A PCB type TVS diode package and its preparation process

Abstract

The present invention discloses a PCB type TVS diode package and a preparation process thereof, comprising a BT resin PCB board and an epoxy resin, wherein a TVS tube is arranged on the outer surface of the BT resin PCB board, and the epoxy resin is placed on the upper surface of the TVS tube. The PCB type TVS diode package and the preparation process thereof mainly adopt BT resin (with bismaleimide (BMI) and triazine as the main resin components) as the substrate, and both the positive and negative sides of the PCB adopt etching circuits as conduction, and the substrate replaces the metal frame, and then the process flow is solid crystal, wire welding, die pressing, cutting, testing, tape braiding, and warehousing; the bonding property of BT resin and the external sealing glue (epoxy resin) during die pressing is very high, which is much higher than the bonding property with the metal frame, thereby making the product more airtight, and at the same time, because both are resin materials, the expansion coefficients when heated and expanded are also close, and there will be smaller internal stress, thereby avoiding the circuit breaker problem of the metal frame when welding at the client end, and the reliability and quality of the product are higher.

Description

Technical Field

[0001] The present invention relates to the technical field of TVS diode packaging, in particular to a PCB type TVS diode packaging and a preparation process thereof. Background Art

[0002] Transient voltage suppression diodes, referred to as TVS diodes, are high-efficiency protection devices in the form of diodes. When the two poles of a TVS diode are subjected to a reverse transient high-energy impact, it can suddenly reduce its impedance at an extremely high speed (up to 10 to the negative 12th power of seconds), while absorbing a large current to clamp the voltage between its two ends to a predetermined value, thereby ensuring that the subsequent circuit components are protected from damage by transient high-energy impacts. At present, the packaging of conventional TVS diodes belongs to semiconductor packaging. In the production process, its production process is: solid crystal, welding, die pressing, T / F (trim / bend) molding, baking, testing, taping, and warehousing; the specific steps are to apply solder paste or silver glue on the lead frame to fix the TVS diode grains and bake and solidify; after solidification, the pads on the TVS are welded to the lead frame using conductive sheets or conductive wires; then sent to the die pressing station to use epoxy resin die pressing packaging; after die pressing, it enters the T / F process, that is, the pins of the die pressing semi-finished products connected in series are trimmed and bent to form a single formed block TVS diode; then use It is baked at high temperature, then subjected to electrical testing and inspection, and finally put into storage for shipment; the key substrate lead frame is divided into two types: copper bracket and iron bracket, both of which are metal brackets, and then the bracket is coated with epoxy glue. However, due to the current process limitations, the number of single pieces is small, and the UPH during production is very low, and a large amount of production equipment is required to increase production capacity; at the same time, the thermal expansion coefficients of metal and epoxy glue cakes are different. When used for welding in the market client, there is a risk of cracking and penetration. There is also the problem of internal stress expansion breaking the welding wire. For this reason, we propose a PCB type TVS diode package and its preparation process. Summary of the invention

[0003] The purpose of the present invention is to provide a PCB type TVS diode package and its preparation process, so as to solve the current process limitations mentioned in the above background technology, that is, the number of single pieces is small, the UPH during production is very low, and a large amount of production equipment needs to be invested to improve production capacity; at the same time, the thermal expansion coefficients of metal and epoxy glue cake are different, and when used for welding in the market client, there is a hidden danger of cracking and penetration, and there is also the problem of internal stress expansion breaking the welding wire.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a PCB type TVS diode package and a preparation process thereof, comprising a BT resin PCB board and an epoxy resin, wherein a TVS tube is arranged on the outer surface of the BT resin PCB board, the epoxy resin is placed on the upper surface of the TVS tube, a matching groove is provided on the left end surface of the epoxy resin, and a flange lip is fixed on the right end surface of the epoxy resin, a groove is provided on the surface where the TVS tube and the epoxy resin are bonded, and a waterproof pad is adhered to the bottom surface of the TVS tube, the upper and lower side surfaces of the BT resin PCB board are both grooved, and a bonding adhesive is coated on the connection end surface of the BT resin PCB board, the connection end surface of the TVS tube, between the epoxy resin and the TVS tube, and between the TVS tube and the BT resin PCB board.

