阅读说明：本技术 0.5mm节距的高频无引线陶瓷外壳及测试方法 (0.5mm pitch high-frequency leadless ceramic shell and test method ) 是由 王轲 乔志壮 刘林杰 于 2020-05-09 设计创作，主要内容包括：本发明提供了一种0.5mm节距的高频无引线陶瓷外壳及测试方法,属于陶瓷封装技术领域,壳体外侧面设有金属化空心孔,金属化空心孔的直径为0.2mm,金属化空心孔包括接地空心孔和射频引出空心孔,接地空心孔沿壳体的外侧面的高度方向贯通设置；射频引出空心孔延伸至壳体的腔体内；壳体的背面还设有与接地焊盘连接的直通焊盘,封口区通过接地空心孔经直通焊盘与接地焊盘连接；直通焊盘与射频焊盘之间的节距为0.5mm。本发明提供的0.5mm节距的高频无引线陶瓷外壳及测试方法,能够使空心孔处达到了良好的阻抗匹配；并通过侧面的金属化空心孔与封口区的直接相连,保证封口区的接地良好,抑制谐振。(The invention provides a 0.5 mm-pitch high-frequency leadless ceramic shell and a test method, belonging to the technical field of ceramic packaging.A metalized hollow hole is arranged on the outer side surface of a shell, the diameter of the metalized hollow hole is 0.2mm, the metalized hollow hole comprises a grounding hollow hole and a radio frequency lead-out hollow hole, and the grounding hollow hole is arranged in a penetrating way along the height direction of the outer side surface of the shell; the radio frequency lead-out hollow hole extends into the cavity of the shell; the back of the shell is also provided with a through bonding pad connected with the grounding bonding pad, and the sealing area is connected with the grounding bonding pad through the grounding hollow hole and the through bonding pad; the pitch between the through pads and the radio frequency pads is 0.5 mm. The high-frequency leadless ceramic shell with the pitch of 0.5mm and the testing method can ensure that the hollow hole can achieve good impedance matching; and the metalized hollow holes on the side surfaces are directly connected with the sealing area, so that the good grounding of the sealing area is ensured, and the resonance is inhibited.)

1. The high-frequency leadless ceramic shell with the pitch of 0.5mm comprises a shell, wherein the outer side surface of the shell is provided with a metalized hollow hole, the back surface of the shell is provided with a grounding pad and a radio frequency pad, and the front surface of the shell is provided with a sealing area; the radio frequency lead-out hollow hole extends into the cavity of the shell and is used for leading out a bonding chip; the back of the shell is also provided with a through bonding pad connected with the grounding bonding pad, and the sealing area is connected with the grounding bonding pad through the grounding hollow hole and the through bonding pad; the pitch between the through bonding pads and the radio frequency bonding pads is 0.5mm, and the pitch between the radio frequency bonding pads is 0.5 mm.

2. The 0.5mm pitch high frequency leadless ceramic package according to claim 1, wherein said ground hollow hole is provided on four outer sides of said housing.

3. The 0.5mm pitch high frequency leadless ceramic package according to claim 1, wherein at least two of said ground vias are provided on four outer sides of said housing, respectively, and said radio frequency outgoing vias are provided between two of said ground vias, and each of said ground vias is provided with a through pad connected to said ground pad, respectively.

4. The 0.5mm pitch high frequency leadless ceramic package of claim 1, wherein said ground hollow holes of opposite outer sides of said housing are symmetrically disposed.

5. The 0.5mm pitch high frequency leadless ceramic package of claim 1 wherein the width of said rf pad is equal to the diameter of said metallized hollow hole and the width of said through pad is equal to the diameter of said metallized hollow hole.

