CN203205400U - Air-tight metal case for surface mounting - Google Patents

Abstract

An air-tight metal case for surface mounting is a device for chip metal packaging, and solves the problem that lead wires of plug-in metal case in the prior art are relatively long, so that insulators are liable to crack and the air tightness is lost, and that insulators in the prior art are poor in air tightness. The metal case comprises a tube socket, insulators, lead wires, and a tube cap. The tube socket is used to mount a chip; the upper ends of the lead wires are connected to the chip by wires; the tube cap is in air-tight sealed connection with the tube socket; the insulators are hollow cylinders with annular skirts at the lower ends; the upper ends of the insulators are located in through holes of the tube socket; the annular skirts at the lower ends seal the gaps between the upper ends of the insulators and the through holes air-tightly; the lead wires pass through the insulators and are attached to the insulators tightly; and the parts of lead wires that extend out of the lower ends of the insulators are totally covered with solder balls. The metal case has relatively short lead wires and is welded onto a PCB through surface mounting, so that the gaps between the insulators and the tube socket are sealed perfectly, and thus the metal case is suitable for occasions with harsh environments.

Description

A kind of surface mount air-tightness metal shell

Technical field

The utility model belongs to chip metallic packaging device, particularly a kind of surface mount air-tightness metal shell.

Background technology

Metallic packaging is to adopt metal as housing or base, chip directly or by substrate is installed on shell or the base, lead-out wire passes a kind of Electronic Packaging form that metal shell or base adopt Technique of glass-to-metal seals mostly, it is widely used in the encapsulation of hybrid circuit, it mainly is special-purpose level Hermetic Package military and customization, in a lot of fields, especially be widely used in military affairs and aerospace field.Metallic packaging is various informative, processing is flexible, can combine together with some parts (as mixing integrated A/D converter or D/A converter), be suitable for the single-chip of low I/O number and the purposes of multi-chip, also be suitable for radio frequency, microwave, photoelectricity, surface acoustic wave and high power device, can satisfy the requirement of small lot, high reliability.Metal shell is as one of key component of integrated circuit; not only play a part to lay, fix, seal, protect chip and strengthen electric heating property; but also be the bridge of linking up chip internal and external circuit; contact on the chip is wired on the lead-out wire of package casing, and these lead-out wires connect by the wire on the printed panel and other devices again.Therefore encapsulation is one of important component part of device, plays very important effect.

As shown in Figure 1, existing plug-in metal shell, comprise base 4, insulator 3, lead-out wire 5, pipe cap 6, have through hole on the base 4, through hole is embedded with insulator 3, lead-out wire 5 passes insulator 3 and fits tightly with it, base 4 is used for laying chip 7, the lead-out wire upper end is used for connecting by wire 8 pin of chip 7, pipe cap 6 is used for and described base 4 Leakless sealings, and its lead-out wire 5 is longer, is inserted into by lead-out wire in the jack of printed circuit board (PCB) 1, form soldered ball 2 in the bottom surface of printed circuit board (PCB) 1 again, to be connected whole packaging with chip together with metal shell and be connected with circuit on the printed circuit board (PCB), the lead-out wire bending can not surpass 3 times, otherwise easily causes insulator to crack even rupture, thereby air-tightness lost efficacy, and this has affected the plug-in mounting of packaging.

Air-tightness is the great difficult problem in metallic packaging and even Electronic Packaging field, therefore, can be used for harsh rugged environment in order to make metallic packaging, and air-tightness is good, and reliability is high, proposes a kind of new metal shell structure and is significant.

Summary of the invention

Above defective or Improvement requirement for prior art, the utility model provides a kind of surface mount air-tightness metal shell, solve existing plug-in metal shell lead-out wire longer, lost efficacy thereby easily cause insulator to crack air-tightness, and the relatively poor problem of insulator air-tightness.

A kind of surface mount air-tightness metal shell provided by the utility model, comprise base, insulator, lead-out wire, pipe cap, have through hole on the described base, through hole is embedded with insulator, lead-out wire passes insulator and fits tightly with it, and described base is used for laying chip, and described lead-out wire upper end is used for the pin by the conductor connecting core sheet, described pipe cap is used for and described base Leakless sealing, it is characterized in that:

Described insulator is the hollow cylinder that the lower end has annular shirt rim, its cross section is inverted T-shape, when insulator was embedded in the through hole of described base, the insulator upper end was positioned at described through hole, and insulator lower end annular shirt rim is with the hole air-tightness sealing between insulator upper end and the described through hole;

The part integral body that described lead-out wire exposes the insulator lower end is implanted with soldered ball.

Described surface mount air-tightness metal shell is characterized in that:

A plurality of insulators lower end annular shirt rim is interconnected as integral body.

