JP2002043493A - Lead frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is difficult to discriminate the filling state of a resin when the thickness of a resin coating predetermined part is thin. SOLUTION: A number of lead frames 10 are continuously connected in the thickness direction, and a rectangular notch 12 in a planar shape is formed on a frame 7 surrounding the resin coating predetermined part 11d of the terminal of the resin flow passage A of the lead frame with which the resin coating predetermined part 11 communicates in the thickness direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lead frame used for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art Portable electronic circuit devices, such as video cameras and notebook personal computers, are required to be small and lightweight.
In addition to those for low power, electronic components such as motors that control relatively large currents are also required to be small and light.

An example of a resin-molded semiconductor device manufactured using a lead frame among such electronic components will be described with reference to FIGS. 3 and 4. FIG.

In FIG. 1, reference numeral 1 denotes an island for mounting a semiconductor pellet 2 as an electronic component body, 3 denotes a lead having one end disposed near the island 1, 4 denotes an electrode (not shown) on the semiconductor pellet 2 and a lead. Reference numeral 5 denotes a resin that electrically covers the main part including the semiconductor pellet 2. The lead 3 is led out from the side wall of the resin 5 and is bent and formed into a crank shape.

A lead frame 6 shown in FIG. 5 is used for manufacturing the semiconductor device. In the figure, reference numeral 7 denotes a rectangular frame, 8 denotes a suspension pin for connecting the island 1 arranged at the center of the frame 7 to the frame 7, and 9 denotes a frame.
2 shows a tie bar in which intermediate portions of a plurality of leads 3 extending toward the island 1 from the inner periphery are connected and integrated. A plurality of lead frames 6 are connected in the longitudinal direction with the frame 7 as a basic unit.

The lead frame 6 is made of a semiconductor pellet 2
Mounting the semiconductor chip on the island 1 via an adhesive (not shown) such as solder or conductive paste, a wire bonding step of electrically connecting the electrode 3 on the semiconductor pellet 2 and the lead 3 with the wire 4, A resin molding step of covering the area surrounded by the tie bar 9 with the resin, and cutting and removing the dependent parts, that is, the frame 7, the suspension pins 8, and the tie bar 9 exposed from the resin of the lead frame 6 whose main part is coated with the resin Then, each lead is made independent, a cutting step of separating the individual semiconductor devices, an inspection step of inspecting and selecting electrical characteristics and appearance, and a stamping step of stamping the surface of the resin 5 based on the inspection result are sequentially performed. 3 is manufactured.

[0007] This type of semiconductor device is required to be smaller and lighter as well as lower in price.
Are connected to each other in a large number of rows to increase the number of semiconductor devices per lead frame, thereby reducing costs.

In such a lead frame 6, it is difficult to supply the resin 5 to each frame 7.
The resin coating portions of the frames 7 arranged adjacent to each other in the width direction are communicated with each other, and the resin 5 supplied from one side of the lead frame 6 is sequentially moved to the connected resin coating portions to the other side. Feeding and resin molding.

Further, this type of semiconductor device is also required to be thinner, and a semiconductor device having a resin thickness of 1.0 mm or less is also manufactured as a semiconductor device which controls opening and closing of a current of several A.

When the thickness of the resin is 1.0 mm or less, the thickness of the island 1 is 0.15 mm and the thickness of the semiconductor pellet 2 is 0.25 mm. The substantial thickness is 0.6 mm or less, and the thickness of the resin on one of the upper and lower sides is 0.3 mm or less.

On the other hand, the thickness of the resin between the leads 3 and between the island 1 and the leads 3 is 0.85 mm or more. The fluidity of the resin in the scheduled area is significantly different.

As described above, when the fluidity of the resin in the portion to be coated with resin is significantly different, if a plurality of portions to be coated with resin are connected in the width direction, the resin
Have a large variation in the filling properties, and problems such as unfilling may occur.

Therefore, it is necessary to perform an appearance inspection to detect unfilled ones and remove them as molding defects. However, in the case of a resin having a small thickness, the outer periphery of a portion to be covered with the resin is covered with the resin to obtain an appearance. Is normal, voids are formed inside and unfilled defects cannot be detected, and when such defects are supplied to the subsequent lead forming process, the leads are pulled out by the forming punch and clogged between the punch and the die. There has been a problem that the operation of the apparatus cannot be continued.

