Flexible metal column-planting carrier and application thereof in defect detection

Abstract

The invention discloses a flexible metal column-planting carrier and application thereof in defect detection, the carrier is used for embedding and fixing a finished solder wire in a linear state, the carrier is in a solid state in a cut state, the carrier is in a fluid state or a liquid state in an atmosphere at a temperature of 49-80 DEG C, and the carrier is in a flexible metal column-planting state. The deformation resistance of the carrier in the cut state is superior to that of the finished solder wire; according to the application of the flexible metal column-planting carrier in the aspect of defect detection, products with unqualified column-planting end face roundness can be conveniently and rapidly removed in the column-planting preparation process, the column-planting end face roundness and column-planting roundness can be guaranteed, the flatness of the column-planting end face can be guaranteed, and the flexible metal column-planting carrier has the advantages of being simple in operation procedure, easy to control, high in efficiency and the like. And the implementation cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of component production and detection, and specifically relates to a flexible metal pillar carrier and its application in defect detection. Background Art

[0002] Ball grid array packaging is the main packaging form of large-scale integrated circuits and is widely used in different fields. Ceramic column grid array (CCGA) packaging can realize many logic and microprocessor functions. Its packaging form determines its high temperature resistance, high voltage resistance and high reliability. It is suitable for large size and multi-lead situations. It occupies an important position in the field of aviation and aerospace electronic product manufacturing. At present, ceramic column grid array devices are mainly realized by planting columns with the pad facing down.

[0003] The pillars used for components are also called solder pillars or solder nipples, mainly including solder copper pillars, solder tin pillars, and solder aluminum pillars. These solder pillars are made of metal materials with low hardness, a diameter not exceeding 0.8mm, and a length not exceeding 10mm (such as aluminum, copper, gold, silver, and tin) and are collectively called flexible metal pillars. It is one of the key components that affect the reliability of integrated circuits.

[0004] In the prior art, document CN102470493B discloses a method for manufacturing a solder column, comprising: a first step of conveying the wire solder from an insertion port for inserting the wire solder to a discharge port for discharging the wire solder inserted into the insertion port, so that the wire solder protrudes from the discharge port; a second step of cutting the wire solder protruding from the discharge port with a first cutting knife, and cutting the wire solder inserted into the insertion port with a second cutting knife; document CN106270294A discloses a solder column cutting machine , including a base, on which a loading device, a conveying device, a correction device, a cutting device and a hopper are arranged in sequence. The loading device is composed of a support frame with a positioning shaft, a clamping ring and a pressure plate, the support frame is arranged on the base, the clamping ring is arranged on the positioning shaft and fixed by a pressure plate; the conveying device is composed of a fixed frame and an active roller shaft, a driven roller shaft and a motor arranged on the fixed frame, the fixed frame is arranged on the base, the active roller shaft is connected to the output shaft of the motor, the driven roller shaft cooperates with the active roller shaft, and the driven roller shaft is arranged above the active roller shaft. As mentioned above, the common method for preparing flexible metal planting columns is to directly cut the finished solder wire according to the required length. However, this method is very likely to cause deformation of the planting column, especially the poor roundness and flatness of the end face of the planting column, and it is not convenient to quickly remove products with unqualified end face roundness of the planting column during the preparation process. Summary of the invention

[0005] One of the purposes of the present invention is to provide a flexible metal column carrier to solve the technical problem of poor roundness and flatness of the column end surface.

[0006] In order to achieve the above object, the present invention adopts the following technical solution.

[0007] A flexible metal pillar carrier, which is used to bury and fix a finished solder wire in a straight state; the carrier is solid when cut, and is fluid or liquid when in an atmosphere with a temperature of 49-80°C, or the carrier can be cracked, and the deformation resistance of the carrier in the cut state is better than that of the finished solder wire.

[0008] As a preferred embodiment of the present invention, when the finished solder wire is tin wire, the solid carrier is columnar paraffin, columnar glutinous rice block, or columnar flour block.

[0009] As another preferred embodiment of the present invention, when the finished solder wire is a copper wire, the solid carrier is an organic glass block or an organic glass rod.

[0010] Furthermore, the solid carrier is a glutinous rice block or a flour block in a frozen state, the freezing temperature is not higher than -10°C, and the water content in the glutinous rice block or the flour block does not exceed 20% of its total weight.

[0011] Furthermore, the glutinous rice block is formed by consolidating glutinous rice flour with a particle size of no more than 800 meshes and paste, and the flour block is formed by consolidating flour with a particle size of no more than 800 meshes and paste.

