 19 is almost entirely filled with the sealing resin, and a portion of it is being cured. Therefore, even if the lubricant for hook stopper is roughly injected in this state, the support plate 2 will not tilt. Gate 15 is in the void created by moving slide molds 12, 13, and 14! Ill stopper resin is injected and filled.

In this embodiment, slide type gates 12, 13, 14 and 15
Contact the creeping surface of the molded air F9T19 provided with
And it was placed near the gate 15. For this reason, the cavity formed after the movement of the slides m12.13, 14 is in a position that opens directly into the gate 15. Therefore, it is possible to easily inject the sealing resin into the cavity. In addition, even if the timing of moving the slide mold 12, 16, 14 is delayed and the fluidity of the sealing resin around the slide mold 12, 13, 14 is lost, the void can be directly sealed from the gate 15. Can be injected with resin. Therefore, sliding type 12.13.1
4, the movement timing can be made later than in the conventional example.

In other words, since the slide mold 12, 13, 14% can be moved after injecting the molding cost pfr 19 with a polycrystalline sealing resin, #l slant Y of the support plate 2 can be reliably prevented.

In this embodiment, the movement timing of the slide molds 12, 13, and 14 is controlled by the height position of the plunger 22. That is,
The amount of sealing resin injected into the molding cavity 19 depends on the distance 117IfK that the plunger 22 is lowered. therefore,
The plunger 22 descends to a predetermined crystallinity and the molding air pk1
When almost the entire portion 9 is filled with the sealing resin 94, the slide molds 12, 13, and 14 are separated from the support plate 2. In addition,
Since the lengths of the resin injection paths extending from the same bot 21 to the molding cavities 19 of several subordinate parts c) (the length c added to the runners 16 and K) 15') are equal, those molding cavities 1
The amount of the sealing resin injected into 9 is equal. Note that even if the length of the resin injection path is different, the same effect can be obtained as long as the capacity is the same.

After the sealing resin injected into the molding cavity 19 is solidified, the lead frame assembly 6 is taken out from the mold 8, and the tie bars and connecting strips connecting the external leads 3 in parallel are cut and removed. As a result, a resin-sealed medium conductor device 23 as shown in FIG. 5 is completed.

1, the entire surface of the live conductor device 26 obtained in this example, including the back surface Y of the support plate 2, is covered with a resin sealing body 7,
There is no exposed part of the gold maple other than the external lead 3.

The effects of this embodiment can be summarized as follows.

(11) Since the sealing resin t can be injected into the upper surface side and the lower surface side of the support plate 2 in a well-balanced manner, a good resin sealing body 7 can be formed on the lower surface side of the support plate 2.

(2) Since the entire surface of the support plate 2 can be covered with the sealing resin, it is possible to provide a resin-sealed medium conductor package fi1 with high dielectric strength.

+31 Since the slide mold 12.13.14 substantially contacts the surface of the molding cavity 19 where the gate 15 is provided and is provided near the gate 15, the slide mold 12.1
3.14 has a large degree of freedom in moving timing. Therefore, movement control of the slide molds 12, 13, and 14 is easy.

(4) Support@2 can be supported on both sides and sealed with resin.

Therefore, a thin resin layer with a constant thickness can be formed on the lower surface side of the support plate 2.

[Modified example]

The present invention is not limited to the above-described embodiments, but can be modified, for example, as follows.

(Several 11 gates Y are provided, and the resin is injected from the gate located above the upper surface of the support plate 2 to the upper surface side of the support plate 2.
You may go. In this case, more than half of the molding cavity 19 is filled! The gate located above is closed by the first slide mold 12 (!However, each of the plurality of gates may lead to different pots.

(21 The top surface of the gate 15? It may be positioned above the top surface of the support plate 2. In this case, the part above the top surface of the support plate 2 is held by the support plate 2. Close it with mold 12.

〔Effect of the invention〕

As described above, according to the present invention, a resin-sealed electronic component with high dielectric strength and excellent reliability and characteristics can be easily provided.

[Brief explanation of the drawing]

1 is a sectional view showing a lead frame assembly and a mold according to an embodiment of the present invention at a portion corresponding to the T line in FIG. 6; FIG. 2 is a sectional view at Rollo@VC in FIG. 1; FIG. 6 is a sectional view showing a part of line III--III in FIG. 2. Is the slide in figure 4 moved? FIG. 5 is a perspective view of the completed semiconductor device, and FIG. 6 is a plan view of the lead frame assembly. DESCRIPTION OF SYMBOLS 1... Lead frame, 2... Support plate, 3... External lead, 4... Semiconductor chip, 6... Chip/lead frame assembly, 7... Resin sealing body, 8... ... Mold, 9... Upper mold, 10... Lower mold, 12... First slide mold, 13... Second slide mold, 14...
Third slide mold, 15...gate, 19...molding cavity.

Claims (1)

[Claims] [1] An electronic element and/or a circuit board is fixed to one main surface of a support plate of a lead frame, and external leads are arranged on one end side of the support plate. A step of preparing a lead frame assembly, and a molding die having a molding cavity formed so that both one main surface side and the other main surface side of the support plate can be sealed with resin. The other end side of the support plate is sandwiched by first and second slide molds which are prepared and movable into and out of the molding cavity, and the other main surface of the support plate and the molding cavity opposite thereto are sandwiched between the other end side of the support plate. The lead frame assembly is arranged in the molding mold such that the distance between the lead frame assembly and the wall surface of the support plate is smaller than the distance between one main surface of the support plate and the wall surface of the molding cavity opposite thereto; Pressing and injecting fluidized sealing resin into the molding cavity from the resin injection port located below the top surface of the plate, and filling approximately half or more of the molding cavity with the sealing resin. After that, the first and second slide molds are moved away from the support plate, and the sealing resin is injected into the void formed by the movement of the first and second slide molds. 1. A method for manufacturing a resin-sealed electronic component, comprising the steps of: