阅读说明：本技术 一种陶瓷一体化封装外壳及其制作工艺 (Ceramic integrated packaging shell and manufacturing process thereof ) 是由 钟永辉 卢彩红 高磊 黄平 崔嵩 于 2020-04-16 设计创作，主要内容包括：本发明公开了一种陶瓷一体化封装外壳及其制作工艺,其由厚膜陶瓷基板和设于所述厚膜陶瓷基板表面的金属薄膜布线层构成,其特征在于,所述金属薄膜布线层由内至外依次为Ti/M/N/Ti/K/Au六层薄膜体系,其中,M层、K层分别独立的选自Pt或Ni,N层为应力释放层,所述应力释放层为Au或Cu。本发明中的陶瓷一体化封装外壳密封可靠性高,气密性好,且拓宽了厚薄膜混合多层陶瓷一体化封装外壳的生产工艺窗口,提高了生产合格率。(The invention discloses a ceramic integrated packaging shell and a manufacturing process thereof, wherein the ceramic integrated packaging shell is composed of a thick film ceramic substrate and a metal thin film wiring layer arranged on the surface of the thick film ceramic substrate, and is characterized in that the metal thin film wiring layer is a Ti/M/N/Ti/K/Au six-layer film system from inside to outside in sequence, wherein M and K layers are respectively and independently selected from Pt or Ni, N layer is a stress release layer, and the stress release layer is Au or Cu. The ceramic integrated packaging shell has high sealing reliability and good air tightness, widens the production process window of the thick-film mixed multilayer ceramic integrated packaging shell, and improves the production qualification rate.)

1. The utility model provides a pottery integration encapsulation shell, its includes thick film multilayer ceramic substrate, thick film multilayer ceramic substrate is by thick film ceramic substrate with locate the metal film wiring layer on thick film ceramic substrate surface constitutes, its characterized in that, metal film wiring layer from interior to exterior is six layers of film systems of Ti/M/N/Ti/K Au in proper order, and wherein, M layer, K layer are independent respectively to be selected from Pt or Ni, and the N layer is the stress release layer, the stress release layer is Au or Cu.

2. The ceramic all-in-one package housing as claimed in claim 1, further comprising a metal frame, wherein the metal frame is disposed on the thick-film multi-layer ceramic substrate, and a solder layer is disposed between the metal frame and the thick-film multi-layer ceramic substrate.

3. The ceramic integrated package shell according to claim 2, wherein the metal frame is made of one selected from the group consisting of 4J42, 4J33 and 4J29 fixed expansion alloys, and a nickel layer and a gold layer are sequentially disposed on the surface of the metal frame from inside to outside.

4. The ceramic integrated package shell of claim 3, wherein the thickness of the nickel layer is 1.27-8.9 μm and the thickness of the gold layer is 0.75-5.7 μm on the surface of the metal enclosure frame.

5. The ceramic all-in-one package housing of claim 1, wherein the thick film ceramic substrate is selected from one of an alumina ceramic substrate, an aluminum nitride ceramic substrate, and an L TCC substrate.

6. The ceramic all-in-one package housing of claim 1, wherein the stress relief layer is Au.

7. The ceramic integrated package shell according to claim 1, wherein in the metal thin film wiring layer, the film thickness of the Ti layer is 0.1-0.6 μ M, the film thickness of the M layer and the K layer is 1-3 μ M, and the film thickness of the N layer is 0.75-3 μ M.

8. A process for manufacturing a ceramic all-in-one package housing according to any one of claims 1 to 7, comprising the steps of:

preparing raw porcelain by pressing and tape casting, sintering or printing the raw porcelain into a thick film ceramic substrate with a built-in passive element, and grinding and polishing the surface of the thick film ceramic substrate;

sputtering the surface of the processed thick film ceramic substrate from inside to outside by adopting a magnetron sputtering method to manufacture a metal film wiring layer, and preparing a required metallized pattern on the metal film wiring layer to manufacture a thick film mixed multilayer ceramic substrate;

sequentially plating a nickel layer and a gold layer on the surface of the metal enclosure frame from inside to outside;

sequentially placing a gold-tin soldering lug and a metal surrounding frame on a metal thin film wiring layer of the thick-film mixed multilayer ceramic substrate to form an integrated packaging shell pre-assembly body;

and feeding the integrated packaging shell pre-assembly body into a brazing furnace, and brazing the integrated packaging shell pre-assembly body into a whole under a protective atmosphere.