[0012] To further facilitate the preparation of the planting column, the thickness of the columnar paraffin, columnar glutinous rice block, and columnar flour block is 18-30 mm; the thickness of the organic glass block or organic glass rod is 5-10 mm. When the planting column is cylindrical, the thickness of the organic glass rod should be understood according to its diameter.

[0013] In order to further facilitate the preparation of the implant column and reduce the difficulty of operation, the side wall of the columnar paraffin, columnar glutinous rice block and columnar flour block has at least one plane along the axial direction.

[0014] Furthermore, the solid carrier can be fixed in a receiving tool (the receiving tool is a part of the carrier, the morphological change of the carrier means that the morphology of the carrier in the inner cavity of the receiving tool can change with temperature changes, the receiving tool and the carrier in the inner cavity of the receiving tool are also referred to as a carrier assembly), and the cut carrier can be taken out of the receiving tool. The second purpose of the present invention is to provide the application of the above-mentioned flexible metal pillar carrier in its defect detection, so as to realize the convenient and rapid removal of the pillar end face roundness unqualified products in the pillar preparation process. First, the carrier embedded with the finished solder wire in a straight state is cut into standard segments, and the short section of solder wire in the standard segment is the pillar, and then the standard segment is placed vertically in the detection field of the roundness detection equipment, and then the roundness of the pillar end face is detected.

[0015] Furthermore, the side wall of the receiving tool is provided with a gap just large enough for the blade of the tool to enter and exit, and the lowest point of the gap is lower than the bottom wall of the inner cavity of the receiving tool; the length of the standard segment is 4-10 mm.

[0016] Beneficial effects: Compared with the existing methods, the preparation of pillars with the aid of the carrier provided by the present invention can not only ensure the roundness of the pillar end face and the flatness of the pillar end face, but also has the advantages of simple operation procedures, easy control, and low implementation cost; more importantly, it is possible to quickly and conveniently remove products with unqualified pillar end face roundness during the preparation process of high-precision pillars, and it is convenient to remove products with unqualified pillar end face roundness in groups. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a top view schematic diagram of the flexible metal pillar carrier in Example 1; Figure 2 is a schematic diagram of the main direction of the flexible metal pillar carrier in Example 1; Figure 3 is a cross-sectional schematic diagram of the flexible metal pillar carrier in the embodiment 1 when in use; Figure 4 It is a cross-sectional schematic diagram of the flexible metal pillar carrier in Example 1 during defect detection.

[0018] In the figure, 1 represents a receiving tool, 2 represents a carrier for embedding finished solder wire, 3 represents finished solder wire, 5 represents an end cover, 6 represents an inner cavity of the receiving tool, 7 represents a gap on a side wall of the receiving tool, 8 represents a cutting direction of a blade, and 9 represents a bottom wall of the inner cavity of the receiving tool. DETAILED DESCRIPTION

[0019] The present invention is further described in conjunction with the accompanying drawings, but the following embodiments are only used to help understand the principle and core idea of ​​the present invention, and are not intended to limit the scope of protection of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, improvements made to the present invention also fall within the scope of protection of the claims of the present invention. Example 1

[0020] See also Figures 1 to 3, a flexible metal pillar carrier, which can be used to manufacture tin pillars, includes a receiving tool 1, in which a solid carrier for burying a finished solder wire 3 is arranged in the inner cavity 6 of the receiving tool 1, and the finished solder wire 3 is built-in and fixed in the solid carrier in a straightened state. In this embodiment, the solid carrier is solid paraffin. Along the width direction of the receiving tool 1, the cross-section of the receiving tool 1 is rectangular, and the width and height of the receiving tool 1 are both 25mm. The receiving tool 1 is made of stainless steel material, and the bottom surface of the receiving tool 1 is a plane with a surface roughness of IT8 level. The wall thickness of the receiving tool 1 is 5mm, and the inner wall of the receiving tool 1 has a self-lubricating coating.

[0021] When in use (to manufacture flexible metal implants - tin pillars), a slit 7 is provided on the side wall of the receiving tool 1, which is just large enough for the blade of the tool to enter and exit. The blade of the tool is always perpendicular to the axis of the finished solder wire 3 after being stretched straight, and the wall thickness of the blade is not more than 1 mm, that is, the blade and the side wall of the slit 7 are matched with a small gap, and the gap between the blade and the slit 7 is controlled within 0.005 mm, and the low point of the slit 7 is lower than the bottom wall 9 of the inner cavity of the receiving tool. The width between two adjacent slits 7 (the distance between the centers of two adjacent slits 7) is equal to the standard width of the solder column. Among them, the finished solder wire 3 passes through the circular holes at both ends of the receiving tool 1, and the aperture of the circular hole is just large enough for the finished solder wire 3 to pass through without causing the finished solder wire 3 to be squeezed, and the two ends of the finished solder wire 3 are fixed on the clamp, and the clamp is fixed on the outside of the receiving tool 1.

