CN202042476U - Device packaging structure - Google Patents

Abstract

The utility model discloses a device packaging structure which comprises a packaging body and a wafer packaged in the packaging body, as well as a pair of leads, wherein the leads are connected with the wafer and extend out of the packaging body, the packaging body has a cylindrical structure, and the pair of leads is respectively led out from two bottoms of the cylindrical structure; the device packaging structure further comprises two metal shells which are respectively arranged at two ends of the packaging body correspondingly, and the metal shells are respectively and electrically connected with the lead at one corresponding end and are respectively and electrically insulated from the metal shell at the opposite end and the lead at the opposite end. The device packaging structure has a large effective radiating area, can not cause environment pollution during using process, and consumes fewer materials.

Description

Device Package Structure

technical field

The utility model relates to a device packaging structure, which belongs to the packaging structure of electronic devices used in circuit boards.

Background technique

In the development process of electronic devices, many packaging forms have been produced in response to the technical level and different objective needs of different periods. At present, electronic devices can be divided into plug-in, surface mount and other categories in terms of packaging form, but the common feature is that they are connected to the circuit board through the leads, the current is transmitted through the leads, and the metal material properties of the leads are used to enhance part of the heat dissipation capacity. The degree of enhanced heat dissipation depends on the heat conduction properties of the lead material, the heat capacity of the lead body and the heat dissipation area of the lead.

In terms of the connection method between the leads of electronic devices and the PCB board, welding is mainly used at present, which can be completed by wave soldering, reflow soldering, manual soldering and other methods. Because welding uses high-temperature solder, and the current high-temperature solder generally contains lead, which is not conducive to environmental protection. Moreover, the equipment needed for circuit board welding consumes a lot of power, which has a bad influence on the working environment. In addition, the PCB board needs to go through high temperature during the welding process, so welding will cause certain damage to the PCB board, especially in the case of disassembly, repeated disassembly and assembly will lead to permanent damage to the local copper skin of the PCB board and the whole The board is scrapped.

The heat dissipation of electronic devices mainly depends on three ways: the shell on the outer surface conducts to the environment, the lead wire conducts to the environment, and the lead wire conducts to the PCB board. The electronic components of the plug-in need to be cut and shaped before use, and limited by the heat dissipation requirements, there are minimum requirements for the length of the lead wires. These procedures and requirements not only increase the cost of semiconductor device users, but also increase the difficulty of use. At the same time, some lead wires that the user must cut off also cause a waste of resources. However, surface-mounted electronic devices do not require redundant processing procedures before users use them, but the structure is complex and difficult to produce, which indirectly increases the production cost of electronic devices, which also increases the user's use cost. The heat dissipation condition is poor. Surface mount devices often need to be bonded with red glue during the board mounting process, which is not conducive to environmental protection.

Although the general trend of the current packaging technology development is integration, miniaturization, and bare chip, for the most common circuit board processing, the currently used plug-in and surface mount packaging forms are still predictable. Mainstream for a while.

The main structures of currently existing plug-in and surface mount package electronic devices are shown in Figures 1, 2 and 3.

FIG. 1 shows a glass-encapsulated plug-in electronic device, which includes a chip 2 , two leads 1 and a glass case 3 . The glass-encapsulated semiconductor device is hermetically sealed. In order to keep the lead 1 in close contact with the glass case 3, the material of the glass case 3 is mixed with lead oxide, and the end of the lead is Dumet wire head 4 (composite material), which can ensure same expansion coefficient. The Dumet wire head 4 is in direct contact with the surface of the wafer 2 . A tin layer 5 is attached to the outer surface of the lead wire 1 outside the glass case 3, which is convenient for soldering.

FIG. 2 shows a resin-encapsulated plug-in electronic device, which includes a chip 2, two leads 1, two solder pieces 7 and a plastic package 6 that wraps them. The lead terminal 8 may be a mesa or a plane according to the size relationship between the chip 2 and the solder pad 7 . The lead wire terminal 8 and the chip 2 are connected as a whole by the welding piece 7 after being melted at high temperature, so as to ensure reliable transmission of electricity. The plastic package body 6 is wrapped on the outside and is mixed with quartz sand, which has high hardness and certain airtightness. It can not only protect the core of the electronic device - the chip 2 from external pollution and damage, but also endow the electronic device with a certain degree of protection. Shape and size, easy to produce, transport and use. The outer surface of the lead wire 1 outside the plastic package 6 is attached with a tin layer 5, which is convenient for soldering.