9. The manufacturing process according to claim 8, wherein the brazing includes a preheating process, a heat-retaining process, and a temperature-reducing process in this order.

10. The manufacturing process according to claim 9, wherein the brazing process comprises the following specific steps: firstly, heating from normal temperature to 250-270 ℃ at the heating rate of 20-30 ℃/min, and then preserving heat for 5-10 min; then heating to 330 ℃ at the heating rate of 20-30 ℃/min, and preserving the heat for 2-10 min; and finally, cooling at the cooling rate of 10-20 ℃/min, and discharging to obtain the ceramic integrated packaging shell.

Technical Field

The invention belongs to the field of electronic packaging shells, and particularly relates to a ceramic integrated packaging shell and a manufacturing process thereof.

Background

Electronic package is a package for mounting a semiconductor integrated circuit chip, which on the one hand serves to mount, secure, seal, protect the chip and enhance the thermal conductivity, and on the other hand serves as a bridge between the chip's internal world and the external circuitry, and in particular, the contacts on the chip are connected by wires to the package's pins, which in turn are connected to other devices by wires on the printed circuit board. Therefore, the packaging technology of electronic package housings is a very critical part of many integrated circuit products.

In order to match the development trend of miniaturization, integration and high frequency of radio frequency components, the application of an integrated packaging shell which is formed by combining a thick-film mixed multilayer ceramic substrate and a metal enclosure frame and has a certain closed space is more and more extensive. The thick film ceramic substrate has the characteristics that multilayer wiring is easy, and interconnection can be realized in a three-dimensional direction, but the thick film ceramic substrate has the defects that microwave transmission loss is relatively large, and the line width and the line spacing are generally more than 50 micrometers; the metallization flatness of the thin film ceramic substrate is high, microwave transmission loss is low, the line width and the line spacing can be about 20 microns, high-density wiring is met, and the defect that thin film metallization can only be performed on the surface layer of the ceramic is overcome. The thick-film hybrid multilayer ceramic substrate combines the advantages of the thick-film hybrid multilayer ceramic substrate and the thick-film hybrid multilayer ceramic substrate, realizes multilayer wiring by using a thick-film process for an inner-layer circuit, and meets high-density wiring and lower microwave transmission loss by using a thin-film circuit for a surface-layer circuit, so that the thick-film hybrid multilayer ceramic substrate has wide application in the field of high-reliability packaging.

The prior art is generally used for manufacturing a thick-film mixed multilayer ceramic integrated packaging shell, a magnetron sputtering method is adopted for sequentially sputtering and manufacturing a Ti/Pt/Au film wiring layer or a Ti/Ni/Au film wiring layer from inside to outside on the surface of a ceramic substrate, then a metal surrounding frame ring frame is welded on the film metallization layer on the surface of the ceramic substrate along the periphery of gold tin or lead tin to form an integrated packaging shell structure, in the film system, the film Ti layer is a ceramic adhesion layer, the film Pt or Ni layer is a welding barrier layer and a brazing filler metal infiltration layer, and the film Au layer is used as an oxidation prevention layer to protect the Ti, Pt and Ni layers. However, the process also has certain problems, for example, when lead-tin alloy solder is adopted for soldering, the melting temperature of the solder is 163 ℃, the subsequent use temperature of the thick-film mixed multilayer ceramic integrated packaging shell can not exceed 163 ℃ (so as to avoid the failure of the lead-tin alloy due to secondary melting), the use of the shell is greatly limited, and the requirements of the environment test can not be met. If the gold-tin eutectic solder with higher temperature is adopted for soldering (the melting point of the gold-tin eutectic solder is 280 ℃), the middle generated by the gold-tin soldering is brittle, the ceramic integrated packaging shell has the risks of welding area cracking and sealing failure, and the manufactured integrated packaging shell has poor reliability and low qualification rate.