Preparation technology of the present utility model comprises the steps:

(1) processes pipe cap stand-by, adopt impact style to process through hole at base;

(2) powder with the insulator material forms the insulator dry body;

(3) lead-out wire is sleeved on the insulator dry body, again the insulator dry body is sleeved in the through hole of base, carry out sintering;

(4) re-plating layer of gold behind base surface and lead-out wire upper and lower side electroplating surface one deck nickel;

(5) the part integral body of exposing the insulator lower end at lead-out wire is planted soldered ball.

When adopting the utility model to consist of packaging, first with on the chip mount base, the pin of chip is by wire connection of being connected with lead-out wire, again with pipe cap and base Leakless sealing.

When packaging is connected with printed circuit board (PCB), only needs soldered ball with Can be welded on the pcb board by the surface mount mode and get final product.

Soldered ball is planted in lead-out wire of the present utility model lower end, and pcb board adopts the surface mount mode to weld, and lead-out wire is shorter, can avoid the lead-out wire bending, the insulator cross section is inverted T-shape, and the hole air-tightness between insulator and the base through hole is sealed, air-tightness is fine, thereby improves package reliability; Be applicable to the harsh abominable occasion of environment, can be widely used in military affairs and aerospace field.

Description of drawings

Fig. 1 is the schematic cross-section of existing plug-in metal shell;

Fig. 2 is the schematic cross-section of the utility model embodiment;

Fig. 3 (a) is insulator schematic cross-section disconnected from each other;

The insulator schematic cross-section of Fig. 3 (b) for being interconnected;

Fig. 4 is assembling schematic diagram of the present utility model.

Mark among the figure: pcb board 1, soldered ball 2, insulator 3, base 4, lead-out wire 5, pipe cap 6, chip 7, wire 8.

Embodiment

Below in conjunction with drawings and Examples the utility model is further specified:

As shown in Figure 2, a kind of embodiment of the present utility model, comprise base 4, insulator 3, lead-out wire 5, pipe cap 6, have through hole on the described base 4, through hole is embedded with insulator 3, and lead-out wire 5 passes insulator 3 and fits tightly with it, and described base 4 is used for laying chip, described lead-out wire upper end is used for the pin by the conductor connecting core sheet, and described pipe cap 6 is used for and described base 4 Leakless sealings;

Shown in Fig. 3 (a), insulator is the hollow cylinder that the lower end has annular shirt rim, and its cross section is inverted T-shape; When insulator was embedded in the through hole of described base 4, the insulator upper end was positioned at described through hole, and insulator lower end annular shirt rim is with the hole air-tightness sealing between insulator upper end and the described through hole;

The part integral body that described lead-out wire exposes the insulator lower end is implanted with soldered ball.

Another kind of embodiment of the present utility model, and the difference of last embodiment is: a plurality of insulators lower end annular shirt rim is interconnected as integral body, shown in Fig. 3 (b), can further increase air-tightness.

Among above-mentioned two embodiment:

The material of base 4 is generally selected kovar alloy, first-selected teleoseal or iron-nickel alloy;

Material selection teleoseal or the iron-nickel alloy of lead-out wire 5;

Insulator 3 is selected the coefficient of expansion and the base 4 of its direct sintering and the insulating material that lead-out wire 5 is complementary, such as molybdenum group glass, silicon boron glass;

Lead-out wire 5 soldered balls that plant the lower end 2 are selected the metals such as copper, silver, tin, or the alloy such as slicker solder, tin lead bronze, silver-bearing copper, gold, silver and bronze, copper tin.

As shown in Figure 4, the packaging that adopts the utility model to consist of is laid chip 7 on the base 4, and the pin of chip 7 is connected the upper end by wire 8 and is connected with lead-out wire; Pipe cap 6 and base 4 Leakless sealings; When packaging was connected with printed circuit board (PCB), the soldered ball of Can was welded on the pcb board 1 by the surface mount mode.

Claims (2)

1. surface mount air-tightness metal shell, comprise base, insulator, lead-out wire, pipe cap, have through hole on the described base, through hole is embedded with insulator, lead-out wire passes insulator and fits tightly with it, and described base is used for laying chip, and described lead-out wire upper end is used for the pin by the conductor connecting core sheet, described pipe cap is used for and described base Leakless sealing, it is characterized in that:

Described insulator is the hollow cylinder that the lower end has annular shirt rim, its cross section is inverted T-shape, when insulator was embedded in the through hole of described base, the insulator upper end was positioned at described through hole, and insulator lower end annular shirt rim is with the hole air-tightness sealing between insulator upper end and the described through hole;

The part integral body that described lead-out wire exposes the insulator lower end is implanted with soldered ball.

2. surface mount as claimed in claim 1 air-tightness metal shell is characterized in that:

A plurality of insulators lower end annular shirt rim is interconnected as integral body.

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