6. A test method of a high-frequency leadless ceramic shell with 0.5mm pitch is characterized by comprising the following steps:

fixing a ceramic package shell to be tested on a test board;

arranging a microstrip straight-through line in a chip mounting area of a ceramic package shell to be tested, wherein two ends of the microstrip straight-through line are connected with a test port through a radio frequency lead-out hollow hole and a radio frequency bonding pad to form a test passage;

connecting a vector network analyzer with a probe station;

setting a test frequency and a power level of an input signal, and calibrating the whole test system by adopting a ceramic calibration piece matched with the probe station;

and taking down the calibration piece, placing the ceramic packaging shell to be tested on a probe station, and testing and recording the return loss and the insertion loss of the ceramic packaging shell.

7. The method for testing a 0.5mm pitch high frequency leadless ceramic package according to claim 6, wherein the resistance of said microstrip through line is 45 Ω -50 Ω.

8. The method for testing a 0.5mm pitch high frequency leadless ceramic package according to claim 6, wherein said radio frequency pad is led out to a test port through a test lead-out.

9. The method for testing a 0.5mm pitch high frequency leadless ceramic package according to claim 6, wherein two ends of said microstrip through line are respectively passed through two gold wires, and said gold wires have a diameter of 20mm to 25 mm.

Technical Field

The invention belongs to the technical field of ceramic packaging, and particularly relates to a 0.5mm pitch high-frequency leadless ceramic shell and a test method.

Background

A typical foreign plastic-encapsulated leadless package has a pitch of 0.50mm, and is exemplified by QFNs (quad flat No-lead packages) arranged uniformly around square terminals, as shown in table 1.

TABLE 1 common dimensions and pin counts for foreign plastic-encapsulated QFN devices

	Overall dimension	Total number of lead-out ends	Number of single-sided outlet ends	Pitch of
					QFN16	3×3	16	4	0.50mm
QFN24	4×4	24	6	0.50mm
					QFN32	5×5	32	8	0.50mm
QFN40	6×6	40	10	0.50mm

If the pads are replaced in situ, the ceramic package pads must still maintain a 0.50mm pitch, whereas the conventional hollow holes have a diameter of 0.25mm, see fig. 8-10, due to the high dielectric constant of the ceramic, about 9.8, and the large diameter of the side hollow holes, which results in low impedance at the side hollow holes, and impedance mismatch which results in reduced microwave performance.

In order to ensure the air tightness of the package, it is necessary to add a seal area metallization, see fig. 8 to 10, the metallization is generally in a suspended or single-point grounding state, and is in a poor grounding state, and under a high frequency condition, the seal area metallization may couple with a signal line to generate resonance, and the microwave performance is seriously deteriorated.

Disclosure of Invention

The invention aims to provide a high-frequency leadless ceramic shell with a 0.5mm pitch, and aims to solve the problems of low impedance at a side hollow hole and microwave performance deterioration caused by resonance.

In order to achieve the purpose, the invention adopts the technical scheme that: the high-frequency leadless ceramic shell with the pitch of 0.5mm is provided, and comprises a shell, wherein the outer side surface of the shell is provided with a metalized hollow hole, the back surface of the shell is provided with a grounding pad and a radio frequency pad, the front surface of the shell is provided with a sealing area, the diameter of the metalized hollow hole is 0.2mm, the metalized hollow hole comprises a grounding hollow hole and a radio frequency leading-out hollow hole, and the grounding hollow hole is arranged in a penetrating manner along the height direction of the outer side surface of the shell and is used for connecting the sealing area with the grounding pad; the radio frequency lead-out hollow hole extends into the cavity of the shell and is used for leading out a bonding chip; the back of the shell is also provided with a through bonding pad connected with the grounding bonding pad, and the sealing area is connected with the grounding bonding pad through the grounding hollow hole and the through bonding pad; the pitch between the through bonding pads and the radio frequency bonding pads is 0.5mm, and the pitch between the radio frequency bonding pads is 0.5 mm.

As another embodiment of the present application, the grounding hollow hole is disposed on each of four outer side surfaces of the housing.

As another embodiment of this application, four lateral surfaces of casing are equipped with at least two respectively the hollow hole of ground connection, two all be equipped with between the hollow hole of ground connection the hollow hole is drawn forth to the radio frequency, every the hollow hole of ground connection respectively correspond be equipped with the through pad that the ground connection pad is connected.

