CN107731775A - Suitable for the row lead frame of TO251 types eight of continuous filling technique - Google Patents

Abstract

The invention discloses a TO251 eight-row lead frame suitable for continuous filling technology, which includes a lead frame body, and a plurality of packaging units connected in an array are respectively arranged in the lead frame body, and each packaging unit includes a The heat sink inserting frame of the product and the product lead inserting frame, the heat sink inserting frames of the two laterally adjacent packaging units are connected by connecting ribs, and the connecting ribs are provided with product heat sink cutouts. The product pin insertion frame is respectively provided with product pin cutouts; a flow channel unit is formed between every two rows of packaging units, and the upper and lower ends of the lead frame body are respectively provided with positioning holes on the upper and lower sides of each flow channel unit Each runner unit includes a main gate arranged at the lower end of the lead frame body and a sub-gate connected between the heat sink inserting frames of two longitudinally adjacent packaging units. The present invention cooperates with MGP mode or AUTO mode to produce, and is easy to use.

Description

Eight-row lead frame TO251 for continuous fill technology

technical field

The invention relates to the field of TO251 lead frames, in particular to a TO251 eight-row lead frame suitable for continuous filling technology.

Background technique

TO251 is a SMD package of power transistors and voltage regulator chips. It is a widely used electronic component in the market. Signs of more and more vigorous, but limited by the shape of the integrated circuit chip and TO251 product package, the carrier of the chip, that is, the structure of the lead frame has not changed much over the years. The most widely used structure on the market is four rows of special-shaped structure, each lead frame can package 112 products, the packaging form is the traditional central extrusion epoxy resin, the packaging part is supplied through the runner and the gate, and cured and formed, due to the thickness of the lead frame of this structure is relatively small Due to the thickness limit, when degate (gate opening) after packaging, the bonding force between the runner and the lead frame is large, resulting in deformation of the lead frame, large gate residue, and serious delamination. At the same time, due to the use of runners In the feeding structure, about 40% of the epoxy resin is wasted on the flow channel, which increases the cost of a single product. In addition, the two ends of the lead frame of the four-row structure are open, and there are few interconnected parts in the middle. After the chip is placed, the stress release in the length direction of the lead frame is uneven, which causes the entire lead frame to deform, and when it is packaged on the mold, there will be problems such as poor positioning and beading, and may even crush the mold.

Contents of the invention

The purpose of the present invention is to provide a TO251 type eight-row lead frame suitable for continuous filling technology to improve the production efficiency of TO251 products, reduce product costs, and reduce product defect rates.

Technical scheme of the present invention is as follows:

A TO251 eight-row lead frame suitable for continuous filling technology, including a lead frame body, characterized in that: a plurality of packaging units connected in an array are respectively arranged in the lead frame body, and each packaging unit is separately It includes a product heat sink insertion frame and a product pin insertion frame. The heat sink insertion frames of two laterally adjacent packaging units are connected by connecting ribs. The connecting ribs are provided with product heat sink cutouts. Each package The product pin insertion frame of the unit is respectively provided with product pin cutouts; a flow channel unit is formed between every two rows of packaging units, and the upper and lower ends of the lead frame body are respectively above and below each flow channel unit. Positioning holes are provided, and each flow channel unit includes a main gate arranged at the lower end of the lead frame body and a sub-gate connected between the heat sink inserting frames of two longitudinally adjacent packaging units.

The TO251 type eight-row lead frame suitable for continuous filling technology is characterized in that: the material of the lead frame body is copper, and the size is 255mm*75mm*0.5mm.

The TO251 type eight-row lead frame suitable for continuous filling technology is characterized in that: the plurality of packaging units has eight rows and 20 columns with a total of 160 packaging units.

The TO251 eight-row lead frame suitable for continuous filling technology is characterized in that: there are 20 flow channel units, and the distance between two adjacent flow channel units is 25.5mm.

The TO251 eight-row lead frame suitable for continuous filling technology is characterized in that the longitudinal distance between two adjacent packaging units is 8.1mm.

The present invention can be used on MGP mode, also can be used on AUTO mode.

Beneficial effects of the present invention:

Compared with the existing TO251 lead frame, the present invention encapsulates 48 more products in a single lead frame, and greatly reduces the consumption of epoxy resin, and also reduces the deformation of the frame after welding, because the shape of the gate is rectangular , the position is between two adjacent products, the gate remains less after the gate is opened, and the plastic package body is not easy to be damaged, which improves production efficiency and yield while reducing production costs.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

FIG. 2 is a schematic structural diagram of a packaging unit in the present invention.

Fig. 3 is a schematic structural view of the flow channel unit in the present invention.