FIG. 3 shows a resin-encapsulated surface mount electronic device, which includes a chip 2, two solder pads 7, two lead frames 9 and a plastic package 6 covering them. The lead frame 9 is connected to the two sides of the chip 2 under the action of the soldering piece 7 inside the plastic package 6 . The lead frame 9 is flatly located under the plastic package 6 after the part outside the plastic package 6 is bent, and the outer surface is attached with a tin layer 5 , which is convenient for soldering.

These packaged electronic devices all need to be soldered in use. Among them, the two kinds of electronic devices shown in Figure 1 and Figure 2 also need to process the leads accordingly before the PCB board is soldered. If in order to reduce the installation volume, the tube body needs to be installed horizontally, and more lead wires need to be cut off, which will affect the heat dissipation performance of the electronic device.

Contents of the invention

Therefore, in order to overcome the structural characteristics of the current device packaging structure, which makes related devices have poor heat dissipation performance during use, pollute the environment and consume a lot of materials, the utility model provides a device that can effectively dissipate heat with a large area and will not pollute during use. A device package structure that is environmentally friendly and consumes less material.

According to the utility model, a packaging structure with a metal shell is provided to reduce or avoid some defects in device installation and use. Usually, for the packaging structure, a packaging method of this type of packaging structure is also provided.

Then, the device packaging structure according to one aspect of the present invention includes a package body, a chip packaged in the package body, and a pair of leads connecting the chip and extending out of the package body, the package body is a columnar structure, The leads are led out from the bottom surface of the columnar structure, one on each of the two bottoms; the device packaging structure also includes a metal shell respectively arranged at both ends of the package body, the metal shell is electrically connected to the lead wire at the corresponding end, and is connected to the different The metal shell on one side and the lead wires on different sides are electrically insulated.

To be precise, the utility model is aimed at a device with two pins, and the metal shell is used to replace the pins as electrodes, and its connection is no longer limited to welding, and other connection methods can be used for matching, such as card Connecting and plugging, because the metal shell has a relatively large connection area, it can ensure the reliability of other electrical connections other than welding, and the connection resistance is small, which can fully meet the connection needs of low-voltage drive devices.

Then, when soldering is avoided, a series of soldering problems can be avoided. For example, it will not increase pollution, and at the same time, the damage to the PCB board will be small, and it will not lead to the scrapping of the entire PCB board, especially the socket. Connecting, multiple plugging and plugging are allowed, not only will not damage the PCB board, but also a small number of unplugging and plugging will not affect the connection performance of the device.

The existence of the metal shell greatly increases the effective heat dissipation area, and the increase of the heat dissipation area can effectively improve the service life of the device.

Since the requirements of the package structure for the length of the pins are limited to the connection with the metal shell, without considering the connection with the PCB board, and because the packaging of the device is carried out through the mold, the consistency is good, so the length of the pins The fixed length can be selected according to the packaging characteristics of the metal shell. This length is much smaller than the length reserved for considering the needs of different fixed positions and connection objects on the PCB, which greatly reduces the amount of pin material used.

In the above-mentioned device packaging structure, the package body is a cylindrical structure, the metal shell is a blind sleeve mounted on the end of the cylindrical structure, and the corresponding side leads are welded to the bottom surface of the corresponding side blind sleeve.

In the above-mentioned device packaging structure, the metal shell is provided with a pit at the lead-out position, and the corresponding side lead is introduced into the pit, and the solder body connecting the lead and the metal shell is formed by filling the pit with solder, and then forms a flat blind Body end face.

In the above device package structure, the pit is an inner pit, and correspondingly, the bottom of the pit is provided with a hole for the corresponding side leads to pass through.

In the above device package structure, the part of the lead extending through the corresponding hole is completely accommodated in the cavity.

In the above device package structure, there is a filling gap between the lead and the hole.

In the above-mentioned device package structure, the end of the lead connected to the chip is preset with a lead end, so that the lead is contacted and connected to the surface of the chip.

In the above-mentioned device packaging structure, a welding piece for welding is provided between the lead terminal and the chip.

Description of drawings

FIG. 1 is a schematic diagram of a packaging structure of a common electronic device with a glass seal.

FIG. 2 is a schematic diagram of a package structure of a common plastic package plug-in electronic device.

FIG. 3 is a schematic diagram of a package structure of a common surface mount electronic device.

FIG. 4 is a schematic diagram of an outline structure of a device packaging structure according to the present invention.

