JP3681856B2 - Resin-sealed electronic components - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin-sealed electronic component.
[0002]
[Prior art]
Conventionally, a resin-encapsulated electronic component has a semiconductor chip, an island on which the semiconductor chip is mounted, and a lead having one end connected to an electrode of the semiconductor chip sealed with a resin, and is exposed from the sealing resin. The exposed lead is refracted and the exposed lead is connected to the circuit board.
[0003]
[Problems to be solved by the invention]
However, since the lead is punched and formed, the peripheral part is unshaped, and the tie bar punch for removing the burr protruding between the leads and the outside of the lead of the lead frame are formed to shape the exposed part of the lead. Edge cutting punches for cutting the lead frame connected to the end are required. These punches require high precision and are expensive. Further, the punch work requires a precise workpiece positioning device, which increases the cost. There is a problem of doing.
[0004]
In addition, since the exposed portion of the lead extends outward from the sealing resin, the outer shape of the resin-encapsulated electronic component is increased, and not only the mounting density on the circuit board cannot be increased, but also the exposed portion is Since it is easily deformed, there is a problem that special care is required for maintenance of the shape and the packaging cost is also expensive.
[0005]
Furthermore, since the lead extends long from the sealing resin, it is necessary to press the terminal part against the printed circuit board with a ceramic pressing jig when soldering for mounting. There is a problem in that a solder bridge is formed between adjacent leads via the circuit, causing a circuit failure.
[0006]
In addition, when testing resin-encapsulated electronic components, precise positioning in two vertical and horizontal directions is required with respect to the tester probe, and the cost is high, and the leads extend from the sealing resin for a long time. There is a risk that the test may be inaccurate due to a contact failure between the terminal portion of the lead tip and the probe, and there is a problem that the lead is deformed when a strong pressure is applied to prevent the contact failure.
[0007]
[Means for Solving the Problems]
Therefore, in the present invention, the chip and the lead connected to the chip are sealed with a sealing resin, the leading end of the lead is exposed to the outside of the sealing resin, and the exposed portion of the lead is exposed to the sealing resin side. In a resin-encapsulated electronic component that is cut in a substantially vertical direction along the end surface and the exposed portion of the remaining lead is used as a terminal portion, the lead passes through an inner refracting portion and an outer refracting portion that are refracted substantially at right angles. It consists of a sealing lead part, a step lead part, and an exposed lead part that is one step lower than the sealing lead part, and the outer refracting part has its refracting center positioned near the side end face of the sealing resin. , thereby forming the stepped lead portion by refracting the lead around the same refractive centered substantially perpendicular upward direction, the exposed lead portion sealed with resin to protrude from the bottom surface of the sealing resin downward, sealing To be flush with the side edge of the resin That the exposed by cutting the lead unit, to St. provide a resin sealed electronic component, characterized in that the lower surface of the formed terminal portion for substantially 1/4 is brought Rutotomoni contact board circuit and line curved in an arc shape It is.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Thus, prior to the resin sealing process of the electronic component, the lead is refracted in the vicinity of the boundary between the sealing portion and the exposed portion, and after the resin sealing, the lead is cut along the side end surface of the sealing resin. Thus, by using the tip of the lead remaining on the sealing resin side as the terminal portion, the terminal portion protrudes downward from the bottom surface of the sealing resin, but the terminal portion extends outward from the side end surface of the sealing resin. A resin-encapsulated electronic component is formed so as not to protrude.
[0009]
【Example】
Embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows a state in which a semiconductor electronic component A as a resin-encapsulated electronic component according to the present invention is inverted, and the electronic component A is a peripheral portion of a bottom surface R1 of a substantially rectangular parallelepiped sealing resin R. In addition, a large number of terminal portions 1 formed at the tips of leads 32 to be described later are projected with a predetermined gap.
[0011]
In the terminal portion 1, the exposed portion of the lead 32 is cut in a substantially vertical direction along the side end surface R 2 of the sealing resin R, and the exposed portion of the remaining lead 32 is used as the terminal portion 1. That is, the terminal portion 1 is formed in a substantially arc shape when viewed from the side, and the side end surface 2 of the terminal portion 1 is formed to be flush with the side end surface R2 of the sealing resin. It does not protrude outward from the side end face R2.
