Ceramic shell with low lead resistance

Abstract

The utility model relates to an electronic packaging accessory, in particular to a ceramic shell with low lead resistance, which comprises a ceramic base body, an inner cavity is arranged on the ceramic base body, a through hole is arranged on the wall of the inner cavity, a pole plate covering the opening of the through hole is arranged on the wall of the inner cavity, and the lead resistance of the pole plate is lower than that of the through hole. A conductive hanging hole pattern layer is arranged on the side wall of the through hole, a copper column is inserted into the through hole, one end of the copper column is flush with the end, away from the inner cavity, of the through hole, the end is connected with a lead, the other end of the copper column is located in the through hole, and a gap is formed between the other end of the copper column and the polar plate; a gap is formed between the copper column and the side wall of the through hole, and the gap and the gap are filled with metal solder. The ceramic shell provided by the utility model is simple to assemble, the saturation degree of the filler in the through hole is high, the requirement on the aperture of the through hole is low, the production operation difficulty is low, the product percent of pass is high, and the performance is stable.

Description

Technical Field

[0001] The utility model relates to an electronic packaging accessory, in particular to a ceramic shell with low lead resistance. Background Art

[0002] Ceramic shell, also known as ceramic package shell, is a component used in electronic packaging. It is an enclosure that carries semiconductor chips, various components, and modules or components integrated with the two. It has the advantages of corrosion resistance and chemical stability. As one of the key components of integrated circuits, the ceramic shell plays a role in mechanical support, environmental protection and sealing for the internal chip, realizes the connection between the internal chip and electrical and optical signals, provides heat dissipation path and electromagnetic radiation shielding for the chip, and provides chemical protection for the internal chip.

[0003] With the continuous improvement of technical indicators, the electrical connection resistance of traditional packaging shells can no longer meet the needs. For some products with relatively high requirements, on the basis of ensuring the small integration of products, it is also necessary to achieve lower lead resistance to meet good conductive performance. Figure 1 As shown, in the existing ceramic housing, the lead 11 located on the outside of the ceramic substrate 10 is usually electrically connected to the electrode 13 located in the inner cavity of the ceramic substrate 10 by means of the metallized filling slurry 12 filled in the through hole of the ceramic substrate 10. When filling the metallized filling slurry 12, due to the influence of factors such as bubbling or condensation shrinkage, it is easy to cause gaps in the metallized filling slurry, which is difficult to fill, resulting in the lead resistance not meeting the standard. The process requirements for the control of the filling amount and the aperture size of the through hole are relatively high, the production operation is difficult, the product qualification rate is low and the performance is unstable.

[0004] In view of this, the applicant conducted an in-depth study on the structure of the ceramic shell, which resulted in this case. Utility Model Content

[0005] The utility model aims to provide a ceramic housing with low lead resistance, low production operation difficulty, high product qualification rate and stable performance.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A ceramic shell with low lead resistance comprises a ceramic substrate, an inner cavity is formed on the ceramic substrate, a through hole is formed on the cavity wall of the inner cavity, a plate covering the mouth of the through hole is provided on the cavity wall of the inner cavity, a conductive hanging hole pattern layer is provided on the side wall of the through hole, a copper column is inserted into the through hole, one end of the copper column is arranged flush with an end of the through hole away from the inner cavity and the end is connected to a lead, the other end of the copper column is located in the through hole and a gap is formed between the copper column and the electrode plate, a gap is formed between the copper column and the side wall of the through hole, and the gap and the gap are filled with metal solder.

[0008] As an improvement of the utility model, a frame is welded on one side of the ceramic substrate.

[0009] As an improvement of the utility model, the frame is a frame made of kovar material, the lead is a lead made of kovar material, the ceramic substrate is an alumina ceramic substrate, the hanging hole pattern layer is a tungsten slurry metallization slurry layer, the copper column is an oxygen-free copper column, and the metal solder is a brazing material.

[0010] As an improvement of the present invention, the diameter of the through hole is greater than 0.3 mm.

[0011] As an improvement of the present invention, the diameter of the copper column is 0.05 mm-0.1 mm smaller than the diameter of the through hole, and the interval distance is 5%-20% of the hole depth of the through hole.

[0012] By adopting the above scheme, the utility model has the following beneficial effects:

[0013] By setting a conductive hanging hole pattern layer on the side wall of the through hole, inserting a copper column in the through hole, and then filling the through hole with metal solder, the electrical connection between the lead and the plate is achieved. The assembly is simple, the filling saturation in the through hole is high, the aperture requirement of the through hole is low, the production operation difficulty is low, the product qualification rate is high and the performance is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an existing ceramic shell;

[0015] Figure 2 It is a structural schematic diagram of the ceramic housing of the utility model;

[0016] Figure 3 This is a schematic diagram of the exploded structure of the ceramic housing of the present invention, in which the metal solder is omitted.