FIG. 5 is a cross-sectional view of a device package structure according to an example of the present invention.

Fig. 6 is a usage mode of a device based on the packaging structure of the technical solution of the present invention.

Fig. 7 is a usage mode of a device based on the packaging structure of the technical solution of the utility model

In the figure: 1: lead wire; 2: chip; 3: glass shell; 4: Dumet wire head; 5: tin layer; 6: plastic package; 7: solder tab; 8: lead end; 9: lead frame; 10: metal shell; 11: solder; 12: slot base; 13: clamp base.

Detailed ways

According to the utility model, a device packaging structure includes a package body and a chip 2 packaged in the package body, and a pair of leads 1 connecting the chip 2 and extending out of the package body, the package body is cylindrical structure, the leads 1 are drawn from the bottom surface of the cylindrical structure, one on each bottom; the device package structure also includes a metal shell 10 respectively arranged at both ends of the package body, and the metal shell is electrically connected to the lead wire at the corresponding end, And it is electrically insulated from the metal shell on the different side and the lead wire on the different side.

As for the metal shell 10, it is nominally used for electrical connection, that is, the conversion of the connection is realized through the connection with the lead wire. At the same time, the metal can be related to the connection between itself and the package body, and can have a specific structure according to the specific connection form, for example, it includes a part extending into the package body, and the package is packaged together with this part. For a simpler structure, the structure shown in Figure 5 can be used, that is, the package body is a cylindrical structure or other cylindrical structure, and the metal shell 10 is a blind sleeve set at the end of the cylindrical structure, directly The socket is simple in structure, and the socket can be directly connected by interference fit without any other auxiliary materials, or by means of adhesion to ensure the reliability of the connection. Of course, after the socket is completed, There are radial protrusions on the blind sleeve to form a reliable connection.

The cylindrical structure has the characteristics of convenient production. Of course, other cylindrical structures can also be used. The sleeve is simply a cylinder. In order to facilitate connection, a bottom is added to the sleeve here to become a blind sleeve. Ground, the corresponding side leads 1 are welded on the bottom surface of the corresponding side blind socket body.

The chip 2 provides the electrical characteristics of the device, which is the core part. Of course, its package body can adopt the current common package, such as the plastic package body 6, which will not affect the existence of the metal shell.

For devices driven by weak voltage, especially conventional electronic devices, the driving voltage is very low, and it is necessary to ensure the reliability of its electrical connection. There is a pit, and the corresponding side lead is introduced into the pit, and the solder 11 is filled in the pit to form the solder body connecting the lead and the metal shell, and then forms a flat end face of the blind sleeve body. Based on this structure, it is ensured that the connection is sufficient. The connection area ensures the expression of electrical connection characteristics.

As for whether the pit is concave or concave, it does not have much influence on the characteristics of the electrical connection. It has a greater impact on the performance of the processing and shape. The concave can be processed, but it is relatively troublesome. At the same time, the protruding part will be It affects the appearance, and also affects the connection of the metal shell as an electrode. Therefore, a better choice is the concave form as shown in Fig. 5, correspondingly, the bottom of the pit is provided with a hole for the corresponding side leads to pass through, so as to ensure the smooth progress of welding.

Further, the part of the lead extending through the corresponding hole is completely accommodated in the cavity, so as to ensure the appearance of the packaging structure and facilitate the installation of the device.

Preferably, there is a filling gap between the lead wire and the hole, so that tin liquid will enter during soldering, thereby forming a more reliable connection.

The above mainly relates to the packaging structure itself. For the above-mentioned packaging structure, the following chip connection method can be selected. The end of the connection between the lead 1 and the chip 2 is preset with a lead terminal 8, so that the lead is connected to the chip surface. To ensure the reliability of the connection, in consideration of the same connection reliability, other structural parts of the package structure above the connection reliability can be used in conjunction with each other to ensure the overall service life and avoid local relatively early failures. Of course, this is the process above What needs to be considered will not be repeated here.

A welding piece 7 for welding is provided between the lead terminal 8 and the chip 2 , and the clamping of the metal shell 10 is realized by the elastic clamp, and the structure is simpler.

