CQFP ceramic shell bonding and bonding clamp

Abstract

The utility model discloses a CQFP ceramic housing bonding and bonding clamp. The CQFP ceramic housing bonding and bonding clamp comprises a base, a top plate and a locking screw connecting the base and the top plate. A raised pedestal is arranged in the center of the base, the pedestal is equal to the ceramic bottom surface of the shell in size, and the height of the pedestal is equal to the height difference between the ceramic bottom surface of the shell and the lead break angle, so that the bottom of the lead break angle does not extrude the plane of the base when the ceramic bottom surface of the shell clings to the pedestal; the base is provided with four positioning corners used for positioning the horizontal position of the shell. The height of the positioning angle is lower than that of the shell, so that bonding and bonding operations are prevented from being influenced; lead grooves are arranged between adjacent positioning angles, and the width of each lead groove needs to be larger than the total width of leads on the side of the shell, so that the leads are prevented from being bent laterally. The positioning angle on the base is used for positioning the horizontal position of the shell, the top plate is used for pressing the side lead to position the vertical position of the shell, and positioning and clamping of the CQFP ceramic shell are completed. And the operation is simple, the clamping is stable, the bonding quality is effectively improved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to a ceramic shell bonding fixture, in particular to a bonding fixture structure design, and an assembly and use process for a flat ceramic shell with four-sided pins. Background Art

[0002] During the chip bonding and bonding process of semiconductor integrated circuits, the shell needs to be effectively positioned to avoid operational errors caused by circuit displacement. Since this type of shell is generally light in weight, the chip may "drift" during the curing stage; the bonding process is prone to the bonding point offset from the designed position, the bonding tail wire is difficult to tear off, and the bonding point quality is poor, which can lead to problems such as product electrical performance parameters exceeding the tolerance and PIND failure. The manual transfer and assembly operations of the shell in multiple processes are prone to cause shell collisions and lead bending, affecting product quality.

[0003] The CQFP ceramic housing has four-sided pins and is one of the common types of military airtight ceramic housings. The housing has a horizontal ceramic bottom surface, and the four side lead angles are slightly lower than the ceramic bottom surface, and the overall mass is relatively small. Combined with the chip bonding, high temperature curing, and bonding process operation requirements, there are several difficulties in positioning this type of housing:

[0004] 1. The total width of the side leads of the shell is close to the side length of the ceramic base, and the fixture must be positioned horizontally within a very small size;

[0005] 2. Since this type of shell is light in weight, the fixture must effectively position the shell in the vertical direction, and the positioning structure must not affect the bonding operation;

[0006] 3. The lead angles on the four sides are slightly lower than the bottom surface of the ceramic. Make sure that the root of the lead is not bent, deformed, scratched or damaged to avoid affecting subsequent tests;

[0007] 4. The fixture must be suitable for the entire process of chip bonding, curing and bonding. Utility Model Content

[0008] The purpose of the utility model is to provide a CQFP ceramic shell bonding fixture, which can be clamped individually or in batches with an array positioning structure. It is simple to operate, stable to clamp, and easy to transfer; it effectively improves the bonding and bonding quality and reduces production costs.

[0009] In order to achieve the above objectives, the utility model adopts the following technical solutions:

[0010] A CQFP ceramic shell bonding fixture comprises a base, a top plate and locking screws connecting the base and the top plate.

[0011] A raised pedestal is provided at the center of the base, the size of the pedestal is equal to the size of the bottom surface of the shell ceramic, and the height is the difference between the bottom surface of the shell ceramic and the height of the lead corner, ensuring that the bottom of the lead corner is not squeezed with the plane of the base when the bottom surface of the shell ceramic is tightly attached to the pedestal; the base is provided with four positioning angles for positioning the horizontal position of the shell; the height of the positioning angle is lower than the height of the shell to avoid affecting the bonding and bonding operations; positioning screw holes are provided at the corners above the positioning angles for connecting the base and the top plate; lead grooves are provided between adjacent positioning angles, and the width of each lead groove must be greater than the total width of the lead on the side of the shell to avoid lateral bending of the lead;

[0012] A top window is provided at the center of the top plate, and its size is larger than that of the outer shell, which is convenient for bonding and bonding operations; limit windows are provided at the four corners of the top window, and their size is larger than that of the positioning angle, ensuring that the positioning angle can be embedded in the limit windows; the thickness of the top plate is equal to the height of the positioning angle, which is convenient for locking screws to be positioned.

[0013] The locking screw squeezes the edge of the limiting window so that the top plate presses the leads on the four sides of the shell to locate the vertical position of the shell.

[0014] When in use, place the ceramic bottom surface of the shell close to the raised pedestal of the base, place the four corners of the shell into the four positioning corners, and the leads on the four sides of the shell pass through the four lead grooves respectively; align the limiting window of the top plate with the pedestal of the base, pass the shell through the top window, and press down the top plate to make it nested with the base; use a locking screw to pass through the limiting window of the top plate and screw it into the screw hole of the base to connect the base and the top plate, thereby completing the clamping and positioning of the shell.

[0015] It can be seen from the above technical scheme that the utility model uses a special fixture to design and use the positioning angle on the base to locate the horizontal position of the shell, and uses the top plate to press the side lead to locate the vertical position of the shell, so as to complete the positioning and support of the CQFP ceramic shell; aluminum is selected as the fixture material, and the fixture can be applied to the whole process of chip bonding, curing, and bonding; the array fixture positioning structure realizes batch clamping and fixing. The fixture is installed before chip bonding and removed after bonding inspection.

[0016] The utility model has the following beneficial effects:

[0017] 1. Safety: The use of the fixture of the utility model can effectively prevent the light-weight tube shell from drifting and colliding during the assembly and transfer process, thereby avoiding unnecessary losses.