In addition, when gold-tin soldering chips and the like are soldered on a ceramic thin film wiring layer, vacuum welding or eutectic friction welding in an air atmosphere is generally adopted, rapid cooling is required after actual solder is melted (the heat preservation time is within 1 minute above the melting point of the solder during soldering), the process window is narrow, and indexes such as air tightness are not involved. The thick-film mixed multilayer ceramic integrated packaging shell serves as a mechanical supporting carrier of an internal circuit and plays a role in sealing and protecting the internal circuit, and the requirement on air tightness of the shell must meet the requirement.

Disclosure of Invention

In view of the above, the present invention provides a ceramic integrated package housing and a manufacturing process thereof, in which a stress release layer is disposed in a film system of the ceramic integrated package housing, the stress release layer is fully utilized, and when a welding stress is transmitted to the stress release layer, the welding stress can be effectively released due to the soft and easy plastic deformation of the material of the stress release layer, so as to avoid the damage to the adhesion and bonding of the ceramic and the bottom film Ti layer, and solve the technical problems of the integrated package housing in the prior art, such as welding crack removal, sealing failure risk and poor sealing reliability.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a pottery integration encapsulation shell, its includes thick film multilayer ceramic substrate, thick film multilayer ceramic substrate is by thick film ceramic substrate with locate the metal film wiring layer on thick film ceramic substrate surface constitutes, metal film wiring layer from interior to exterior is six layers of film systems of Ti/M/N/Ti/K/Au in proper order, and wherein, M layer, K layer independent respectively are selected from Pt or Ni, and the N layer is the stress release layer, the stress release layer is Au or Cu.

Furthermore, the metal enclosure frame is arranged on the thick-film multilayer ceramic substrate, and a gold-tin welding layer is arranged between the metal enclosure frame and the thick-film multilayer ceramic substrate.

Furthermore, the material of the metal enclosure frame is selected from one of 4J42, 4J33 and 4J29 fixed expansion alloys, and a nickel layer and a gold layer are sequentially arranged on the surface of the metal enclosure frame from inside to outside.

Preferably, the thickness of the nickel layer on the surface of the metal enclosure frame is 1.27-8.9 μm, and the thickness of the gold layer is 0.75-5.7 μm.

Further, the thick film ceramic substrate is selected from one of an alumina ceramic substrate, an aluminum nitride ceramic substrate and an L TCC substrate.

Preferably, the stress release layer is Au.

Furthermore, in the metal thin film wiring layer, the film thickness of the Ti layer is 0.1-0.6 μ M, the film thickness of the M layer and the K layer is 1-3 μ M, and the film thickness of the N layer is 0.75-3 μ M.

Another objective of the present invention is to provide a manufacturing process of the ceramic integrated package housing, which includes the following steps:

preparing raw porcelain by pressing and tape casting, sintering or printing the raw porcelain into a thick film ceramic substrate with a built-in passive element, and grinding and polishing the surface of the thick film ceramic substrate;

sputtering the surface of the processed thick film ceramic substrate from inside to outside by adopting a magnetron sputtering method to manufacture a metal film wiring layer, and preparing a required metallized pattern on the metal film wiring layer to manufacture a thick film mixed multilayer ceramic substrate;

sequentially plating a nickel layer and a gold layer on the surface of the metal enclosure frame from inside to outside;

sequentially placing a gold-tin soldering lug and a metal surrounding frame on a metal thin film wiring layer of the thick-film mixed multilayer ceramic substrate to form an integrated packaging shell pre-assembly body;

and feeding the integrated packaging shell pre-assembly body into a brazing furnace, and brazing the integrated packaging shell pre-assembly body into a whole under a protective atmosphere.