[0012]
A curved bottom surface 5 having a substantially 1/4 arc shape is formed from the leading edge 3 of the terminal portion side end surface 2 to the inner edge 4 where the terminal portion 1 intersects the lower bottom surface R1 of the sealing resin R.
[0013]
The left and right side surfaces 6 of the terminal portion 1 are substantially orthogonal to the lower bottom surface R1 of the sealing resin R, the terminal portion side end surface 2, and the curved bottom surface 5.
[0014]
Inside the sealing resin R, a semiconductor chip 35 to be described later, an island 33 for supporting the semiconductor chip 35, and an inner portion of a lead 32 whose inner end is connected to the semiconductor chip 35 via a bonding wire 36 are incorporated. In addition, the connection between the semiconductor chip 35 and the external circuit is made through the numerous terminal portions 1 described above.
[0015]
FIG. 2 shows a resin-encapsulated semiconductor component A mounted on the upper surface of the printed circuit board 10 as an external circuit. A large number of substrate circuits 11 formed on the upper surface of the printed circuit board 10 and a large number of resin-encapsulated semiconductor components A are shown. The terminal portion 1 is brought into contact with each other, and each substrate circuit 11 in contact and the terminal portion 1 are electrically connected and fixed by soldering. In the figure, 12 is solder.
[0016]
As described above, in the resin-encapsulated semiconductor component A of the present invention, since the terminal portion 1 of the lead 32 does not project outward from the side end surface R2 of the encapsulating resin R, only the lower lower bottom surface R1 projects. It is possible to reduce the size of the sealed semiconductor component A and increase the mounting density on the printed circuit board 10 or the like.
[0017]
Further, since the terminal portion 1 protrudes from the lower surface of the sealing resin R, a standoff 13 for isolating the substrate circuit 11 of the printed board 10 and the resin-encapsulated semiconductor component A can be secured.
[0018]
Further, since the protruding amount of the terminal portion 1 is small, the terminal portion 1 is not deformed, the shape can be easily maintained and the packaging cost can be reduced.
[0019]
Furthermore, since the protruding amount of the terminal portion 1 is small, the rigidity is high, and the protruding height is easy to align, and furthermore, the terminal portion 1 is in line contact with the circuit board 11, so that the terminal portion can be used when soldering to the printed circuit board 10 or the like. There is no need to press 1 separately, and therefore, the formation of a solder bridge between the leads 32 using the pressing jig as a medium is prevented.
[0020]
Further, since the curved bottom surface 5 is formed at the lower end portion of the terminal portion 1 during the soldering, a substantially wedge shape with a roundness between the curved bottom surface 5 and the upper surface of the substrate circuit 11 of the printed circuit board 10 is formed. Thus, the molten solder flows into the gap due to the capillary phenomenon, and the soldering reliability can be improved.
[0021]
FIG. 3 shows a test state of the resin-encapsulated semiconductor component A. As shown in the drawing, the encapsulating resin side end face R2 is sandwiched between the guide members 20 and 20 arranged on both sides, thereby encapsulating. Positioning is performed using the resin side end surface R2 as a guide so that each terminal portion 1 can be accurately positioned on the upper surface of each probe 21, so that an expensive positioning device or the like is not required, and the rigidity of the terminal portion 1 is further increased. Since it is high, each terminal part 1 can be brought into reliable contact with each probe 21 without deforming each terminal part 1 simply by pressing the sealing resin R part in the direction of the probe 21. Can be improved.
[0022]
The probe 21 is formed in a substantially U-shape that is open in the horizontal direction and has a slight elasticity in the vertical direction. Even if there is a slight difference in the downward protrusion amount of the terminal portion 1, The probe 21 is surely in contact with the terminal portion 1.
[0023]
Next, with reference to FIGS. 4-7, manufacture of the said resin-encapsulated semiconductor component A is demonstrated.