[0022] The flexible metal pillar carrier of this embodiment is used in defect detection, specifically: Steps 1-2, straighten the finished tin wire (finished solder wire 3, the same below, with a roundness error of 0.3-0.8 μm); the straightened finished tin wire is located in the receiving tool 1 (the segment to be cut is located in the receiving tool 1); specifically, the finished tin wire (with a diameter of 0.5 mm) is first passed through the round holes at both ends of the receiving tool 1, and then the finished tin wire 3 is straightened and fixed on the fixture, so that the straightness of the straightened tin wire is not less than 0.01 mm; Step 3, first use a high temperature resistant tape (Teflon tape) to seal the gap 7 on the side wall of the receiving tool 1, and then pour the melted paraffin into the receiving tool 1. The temperature of the melted paraffin is controlled to be 110°C. After the paraffin submerges the tin wire, stop pouring. At this time, the straightened tin wire is built into the middle of the paraffin body. When pouring the melted paraffin, pour it from the side of the tin wire, and do not let the fluid paraffin fall directly on the tin wire. Step 4, waiting for the fluid paraffin to cool and solidify to form solid paraffin; Step 5, transfer the container tool 1 with solid paraffin and tin wire as a whole to the operating workshop at 15℃, tear off the high temperature resistant tape, check and adjust the blade for cutting solid paraffin so that it is perpendicular to the axis of the stretched tin wire, cut the solid paraffin into short sections (paraffin short sections, also known as standard sections), and the short sections of solder wire in the standard sections are the planting columns. For the cutting direction, refer to Figure 1 As shown by the middle arrow 8, the standard length of the short section (i.e., the standard segment length) is 4.5 mm; Step 6: Place the standard segment vertically in the detection field of view of the roundness detection equipment. The magnification of the roundness detection equipment is 50 times, which can meet the detection requirements (the same below). Then, the roundness of the end face of the planting column is detected. If the end face of the standard segment of the tin column is as follows: Figure 3 The circular state shown in the figure indicates that the end face of the implant column is qualified; if the end face of the standard segment of the tin column obtained by the test is as follows Figure 4 The non-circular state shown indicates that the end face of the column is unqualified and should be removed; Step 7, heat the obtained qualified short section (standard section) to 75°C, and use tweezers or other tools to remove the tin column after the short section is melted.

[0023] The height difference of the tin column end face finally obtained in this embodiment (the size difference between different parts of the same end face of the tin column relative to the reference plane) is about 0.001-0.002mm, and the accuracy reaches the micron level. The length of the tin column is 4.5mm±0.01mm, and the straightness meets the requirements (because the solder wire 3 has been straightened and wrapped before cutting, as long as the carrier does not deform during the cutting process, it will hardly affect the straightness of the obtained tin column). With the help of a roundness detector, the roundness errors of the end faces are measured to be 7μm and 8μm respectively. Example 2

[0024] A flexible metal pillar carrier, which can be used to manufacture tin pillars, includes a receiving tool 1, in which a solid carrier for burying a finished solder wire 3 is arranged in the inner cavity 6 of the receiving tool 1, and the finished solder wire 3 is built-in and fixed in the solid carrier in a straightened state. In this embodiment, the solid carrier is a glutinous rice block in a frozen state (the freezing temperature is -15°C), and the glutinous rice block is formed by consolidating glutinous rice powder (80% of the total weight) with a particle size of no more than 800 meshes and paste (the water content of which is 10% of the total weight). In this embodiment, along the width direction of the receiving tool 1, the cross-section of the receiving tool 1 is U-shaped, and the width and height of the receiving tool 1 are both 20mm. The receiving tool 1 is made of stainless steel material, and the bottom surface of the receiving tool 1 is a plane with a surface roughness of IT8 level, and the wall thickness of the receiving tool 1 is 5mm. In this embodiment, a slit 7 is provided on the side wall of the receiving tool 1, which is just enough for the blade of the tool to enter and exit. The blade of the tool is always perpendicular to the axis of the finished solder wire 3 after being stretched straight, and the wall thickness of the blade is not more than 1mm, that is, the blade and the side wall of the slit 7 are matched with a small gap, and the gap between the blade and the slit 7 is controlled within 0.005mm, and the low point of the slit 7 is lower than the bottom wall 9 of the inner cavity of the receiving tool. The width between two adjacent slits 7 (the distance between the centers of two adjacent slits 7 is 2.2mm) is equal to the standard width of the solder column. Among them, the finished solder wire 3 passes through the circular holes at both ends of the receiving tool 1, and the aperture of the circular hole is just enough for the finished solder wire 3 to pass through without causing the finished solder wire 3 to be squeezed, and the two ends of the finished solder wire 3 are fixed on the clamp, and the clamp is fixed on the outside of the receiving tool 1.

