Leadless package pressure sensor and method of manufacturing the same

Abstract

The application provides a leadless packaging pressure sensor and a preparation method thereof. The leadless packaging pressure sensor comprises a sintering tube shell and a carrier chip inverted on a substrate of the sintering tube shell. The sintering tube shell comprises a plurality of lead pillars extending through the substrate and along the shell wall of the sintering tube shell, one end of the lead pillar extending out of the substrate. The carrier chip is provided with a connecting hole corresponding to the lead pillar. The bottom of the connecting hole is provided with a gold ball implanted by a cleaver. The connecting hole is filled with conductive paste. When the carrier chip is inverted and bonded to the substrate, the connecting hole is buckled outside the corresponding lead pillar. The lead pillar is inserted into the conductive paste, and the gold ball is opposite to the end of the lead pillar. The packaging method of implanting the gold ball and connecting the gold ball and the lead pillar by the conductive paste can effectively solve the influence of high-temperature sintering on the performance of the carrier chip and improve the service life of the sensor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure sensor, in particular to a leadless packaging pressure sensor and a preparation method thereof. BACKGROUND

[0002] The pressure sensor is applied more and more in high temperature environment, and the pressure chip on the market has certain limitations in high temperature resistance. The electrode system of the chip will fail when the temperature exceeds a certain temperature. The leadless packaging of the main domestic and foreign needs high temperature sintering, and the sintering temperature is often 100 DEG C higher than the long-term use temperature. Therefore, the short-term high temperature resistance of the pressure chip is required to be higher. In order to solve the influence of high temperature sintering on the performance of the pressure chip, a new leadless packaging pressure sensor and a preparation method thereof are provided under the premise of ensuring the effective packaging of the pressure chip. SUMMARY

[0003] The present application is to provide a leadless packaging pressure sensor and a preparation method thereof to solve the above problems in the prior art.

[0004] The object of the present application can be achieved by the following technical solutions:

[0005] In order to achieve the above object, the present application provides a leadless packaging pressure sensor, comprising a sintering tube shell and a carrier chip inverted on the substrate of the sintering tube shell.

[0006] The sintering tube shell comprises a plurality of lead posts penetrating through the substrate and extending along the shell wall of the sintering tube shell, and one end of the lead post extends out of the substrate.

[0007] The carrier chip is provided with a connecting hole corresponding to the lead post, the bottom of the connecting hole is provided with a gold ball implanted by a wedge, and the connecting hole is filled with conductive paste.

[0008] When the carrier chip is inverted and bonded to the substrate, the connecting hole is engaged outside the corresponding lead post, the lead post is inserted into the conductive paste, and the gold ball is opposite to the end of the lead post.

[0009] Preferably, the substrate is a glass blank, the end surface of the substrate is circular, the circular end surface is coated with a polyimide glue layer, and the carrier chip is sealed and bonded to the substrate by the polyimide glue layer.

[0010] Preferably, the lead post is a gold-plated cylinder, and the lead post is provided with four lead posts, which are uniformly arranged on the substrate.

[0011] Preferably, the connecting hole is a tapered hole, and the hole diameter of the connecting hole gradually decreases from the bonding side of the substrate to the direction close to the gold ball.

[0012] Preferably, the polyimide glue layer is screen printed onto the substrate.

[0013] Preferably, the leadless package pressure sensor further comprises a protective cover covering the sintering tube shell, the protective cover and the sintering tube shell are configured as a cavity, and the carrier chip is arranged in the cavity.

[0014] The application also provides a packaging method of a leadless pressure sensor, comprising the following steps:

[0015] Screen printing polyimide glue onto the substrate of the sintering tube shell to form a polyimide glue layer;

[0016] Implanting gold balls into the bottom of the connecting hole of the carrier chip by a special wedge knife;

[0017] Filling conductive paste into the connecting hole;

[0018] Ducking the filled carrier chip onto the polyimide glue layer by a patch machine, and inserting the lead column end of the sintering tube shell into the connecting hole;

[0019] Sintering and sealing the carrier chip to the sintering tube shell.