Furthermore, the brazing sequentially comprises a preheating process, a heat preservation process and a cooling process.

Preferably, the brazing specific process is as follows: firstly, heating from normal temperature to 250-270 ℃ at the heating rate of 20-30 ℃/min, and then preserving heat for 5-10 min; then heating to 330 ℃ at the heating rate of 20-30 ℃/min, and preserving the heat for 2-10 min; and finally, cooling at the cooling rate of 10-20 ℃/min, and discharging to obtain the ceramic integrated packaging shell.

Compared with the prior art, the invention has the following beneficial effects:

six-layer film system is adopted between the thick film ceramic substrate and the metal enclosure frame, and metal with soft material and easy plastic deformation is added in the film system to serve as a stress release layer, so that welding stress is transmitted to the stress release layer. Therefore, the sealing reliability of the gold-tin brazing between the thick film ceramic substrate and the metal enclosure frame in the batch production of the thick film and thin film mixed multilayer ceramic integrated packaging shell is improved, and the shell is GJB2440A-2006<Hybrid integrated circuit package universal specification>The test requirement of (1) is that the air tightness is better than 1.0 × 10 after the test of the environment with the temperature of-65 ℃ to +175 ℃ circulating for 100 times and the thermal shock of-65 ℃ to +150 ℃ for 15 times^-9Pa.m³.s^-1. Meanwhile, the production process window of the thick-film mixed multilayer ceramic integrated packaging shell is widened, and the production qualified rate is improved.

Drawings

FIG. 1 is a schematic structural diagram of a thick-film hybrid multilayer ceramic integrated package in accordance with a preferred embodiment of the present invention;

fig. 2 is a partially enlarged schematic view of the metal thin film wiring layer 20 in fig. 1;

FIG. 3 is a block diagram of the process for manufacturing the integrated package casing of thick-film hybrid multi-layer ceramic in accordance with a preferred embodiment of the present invention.

In the figure: 10-thick film ceramic substrate, 20-metal thin film wiring layer, 30-gold tin welding layer, 40-metal surrounding frame, 201-Ti layer, 202-M layer, 203-N layer, 204-K layer and 205-Au layer.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the specific embodiments illustrated. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The invention discloses a thick-film and thin-film mixed multilayer ceramic integrated packaging shell which comprises a thick-film and thin-film multilayer ceramic substrate and a metal thin-film wiring layer arranged on the thick-film ceramic substrate, wherein the metal thin-film wiring layer is a Ti/M/N/Ti/K/Au six-layer film system from inside to outside in sequence, the M layer and the K layer are respectively and independently selected from Pt or Ni, and the N layer is made of soft metal and easy to plastically deform.

When the existing traditional Ti/Pt/Au or Ti/Ni/Au three-layer film on the ceramic surface and the metal enclosure frame are subjected to gold-tin eutectic brazing, the film Au layer can be dissolved in the gold-tin brazing filler metal, the Ni or Pt film layer serving as a diffusion barrier layer can perform metallurgical reaction with Sn element in the gold-tin brazing filler metal to form a brittle intermediate phase, and although the existence of the intermediate phase ensures that the metal enclosure frame is connected with the ceramic to have certain mechanical strength, the brittle intermediate phase cannot release welding stress, so that the combination of the film Ti layer serving as an adhesion layer and the ceramic can be influenced, the process window of the gold-tin brazing of the ceramic and the metal enclosure frame is relatively narrow, and the ceramic integrated packaging shell has the risks of welding area cracking, sealing failure and poor sealing reliability.

Aiming at the problems, the surface of the thick-film mixed multilayer ceramic substrate adopts a Ti/M/N/Ti/K/Au low-stress six-layer film system, wherein the N layer is made of soft metal easy to plastically deform, and the plasticity of the metal in the N layer is fully utilized to take the N layer as a stress release layer. Under the same condition, although the welding stress still exists when the metal enclosure frame and the ceramic are connected by gold-tin brazing, when the welding stress is transferred to the middle N layer, the welding stress can be effectively released because the material is soft and easy to plastically deform, and the damage to the adhesion and the combination of the ceramic and the bottom thin film Ti layer is avoided. It is understood that examples specifically mentioned herein for the stress relieving layer include those selected from Au or Cu.