[0018] 2. Efficiency: The utility model can be used in conjunction with automatic bonding and bonding equipment to achieve batch bonding and curing of chips.

[0019] 3. Economical: The fixture of the utility model has a simple structure, low manufacturing cost, low maintenance cost and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a schematic diagram of the CQFP48M ceramic housing;

[0021] Figure 2 This is a schematic diagram of a metal base in an embodiment of the utility model;

[0022] Figure 3 This is a schematic diagram of a metal top plate in an embodiment of the utility model;

[0023] Figure 4 This is a schematic diagram of the assembly structure of the clamp in the embodiment of the utility model;

[0024] Figure 5 This is a schematic diagram of a clamp holding a housing according to an embodiment of the utility model;

[0025] Figure 6 This is a schematic diagram of batch clamping in an embodiment of the utility model;

[0026] Description of the accompanying drawings: housing 10, ceramic bottom surface of the housing 11, lead angle 12, base 20, pedestal 21, positioning angle 22, positioning screw hole 23, lead groove 24, top plate 30, top window 31, limit window 32, locking screw 40. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with an example of a CQFP48M ceramic housing, and the example is a detailed explanation of the present invention rather than a limitation.

[0028] like Figure 1 As shown, this embodiment is a CQFP ceramic housing 10 with 48 leads, the housing ceramic bottom surface 11 is slightly higher than the lead corner 12, and the total width of the side leads is similar to the side length of the ceramic base 20.

[0029] like Figure 2 As shown, in this embodiment, a pedestal 21 is provided at the center of the metal base 20, and the base is provided with four positioning angles 22, and between adjacent positioning angles there are lead grooves 24. The height of the pedestal 21 is the difference between the height of the shell ceramic bottom surface 11 and the lead angle 12, and when the shell 10 is placed on the pedestal 21, no extrusion occurs at the lead angle 12; the positioning angle 22 clamps the top angle of the shell 10 to locate its horizontal position; the positioning screw hole 23 is set at the corner above the positioning angle 22, so as to facilitate the connection between the base 20 and the top plate 30.

[0030] like Figure 3As shown, a top window 31 is provided at the center of the metal top plate 30 of the present embodiment, and the size of the top window 31 is slightly larger than the maximum outline size of the outer shell 10. Since the upper size of the outer shell 10 is smaller than the lower size, the top of the outer shell 10 can pass through the top window 31 in a clamped state, which is convenient for bonding and bonding operations; limiting windows 32 are provided at the four corners of the top window 31, and the size of the limiting window 32 is slightly larger than the size of the positioning angle 22, ensuring that the positioning angle 22 can be embedded in the limiting window 32; the thickness of the top plate 30 is equal to the height of the positioning angle 22, which is convenient for locking the screws 40 to position.

[0031] like Figure 4 , Figure 5 The figure is a schematic diagram of the assembly structure of this embodiment. The four corners of the housing 10 are placed into the four positioning corners 22, the ceramic bottom surface 11 of the housing is close to the base 21, and the top plate 30 is covered so that the positioning corners 22 are embedded in the limiting windows 32. The base 20 and the top plate 30 are fastened by locking screws 40 with large-sized screw heads, and the edges of the limiting windows 32 are squeezed so that the top plate 30 is pressed against the side leads to complete the clamping.

[0032] like Figure 6 The figure shows a schematic diagram of a four-link positioning clamp.

Claims

1. A CQFP ceramic shell bonding fixture, characterized by It comprises a base (20), a top plate (30), and a locking screw (40) connecting the base and the top plate; A raised pedestal (21) is provided at the center of the base (20), the size of the pedestal is equal to the size of the ceramic bottom surface (11) of the shell, and the height of the pedestal is the difference between the height of the ceramic bottom surface (11) of the shell and the height of the lead angle (12), so as to ensure that when the ceramic bottom surface (11) of the shell and the pedestal (21) are in close contact, the bottom of the lead angle (12) is not pressed against the plane of the base; the base (20) is provided with four positioning angles (22) for positioning the horizontal position of the shell; the height of the positioning angle (22) is lower than the height of the shell (10) to avoid affecting the bonding and bonding operations; positioning screw holes (23) are provided at the corners above the positioning angles (22) for connecting the base (20) and the top plate (30); lead grooves (24) are provided between adjacent positioning angles, and the width of each lead groove (24) must be greater than the total width of the lead on the side of the shell to avoid lateral bending of the lead; A top window (31) is provided at the center of the top plate (30), and the size of the top window (31) is larger than the size of the housing (10); limiting windows (32) are provided at the four corners of the top window (31), and the size of the limiting windows (32) is larger than the size of the positioning angle (22), so as to ensure that the positioning angle (22) can be embedded in the limiting windows (32); the thickness of the top plate (30) is equal to the height of the positioning angle (22), so as to facilitate the positioning of the locking screws (40); The locking screw (40) squeezes the edge of the limiting window (32), so that the top plate (30) presses the leads on the four sides of the shell, thereby positioning the shell (10) in the vertical direction.

2. The CQFP ceramic housing bonding fixture as claimed in claim 1, characterized in that: The positioning angle (22) on the base positions the housing in the horizontal direction, and the top plate (30) presses the side leads to position the housing in the vertical direction, thereby completing the positioning and support of the CQFP ceramic housing.

3. The CQFP ceramic housing bonding fixture as claimed in claim 1, characterized in that: The fixture is suitable for the entire process of chip bonding, curing and bonding; The chip bonding is cured at high temperature and the gold wire bonding is done by thermoacoustic bonding. The maximum temperature of the gold wire thermoacoustic bonding process is 150°C. The fixture is installed before chip bonding and removed after bonding inspection.

Images