CN2591779Y - Leadless Semiconductor Components - Google Patents

Abstract

A leadless semiconductor component, comprising: a metal lead frame having a plurality of straight leads, with isolation gaps between adjacent leads and between opposite leads, and with concave portions formed on the bottom surfaces of the inner ends of the leads; a chip fixed on the inner side of the lead frame center and with its I/O contacts facing downwards, each I/O contact of the chip being electrically connected with the corresponding lead of the lead frame by metal wires; and a colloid which is formed and fixed on the lead frame and is arranged on the outer side of the chip, and is filled in the isolation gap and the concave part between the leads in the lead frame, the metal wire connected between the chip and the leads of the lead frame is sealed in the colloid, and the bottom surface of the outer side end of each lead of the lead frame is exposed outside. The utility model discloses can save mould expense, make portably and can reduce product thickness to have advantages such as frivolous short and small.

Description

Leadless Semiconductor Components

【Technical field】

The utility model relates to a leadless semiconductor assembly.

【Background technique】

Now common leadless semiconductor component package structure, as shown in Figure 3, it has a metal lead frame (40) that includes a plurality of pins (41), and each pin (41) inner end forms a raised shape upwards, Then the chip (50) is glued on the raised part of the inner side of the pin (41) in the center of the lead frame (40) by double-sided adhesive tape (52) with the I/O contact facing down, and gold wire ( 51) Connect each I/O contact point of the chip (50) to the inner end bottom surface of the pin (41) corresponding to the lead frame (40), and then form a colloid (60) on the outer side with a mold sealing to form a lead frame (40). A leadless semiconductor component exposed at the outer end of the pin (41).

In addition, because the chip of the non-lead semiconductor component disclosed above is completely sealed in the colloid, the high temperature generated during the operation of the chip is difficult to dissipate. Therefore, someone made another double lead frame structure as shown in Figure 4. It mainly has a metal first lead frame (70) including a plurality of pins (71), the inner side of the pins (71) faces upwards to form a raised shape, and the chip (80) is placed downwards with the I/O contacts The pattern is glued on the inner side of the central pin (71) of the first lead frame (70) by double-sided adhesive tape (82), and is connected to each I/O contact of the chip (80) and the first lead frame (70) with a gold wire (81). At the bottom surface of the inner side of the pin (71) corresponding to the lead frame (70), a second lead frame (100) of a chip welding pad (101) is adhered on the chip (80) with silver glue or double-sided adhesive tape, and then placed on the chip (80) A colloid (90) is molded on the outer side to form a colloid (90) to form a chip pad (101) and a leadless semiconductor component with the outer end of the pin (71) exposed.

Although the conventional pinless semiconductor components disclosed above are straight, the exposed ends of the pins are straight, so as to reduce the overall thickness of the finished components, and can be directly mounted on the circuit board by flat soldering, and the semiconductor components shown in Figure 4 are even more With the design of the metal pad on the chip exposed outside the colloid, the high temperature generated by the chip in the module can be dissipated directly through the metal pad.

However, although the structure of the previously disclosed leadless semiconductor component has the characteristics of being thinner and shorter than the existing semiconductor component with bent and protruding pins, it still has the following disadvantages in its structure:

1. The mold cost of the lead frame is high: In order to provide accommodating space for the metal wires connected between the chip and the pins of the conventional two-lead semiconductor component, it is necessary to combine the mold to form the inner end of the lead frame pins by punching. A high-rise part requires an increase in mold expenses and processing costs.

2. The finished component is thicker: As mentioned above, the conventional two-lead semiconductor component is combined with a mold to form a raised part on the inner side of the lead frame pin by punching, so as to provide a connection between the chip and the metal wire between the pins. The accommodating space makes the overall thickness of the two semiconductor components relatively high.

【Content of utility model】

In view of this, in order to improve the disadvantages of the packaging structure of the previously disclosed leadless semiconductor assembly, the purpose of the utility model is to provide a non-leading semiconductor assembly that can save mold costs, is easy to manufacture, and can reduce product thickness. pin semiconductor components.

