CN-122026845-A - Filter packaging method, filter and radio frequency front end module

CN122026845ACN 122026845 ACN122026845 ACN 122026845ACN-122026845-A

Abstract

The invention provides a filter packaging method, a filter and a radio frequency front end module, relating to the technical field of semiconductors, the filter packaging method comprises the steps of selecting a material with flow characteristics smaller than those of epoxy resin as a target packaging material, and determining a first packaging technological parameter corresponding to the target packaging material; or selecting a material with flow characteristics smaller than those of the epoxy resin and permeability characteristics smaller than those of the epoxy resin as a target packaging material, determining a first packaging process parameter corresponding to the target packaging material, and packaging the target packaging material, the filter chip and the first substrate based on the first packaging process parameter to obtain the target filter. According to the invention, the material with small flow characteristics or the material with small flow characteristics and small permeability is selected as the target packaging material, and the target filter is obtained by packaging based on the corresponding first packaging process parameters, so that the problem of uneven thickness caused by large fluidity of the epoxy resin is solved.

Inventors

JIANG WEI
GAO ANMING

Assignees

天津曜盛电子有限公司

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (10)

1. A method of packaging a filter, comprising: selecting a material with flow characteristics smaller than those of the epoxy resin as a target packaging material, and determining a first packaging technological parameter corresponding to the target packaging material, or selecting a material with flow characteristics smaller than those of the epoxy resin and permeability smaller than those of the epoxy resin as a target packaging material, and determining a first packaging technological parameter corresponding to the target packaging material; and packaging the target packaging material, the filter chip and the first substrate based on the first packaging process parameters to obtain the target filter.
2. The method of claim 1, wherein the target encapsulation material comprises a modified polytetrafluoroethylene material, and wherein determining the first encapsulation process parameter corresponding to the target encapsulation material comprises: Based on the characteristic difference between the modified polytetrafluoroethylene material and the epoxy resin, adjusting a second packaging process parameter corresponding to the epoxy resin, and determining the first packaging process parameter; The first packaging process parameters comprise a first material thickness, a first temperature return time, a first packaging temperature, a first vacuum parameter, a first pressure parameter and a first curing parameter, the second packaging process parameters comprise a second material thickness, a second temperature return time, a second packaging temperature, a second vacuum parameter, a second pressure parameter and a second curing parameter, the first material thickness is smaller than the second material thickness, the first packaging temperature is higher than the second packaging temperature, and the curing time of the first curing parameter is different from the curing time of the second curing parameter.
3. The method of claim 2, wherein the first curing parameter is used to characterize a preset curing temperature maintained for a first period of time followed by a preset curing temperature maintained for a second period of time, the second period of time being greater than the first period of time, the second curing parameter being used to characterize a preset curing temperature maintained for a third period of time.
4. The filter packaging method according to claim 2, wherein the first packaging temperature ranges from 105 ℃ to 115 ℃ and the second packaging temperature ranges from 60 ℃ to 70 ℃.
5. The filter packaging method of claim 2, wherein the first material thickness ranges from 0.025mm to 0.035mm and the second material thickness ranges from 0.215mm to 0.305mm.
6. The method of packaging a filter according to any one of claims 2 to 5, wherein the packaging the target packaging material, the filter chip, and the first substrate based on the first packaging process parameter to obtain a target filter includes: Preparing a modified polytetrafluoroethylene material prepreg, a filter chip and a first substrate, wherein the thickness of the modified polytetrafluoroethylene material prepreg is the thickness of the first material, and a bonding pad corresponding to the filter chip is arranged on the first substrate; carrying out temperature returning treatment on the modified polytetrafluoroethylene material prepreg based on the first temperature returning time to obtain the modified polytetrafluoroethylene material prepreg after temperature returning; attaching the filter chip to a bonding pad of the first substrate, and covering the modified polytetrafluoroethylene material prepreg subjected to temperature return on the first substrate attached with the filter chip to obtain a device to be packaged; Performing vacuum treatment on the device to be packaged based on the first vacuum parameter, heating the device to be packaged after the vacuum treatment to the first packaging temperature, and performing lamination treatment based on the first pressure parameter in the heating process to obtain a packaged device; and curing the packaging device based on the first curing parameter to obtain the target filter.
7. The filter packaging method according to claim 6, further comprising, before the vacuum processing of the device to be packaged based on the first vacuum parameter: And arranging a forming auxiliary plate above the device to be packaged so that the target filter is in a convex structure.
8. The filter is characterized in that the filter is obtained by packaging a target packaging material, a filter chip and a first substrate according to first packaging process parameters corresponding to the target packaging material, wherein the target packaging material is a material with flow characteristics smaller than those of epoxy resin or a material with flow characteristics smaller than those of the epoxy resin and permeation characteristics smaller than those of the epoxy resin.
9. A radio frequency front end module comprising the filter of claim 8.
10. The rf front-end module of claim 9, wherein the rf front-end module encapsulates the filter on the second substrate with a third encapsulation process parameter corresponding to an epoxy, the third encapsulation process parameter comprising a third material thickness, a third soak time, a third encapsulation temperature, a third vacuum parameter, and a third cure parameter.