As another embodiment of the present application, a width of the rf pad is equal to a diameter of the metalized hollow hole, and a width of the through pad is equal to the diameter of the metalized hollow hole.

As another embodiment of the present application, the ground hollow holes of the opposite outer sides of the housing are symmetrically disposed.

The invention also provides a test method of the high-frequency leadless ceramic shell with the pitch of 0.5mm, which comprises the following steps:

fixing a ceramic package shell to be tested on a test board;

arranging a microstrip straight-through line in a chip mounting area of a ceramic package shell to be tested, wherein two ends of the microstrip straight-through line are connected with a test port through a radio frequency lead-out hollow hole and a radio frequency bonding pad to form a test passage;

connecting a vector network analyzer with a probe station;

setting a test frequency and a power level of an input signal, and calibrating the whole test system by adopting a ceramic calibration piece matched with the probe station;

and taking down the calibration piece, placing the ceramic packaging shell to be tested on a probe station, and testing and recording the return loss and the insertion loss of the ceramic packaging shell.

As another embodiment of the present application, the resistance of the microstrip through line is 45 Ω -50 Ω.

As another embodiment of the application, the radio frequency pad is led out to a test port through a test outgoing line.

As another embodiment of the application, two ends of the microstrip straight-through line are respectively bonded through two gold wires, and the diameter of each gold wire is 20-25 mm.

The high-frequency leadless ceramic shell with 0.5mm pitch provided by the invention has the beneficial effects that: compared with the prior art, the high-frequency leadless ceramic shell with 0.5mm pitch is compatible with a 0.50mm pitch plastic package device, and the scheme that the metalized hollow holes are small hollow holes with the diameter of 0.2mm is adopted, so that the hollow holes achieve good impedance matching; in the back radio frequency bonding pad, one part of the radio frequency bonding pads is directly communicated with the grounding bonding pad to realize forced grounding, and the radio frequency bonding pads are directly connected with the sealing area through the metalized hollow holes on the side surface, so that the good grounding of the sealing area is ensured, and the resonance is inhibited.

The ceramic packaging shell provided by the invention achieves impedance matching, inhibits resonance, achieves high frequency and can cover a Ka frequency band.

The invention can make the pitch and the position of the welding pad consistent with the shell of the plastic package device, so the invention is compatible with the plastic package device, and is not only suitable for the square CQFN shell with 0.50mm pitch, but also suitable for the LCC ceramic shell with 0.50mm pitch and rectangle.

The testing method of the high-frequency leadless ceramic shell with the pitch of 0.5mm provided by the invention provides a test basis for the reliability of the ceramic packaging shell provided by the invention through testing the return loss and the insertion loss of the shell.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a first schematic perspective view of a 0.5mm pitch high frequency leadless ceramic package according to an embodiment of the present invention;

FIG. 2 is a schematic perspective view of a 0.5mm pitch high frequency leadless ceramic package according to an embodiment of the present invention;

FIG. 3 is a schematic top view of a 0.5mm pitch high frequency leadless ceramic package according to an embodiment of the present invention;

FIG. 4 is a schematic bottom view of the 0.5mm pitch high frequency leadless ceramic package shown in FIG. 3;

FIG. 5 is a schematic side view of the 0.5mm pitch high frequency leadless ceramic package shown in FIG. 3;

FIG. 6 is a schematic structural diagram of a test fixture for a high-frequency leadless ceramic package with a pitch of 0.5mm according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a 0.5mm pitch high frequency leadless ceramic package test provided by an embodiment of the present invention;

FIG. 8 is a graph of a test of a 0.5mm pitch high frequency leadless ceramic package provided by an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a ceramic package provided in the prior art;

FIG. 10 is a side view of the structure of FIG. 9;

fig. 11 is a bottom view of the structure of fig. 9.

