CN113933549A

CN113933549A - DDR signal quality auxiliary test fixture and test method

Info

Publication number: CN113933549A
Application number: CN202111229201.5A
Authority: CN
Inventors: 邓林; 陈勇; 熊春霖; 陆超杰; 章润林; 罗旦; 颜磊; 黎源华
Original assignee: National University of Defense Technology
Current assignee: National University of Defense Technology
Priority date: 2021-10-21
Filing date: 2021-10-21
Publication date: 2022-01-14

Abstract

The invention discloses a DDR signal quality auxiliary test fixture and a test method, the fixture comprises a substrate and a connecting plate, one side of the substrate is welded with DDR particles, and the other side of the substrate is provided with solder balls connected with the DDR particles; the connecting plate is detachably arranged on the mainboard, a plurality of probes are arranged on the connecting plate, one end of each probe is connected with the mainboard, and the other end of each probe is in one-to-one corresponding contact with the solder balls on the substrate; and the connecting plate is also provided with a clamping assembly for clamping the DDR particles and the substrate on the connecting plate. The invention has the advantages of simple structure, convenient assembly and disassembly, reusability and the like.

Description

DDR signal quality auxiliary test fixture and test method

Technical Field

The invention mainly relates to the technical field of DDR on-board particle testing, in particular to a DDR signal quality auxiliary testing jig and a testing method.

Background

The onboard DDR signal quality test mainly measures the quality of a DDR signal channel of a PCB mainboard by using an oscilloscope, and leads out a signal through a DDR substrate, so that a waveform closest to the DDR signal channel is intercepted. For the prior art, the front side and the back side of the DDR substrate are respectively welded with the DDR particles and the mainboard to be tested through bonding pads. Because the substrate is a multilayer buried resistance plate in a direct welding mode, after welding and dismantling, the impedance of the substrate can be influenced, so that the substrate is almost disposable and cannot be used for multiple times. Because the unit price ratio of base plate is higher, if the mainboard that is surveyed is more, then the base plate can cause huge cost to waste.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the problems in the prior art, the invention provides a DDR signal quality auxiliary test fixture and a test method which are simple in structure, simple and convenient to disassemble and assemble and capable of being repeatedly used.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a DDR signal quality auxiliary test fixture comprises a substrate and a connecting plate, wherein one side of the substrate is welded with DDR particles, and the other side of the substrate is provided with solder balls connected with the DDR particles; the connecting plate is detachably arranged on the mainboard, a plurality of probes are arranged on the connecting plate, one end of each probe is connected with the mainboard, and the other end of each probe is in one-to-one corresponding contact with the solder balls on the substrate; and the connecting plate is also provided with a clamping assembly for clamping the DDR particles and the substrate on the connecting plate.

As a further improvement of the above technical solution:

the connecting plate is detachably mounted on the main board through bolts or screws.

The clamping assembly is a steel wire buckle.

A plurality of accommodating grooves are formed in the connecting plate, and the DDR particles and the substrate are located in the accommodating grooves.

Test points are arranged on two sides of the substrate.

The invention also discloses a test method based on the DDR signal quality auxiliary test fixture, which comprises the following steps:

firstly, welding DDR particles on the front surface of a substrate;

planting balls on a bonding pad on the back of the substrate, putting the substrate with the planted balls and DDR particles on a connecting plate integrally, and simultaneously ensuring that BGA balls on the back of the substrate can be well contacted with the top end of a probe on the connecting plate;

then fixing the connecting plate on the main board to ensure the bottom end of the probe to be in good contact with the main board;

then testing is carried out, and through the test points on the substrate, the oscillograph probe is used for transmitting signals into the oscillograph for carrying out signal quality test;

and directly disassembling the bolt to integrally disassemble the connecting plate from the main plate.

Compared with the prior art, the invention has the advantages that:

according to the DDR signal quality auxiliary test fixture, DDR particles on the substrate and a mainboard are connected through the probes on the connecting plate, the connecting plate is fastened on the mainboard, and the test substrate is fastened on the connecting plate through the clamping assembly, so that the two ends of the probes are ensured to be in close contact with the test substrate and the mainboard, and the electrical connection reliability of the probes is ensured; the test substrate is fastened through the clamping assembly (such as a steel wire fastener), the assembly and disassembly are simple and convenient, the electrical performance of the substrate is not influenced, the change of the electrical performance of the substrate caused by overhigh temperature due to the unsoldering is avoided, and the substrate can be repeatedly used through the connection mode.

Drawings

Fig. 1 is a perspective view of the present invention.

Fig. 2 is a sectional structural view of the present invention in an embodiment.

Illustration of the drawings: 1. a main board; 2. a connecting plate; 201. a probe; 202. a bolt; 3. a substrate; 301. a solder ball; 302. testing points; 4. DDR particles; 5. and a clamping assembly.

Detailed Description

The invention is further described below with reference to the figures and the specific embodiments of the description.