[0017] The markings in the figure correspond to the following:

[0018] 10-ceramic substrate; 11-lead;

[0019] 12-metallization filling slurry; 13-polar plate;

[0020] 14-inner cavity; 15-conductive hanging hole pattern layer;

[0021] 20-copper column; 30-frame;

[0022] 40-Metal solder. DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] like Figure 2-Figure 3 As shown, this embodiment provides a ceramic housing with low lead resistance, including a ceramic substrate 10. The ceramic substrate 10 is an alumina ceramic substrate with a multilayer structure, which mainly serves as a carrier, support, and insulation. It is provided with an inner cavity 14 for placing semiconductor chips, various components, and an encapsulation of a module or component integrated with the two. The cavity wall of the inner cavity 14 is provided with through holes. The number of through holes can be set according to actual needs. The specific size (diameter or depth, etc.) of each through hole may be different, but the structure is the same. For the convenience of description, one of the through holes is used as an example for description below. It should be noted that the low lead resistance mentioned in this embodiment refers to the lead resistance with a relatively high resistance value relative to the existing one, and does not refer to a specific resistance value.

[0025] The cavity wall of the inner cavity 14 is provided with a pole plate 13 covering the mouth of the through hole and arranged flush with the corresponding mouth. There can be multiple pole plates 13, but usually each through hole is arranged corresponding to only one pole plate 13, that is, one pole plate 13 can cover only one through hole or multiple through holes.

[0026] The aperture (diameter) of the through hole is larger than that of the through hole of the traditional ceramic shell, and its aperture is usually larger than 0.3 mm, preferably 0.5 mm-1 mm. A conductive hanging hole pattern layer 15 is provided on the side wall of the through hole to ensure the conductivity of the through hole itself. The conductive hanging hole pattern layer 15 is a tungsten slurry metallization slurry layer. Since the tungsten slurry metallization slurry has good fluidity, good bonding and low resistance, it can form a conductive hanging hole pattern layer 15 uniformly adhered to the side wall of the through hole after co-firing with the ceramic. The through hole is interspersed with a copper column 20, which is preferably an oxygen-free copper column with good conductivity and high solderability. One end of the copper column 20 is arranged flush with the end of the through hole away from the inner cavity and is connected to a lead 11. The lead 11 is a lead made of a varable material and has a good brazing effect with ceramics. The other end of the copper column 20 is located in the through hole and is spaced from the electrode 13. The distance of the space is 5%-20% of the depth of the through hole, that is, the length of the copper column 20 is 80%-95% of the depth of the through hole. The copper column 20 and the through hole are A gap is formed between the side walls, and the gap and the above-mentioned interval can be used as an assembly gap, which helps to reduce the difficulty of assembly and facilitate production operations. In addition, the above-mentioned interval and gap are filled with metal solder 40. Preferably, the metal solder 40 is a brazing material, and the diameter of the copper column 20 is 0.05mm-0.1mm smaller than the diameter of the through hole. This helps to avoid the generation of gaps when filling the metal solder 40, improve the filling saturation, and allow the electrode 13, copper column 20 and lead 11 to be brazed to form an integral structure to achieve lower resistance requirements.

[0027] The ceramic housing provided in this embodiment is the same as the existing ceramic housing, and a frame 30 is also welded on one side of the ceramic base 10. The frame 30 is preferably a frame of a calender material, which plays the role of a cover plate package. Of course, a metallization pattern is also provided on the ceramic base 10, which is obtained by silk-screening and co-firing with tungsten slurry, and is located on the surface and inside of the ceramic base 10, mainly playing the role of brazing and conducting electricity. The specific setting method and structure of the metallization pattern are the same as those of the existing ceramic housing, which is not the focus of this embodiment and will not be described in detail here.

[0028] The present invention is described in detail above with reference to the accompanying drawings, but the embodiments of the present invention are not limited to the above embodiments. Those skilled in the art can make various equivalent substitutions for the present invention based on the prior art, which all belong to the protection scope of the present invention.

Claims

1. A ceramic housing with low lead resistance, comprising a ceramic substrate, wherein an inner cavity is formed on the ceramic substrate, and a through hole is formed on the wall of the inner cavity, wherein: The cavity wall of the inner cavity is provided with an electrode plate covering the mouth of the through hole, the side wall of the through hole is provided with a conductive hanging hole pattern layer, and a copper column is inserted in the through hole, one end of the copper column is arranged flush with the end of the through hole away from the inner cavity and the end is connected to a lead, the other end of the copper column is located in the through hole and a gap is formed between the electrode plate, a gap is formed between the copper column and the side wall of the through hole, and the gap and the gap are filled with metal solder.

2. The ceramic package with low lead resistance according to claim 1, characterized in that A frame is welded on one side of the ceramic substrate.

3. The ceramic package with low lead resistance according to claim 2, characterized in that The frame is a frame made of kovar material, the leads are leads made of kovar material, the ceramic substrate is an alumina ceramic substrate, the hanging hole pattern layer is a tungsten slurry metallization slurry layer, the copper column is an oxygen-free copper column, and the metal solder is a brazing material.

4. The ceramic package with low lead resistance according to claim 1, characterized in that The diameter of the through hole is greater than 0.3 mm.

5. The ceramic package with low lead resistance according to claim 1, characterized in that The diameter of the copper column is 0.05 mm-0.1 mm smaller than the diameter of the through hole, and the interval distance is 5%-20% of the hole depth of the through hole.

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