TWI411782B - An improved load board and load board assembly - Google Patents

Abstract

According to a first aspect of the present, there is provided a load board for use in a testing process, including a primary board, a secondary board and a communication means to enable communication between the primary and secondary board, wherein the secondary board is removably engaged to the primary board. The present invention further relates to an improved load board assembly, the load board assembly including the improved load board and a stiffener which includes resilient means to resiliently receive the load board to minimize vibration and withstand tensile forces exerted by a material hander and an automatic test equipment, when in use in a testing process.

Description

Improved load board and load board assembly

The present invention relates to a test method for an integrated circuit, and more particularly to an improved load board and load board assembly for testing an integrated circuit.

In the field of manufacturing integrated circuits (ICs), manufactured ICs must undergo functional testing before they are issued. This test method reduces the risk of issuing defective ICs and reduces the associated costs for repairs. Therefore, there is a need for a test method that is efficient, stable, correct, and has the shortest downtime.

In this test method, the handler in the material handling system removes the integrated circuit (or device) from the carrier and loads them into the test socket to utilize the Automatic Test Equipment (ATE). carry out testing. The pins of each device must be inserted into a test socket that is coupled to the interface board of the so-called load board. There must be a stable and correct interconnection between the device pins and the test socket, which is important for achieving the correct test. The pressure distribution of the contact of each device pin on the test socket is uneven, which may result in undesired changes in the test results, resulting in product test yield and corresponding increased test cost.

Moreover, when the load plate assembly is coupled to a material handler and ATE, the load plate assembly experiences an upward tension from the material handler and a downward tension from the ATE during testing. As a result, it is quite common for the load plate to be deformed and damaged. As a result, it will also damage the test yield.

As shown in FIG. 1, a conventional load board is a single board body composed of a plurality of test sockets that are operatively coupled with a plurality of parts to establish a test of the integrated circuit, and in the apparatus. Test and reaction signals are transmitted between the ATE and the ATE. The test socket is secured to a top surface of the load board for coupling to the ATE.

When used, the test socket system often changes during structural changes. For its part, the socket guiding pins on the load board are easily damaged, thus inevitably causing production delays.

Since various tests and various physical limitations of each device may be required, it is often desirable to customize the load board. For each new test requirement or device limitation, a complete load board must be designed and manufactured, which adds time and cost.

During the design phase of the customized load board, it will almost certainly be necessary to weld the components to each other or to de-soldering. This is especially true for RF testing during impedance matching. The load plate is subject to repeated thermal cycling cycles, which often damage the liner, the most common occurrence being the liner bulge. This in turn leads to delays in the design phase and higher costs.

It is an object of the invention to improve the above problems.

According to a first aspect of the present invention, a load board for a test method is provided, comprising: a main board, an auxiliary board and a communication mechanism, the communication mechanism capable of generating communication between the main board and the auxiliary board Where the auxiliary plate is removably snapped to the main plate.

Preferably, the load board further includes a snap mechanism for removably engaging the auxiliary board from the main board.

Preferably, the main panel is sized to receive the auxiliary panel.

Still preferably, when the auxiliary plate is received by the main plate, a surface of the main plate is flush with a surface of the auxiliary plate.

In an embodiment, the communication mechanism is a cable system.

Preferably, the cable system is an impedance controlled coaxial cable.

Preferably, the coaxial cable is received by an auxiliary board at a first end and is received by a main board at a second end, so that communication can be achieved between the main board and the auxiliary board. .

In one embodiment, the coaxial cable is attached to a first printed circuit board at a first end for internal signal transfer.

Preferably, the printed circuit board is detachably coupled to a connector attached to an auxiliary board.

Preferably, the coaxial cable is attached to a second printed circuit board at a second end for internal signal transfer.

Preferably, the second printed circuit board is detachably coupled to a connector attached to a main board.

In an embodiment, the snap mechanism is a screw.

According to a second aspect of the present invention, a load board assembly for a test method is provided. The load board assembly includes: a main board, an auxiliary board, and a communication mechanism, and the communication mechanism can be on the main board and Communication occurs between the auxiliary boards, wherein the auxiliary board is removably snapped to the main board, and the load board assembly further includes a reinforcement for receiving the auxiliary board.

Preferably, the load board of the load board assembly further includes a snap mechanism for removably engaging the auxiliary board from the main board.

In an embodiment, the communication mechanism is a cable system.

Preferably, the cable system is an impedance controlled coaxial cable.

Preferably, the coaxial cable is received by an auxiliary board at a first end and is received by a main board at a second end, so that communication can be achieved between the main board and the auxiliary board. .

In one embodiment, the coaxial cable is attached to a first printed circuit board at a first end for internal signal transfer.

Preferably, the printed circuit board is detachably coupled to a connector attached to an auxiliary board.

Preferably, the coaxial cable is attached to a second printed circuit board at a second end for internal signal transfer.

Preferably, the second printed circuit board is detachably coupled to a connector attached to a main board.

In an embodiment, the snap mechanism is a screw.

Preferably, the load board of the load board assembly further comprises an elastic mechanism for elastically receiving the main board.