As shown in fig. 1 and fig. 2, the DDR signal quality auxiliary test fixture of the present embodiment includes a substrate 3 and a connection board 2, a top side of the substrate 3 is soldered to the DDR particles 4 and is provided with a test point 302, a bottom side of the substrate 3 is provided with solder balls 301 connected to the DDR particles 4, and the substrate 3 and the DDR particles 4 form a test substrate as a whole; the connecting plate 2 is detachably mounted on the mainboard 1, a plurality of probes 201 are arranged on the connecting plate 2, one end of each probe 201 is connected with the mainboard 1, and the other end of each probe 201 is in one-to-one corresponding contact with the solder balls 301 on the substrate 3; the connecting plate 2 is further provided with a clamping assembly 5 for clamping the DDR particles 4 and the substrate 3 (test substrate) on the connecting plate 2 to ensure reliable contact with the probe 201.

In an embodiment, the connecting plate 2 is detachably mounted on the main plate 1 by means of bolts 202 and nuts. Of course, the fastening to the main board 1 may be directly by screws. Wherein, a plurality of holding grooves are arranged on the connecting plate 2, and the whole body of each DDR particle 4 and the substrate 3 is positioned in the holding grooves. The size and the style of the connecting plate 2 can be customized according to the actual plate type, and one connecting plate 2 can hold a plurality of substrates 3 so as to meet the requirement of the tested mainboard 1 on the number of DDR particles 4.

In one embodiment, the clamping assembly 5 is a steel wire fastener, and has a simple structure and is easy to operate.

According to the DDR signal quality auxiliary test fixture, DDR particles 4 on a substrate 3 and a mainboard 1 are connected through probes 201 on a connecting plate 2, wherein the connecting plate 2 is fastened on the mainboard 1, and a test substrate is fastened on the connecting plate 2 through a clamping assembly 5, so that two ends of the probes 201 are ensured to be in close contact with the test substrate and the mainboard 1, and the electrical connection reliability of the probes is ensured; the test substrate is fastened through the clamping assembly 5 (such as a steel wire fastener), the assembly and disassembly are simple and convenient, the electrical performance of the substrate 3 is not affected, the phenomenon that the temperature is too high due to the unsoldering and the electrical performance of the substrate 3 is changed is avoided, and the substrate 3 can be repeatedly used through the connection mode.

The embodiment of the invention also discloses a test method based on the DDR signal quality auxiliary test fixture, which comprises the following steps:

firstly, welding DDR particles 4 on the front surface of a substrate 3;

planting balls on a bonding pad on the back side of the substrate 3, integrally placing the substrate 3 with the planted balls and the DDR particles 4 on the connecting plate 2, and simultaneously ensuring that the BGA balls on the back side of the substrate 3 can be well contacted with the top end of the probe 201 on the connecting plate 2;

fixing the connecting plate 2 on the main board 1 by screws in a mechanical mode to ensure that the bottom end of the probe 201 is in good contact with the main board 1;

then, the test is performed, and the oscilloscope probe is used for transmitting the signal into the oscilloscope through the test point 302 on the substrate 3, so that the oscilloscope can be used for performing the signal quality test.

After the test is finished, the bolt 202 is directly disassembled, and the connecting plate 2 is integrally disassembled from the main plate 1, so that the test board can be repeatedly used.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.

Claims

1. The DDR signal quality auxiliary test fixture is characterized by comprising a substrate (3) and a connecting plate (2), wherein one side of the substrate (3) is welded with DDR particles (4), and the other side of the substrate (3) is provided with solder balls (301) connected with the DDR particles (4); the connecting plate (2) is detachably mounted on the main board (1), a plurality of probes (201) are arranged on the connecting plate (2), one end of each probe (201) is connected with the main board (1), and the other end of each probe (201) is in one-to-one corresponding contact with the solder balls (301) on the substrate (3); and the connecting plate (2) is also provided with a clamping assembly (5) for clamping the DDR particles (4) and the substrate (3) on the connecting plate (2).

2. The DDR signal quality auxiliary test fixture as claimed in claim 1, wherein the connection plate (2) is detachably mounted on the main board (1) through bolts (202) or screws.

3. The DDR signal quality auxiliary test fixture of claim 1 or 2, wherein the clamping assembly (5) is a steel wire fastener.

4. The DDR signal quality auxiliary test fixture as claimed in claim 1 or 2, wherein the connection board (2) is provided with a plurality of receiving slots, and each DDR particle (4) and the substrate (3) are located in the receiving slots.

5. The DDR signal quality auxiliary test fixture as claimed in claim 1 or 2, wherein test points (302) are arranged on two sides of the substrate (3).

6. The DDR signal quality auxiliary test fixture testing method as claimed in any one of claims 1 to 5, wherein the DDR signal quality auxiliary test fixture testing method comprises the following steps:

firstly, welding DDR particles (4) on the front surface of a substrate (3);

planting balls on a bonding pad on the back side of the substrate (3), integrally placing the substrate (3) and the DDR particles (4) which are well planted on the connecting plate (2), and simultaneously ensuring that the BGA balls on the back side of the substrate (3) can be well contacted with the top end of the probe (201) on the connecting plate (2);

then fixing the connecting plate (2) on the main board (1) to ensure that the bottom end of the probe (201) is in good contact with the main board (1);

then testing is carried out, and through the test point (302) on the substrate (3), the oscilloscope probe is used for transmitting a signal into the oscilloscope for carrying out signal quality test;

after the test is finished, the bolts (202) are directly disassembled, and the connecting plate (2) is integrally disassembled from the main plate (1).