CN201812815U - Rectifier for preventing crystal grains from drifting - Google Patents

Abstract

The utility model discloses a rectifier for preventing crystal grains from drifting. A connecting piece, a lead frame and a diode crystal grain group are arranged inside an epoxy encapsulation body of the rectifier, wherein a welding area of the lead frame is connected with the diode crystal grains by soldering paste. The rectifier is characterized in that a groove is arranged on the upper surface of the welding area of the lead frame; the soldering paste is positioned in the groove and the periphery of the groove; and the diode crystal grains are positioned above the groove and are connected with the welding area of the lead frame by the soldering paste. The utility model can prevent the problem that the diode crystal grains drift when the soldering paste is in a fused state during the welding process.

Description

A rectifier against grain drift

technical field

The utility model relates to a rectifier, in particular to a rectifier for preventing grain drift. the

Background technique

The rectifier uses the unidirectional conductivity of the diode to rectify alternating current, so it is widely used in circuits that convert alternating current into direct current. The common structure of the welding area of the lead frame of the existing rectifier diode grain is a planar structure. Apply some solder paste to the welding area of the lead frame, and after placing the diode crystal, the solder paste is in a molten state during the soldering process in the furnace, and it is difficult to accurately control the positional deviation of the diode crystal after welding. Therefore, how to solve the problem of diode crystal grain drift in the existing solder paste welding process is the problem studied by the utility model. the

Contents of the invention

The utility model provides a rectifier for preventing crystal grain drift, and the rectifier can prevent the problem of crystal grain drift when the solder is molten during the welding process. the

In order to achieve the above purpose, the technical solution adopted by the utility model is: a rectifier for preventing crystal grain drift, the epoxy package of the rectifier is composed of connecting piece, lead frame, and diode crystal grain, the welding area of the lead frame and The diode crystal grains are connected by solder paste; the upper surface of the welding area of the lead frame is provided with a groove, the solder paste is located in the groove and around the groove, and the diode crystal grain is located in the groove above and connected to the solder pads of the lead frame through the solder paste. the

The relevant content in the above-mentioned technical scheme is explained as follows:

1. In the above solution, the groove is square or circular. the

Due to the use of the above-mentioned technical solutions, the utility model has the following advantages compared with the prior art:

The utility model relates to a rectifier for preventing crystal grain drift. There is a circular or square groove smaller than the grain size at the center of the grain welding area of the lead frame. During the soldering process in the furnace, the thickness of the solder paste in the groove is greater than that of the surrounding plane area. When the solder paste is in a high-temperature melting state, the bonding force of the chip by the liquid solder paste in the groove is greater than that of the surrounding area, so this structure can effectively reduce Chip drift, so that the position of the grain after welding tends to be closer to the center of the welding area. This structure has two other advantages at the same time. First, when the chip is placed slightly away from the center of the soldering area, the chip can be automatically aligned to the center due to the adhesive force of the solder paste in the groove; second, when the soldering area is coated with When the amount of solder paste is slightly more than the normal level, a certain amount of solder paste can be contained in the groove to avoid problems such as serious chip offset or chip short-circuit pollution due to excessive solder paste. the

Description of drawings

Accompanying drawing 1 is existing existing lead frame structure;

Accompanying drawing 2 is a front view of the utility model lead frame structure;

Accompanying drawing 3 is the side view of accompanying drawing 2;

Accompanying drawing 4 is the structure diagram of the utility model. the

In the above drawings: 1. Connecting piece; 2. Lead frame; 3. Diode grain; 4. Welding area; 5. Solder paste; 6. Current transmission end; 7. Groove. the

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

Embodiment: a kind of rectifier that prevents grain from drifting,

The interior of the epoxy package of the rectifier is mainly composed of a connecting piece 1, a lead frame 2, and a diode crystal grain 3. The welding area 4 at one end of the lead frame 2 is connected to the diode crystal grain 3 through solder paste 5. The lead wire The other end of the frame 2 is used as the current transmission end 6 of the rectifier; it is characterized in that: the upper surface of the welding area 4 of the lead frame 2 is provided with a groove 7, and the solder paste 5 is located in the groove 7 and the groove 7 , the diode crystal grain 3 is located above the groove 7 and connected to the welding area 4 of the lead frame 2 through the solder paste 5 . the

The groove 7 is square or circular. the

The center of the diode crystal 3 overlaps with the center of the groove 7 in the horizontal direction of the diode crystal 3 . the

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present utility model, and its purpose is to enable those familiar with this technology to understand the content of the present utility model and implement it accordingly, and not to limit the protection scope of the present utility model. All equivalent changes or modifications made according to the spirit of the utility model shall fall within the protection scope of the utility model. the

Claims (2)

1. A rectifier for preventing grain drift, the inside of the epoxy package of the rectifier is mainly composed of a connecting piece (1), a lead frame (2), and a diode crystal grain (3), the welding of one end of the lead frame (2) The region (4) is connected to the diode crystal grain (3) through solder paste (5), and the other end of the lead frame (2) is used as the current transmission end (6) of the rectifier; it is characterized in that: A groove (7) is provided on the upper surface of the welding area (4) of the lead frame (2), the solder paste (5) is located in the groove (7) and around the groove (7), and the diode crystal grain ( 3) Located above the groove (7) and connected to the welding area (4) of the lead frame (2) through the solder paste (5). 2. The rectifier according to claim 1, characterized in that: the groove (7) is square or circular. the

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