Then, based on the above-mentioned structure, the chip 2 provides the electrical characteristics of the device, and is connected to the lead terminal 8 through the solder piece 7 after melting, which is surface contact; Larger area connections. Wherein the chip 2 can be square, regular hexagonal or circular, the solder piece 7 is circular, the shape of the lead 1 can be a slender cylinder or a thin prism, and the lead end 8 can be a circular truncated shape, a round cake shape or a sheet shape. , the lead wire 1 is made of the same material as the lead wire terminal 8, which is oxygen-free copper. The shape of the plastic package 6 is a cylinder or a polygonal prism. The shape of the metal shell 10 is consistent with the shape of the plastic package 6. The material can be made of copper, iron and other materials that are easy to machine. Tin layer 5, in order to prevent oxidation and connect with leads.

Referring to accompanying drawing 6 of the specification, the upper part is a device based on the package structure of the present invention, and the lower part is a grooved base. The width of the groove needs to ensure that the metal shell 10 can be clamped. At the same time, in order to facilitate the picking and placing of the device, the clamping Part of the branch is used to clamp the metal shell, and other parts are open structures.

As for the use method shown in Figure 7 of the specification, it is a typical clip-type base. The clips are a pair of opposite elastic pieces, and the clamping part is set to match the curvature of the metal shell (the metal shell is cylindrical. structure), the same, to ensure the reliable contact of the clamping, in addition, it is enough to set a guide part at the buckle-in end, such as an inclined introduction part.

Further, for the above-mentioned device packaging structure, a packaging method of the device packaging structure includes the steps of assembling and welding the chip 2, the solder piece 7 and the two leads 1, so that the two leads extend in opposite directions, and then perform Packaged into a cylindrical structure, part of the lead wires exposed, this is a general processing method, then according to the utility model, it is characterized in that: the lead wire is a given length, packaged by a shaping mold, so as to control the pre-exposing of the lead wire when the package is formed The pre-exposed amount needs to start with the reliable connection with the metal shell, which is very easy for those skilled in the art to handle. The packaging method further includes the following steps:

Assembling the metal shell 10, the metal shell is a prefabricated bottom with a central hole blind sleeve structure, the two ends of the metal shell are respectively placed on the two ends of the cylindrical structure, and the lead wires are connected from the Corresponding side center hole pierces;

Welding, welding the metal shell to the lead wire on the corresponding side.

The bottom surface of the metal shell is pre-pressed with a pit, so as to lead the lead wire into the pit, and then perform the welding step, and in this welding step, it is necessary to ensure that the pit is completely filled, so that the end surface of the metal shell becomes a flat electrode Surface, to ensure the reliability of use and connection;

The metal shell includes a step of forming a tin layer 5 on the surface of the metal shell before the step of assembling the metal shell to facilitate connection.

Claims (8)

1. device encapsulation structure, comprise packaging body and be encapsulated in the interior wafer (2) of this packaging body, and connect this wafer (2) and extend a pair of lead-in wire (1) of described packaging body, it is characterized in that: described packaging body is a column construction, described lead-in wire (1) is drawn from the bottom surface of column construction, two ends each one; This device encapsulation structure also comprises relative set each metal shell (10) at the packaging body two ends, and this metal shell is electrically connected with the respective end lead-in wire, and with the electric insulation that goes between of heteropleural metal shell and phase heteropleural mutually.

2. device encapsulation structure according to claim 1, it is characterized in that: described packaging body is a cylindrical structural, described metal shell (10) is for being sleeved on the blind body of cylindrical structural end, and respective side lead-in wire (1) is welded on the bottom surface of the blind body of respective side.

3. device encapsulation structure according to claim 1 and 2, it is characterized in that: described metal shell is drawn the position at lead-in wire and is provided with pit, the respective side lead-in wire is introduced this pit, the scolding tin body that in pit, fill to form connects lead-in wire and metal shell by scolding tin (11), and and then form smooth blind body end face.

4. device encapsulation structure according to claim 3 is characterized in that: described pit is an inside recess, and correspondingly, pit bottom is provided with and is used for the hole that the respective side lead-in wire passes.

5. device encapsulation structure according to claim 4 is characterized in that: described lead-in wire passes corresponding described hole and extended part fits in the described pit fully.

6. device encapsulation structure according to claim 4 is characterized in that: leave between described lead-in wire and the described hole and fill the gap.

7. device encapsulation structure according to claim 1 is characterized in that: the end that described lead-in wire (1) is connected with described wafer (2) is preset with lead ends (8), so that lead-in wire is connected with the wafer face contact.

8. device encapsulation structure according to claim 7 is characterized in that: be provided with the weld tabs (7) that is used for melting welding between described lead ends (8) and described wafer (2).

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