[0024]
FIG. 4 shows a lead frame 30, in which a large number of leads 32 project inward from the outer peripheral portion 31 of the lead frame 30, and an island 33 is formed at a central portion separated from the lead 32. The inner portion of each lead 32 and the island 33 are set at a position one step higher than the outer periphery of the lead frame 30.
[0025]
As shown in FIG. 5, each lead 32 includes a high-level sealed lead portion 32a, a one-step lower-level exposed lead portion 32b, and a stepped lead portion 32c between the sealed lead portion 32a and the exposed lead portion 32b. Each lead portion 32a, 32b, 32c is continuous through inner and outer refracting portions 32d, 32e that are refracted substantially at right angles, and in particular, the outer refracting portion 32d has its refracting center 34. Is positioned in the vicinity of the sealing resin side end surface R2 described later.
[0026]
That is, a refraction center 34 is set at a slightly inner high position from the projecting base portion from the lead frame 30, and the lead 32 is refracted substantially vertically upward with the refraction center 34 as a center to form a step lead portion 32c. The lead 32 is refracted in a substantially perpendicular inner direction to form a sealed lead portion 32a.
[0027]
As described above, since the lead 32 is refracted at a substantially right angle with the center of refraction 34 as the center, the bottom surface of the terminal portion 1 is curved into a substantially 1/4 arc shape, and the above-described curved bottom surface is processed without additional processing. 5 will be formed.
[0028]
FIG. 5 shows a semi-finished product in which a semiconductor chip 35 is mounted on the upper surface of the island 33 shown in FIG. 4 and each electrode pad of the semiconductor chip 35 and the inner end of the lead 32 are connected by a bonding wire 36.
[0029]
FIG. 6 shows a semi-finished product in which the semiconductor chip 35, the inner portion of the lead 32, the bonding wire 36, etc. of the semi-finished product shown in FIG. 5 are sealed with a sealing resin R having a substantially rectangular parallelepiped shape. The bottom surface R1 of R is set to be substantially the same height as the top surface of each lead 32, and the lead 32 outside the refraction center 34 so that the sealing resin side end surface R2 passes near the refraction center 34. The outer peripheral portion 31 of the lead frame 30 is exposed from the sealing resin R to the outside.
[0030]
7 shows that the exposed portion 37, that is, the outer peripheral portion 31 of the lead frame 30 and the lead 32 in the vicinity of the outer peripheral portion 31 are cut from the semi-finished product shown in FIG. 6 in the same plane as the sealing resin side end surface R2. The finished product of the resin-encapsulated semiconductor component A with the remaining lead 32 as the terminal portion 1 and the cut surface as the terminal portion side end surface 2 is shown.
[0031]
As described above, the outer peripheral part 31 and the exposed lead part 32b of the lead frame 30 are cut off in the same plane as the sealing resin side end face R2, so the cutting edge is simply aligned with a straight punch and die. This eliminates the need for a punch and die having a complicated shape as in the case of the resin-encapsulated semiconductor, and further eliminates the need for a tie bar cut for removing the resin protruding from the encapsulating resin R, thereby reducing the manufacturing cost. .
[0032]
Furthermore, since the terminal portion 1 is close to the sealing resin R, it is not easily affected by the deformation of the lead frame 30, and no lead shape intermediate inspection or lead reforming after the resin sealing process is required. Further, the cost can be reduced.
[0033]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0034]
According to the first aspect of the present invention, the chip and the lead connected to the chip are sealed with the sealing resin, the leading end portion of the lead is exposed to the outside of the sealing resin, and the exposed portion of the lead is sealed with the sealing resin. In a resin-encapsulated electronic component in which the exposed portion of the remaining lead is used as a terminal portion by cutting in a substantially vertical direction along the side end surface of the lead, the lead has an inner refracting portion and an outer refracting portion that are refracted substantially at right angles. And an exposed lead portion that is one step lower than the sealing lead portion, and the outer refractive portion is located near the side end face of the sealing resin. And forming the stepped lead portion by refracting the lead in a substantially right angle upward direction with the same refraction center as the center, and projecting the exposed lead portion downward from the bottom surface of the sealing resin, and resin sealing, It becomes flush with the side end face of the sealing resin. By cutting urchin the exposed lead portion, by which the resin sealed type electronic component, characterized in that the lower surface of the formed terminal portion for substantially 1/4 circular arc shape is curved Rutotomoni contact substrate circuit and the line, The outer end of the terminal portion does not protrude outward from the side end surface of the sealing resin, so that the resin-encapsulated electronic component can be miniaturized and the mounting density on a printed circuit board or the like can be increased.