In order to achieve the purpose disclosed above, a leadless semiconductor component proposed by the utility model is characterized in that it includes:

A metal lead frame, which has a plurality of straight pins, there are isolation gaps between adjacent pins and opposite pins, and a concave portion is formed on the bottom surface of the inner end of each pin;

A chip is fixed on the inner side of the pins in the center of the lead frame with the I/O contacts facing down, and each I/O contact of the chip is electrically connected to the corresponding pins of the lead frame with metal wires; and

A colloid, which is formed and fixed on the lead frame to cover the outside of the chip, and fills the isolation gap and recess between the pins in the lead frame, and seals the metal wire connected between the chip and the lead frame pins inside , the bottom surface of the outer end of each pin of the lead frame is exposed outside.

The leadless semiconductor assembly of the present utility model can also have the following additional technical features:

The pins of the lead frame can be distributed on both sides in a corresponding shape.

The pins of the lead frame can also be distributed on four sides to form two corresponding shapes.

The height of the concave part arranged on the bottom surface of the pin of the lead frame is no more than half of the thickness of the lead frame.

The colloid can completely cover the chip inside.

The colloid can also be coated on the periphery and the bottom surface of the chip, and the upper surface of the chip is exposed outside.

The outer edge of the glue is flush with the outer edge of the lead frame pin.

The outer edge of the pin of the lead frame protrudes from the outer edge of the glue.

A layer of silver or nickel-palladium-gold alloy can be plated on the recess of the lead frame.

After the foregoing description, and compared with the conventional two leadless semiconductor components, it can be known that the features of the present invention include at least:

1. It can save the cost of the mold for manufacturing the lead frame: the lead frame of the utility model can be directly manufactured and formed by etching, and there is no need to use the mold to punch out the high rise on the inner side of the pin after etching or punching the prototype lead frame The cumbersome procedures of the department can save the cost of molds for manufacturing lead frames.

2. The thickness of the product can be reduced to achieve the purpose of lightness, thinness and shortness: the semiconductor component of this utility model uses the concave part formed by half-etching the inner side of the straight pin of the lead frame to directly provide accommodating space for connecting the metal wire between the chip and the pin. There is no need to use the accommodating space provided by bending the inner end of the lead frame pin into a raised shape, so the thickness of the component can be reduced, and the thinnest and shortest shape is presented.

3. High heat dissipation: the semiconductor component of this utility model occupies most of the exposed area of the bottom surface of the component because of its straight metal pins, and the chip is directly fixed on the pin, and the back of the chip of the component can be exposed Therefore, the heat generated when the chip is working can be directly conducted to the outside through the pins or the back of the chip, so it has an excellent heat dissipation effect.

4. Can reduce signal transmission delay phenomenon: the electrical connection of the semiconductor component of the utility model is directly derived from the straight pins of the lead frame, and its signal transmission path is shorter than that of the zigzag pins in the conventional semiconductor component, so it can Reduce signal transmission delay phenomenon.

In order to further understand the structural features and other purposes of the present utility model, the drawings are attached in detail as follows:

【Description of drawings】

Fig. 1 is a schematic plan view of an embodiment of the utility model.

Fig. 2 is a schematic plan view of another embodiment of the utility model.

FIG. 3 is a schematic plan view of the first conventional leadless semiconductor component.

FIG. 4 is a schematic plan view of a second conventional leadless semiconductor component.