[0025] The flexible metal pillar carrier of this embodiment is used in defect detection, specifically: Steps 1-2, straighten the finished tin wire; the straightened finished tin wire is located in the receiving tool 1 (the segment to be cut is located in the receiving tool 1); specifically, the finished tin wire (with a diameter of 0.5 mm and a roundness error of 0.3-0.8 μm) is first passed through the round holes at both ends of the receiving tool 1, and then the finished tin wire 3 is straightened and fixed on the fixture, so that the straightness of the straightened tin wire is not less than 0.01 mm / m; Step 3, first use a high temperature resistant tape (Teflon tape) to seal the gap 7 on the side wall of the receiving tool 1, and then pour a fluid and evenly stirred carrier (i.e., a mixture of glutinous rice flour, paste and water) into the receiving tool 1, and stop pouring after the fluid mixture submerges the tin wire. At this time, the straightened tin wire is built into the middle of the fluid mixture; when pouring the fluid mixture, pour it from the side of the tin wire, and do not let the fluid mixture fall directly on the tin wire; Step 4, then quickly transfer the aforementioned receiving tool 1 to an atmosphere of -15°C, and wait for the fluid mixture to cool and solidify to form a solid glutinous rice block; Step 5, tear off the high temperature resistant tape, check and adjust the blade for cutting the solid glutinous rice block so that it is perpendicular to the axis of the straightened tin wire, and cut the solid glutinous rice block into short sections (glutinous rice block short sections). For the cutting direction, refer to Figure 1 As shown by the middle arrow 8, the standard length of the short section is 2.2 mm; Step 6, place the standard segment vertically in the detection field of view of the roundness detection equipment, and then detect the roundness of the end face of the column; if the end face of the standard segment of the tin column detected is a circular state within the allowable error range, it means that the end face of the column is qualified; if the end face of the standard segment of the tin column detected is a non-circular state outside the allowable error range, it means that the end face of the column is unqualified and should be removed; Step 7, transfer the obtained qualified short section (standard section) to an atmosphere of 20-35°C, remove the tin column after the short section dissolves by itself, clean it, dry it naturally, and package it.

[0026] The height difference of the end face of the tin column prepared in this embodiment (the size difference between different parts of the same end face of the tin column relative to the reference surface) is about 0.0015-0.002mm, the accuracy reaches the micron level, and the length of the tin column is 2.2mm±0.01mm; with the help of a roundness detector, the roundness errors of the end faces are measured to be 10μm and 5μm respectively. Example 3

[0027] A flexible metal column carrier, referring to Example 2, differs from Example 2 in that: the solid carrier accommodating the inner cavity of tool 1 is a flour block in a frozen state (freezing temperature is -20°C), and the flour block is formed by consolidating flour with a particle size of no more than 800 mesh (weight accounting for 60% of the total weight) and paste (the water content of which accounts for 15% of the total weight). Example 4

[0028] A flexible metal column carrier, the solid carrier of the inner cavity of the accommodating tool 1 is a glutinous rice block in a frozen state (freezing temperature is -25°C), the glutinous rice block is formed by consolidating glutinous rice flour with a particle size not greater than 800 mesh (weight proportion is 70% of the total weight) and paste (the water proportion of which is 8% of the total weight). Example 5

[0029] A flexible metal column carrier, the solid carrier of the inner cavity of the accommodating tool 1 is a glutinous rice block in a frozen state (freezing temperature is -10°C), the glutinous rice block is solidified by glutinous rice flour with a particle size not greater than 800 mesh (weight proportion is 65% of the total weight) and paste (the water proportion of which is 15% of the total weight). Example 6

[0030] A flexible metal column carrier, the solid carrier accommodating the inner cavity of the tool 1 is a flour block in a frozen state (freezing temperature is -18°C), the flour block is solidified by flour with a particle size not greater than 800 mesh (weight accounting for 75% of the total weight) and paste (the water content of which accounts for 12% of the total weight).