[0020] Preferably, after sintering and sealing the carrier chip to the sintering tube shell, the method further comprises:

[0021] Checking whether the sintered carrier chip and the sintering tube shell are completely matched and have stable electrical signals.

[0022] The application has the beneficial effect of providing a leadless package pressure sensor comprising a sintering tube shell and a carrier chip inverted on the substrate of the sintering tube shell;

[0023] The sintering tube shell comprises a plurality of lead columns extending through the substrate and along the shell wall of the sintering tube shell, one end of the lead column extending out of the substrate;

[0024] The carrier chip is provided with a connecting hole corresponding to the lead column, the bottom of the connecting hole is provided with a gold ball implanted by a wedge knife, and the connecting hole is filled with conductive paste;

[0025] When the carrier chip is inverted and bonded to the substrate, the connecting hole is buckled outside the corresponding lead column, the gold ball is opposite to the end of the lead column, and the conductive paste fills the remaining space in the connecting hole.

[0026] The beneficial effects of this invention are that it provides a leadless packaged pressure sensor and its fabrication method. The leadless packaged pressure sensor includes a sintered housing and a carrier chip inverted on a substrate of the sintered housing. The sintered housing includes a plurality of lead posts extending through the substrate and along the shell wall of the sintered housing, with one end of each lead post extending out of the substrate. The carrier chip has connection holes corresponding to each lead post, and a gold ball implanted by a wedge is located at the bottom of each connection hole. The connection hole is filled with conductive paste. When the carrier chip is inverted and bonded to the substrate, the connection hole is engaged with the corresponding lead post, the lead post is inserted into the conductive paste, and the ends of the gold balls and lead posts are opposite each other. This invention, by implanting gold balls and using conductive paste to connect the gold balls and lead posts, effectively solves the impact of high-temperature sintering on the performance of the carrier chip and improves the service life of the sensor. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a leadless packaged pressure sensor according to an embodiment of the present invention.

[0028] Figure 2 yes Figure 1 Sectional view along direction AA.

[0029] Figure 3 yes Figure 1 The schematic diagram shows the structure of the carrier chip, which uses a specially designed split-blade gold-impregnated ball.

[0030] Figure 4 yes Figure 3 A schematic diagram of the structure after the carrier chip is implanted into the ball and filled with conductive paste.

[0031] Figure 5 yes Figure 1 A schematic diagram of the sintered tube shell structure.

[0032] Figure 6 yes Figure 4 and Figure 5 Schematic diagram of the assembly structure of the carrier chip and the sintered casing.

[0033] Figure description: 1. Carrier chip; 11. Connecting hole; 2. Gold ball; 3. Conductive paste; 4. Lead post; 5. Polyimide water layer; 6. Protective cover; 61. Pore; 7. Sintered tube shell; 71. Substrate; 72. Step; 8. Cleaver. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] It is to be understood that where an element such as a layer, region or substrate is described as being "on" another element, it can be directly on the other element or intervening elements can also be present. Where an element such as a layer, region or substrate is described as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present.

[0036] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the application is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the application as illustrated therein being contemplated as would normally occur to one skilled in the art to which the application relates.

[0037] Reference will now be made to Figures 1-6 The leadless packaging pressure sensor provided by the embodiment of the present application comprises a sintering tube shell 7, a protective cover 6 covering the sintering tube shell 7 and forming a cavity with the sintering tube shell 7, and a carrier chip 1 accommodated in the cavity and invertedly buckled on the substrate of the sintering tube shell 7.