The ceramic integrated packaging shell improves the sealing reliability of gold-tin brazing between the ceramic substrate and the metal surrounding frame in batch production, and the shell is GJB2440A-2006<Hybrid integrated circuit package universal specification>The test requirement of (1) is that the air tightness is better than 1.0 × 10 after the test of the environment with the temperature of-65 ℃ to +175 ℃ circulating for 100 times and the thermal shock of-65 ℃ to +150 ℃ for 15 times^-9Pa.m³.s^-1. Meanwhile, the production process window of the thick-film mixed multilayer ceramic integrated packaging shell is widened, and the production qualified rate is improved.

Further, the thick film ceramic substrate may be a conventional choice in the field of electronic housing packaging, and specific examples include, but are not limited to, one of an alumina ceramic substrate, an aluminum nitride ceramic substrate, and L TCC substrate.

Furthermore, the ceramic integrated package housing further comprises a metal surrounding frame, wherein the metal surrounding frame is arranged on the surface of the thick-film multilayer ceramic substrate, and a gold-tin welding layer is arranged between the metal surrounding frame and the thick-film multilayer ceramic substrate.

Furthermore, the material of the metal enclosure frame is selected from one of 4J42, 4J33 and 4J29 fixed expansion alloys, and a nickel layer and a gold layer are sequentially arranged on the surface of the metal enclosure frame from inside to outside. The material of the metal enclosure frame may be selected conventionally in the art, and is preferably a material of the enclosure frame with a thermal expansion coefficient close to that of the ceramic substrate, so as to reduce the gold-tin welding stress, and in some specific embodiments of the present invention, may be specifically selected from one of 4J42, 4J33 and 4J29 fixed expansion alloys.

Furthermore, the thickness of the nickel layer is 1.27-8.9 μm and the thickness of the gold layer is 0.75-5.7 μm on the surface of the metal enclosure frame.

Further, the stress release layer is Au.

Furthermore, in the metal thin film wiring layer, the film thickness of the Ti layer is 0.1-0.6 μ M, the film thickness of the M layer is 1-3 μ M, and the film thickness of the N layer is 0.75-3 μ M.

The invention also discloses a manufacturing process of the thick-film mixed multilayer ceramic integrated packaging shell according to the first aspect of the invention, which comprises the following steps:

preparing raw porcelain by pressing and tape casting, sintering or printing the raw porcelain into a thick film ceramic substrate with a built-in passive element, and grinding and polishing the surface of the thick film ceramic substrate; it is understood that pressing and casting to obtain green ceramic, sintering and printing patterns, and grinding and polishing the surface of the thick film ceramic substrate are conventional means in the art, and the specific processes are different according to the material of the substrate, which are conventional means possessed by those skilled in the art, and therefore, the invention is not limited in detail herein.

Sputtering the surface of the processed thick film ceramic substrate from inside to outside by adopting a magnetron sputtering method to manufacture a metal film wiring layer, and preparing a required metallized pattern on the metal film wiring layer to manufacture a thick film mixed multilayer ceramic substrate; it is understood that the magnetron sputtering and the preparation of the metallization pattern are well known in the art and can be adjusted according to the metal to be sputtered, and therefore, are not limited to the specific embodiments.

Sequentially plating a nickel layer and a gold layer on the surface of the metal enclosure frame from inside to outside;

sequentially placing a gold-tin soldering lug and a metal surrounding frame on a metal thin film wiring layer of the thick-film mixed multilayer ceramic substrate to form an integrated packaging shell pre-assembly body;

and feeding the integrated packaging shell pre-assembly body into a brazing furnace, and brazing the integrated packaging shell pre-assembly body into a whole under a protective atmosphere. The protective atmosphere here is mainly to provide an oxygen-free environment during brazing, and therefore, the protective atmosphere here may be selected from one of nitrogen and inert gas.