In the figure: 1. a housing; 2. a radio frequency lead-out hollow hole; 3. a ground hollow bore; 4. a chip mounting area; 5. a seal area; 6. a ground pad; 7. a radio frequency pad; 8. a through pad; 9. a test board; 10. gold wire; 11. a microstrip straight line; 12. and testing the outgoing line.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1 to 5, a 0.5mm pitch high frequency leadless ceramic package provided by the present invention will now be described. The high-frequency leadless ceramic shell with the pitch of 0.5mm comprises a shell 1, wherein the outer side surface of the shell 1 is provided with a metalized hollow hole, the back surface of the shell 1 is provided with a grounding pad 6 and a radio frequency pad 7, the front surface of the shell 1 is provided with a sealing area 5, the diameter of the metalized hollow hole is 0.2mm, the metalized hollow hole comprises a grounding hollow hole 3 and a radio frequency leading-out hollow hole 2, and the grounding hollow hole 3 is arranged in a penetrating manner along the height direction of the outer side surface of the shell 1 and is used for connecting the sealing area 5 with the grounding pad 6; the radio frequency lead-out hollow hole 2 extends into the cavity of the shell 1 and is used for leading out a bonding chip; the back surface of the shell 1 is also provided with a through pad 8 connected with the grounding pad 6, and the sealing area 5 is connected with the grounding pad 6 through the grounding hollow hole 3 and the through pad 8; the pitch between the through bonding pads 8 and the radio frequency bonding pads 7 is 0.5mm, and the pitch between the radio frequency bonding pads 7 is 0.5 mm.

The high-frequency leadless ceramic shell with 0.5mm pitch provided by the invention is compatible with a plastic package device with 0.50mm pitch, compared with the prior art, the scheme that the diameter of a small hollow hole with 0.2mm is selected for a metalized hollow hole is adopted, so that the hollow hole achieves good impedance matching; in the back radio frequency bonding pad 7, a part of the radio frequency bonding pad 7 is directly communicated with the grounding bonding pad 6 to realize forced grounding, and the sealing area 5 is directly connected through a part of metalized hollow holes on the side surface, so that good grounding of the sealing area 5 is ensured, and resonance is inhibited. According to the function of the conventional radio frequency bonding pad 7 and convenience in description, a part of the radio frequency bonding pad 7 is named as a through bonding pad 8, the through bonding pad 8 is connected with a grounding bonding pad 6 through a gold wire 10, and direct grounding is achieved, so that the sealing area 5 can be well grounded, resonance is inhibited, and the working performance of microwaves is improved.

The ceramic packaging shell provided by the invention achieves impedance matching, inhibits resonance, achieves high frequency and can cover a Ka frequency band.

The invention can make the pitch and the position of the welding pad consistent with the shell of the plastic package device, so the invention is compatible with the plastic package device, and is not only suitable for the square CQFN shell with 0.50mm pitch, but also suitable for the LCC ceramic shell with 0.50mm pitch and rectangle.

Referring to fig. 1 to 5, as a specific embodiment of the high-frequency leadless ceramic package with 0.5mm pitch provided by the present invention, the grounding hollow holes 3 are disposed on four outer side surfaces of the housing 1. By providing a plurality of ground hollow holes 3, the grounding performance of the seal area 5 is improved, and the effect of suppressing resonance is improved.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 1 to 5, at least two grounding hollow holes 3 are respectively disposed on four outer side surfaces of the housing 1, the radio frequency outgoing hollow hole 2 is disposed between the two grounding hollow holes 3, and each grounding hollow hole 3 is correspondingly disposed with a through pad 8 connected to the grounding pad 6.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 1 to 5, the grounding hollow holes 3 on the opposite outer sides of the housing 1 are symmetrically disposed. The symmetrical arrangement of the grounding hollow holes 3 also serves to inhibit resonance and improve the working performance of the microwave device.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 1 to 5, the width of the rf pad 7 is equal to the diameter of the metalized hollow hole, and the width of the through pad 8 is equal to the diameter of the metalized hollow hole. As mentioned above, the through pad 8 is actually a function of grounding a part of the rf pad 7, so that the sealing region 5 can be directly connected to the grounding pad 6, thereby achieving a good effect of suppressing resonance.