[0038] The sintering tube shell 7 comprises a substrate 71 and a plurality of lead pillars 4 penetrating through the substrate 71. The sintering tube shell 7 is a cylinder, the substrate 71 is prepared by a glass blank, and the end face thereof is circular. The lead pillars 4 are four in number and uniformly distributed on the substrate 71, and one end of each lead pillar 4 penetrates through the end face of the substrate 71. The lead pillars 4 are gold-plated cylinders, and the shape of the lead pillars 4 includes but is not limited to the shape shown in the embodiment. The end face of the substrate 71 is coated with a polyimide glue layer, and the carrier chip 1 is sealed and bonded to the substrate 71 through the polyimide glue layer 5.

[0039] The carrier chip 1 is provided with a plurality of connecting holes 11, the connecting holes 11 are arranged in one-to-one correspondence with the lead pillars 4, and the connecting holes 11 are tapered holes. Gold balls 2 are planted at the bottom of the connecting holes 11, the gold balls 2 are planted at the bottom of the connecting holes 11 by special choppers 8, and the gold balls 2 are in electrical communication with the electrodes of the carrier chip 1. The connecting holes 11 are also filled with conductive paste 3.

[0040] When the carrier chip 1 is invertedly buckled on the sintering tube shell 7 and bonded and packaged with the substrate 71, each connecting hole 11 is buckled on the corresponding lead pillar 4, so that the end of the lead pillar 4 is inserted into the conductive paste 3, and the end of the lead pillar 4 is arranged opposite to the gold ball 2, and the conductive paste 3 connects the gold ball 2 and the lead pillar 4. Optionally, the hole diameter of the connecting hole 11 gradually decreases from the side bonded to the substrate 71 to the direction close to the gold ball 2.

[0041] In an optional embodiment, the protective cover 6 is cylindrical, and the side wall of the sintering tube shell 7 is provided with a step 72 extending along the circumference of the side wall, and the side wall of the protective cover 6 is buckled on the step 72. The protective cover 6 is arranged on the sintering tube shell 7 to prevent dust and avoid interference of external factors on the internal structure of the carrier chip 1, thereby ensuring the sensitivity of the sensor, and a plurality of air holes 61 are arranged on the top of the protective cover 6.

[0042] The leadless packaging pressure sensor of the embodiment of the present application implants the gold ball 2 in the connecting hole 11 of the carrier chip 1 through the special splitting knife 8, the gold ball 2 is connected to the electrode on the carrier chip 1, and the connecting hole 11 is filled with the conductive paste 3. When the carrier chip 1 is packaged on the sintering tube shell 7, the lead column 4 on the sintering tube shell 7 is inserted into the conductive paste 3, and the conductive paste 3 conducts the gold ball 2 and the lead column 4. The combination of the gold ball 2 implanted by the special splitting knife 8, the conductive paste 3 and the lead column 4 can avoid the situation that the sintering temperature is higher than the working temperature after packaging, thereby affecting the performance of the pressure sensor. The leadless packaging pressure sensor of the present application is beneficial to improve the service life of the pressure sensor and ensure the performance stability of the pressure sensor.

[0043] Based on the leadless packaging pressure sensor of the above embodiment, the present application further provides a packaging method of a leadless packaging pressure sensor, which comprises the following steps:

[0044] Step S1, screen printing polyimide glue on the substrate of the sintering tube shell to form a polyimide glue layer 5;

[0045] Step S2, implanting the gold ball 2 into the bottom of the connecting hole 11 of the carrier chip 1 through the special splitting knife 8;

[0046] Step S3, filling the conductive paste 3 into the connecting hole 11;

[0047] Step S4, buckling the filled carrier chip 1 on the polyimide glue layer by the chip mounter, and inserting the end of the lead column 4 on the sintering tube shell 7 into the connecting hole 11;

[0048] Step S5, sintering and sealing the carrier chip 1 to the sintering tube shell 7;

[0049] Step S6, checking whether the carrier chip and the sintering tube shell are completely matched and have stable electrical signals after sintering.

[0050] Specifically, the inspection of the leadless packaging pressure sensor: (1) the connecting position between the carrier chip 1 and the lead column 4 of the sintering tube shell 7 can be checked under a microscope; (2) whether the conductive paste 3 filled inside is filled full can be seen; (3) whether the polyimide glue layer between the carrier chip 1 and the sintering tube shell 7 is filled full can be checked.