Preferably, the resilient mechanism is a spring plunger.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, and embodiments of the present invention are described in the drawings. Although the invention has been described in terms of these preferred examples, the invention is not limited to such examples. Conversely, this The invention is intended to cover all alternatives, modifications and equivalents

Further, in the following detailed description of the invention, reference to the claims However, it will be apparent to those skilled in the art that the present invention may be practiced without these details. In other instances, well-known methods, procedures, compositions and features are not described in detail in order to unnecessarily obscure the inventive concept.

Figure 1 shows a conventional load plate assembly 1000 for a test method. The load board assembly includes a single load board 100 having a plurality of test sockets 110 secured to a top surface of the load board 100 for device pin insertion to perform testing.

In use, the load plate 100 is coupled to the material handling system and the automated test equipment (to avoid confusing the invention, the material handling system and automatic test equipment are not shown). The load plate 100 is housed on a reinforcement 200 to form a conventional load plate assembly.

As previously stated, conventional load board assemblies suffer from a number of problems, thus affecting their test structure, manufacturing time, and cost.

2 shows a load board of the present invention. The load board 2000 includes a main board 300 and an auxiliary board 400. The auxiliary board 400 is removably engaged to the main board 300 through a latching mechanism; in a preferred embodiment, the latching mechanism is a screw 410. It is conceivable that the snap mechanism can also be any other snap mechanism that allows easy removal and snapping, such as electromagnetic and mechanical clamps or clips; for example, latches, rivets, nails or other fasteners; Even an adhesive without departing from the scope of the invention.

The main panel 300 has a generally centrally located pocket 320 that is sized to receive the auxiliary panel 400. When engaged, a surface of the primary panel is flush with the auxiliary panel to form a generally planar surface.

At least one test socket 110 is attached to a surface of the auxiliary board 400 to allow coupling to an automated test equipment for testing. Advantageously, only the auxiliary board 400 needs to be reconfigured for each structural change, or to accommodate a varying device pin structure. This can prevent manufacturing interference to the main board 300, and in the prior art, the main board can easily be damaged or fatigued after various structures have been introduced. Therefore, the load board 2000 of the present invention can save cost and rebuild time.

In order to generate communication between the main board and the auxiliary board, a communication mechanism in the form of a cable system is provided. This cable system is designed to transmit high density and high speed signals, high speed and balanced analog differential signals, and the correct power voltage to the auxiliary board 400 for testing of the test socket 110. In order to enable controlled signal performance to generate communication between the main board and the auxiliary board, high performance coaxial cable, analog signal cable and power cable can be used. Signal performance is measured with parameters S11, S21, offset, time delay, and the like.

In this embodiment, the test performed is an RF test, and the requirements for selecting a cable are for an application scenario of the RF test.

Signal tracking, length and impedance control are key to ensuring good signal performance between the main board 300 and the auxiliary board 400.

In one embodiment, the signal frequency is selected to be 200 MHz. Figure 3 shows the coaxial cable used in the present invention. A coaxial cable 310 having a bandwidth in excess of 1 GHz is selected, which is five times the signal frequency. The selected analog signal cable is a special cable called a differential cable 311, which is specifically selected for special application scenarios for RF testing. The differential cable 311 controls the 1/Q differential signal, S11 and S21 parameters to achieve good and balanced signal performance. The 1/Q differential signal needs to be controlled because an unbalanced signal can adversely affect the test results.

The power cable is selected by considering high-density, low-current leakage power channels with high accuracy over a limited projected area and low inducer power tracking of the auxiliary board.

Mechanical considerations include stability issues to ensure that no losses are generated from the cable system or that losses are minimized. The cable used in the present invention is a U-shaped cable having at least two layers of structure to cope with high density problems; and a cable connector lock 312 designed to protect a stable signal from being used Vibration is generated when the auxiliary board is used. When in use, the first end 313 of the cable is attached to the auxiliary board 400 and the opposite second end 314 is attached to the main board 300. The advantage of using such a U-shaped cable is that in this configuration, there is inherent elongation and cushioning characteristics when manipulating the main plate and the auxiliary plate. In use, when it is desired to dock, the auxiliary board 400 can be moved up and down with respect to the main board 300. Such U-shaped cables have the effect of elongation and cushioning to reduce any jerk generated during docking. It is envisioned that any other cable can be used on the main board and the auxiliary board, and the U-shaped cable is only a preferred embodiment of the present invention.

Figure 4 shows a detailed view of the first end 313 of the cable. As is clear from the figure, the first end 313 of the cable provides a two-layer impedance controlled coaxial cable. The following description is directed to the first end 313 of the cable to be connected to the auxiliary board 400. It should be noted that the following description can also be applied to the cable second end 314 that is connected to the main board.

The cable includes a first internal signal transfer printed circuit board (PCB) 315. The cable is attached to the first printed circuit board 315 by soldering at one end and attached to a cable terminal 316 at the other end of the printed circuit board for connection to a connector 317. This connector 317 is attached to the auxiliary board 400. Printed circuit board 315 is typically shielded by a housing 318. The outer casing 318 includes an attachment mechanism 319 for attachment to the auxiliary plate 400.