[0035]
Further, there is no deformation of the terminal portion, the shape can be easily maintained and managed, and the packaging cost can be reduced.
[0036]
Also, when testing a resin-encapsulated electronic component, each terminal portion as a terminal can be accurately positioned on each probe upper surface of the tester by positioning using the end surface on the sealing resin side as a guide. Since the rigidity is high, simply pressing the sealing resin part in the direction of the probe can ensure that each terminal part and each probe are in contact with each other to improve the reliability of the test. Can be prevented.
[0037]
A terminal part whose refractive center is located in the vicinity of the outer peripheral edge of the bottom surface of the sealing resin is formed on the outer end portion of the lead, and the lower end portion of the terminal part projects downward from the bottom surface of the sealing resin. Since the exposed part is cut off in the same plane as the end face of the sealing resin side, it is only necessary to use a punch and die with a straight edge and a complicated shape like a conventional resin-sealed electronic component. A punch and a die are not required, and further, a tie bar cut for removing the resin protruding from the sealing resin is not required, and the manufacturing cost can be reduced.
[0038]
Furthermore, since the terminal part can be brought into line contact with the circuit board, there is no need to press the terminal part separately when soldering to the printed circuit board, and solder bridges between the leads generated using a pressing jig as a medium are prevented. When soldering, a curved bottom surface is formed at the lower end of the terminal portion, so that a substantially wedge-shaped gap with a round shape can be formed between the curved bottom surface and the top surface of the printed circuit board. In addition, it is possible to improve the soldering reliability because it is possible to improve the flow of the molten solder into the gap by causing a capillary phenomenon.
[Brief description of the drawings]
FIG. 1 is a perspective view of a resin-encapsulated electronic component according to the present invention.
FIG. 2 is a side view of a resin-sealed electronic component mounted on a printed board.
FIG. 3 is an explanatory diagram showing a test situation of a resin-encapsulated electronic component.
FIG. 4 is a side view of the lead frame.
FIG. 5 is a cross-sectional side view of a semi-finished product after wire bonding.
FIG. 6 is a cross-sectional side view of a semi-finished product after resin sealing.
FIG. 7 is a cross-sectional side view of a finished product.
[Explanation of symbols]
A Resin-sealed semiconductor (resin-sealed electronic components)
R Sealing resin 1 Terminal part
32 leads
33 Island
34 Center of refraction
35 Semiconductor chip

Claims (1)

The chip and the lead connected to the chip are sealed with a sealing resin, the leading end of the lead is exposed to the outside of the sealing resin, and the exposed part of the lead is substantially vertical along the side end surface of the sealing resin. In a resin-encapsulated electronic component that is cut in the direction and the exposed portion of the remaining lead is used as a terminal portion,
The lead is composed of a sealed lead portion, a stepped lead portion, and an exposed lead portion positioned one step lower than the sealed lead portion through an inner refracted portion and an outer refracted portion refracted substantially at right angles,
The outer refracting portion has its refracting center positioned in the vicinity of the side end surface of the sealing resin, and the lead is refracted in a substantially right angle upward direction with the refracting center as a center. The resin is sealed by protruding downward from the bottom surface of the sealing resin,
The exposed by cutting the lead portion so that the side end face of the sealing resin and the flush continuous, that it has formed a terminal portion which is substantially 1/4 is brought Rutotomoni contact board circuit and line curved in an arc shape lower surface A resin-sealed electronic component.

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