[0031] By using the carrier provided in the embodiment to prepare the column, not only the roundness of the column end face and the flatness of the column end face can be ensured, but also the operation process is simple, easy to control, and the implementation cost is low. More importantly, in the process of preparing high-precision columns, products with unqualified column end face roundness can be quickly and conveniently removed, and products with unqualified column end face roundness can be easily removed in groups. Figure 1 As shown, if the end surface of the 11th tin pillar standard segment 11 is detected in step 6 as follows Figure 4 If the 12th tin pillar standard segment 12 is in a non-circular state, then one of the end faces of the 12th tin pillar standard segment 12 must also be in a non-circular state (only the other end face of the tin pillar standard segment 12 can be tested), so a group of tin pillar standard segments (i.e. the 12th tin pillar standard segment 12 and the 11th tin pillar standard segment 11) can be eliminated at the same time, and then the 13th tin pillar standard segment 13 can be tested in sequence. In the traditional testing scheme, the tin pillars are usually clamped one by one and placed in the precision carrier of the testing equipment (commonly known as the tin pillar laying process), and then tested one by one. Since the tin pillars are not laid in the cutting order at this time, it is impossible to quickly eliminate the products with unqualified roundness of the end faces of the planting pillars in units. Due to the use of the carrier with a specific structure in the present invention, the qualified placement requirements of the tin pillar to be tested can be achieved by simply placing the standard segment vertically, and the placement requirements of a standard segment can be completed within three seconds (that is, the tin pillar detection and placement requirements can be completed within three seconds), which not only saves the precision carrier in the traditional solution, but also saves the cumbersome, time-consuming, and high-demand tin pillar laying process. Using the solution in Example 1, the efficiency of detecting whether the roundness of the end face of the tin pillar is qualified is increased from the original average of about 40 seconds / root to an average of about 27 seconds / root, and the detection efficiency is also significantly improved.

Claims

1. A flexible metal pillar carrier, characterized in that: The carrier is used to bury and fix the finished solder wire in a straight state; the carrier is solid in a cut state, the carrier is fluid or liquid when in an atmosphere with a temperature of 49-80°C, or the carrier can be cracked, and the deformation resistance of the carrier in the cut state is better than that of the finished solder wire.

2. The flexible metal pillar carrier according to claim 1, characterized in that: When the finished solder wire is tin wire, the solid carrier includes columnar paraffin, columnar glutinous rice blocks or columnar flour blocks.

3. The flexible metal pillar carrier according to claim 1, characterized in that: When the finished solder wire is a copper wire or an aluminum wire, the solid carrier is an organic glass block or an organic glass rod.

4. The flexible metal pillar carrier according to claim 2, characterized in that: The solid carrier includes glutinous rice blocks or flour blocks in a frozen state, the freezing temperature is not higher than -10°C, and the water content in the glutinous rice blocks or flour blocks does not exceed 20% of their total weight.

5. The flexible metal pillar carrier according to claim 4, characterized in that: The glutinous rice block is formed by consolidating glutinous rice flour with a particle size not greater than 800 meshes and paste, and the flour block is formed by consolidating flour with a particle size not greater than 800 meshes and paste.

6. The flexible metal pillar carrier according to claim 5, characterized in that: The thickness of the columnar paraffin wax, columnar glutinous rice block and columnar flour block is 18-30 mm; the thickness of the plexiglass block or plexiglass rod is 5-10 mm.

7. The flexible metal pillar carrier according to claim 6, characterized in that: Along the axial direction, two side walls of the columnar wax, columnar glutinous rice block and columnar flour block have at least one plane.

8. The flexible metal pillar carrier according to claim 7, characterized in that: The carrier in a solid state can be fixed in a receiving tool, and the cut carrier can be taken out of the receiving tool.

9. An application of the flexible metal pillar carrier according to any one of claims 1 to 8 in defect detection, characterized in that: First, cut the carrier with the finished solder wire embedded in a straight state into standard segments. The short sections of solder wire in the standard segments are the planting columns. Then, place the standard segments vertically in the detection field of the roundness detection equipment, and then detect the roundness of the end face of the planting column.

10. The application of the flexible metal pillar carrier in defect detection according to claim 9 is characterized in that: The side wall of the receiving tool is provided with a gap just enough for the blade of the tool to enter and exit, and the lowest point of the gap is lower than the bottom wall of the inner cavity of the receiving tool; the length of the standard segment is 4~10mm.

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