The invention also provides a test method of the high-frequency leadless ceramic shell with 0.5mm pitch, referring to fig. 6 and 7, the requirements of the test instrument and the tool are as follows:

a) vector network analyzer: the frequency range and precision of the device meet the test requirements;

b) probe platform, probe, calibration piece, test board 9, radio frequency cable: the working frequency of the device is covered with the testing frequency of the device to be tested;

the remarks are as follows:

A) before testing, the probe table top is ensured to be clean and free from foreign matters so as to avoid influencing the grounding effect of the bottom surface of the piece to be tested;

B) before testing, the piece to be tested is ensured to be clean and free from foreign matters so as to avoid the influence of unknown electromagnetic interference on the test result;

C) when the probes contact the piece to be tested, the pressure balance of the probes on the two sides on the piece to be tested is ensured so as to prevent the unbalanced pressure from causing the tilting of one side of the piece to be tested and influencing the test result.

The samples were prepared as follows:

and mounting a 50-ohm microstrip straight-through line 11 on the chip mounting area 4 of the tested piece, bonding two 25-micron gold wires 10 at each position, and then welding the tested piece on the test board 9, wherein the welding ensures that the leading-out end of the shell is well connected with the test board 9 and has no short circuit or insufficient welding phenomenon.

Referring to fig. 7, the present invention provides a specific test method comprising the steps of:

s1, welding the ceramic package shell to be tested on the test board 9;

s2, arranging a microstrip straight-through line 11 in a chip mounting area 4 of the ceramic package shell to be tested, wherein two ends of the microstrip straight-through line 11 are connected with a test port through a radio frequency lead-out hollow hole 2 and a radio frequency pad 7 to form a test path; wherein. The chip mounting region 4 is connected with the radio frequency bonding pad 7 through a gold wire 10;

s3, connecting the vector network analyzer with a probe station;

s4, setting the test frequency and the power level of the input signal, and calibrating the whole test system by adopting a ceramic calibration piece matched with the probe station;

and S5, taking down the calibration piece, placing the ceramic package shell to be tested on a probe station, and testing and recording the return loss and the insertion loss of the ceramic package shell.

The invention relates to a vector network analysis instrument, which is a test device for electromagnetic wave energy. The vector network analyzer can measure various parameter amplitudes of a single-port network or a two-port network, can also measure phases, and can display test data by using a Smith chart. The vector network analyzer adopts the prior art.

The probe station is mainly applied to the testing of semiconductor industry, photoelectric industry, integrated circuits and packaging. The method is widely applied to the research and development of precise electrical measurement of complex and high-speed devices, and aims to ensure quality and reliability and reduce research and development time and cost of device manufacturing processes. The prior art is adopted.

As a specific implementation manner of the embodiment of the present invention, the resistance of the microstrip through line 11 is 45 Ω to 50 Ω.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 6, the rf pad 7 is led out to the test port through the test lead 12. Arrows at two ends of the test board 9 are test ports, wherein the test outgoing lines 12 welded on the test board 9 are connected with the radio frequency bonding pads 7, and signals of the chip mounting area 4 are led out to the test ports.

As a specific implementation manner of the embodiment of the present invention, please refer to fig. 6, two ends of the microstrip through line 11 are respectively bonded through two gold wires 10, and a diameter of the gold wire 10 is 20mm to 25 mm.

The test aim of the invention is to test the return loss and the insertion loss of the shell under the specified conditions, and the test curve chart 8 can show that S11 and S21 respectively correspond to the return loss and the insertion loss of the high-frequency leadless ceramic shell with the 0.5mm pitch and the test method of the test method, and the test of the return loss and the insertion loss of the shell shows that the return loss and the insertion loss are within 40G, so that the indexes of the return loss and the insertion loss are good, and the test basis is provided for the reliability of the ceramic packaging shell provided by the invention.

The requirements of the test instrument and the tooling are as follows:

the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.