An unfilled semiconductor device also has a problem that its moisture resistance is poor and its reliability cannot be guaranteed.

For this reason, it is known to detect the state of resin filler formed between the portion to be coated with resin and the tie bar 9 to detect non-filling. For example, JP-A-59-22872
No. 7 (Prior Art 1)

It is also known that a detection hole is formed in a part of a frame adjacent to a portion to be coated with a resin, and a state of filling of the detection hole with the resin is detected to detect an unfilled state. For example, JP-A-1-204438 (Prior Art 2)

[0017]

It is known that the prior arts 1 and 2 detect unfilled resin.
A number of resin coating sections are connected to each other, and the resin thickness is 1.0 m
When the technology disclosed in Prior Art 1 is applied to a thin material having a thickness of not more than m, the resin burrs to be filled between the resin coating scheduled portion and the tie bar are small, and the resin burrs are missing or lacking and are not filled. Some of them were actually completely filled, and it was not possible to detect non-filling only with resin burrs.

[0018] Further, even if the detection hole is formed in a part of the frame as disclosed in the prior art 2, the flow path of the resin becomes long when a large number of resin coating portions are connected, and the resin coating portion becomes large. If the resin is thin, the resin will be more susceptible to heat from the mold, the viscosity will increase during the movement of the resin, and the fluidity will decrease. In some cases, even if the resin was filled, the detection hole was not filled, and the state of filling of the resin could not be accurately detected.

[0019]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems. A plurality of frames are connected in a width direction and a longitudinal direction, and islands are arranged in each frame. A plurality of leads are extended toward the main frame, and the main part in the frame including the semiconductor pellet mounted on the island and electrically connected to the leads is covered with resin. A notch having a substantially rectangular planar shape is formed at a portion adjacent to a portion to be coated with resin at an end of a resin supply path in which resin sequentially moves from one end side to the other end side of the plurality of frames. Is provided.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A lead frame according to the present invention
A lead frame in which a large number of frames are arranged in the width direction and the longitudinal direction, and the resin coating portion in the width direction is communicated to supply the resin from one end to the other end. A cutout having a substantially rectangular shape in a plan view, the resin coating scheduled portion is rectangular, and a resin injection portion and a resin discharge portion of a resin supply path are formed at diagonal positions thereof. A notch can be formed in the resin discharge portion at the end of the supply path.

A plurality of frames connected in the width direction are
The notch can be formed in the frame at the end of the resin supply path of each set that is connected in the set and the longitudinal direction and located in the middle in the width direction.

Further, the lead frame according to the present invention has a remarkable effect when the thickness of the portion to be coated with the resin is 1.0 mm or less.

[0023]

FIG. 1 shows an embodiment of the present invention.
In the figure, the same parts as those described in FIGS. 3 to 5 are denoted by the same reference numerals, and redundant description will be omitted. The lead frame 10 according to the present invention is formed by connecting a large number of frames 7 indicated by alternate long and short dash lines in the width direction and the longitudinal direction, and the resin coating portions 11a and 11b surrounded by the dotted lines in the frames 7a, 7b and 7c connected in the width direction. , 11c are communicated with each other, and the fluidized resin is sequentially supplied to the respective resin coating portions 11a, 11b, 11c to perform resin coating.

In the lead frame 10, the resin coating portions 11a, 11b, and 11c are rectangular in plan view, and the resin flow path A is set diagonally. Therefore, the fluidized resin meanders on the lead frame 10. A cutout 12 having a substantially rectangular planar shape is formed at the resin discharge portion at the end of the resin flow path A.

The notch 12 communicates with the portion 11c to be coated with resin, but the thickness is determined by the thickness of the frame 7.
The thickness of the notch 12 is set to about 0.15 mm, and the opening diameter thereof is set to about 1.0 mm, while the thickness of the resin coating portion 11 is 1.0 mm or less.