FIG. 4 is an enlarged schematic diagram of a partial structure of FIG. 3 .

detailed description

Referring to the accompanying drawings, a TO251 type eight-row lead frame suitable for continuous filling technology includes a lead frame body 1, and a plurality of packaging units 2 connected in an array are respectively arranged in the lead frame body 1, and each packaging unit Respectively include a product heat sink insertion frame 2-1 and a product pin insertion frame 2-2, the heat sink insertion frames of two laterally adjacent packaging units are connected by connecting ribs, and the connecting ribs are provided with product heat sinks. Segment cutouts 2-3, product pin cutouts 2-4 are respectively provided on the product pin insertion frame of each packaging unit; a flow channel unit 3 is formed between every two rows of packaging units, and the lead frame body 1 The upper and lower ends are respectively provided with positioning holes 4 above and below each flow channel unit, and each flow channel unit includes a main gate 3-1 arranged at the lower end of the lead frame body 1 and two adjacent longitudinally connected The sub-gate 3-2 between the heat sink inserting frames of the packaging unit.

In the present invention, the material of the lead frame body 1 is copper, and the size is 255mm*75mm*0.5mm.

The plurality of packaging units 2 has 160 packaging units in eight rows and 20 columns.

There are 20 flow channel units 3, and the distance between two adjacent flow channel units is 25.5mm.

The vertical distance between two adjacent packaging units is 8.1mm.

The present invention will be further described below in conjunction with accompanying drawing:

Referring to Figures 1, 2, and 3, the size of the lead frame body 1 is 255mm*75mm*0.5mm, which is not only suitable for MGP packaging with a four-group mold box structure, but also suitable for AUTO mold packaging. There are 20 flow channel units 3 adjacent to each other. The distance between the two flow channel units is 25.5mm, and the multiple packaging units 2 have eight rows and 20 columns with a total of 160 packaging units. The longitudinal distance between two adjacent packaging units is 8.1mm, and the heat sink of the product is inserted. The thickness of the frame 2-1 is the same as that of the product pin insertion frame 2-2, which is 0.5mm. The number of pins that can be inserted into the product pin insertion frame 2-2 is 3, and the spacing and shape are reasonable. It can make reasonable use of copper and provide sufficient strength, which is convenient for mold design and processing.

See Figure 2. After packaging, the heat sink of the product can be cut off from the product heat sink cutout 2-3. Since the TO251 is a three-leg in-line type, no bending is required. Cut off at 2-4 places.

Referring to Figures 3 and 4, the lead frame of the present invention adopts the continuous filling and packaging technology. The epoxy resin is filled from the position of the main gate 3-1 along the direction of the arrow. After filling the first product, it passes through the sub-gate 3 -2 Fill the next product until all eight rows of products are filled.

To sum up, using the lead frame of the present invention and using the packaging method of MGP mold or AUTO mold, the continuous filling technology is used to fill the product, which saves the part of the main channel, and only needs the center supply and gate to complete the process. Filling reduces the flow length and pressure loss of the resin, greatly improves the utilization rate of the resin, and saves about 40% of the cost of epoxy resin. At the same time, each group of mold boxes produces 96 more products, which improves the production efficiency. Furthermore, the lead frame of the present invention has less welding stress and is not easily deformed.

Claims (5)

1. A TO251 type eight-row lead frame suitable for continuous filling technology, comprising a lead frame body, characterized in that: a plurality of packaging units connected in an array are respectively arranged in the lead frame body, and each package The units respectively include a product heat sink insertion frame and a product pin insertion frame. The heat sink insertion frames of two laterally adjacent packaging units are connected by connecting ribs. The product pin insertion frame of each packaging unit is respectively provided with product pin cutouts; a flow channel unit is formed between every two rows of packaging units, and the upper and lower ends of the lead frame body are on the upper and lower sides of each flow channel unit Positioning holes are respectively provided on each side, and each runner unit includes a main gate arranged at the lower end of the lead frame body and a sub-gate connected between the heat sink inserting frames of two longitudinally adjacent packaging units . 2. The TO251 eight-row lead frame suitable for continuous filling technology according to claim 1, characterized in that: the material of the lead frame body is copper, and the size is 255mm*75mm*0.5mm. 3. The TO251 type eight-row lead frame suitable for continuous filling technology according to claim 1, characterized in that: said plurality of packaging units have eight rows and 20 rows of a total of 160 packaging units. 4. The TO251 eight-row lead frame suitable for continuous filling technology according to claim 1-3, characterized in that: there are 20 flow channel units, and the distance between two adjacent flow channel units is 25.5 mm. 5. The TO251 eight-row lead frame suitable for continuous filling technology according to claim 1-3, characterized in that: the longitudinal distance between two adjacent packaging units is 8.1mm.