The second end 314 of the cable includes a second printed circuit board (PCB) 315' for connection as described above.

Figure 5 shows the load plate 2000 in the load plate assembly 3000 of the present invention.

The load board assembly includes a load board as shown in FIG. 2 and further includes a reinforcement 200. This stiffener 200 is for holding the load plate 2000 and is specifically for receiving the main plate 300.

In order to minimize and address possible vibrations during testing and construction, and to provide flexibility to the tension from both the tester and the material handler, a resilient mechanism 210 is provided to elastically engage the primary panel 300 to the reinforcement. On piece 200. Advantageously, the provision of an elastic mechanism between the main plate and the reinforcement prevents damage to the plate that may occur when the load plate is incorrectly docked. Moreover, the elastic mechanism is able to balance the opposing forces of the carrier and the tester when docked.

In a preferred embodiment, the elastic mechanism 210 is a spring plunger 211, a shoulder screw 212, and a base member 213. The base member 213 is placed on the spring plunger 211 and the shoulder screw. One end of 212. In use, the base member 213 contacts the main panel. Alternatively, the resilient mechanism is a coil spring assembly or coil. In order to create elasticity, the design must be based on the calculated force and contact interface requirements to select a spring plunger, and select the length and diameter of the shoulder screw. The corresponding shoulder screw bracket must be sized to accommodate the shoulder screw to balance the situation when the docking is incorrect.

Figure 6 shows the load plate assembly 3000 when assembled for use in the test method. As can be seen from the figure, when engaged, the main plate and the surface of the auxiliary plate are flush to form a substantially planar surface.

Some embodiments of the invention have been described by way of example, but many modifications may be made without departing from the scope of the invention.

100. . . Load board

110. . . Test socket

200. . . Firmware

210. . . Elastic mechanism

211. . . Spring plunger

212. . . Shoulder screw

213. . . Base member

300. . . Main board

310. . . Coaxial cable

311. . . Differential cable

312. . . Cable connector lock

313. . . First end of the cable

314. . . Second end of the cable

315. . . First printed circuit board (PCB)

315’. . . Second printed circuit board (PCB)

316. . . Cable terminal

317. . . Connector

318. . . shell

319. . . Attachment mechanism

320. . . Pocket

400. . . Auxiliary board

410. . . Screw

1000. . . Conventional load board assembly

2000. . . Load board assembly

3000. . . Load board assembly

In order that the invention may be more clearly understood, the embodiments of the invention are illustrated by way of example

Figure 1 shows a conventional load board assembly.

Figure 2 is a view showing a preferred embodiment of the load plate of the present invention.

Figure 3 is a diagram showing a preferred embodiment of a cable for generating communication between the primary and secondary panels of the present invention.

Figure 4 is a detailed view showing the first end of the cable of the present invention.

Figure 5 is a view showing a preferred embodiment of the load plate assembly of the present invention.

Figure 6 shows the load board assembly for the test method.

In each of the embodiments and variations, the present invention is more readily understood, and the same reference numerals are used to refer to like parts.

200. . . Firmware

210. . . Elastic mechanism

211. . . Spring plunger

212. . . Shoulder screw

213. . . Base member

300. . . Main board

400. . . Auxiliary board

410. . . Screw

2000. . . Load board assembly

3000. . . Load board assembly

Claims (15)

A load board for a test program, comprising: a main board; an auxiliary board; and a communication mechanism capable of generating communication between the main board and the auxiliary board, wherein the auxiliary board is removable The ground is snapped to the main board. The load board of claim 1, wherein the load board further comprises a snap mechanism for removably engaging the auxiliary board from the main board. The load board of claim 2, wherein the main board is sized to receive the auxiliary board. The load board of claim 3, wherein when the auxiliary board is received by the main board, a surface of the main board is flush with a surface of the auxiliary board. For example, the load board of claim 1 is wherein the communication mechanism is a cable system. The load board of claim 5, wherein the cable system is an impedance controlled coaxial cable. The load board of claim 6, wherein the coaxial cable is received by an auxiliary board at a first end and is received by a main board at a second end, so that the main board can be And communication between the auxiliary boards. The load board of claim 7, wherein the coaxial cable is attached to a first printed circuit board at a first end for internal signal transfer. The load board of claim 8, wherein the printed circuit board is detachably coupled to a connector attached to an auxiliary board. The load board of claim 7, wherein the coaxial cable is attached to a second printed circuit board at a second end for internal signal transfer. The load board of claim 8 wherein the second printed circuit board is detachably attachable to a connector attached to a main board. The load board of claim 2, wherein the engaging mechanism is a screw. A load board assembly for a test program, the load board assembly comprising the load board of any one of claims 1 to 12, and further comprising a reinforcement for receiving the auxiliary board. The load board assembly of claim 13, wherein the load board further comprises an elastic mechanism for elastically receiving the main board. The load board assembly of claim 14, wherein the elastic mechanism is a spring plunger.