[0051] Specifically, the lead pillars 4 of the sintering tube shell 7 penetrate the substrate 71 of the sintering tube shell 2, the substrate 71 of the application has a flat end face, and the substrate 71 is prepared by a glass embryo, the polyimide glue layer 5 can be printed on the end face of the substrate 71 by screen printing, the four connecting holes 11 of the leadless pressure sensor carrier chip 1 have gold balls 2 implanted by special splitting knives 8, the gold balls 2 are connected with electrodes, and after the gold balls are implanted, a certain volume of conductive paste 3 is filled, the leadless pressure sensor carrier chip 1 is buckled to the substrate 71 of the sintering tube shell 7 by a chip mounter, and the four exposed lead pillars 4 of the sintering tube shell 1 are inserted into the four connecting holes 11, so that the end of the lead pillar 4 is inserted into the conductive paste 3, realizing that the electrodes inside the leadless pressure sensor carrier chip 1 are electrically connected with the four lead pillars 31 through the filled conductive paste 3 through the gold balls 2.

[0052] The above embodiments only express the preferred embodiments of the application, which are described in detail, but cannot be understood as the limitation of the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which belong to the protection scope of the application. Therefore, the protection scope of the patent of the application should be subject to the appended claims.

Claims

1. A leadless, packaged pressure sensor, characterized by, The sintering tube shell and the carrier chip are inverted on the substrate of the sintering tube shell; The sintering tube shell comprises a plurality of lead pillars extending through the substrate and along the shell wall of the sintering tube shell, one end of the lead pillar extending out of the substrate; The carrier chip is provided with a connecting hole corresponding to the lead pillar, the bottom of the connecting hole is provided with a gold ball implanted by a wedge, the gold ball and the electrode of the carrier chip are in conduction, and the connecting hole is filled with conductive paste; When the carrier chip is inverted and bonded to the substrate, the connecting hole is buckled outside the corresponding lead pillar, the lead pillar is inserted into the conductive paste, the gold ball is opposite to the end of the lead pillar, and the conductive paste connects the gold ball and the lead pillar; The substrate is a glass blank, the end surface of the substrate is circular, the circular end surface is coated with a polyimide glue layer, and the carrier chip is sealed and bonded to the substrate through the polyimide glue layer.

2. The leadless, packaged pressure sensor of claim 1, wherein, The lead pillar is a gold-plated cylinder, and four lead pillars are uniformly arranged on the substrate.

3. The leadless, packaged pressure sensor of claim 1, wherein, The connecting hole is a tapered hole, and the aperture of the connecting hole gradually decreases from the bonding side of the substrate to the direction close to the gold ball.

4. The leadless, packaged pressure sensor of claim 1, wherein, The polyimide glue layer is screen printed on the substrate.

5. The leadless, packaged pressure sensor of claim 1, wherein, The leadless packaging pressure sensor further comprises a protective cover arranged on the sintering tube shell, the protective cover and the sintering tube shell are arranged in a cavity, and the carrier chip is arranged in the cavity.

6. A method of packaging a leadless pressure sensor, characterized by, The method comprises the following steps: Screen printing polyimide glue on the substrate of the sintering tube shell to form a polyimide glue layer; Implanting a gold ball into the bottom of the connecting hole of the carrier chip by a special wedge; Filling conductive paste into the connecting hole; Buckling the filled carrier chip onto the polyimide glue layer by a chip mounter, and inserting the end of the lead pillar of the sintering tube shell into the connecting hole; Sintering and sealing the carrier chip to the sintering tube shell.

7. The method of packaging a leadless pressure sensor of claim 6, wherein, After sintering and sealing the carrier chip to the sintering tube shell, it further comprises: checking whether the sintered carrier chip and the sintering tube shell are completely matched and have stable electrical signals.

Images