【Detailed ways】

Concrete embodiments of the leadless semiconductor assembly of the present invention, as shown in Figures 1 and 2, include:

A metal lead frame (10), which has a plurality of straight pins (11), the pins (11) of the lead frame (10) can be distributed on two opposite sides or around the periphery, etc. There is an isolation gap (12) between adjacent pins (11) and between opposite pins (11), and a recess (13) is formed on the bottom surface of the inner side of each pin (11) by half etching, and the recess (13) The height is best no more than one half of the thickness of the lead frame (10);

A chip (20) is fixed on the inner side of the pin (11) at the center of the lead frame (10) by means of a double-sided adhesive tape (22) with the I/O contacts facing down, and the chip (20) I/O The O contact is facing the isolation gap (12) between the opposite pins (11) of the lead frame (10), and is connected to each I/O contact of the chip (20) and the corresponding lead of the lead frame (10) with a metal wire (21). An electrical connection is formed between the pins (11); and

A colloid (30), which is molded and fixed on the lead frame (10) and coated on the outside of the chip (20), and fills the isolation gap (12) between the pins (11) in the lead frame (10) and in the recess (13), so that the metal wire (21) connected between the chip (20) and the pin of the lead frame (10) is sealed inside, and the bottom surface of the outer end of each pin (11) of the lead frame (10) exposed outside to form a package structure of a leadless semiconductor component.

Aforesaid colloid (30) can allow chip (20) upper surface to be exposed outside as shown in Figure 1, to facilitate heat dissipation, or as shown in Figure 2, chip (20) can be fully coated in the inside; again colloid (30) The outer edge can be flush with the outer edge of the lead frame (10) pin (11), or the outer end of the lead frame (10) pin (11) protrudes slightly on the outer edge of the colloid (30); ) is plated with a layer of silver or nickel-palladium-gold alloy at the recess (13) for the metal wire (21) to be connected to the pin (11).

The semiconductor component can be assembled on a circuit board in combination with other electronic components, and its straight pins can be directly soldered on the circuit board to form an electrical connection, so as to provide its specific working performance, and It can present its light, thin and small shape; in addition, the semiconductor component can be exposed through the exposed end of the lead frame, so that the function or open circuit/short circuit can be detected directly through the exposed end of the pin.

Claims (10)

1, a kind of pin-free semi-conductor component, it is characterized in that: it comprises:

One conductive metal frames, it has the pin of most flat, has external series gap between pin between its adjacent leads and relatively, and each pin medial extremity bottom surface forms recess;

One chip is to be fixedly arranged on the pin medial extremity of lead frame central authorities and to make the I/O contact down, constitutes with metal wire between each I/O contact of this chip pin corresponding with lead frame to electrically connect; And

Colloid, be that moulding is fixedly arranged on and covers on the lead frame in the chip outside, and filling is in this lead frame in the external series gap and recess between pin, will be connected in metal wire between chip and lead frame pin is sealed in, outside each pin outboard end bottom surface of lead frame is revealed in.

2, pin-free semi-conductor component as claimed in claim 1 is characterized in that: the pin of this lead frame is corresponding shape for being distributed in both sides.

3, pin-free semi-conductor component as claimed in claim 1 is characterized in that: the pin of this lead frame is two corresponding shapes for being distributed in four limits.

4, pin-free semi-conductor component as claimed in claim 1 is characterized in that: the height of being located at the recess of lead frame pin bottom surface is no more than 1/2nd of lead frame thickness.

5, pin-free semi-conductor component as claimed in claim 1 is characterized in that: in this colloid is coated on chip fully.

6, pin-free semi-conductor component as claimed in claim 1 is characterized in that: this colloid is coated on chip periphery and bottom surface, and allows outside chip upper surface is revealed in.

7, pin-free semi-conductor component as claimed in claim 1 is characterized in that: this colloid outer rim is concordant with lead frame pin external end edge.

8, pin-free semi-conductor component as claimed in claim 1 is characterized in that: this lead frame pin external end edge convexedly stretches in the colloid outer rim.

9, pin-free semi-conductor component as claimed in claim 1 is characterized in that: one deck silver is established in the recess place plating of this lead frame.

10, pin-free semi-conductor component as claimed in claim 1 is characterized in that: the alloy of one deck nickel-palladium-Jin is established in the recess place plating of this lead frame.

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