The lead frame, which is the premise of the present invention, communicates with a large number of resin coating portions 11a, 11b, and 11c to supply the resin which has been fluidized sequentially, so that the resin travels in the resin coating portions 11a, 11b, and 11c. As the curing proceeds, the viscosity increases and the fluidity decreases. Therefore, the fluidity of the resin in the terminal resin coating portion 11c is extremely reduced, and it is difficult for the resin to flow into the notch 12 limited by the thickness of the frame 7 even when the resin is filled.

However, since the notch has a sufficiently large opening diameter as compared with the thickness, it is possible to accommodate even a resin having a reduced fluidity. It hardens quickly due to heat and loses fluidity. Therefore, by detecting the depth of progress of the resin injected into the notch 12, the resin coating scheduled portion 11 is detected.
The state of filling of the resin in the inside can be reliably detected.

As shown in FIG. 2A, when the notch 12 is completely filled with the resin 5, the terminal resin coating portion 11c at the end is also filled with the resin under sufficient pressure. Further, as shown in FIG.
The filling state is good even in the state where the filling is performed up to the intermediate position of No. 2. However, as shown in FIG. 2 (c), the resin coating portion 11c appears to be filled with the resin 5, but when the notch 12 does not contain the resin 5, there is a cavity inside, and It is determined to be defective.

The filling state of the notch 12 with the resin can be easily detected by an optical sensor, and more detailed judgment can be made by an image recognition device using a television camera.

Further, the state of filling of the resin on the lead frame can be analyzed in detail based on the result of this determination, and the optimum conditions for resin molding can be set based on the result of the clause.

In the lead frame according to the present invention, a plurality of frames are connected from both sides in the width direction, the resin is supplied to the resin coating portions connected from both sides in the width direction, and the terminal resin coating portions are arranged at the middle portion in the width direction. In this case, a notch may be formed in the portion to be covered with the resin in the middle portion in the width direction.

The present invention is not limited only to the above embodiment. For example, the thickness of the resin coating portion 11 is
It can also be applied to those exceeding 1.0 mm.

In addition to supplying resin to be fluidized from a single pot, a large number of pots are arranged on one side or both sides of the lead frame, and the resin is supplied from each pot to the shortest resin coating portion. A resin may be supplied.

[0034]

As described above, according to the present invention, it is possible to accurately detect the filling state of the resin in each of the resin coating portions of the lead frame in which a large number of the resin coating portions communicate in the width direction. Frames can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a lead frame according to the present invention.

FIG. 2 is a plan view of a main part showing a state of filling a resin on a lead frame according to the present invention.

FIG. 3 is a partial cross-sectional plan view illustrating an example of a resin-molded electronic component.

4 is a front sectional view of the electronic component in FIG. 3;

FIG. 5 is a plan view of a main part of a lead frame used for manufacturing an electronic component.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 island 2 semiconductor pellet 3 lead 4 wire 5 resin 6 lead frame 7 frame 7 a, 7 b, 7 c frame 8 pin 9 tie bar 10 lead frame 11 scheduled resin coating portion 11 a, 11 b, 11 c scheduled resin coating portion 12 notch A resin flow path

Claims (4)

[Claims] A plurality of frames are connected in a width direction and a longitudinal direction, an island is arranged in each frame, a plurality of leads extend from the frame toward the island, and the leads are electrically connected to the leads. In a lead frame in which a main part in a frame including a semiconductor pellet connected to a resin is covered with a resin, the resin in which the resin sequentially moves from one end to the other end of the plurality of frames connected in the width direction is used. A lead frame, wherein a notch having a substantially rectangular planar shape is formed in a portion adjacent to a resin coating portion at an end of a supply path. 2. A resin injection section and a resin discharge section of a resin supply path are formed at diagonal positions of a rectangular resin coating section, and a notch is formed at a resin discharge section at an end of the resin supply path. The lead frame according to claim 1. 3. Two sets of a plurality of frames connected in the width direction,
2. The lead frame according to claim 1, wherein a notch is formed in a frame at the end of each pair of resin supply paths which is connected in the longitudinal direction and located at the middle in the width direction. 4. The lead frame according to claim 1, wherein the thickness of the portion to be covered with the resin is 1.0 mm or less.