Furthermore, the brazing sequentially comprises a preheating process, a heat preservation process and a cooling process. It is understood that the temperature and time of the preheating, the holding and the cooling herein can be adjusted according to the material of the substrate, and therefore, are not limited herein.

Preferably, in some specific embodiments of the present invention, the brazing process is: firstly, heating from normal temperature to 250-270 ℃ at the heating rate of 20-30 ℃/min, and then preserving heat for 5-10 min; then heating to 330 ℃ at the heating rate of 20-30 ℃/min, and preserving the heat for 2-10 min; and finally, cooling at the cooling rate of 10-20 ℃/min, and discharging to obtain the ceramic integrated packaging shell. In the brazing process, the shell preassembly is uniformly heated before the welding flux is melted by preheating and then carrying out gradient temperature rise for heat preservation, and during temperature reduction, the temperature is directly reduced from high temperature in order to avoid failure caused by welding stress because the stress release layer is made of soft metal easy to plastically deform.

The technical solution of the present invention will be more clearly and completely described below with reference to specific embodiments.

As shown in fig. 1, a ceramic integrated package housing includes a thick-film hybrid multilayer ceramic substrate, where the thick-film hybrid multilayer ceramic substrate is composed of a thick-film ceramic substrate 10 and a metal-film wiring layer 20, and the metal-film wiring layer 20 is disposed on a surface of the thick-film ceramic substrate 10, in this embodiment, a magnetron sputtering method is adopted, and it is understood that other methods for manufacturing the metal-film wiring layer 20 in the art may also be used in the present invention as long as the technical solution of the present invention can be implemented. Referring to fig. 1, a metal frame 40 is disposed on the metal film wiring layer 20, and a gold-tin solder layer 30 is disposed between the metal frame 40 and the metal film wiring layer 20, so as to ensure the sealing reliability and the air tightness of the ceramic integrated package.

Further, the thick film ceramic substrate 10 is selected from one of an alumina ceramic substrate, an aluminum nitride ceramic substrate, and an L TCC substrate.

Further, the material of the metal enclosure frame 40 is selected from one of 4J42, 4J33 and 4J29 fixed expansion alloys, and a nickel layer and a gold layer are sequentially arranged on the surface of the metal enclosure frame from inside to outside, specifically, in this embodiment, the thickness of the nickel layer is 1.27 to 8.9 μm, and the thickness of the gold layer is 0.75 to 5.7 μm.

Specifically, referring to fig. 1 and fig. 2, in the present embodiment, the metal thin film wiring layer 20 is a six-layer thin film system, and sequentially includes a Ti layer 201, an M layer 202, an N layer 203, a Ti layer 201, a K layer 204, and an Au layer 205 from inside to outside, wherein the M layer 202 and the K layer 204 are respectively and independently selected from Pt or Ni, and the N layer 203 is selected from a soft and easily plastically deformable metal, which may be Au or Cu, and in the present embodiment, is preferably Au. Preferably, the thickness of each metal layer in the metal thin-film wiring layer 20 is different, and in some embodiments of the present invention, the thickness of the Ti layer 201 is 0.1-0.6 μ M, the thickness of the M layer 202 and the K layer 204 is 1-3 μ M, and the thickness of the N layer 203 and the Au layer 205 is 0.75-3 μ M in the metal thin-film wiring layer 20.

As shown in the flow chart of fig. 3, the manufacturing process of the integrated package housing of the present invention mainly includes three steps: firstly, a thick film ceramic substrate is manufactured, then a metal thin film wiring layer is manufactured on the thick film ceramic substrate to obtain a thick-thin film mixed multilayer ceramic substrate, and then the thick-thin film mixed multilayer ceramic substrate and a metal enclosure frame are brazed to obtain the thick-thin film mixed multilayer integrated packaging shell.

The following describes the manufacturing process of the integrated package casing according to the present invention with reference to specific embodiments.