Description

Filter packaging method, filter and radio frequency front end module Technical Field The present invention relates to the field of semiconductor technologies, and in particular, to a filter packaging method, a filter, and a radio frequency front end module. Background The Surface Acoustic wave filter (Surface Acoustic wave WAVE FILTER, SAW) is a radio frequency device for frequency selection by utilizing the piezoelectric effect, an electric signal is converted into a Surface Acoustic wave through an interdigital transducer at an input end, after the sound wave propagates on the Surface of a piezoelectric substrate, the interdigital transducer at an output end converts back the electric signal, so that the specific frequency signal is filtered or inhibited, and the Surface Acoustic wave filter has the advantages of small volume, light weight, good frequency selectivity, strong electromagnetic interference resistance, suitability for mass production and the like, and the working frequency range is generally between 10MHz and 3GHz, and is widely applied to the fields of satellite communication, radar, mobile communication (such as mobile phones), broadcast television and the like. SAW filters are typically encapsulated with an epoxy material that covers the entire substrate surface, and the underlying inter-chip space is filled by the fluidity of the epoxy, the amount of filling determining the thickness of the final finished product. However, it is difficult to secure thickness uniformity of the SAW filter due to the large flow characteristics of the epoxy material. Disclosure of Invention The invention provides a filter packaging method, a filter and a radio frequency front end module, which are used for solving the defect that the thickness uniformity of a SAW filter is difficult to ensure due to the flow characteristic of an epoxy resin material in the prior art. The invention provides a filter packaging method, which comprises the following steps: selecting a material with flow characteristics smaller than those of the epoxy resin as a target packaging material, and determining a first packaging technological parameter corresponding to the target packaging material, or selecting a material with flow characteristics smaller than those of the epoxy resin and permeability smaller than those of the epoxy resin as a target packaging material, and determining a first packaging technological parameter corresponding to the target packaging material; and packaging the target packaging material, the filter chip and the first substrate based on the first packaging process parameters to obtain the target filter. According to the filter packaging method provided by the invention, the target packaging material comprises a modified polytetrafluoroethylene material, and the determining of the first packaging process parameters corresponding to the target packaging material comprises the following steps: Based on the characteristic difference between the modified polytetrafluoroethylene material and the epoxy resin, adjusting a second packaging process parameter corresponding to the epoxy resin, and determining the first packaging process parameter; The first packaging process parameters comprise a first material thickness, a first temperature return time, a first packaging temperature, a first vacuum parameter, a first pressure parameter and a first curing parameter, the second packaging process parameters comprise a second material thickness, a second temperature return time, a second packaging temperature, a second vacuum parameter, a second pressure parameter and a second curing parameter, the first material thickness is smaller than the second material thickness, the first packaging temperature is higher than the second packaging temperature, and the curing time of the first curing parameter is different from the curing time of the second curing parameter. According to the filter packaging method provided by the invention, the first curing parameter is used for representing the preset curing temperature maintained in the first time period and then maintaining the preset curing temperature in the second time period, the second time period is larger than the first time period, and the second curing parameter is used for representing the preset curing temperature maintained in the third time period. According to the filter packaging method provided by the invention, the range of the first packaging temperature is 105-115 ℃, and the range of the second packaging temperature is 60-70 ℃. According to the filter packaging method provided by the invention, the thickness of the first material ranges from 0.025mm to 0.035mm, and the thickness of the second material ranges from 0.215mm to 0.305mm. According to the method for packaging the filter provided by the invention, the target packaging material, the filter chip and the first substrate are packaged based on the first packaging process parameter to obtain the target filte