[0005] Preferably, the specific process steps of the preparation process of the PCB type TVS diode package are as follows:

[0006] a. Prepare raw materials: Use BT resin substrate as the base material, design the pad position according to the TVS size, and make a complete lead circuit;

[0007] b. Bonding: Attach the TVS to the front of the PCB through bonding adhesive;

[0008] c. Baking: Fix the chip on the PCB substrate by baking;

[0009] d. Wire bonding: The positive and negative electrodes of the chip are fixed to the PCB board through wire bonding to form a path;

[0010] e. Molding: Use encapsulation glue and mold it on the PCB through a mold;

[0011] f. Baking: curing the encapsulation glue by baking;

[0012] g. Cutting: Cut the product into designed size;

[0013] h. Testing;

[0014] i. Taping;

[0015] j. Storage.

[0016] Preferably, the overall structural size of the small-size package composed of the BT resin PCB board, TVS tube and epoxy resin is 1.0 mm×0.5 mm×0.6 mm, and the allowable size variation range is ±0.5 mm.

[0017] Preferably, the BT resin substrate has bismaleimide (BMI) and triazine as main resin components.

[0018] Preferably, in the raw material preparation stage, etching circuits are used for conduction on both the positive and negative sides of the PCB using BT resin as a substrate.

[0019] Preferably, the packaging glue is made of Epoxy or Silicone.

[0020] Preferably, the positions of the matching grooves and the flange lips correspond one to one, and the sizes of the matching grooves and the flange lips match each other, and every two epoxy resins are connected through the matching grooves and the flange lips.

[0021] Preferably, the grooves are evenly arranged in the horizontal direction of the upper surface of the TVS tube, and the cross-sectional shape of the grooves is trapezoidal, and the depths of the grooves are equal.

[0022] Preferably, the slots are equidistantly arranged in the horizontal direction of the upper and lower surfaces of the BT resin PCB board, and the slots on the upper surface of the BT resin PCB board correspond to the slots on the lower surface of the BT resin PCB board in one-to-one position.

[0023] Preferably, the left and right outer surfaces of the BT resin PCB board are in contact with the left and right inner surfaces of the TVS tube, and the bottom area of ​​the TVS tube is equal to the surface area of ​​the waterproof pad.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention mainly adopts BT resin (bismaleimide (BMI) and triazine as the main resin components) as the substrate of the PCB, and both the positive and negative sides adopt etching circuits as conduction, and this substrate replaces the metal frame. The subsequent process flow is solid crystal, wire bonding, molding, cutting, testing, taping, and warehousing.

[0026] 2. The bonding between BT resin and the external sealing glue (epoxy resin) during molding is very high, much higher than the bonding with the metal frame, which makes the product more airtight. At the same time, because they are both resin materials, the expansion coefficients when heated are also similar, and there will be smaller internal stress, thus avoiding the circuit breaker problem of the metal frame when welding on the client side, and the product reliability and quality are higher.

[0027] 3. The manufacturing process of the substrate will increase the single-chip arrangement density of the substrate, which can reach 6000~8000pcs per piece, which is much larger than the 50~200pcs / piece of the metal frame, and the efficiency in packaging production will be very high.

[0028] 4. The sizes of the matching groove and the flange lip match each other, which is conducive to the end-to-end clamping of the two epoxy resins. The matching gap between the matching groove and the flange lip is filled with solid crystal glue, so that the epoxy resins of the two packages are firmly and tightly connected, the gap is reduced, the space is saved, the chip arrangement is increased, and the product strength and firmness are enhanced; the BT resin PCB board is wrapped in the TVS tube, which is protected by the TVS tube and supplemented with structural strength. The waterproof pad is set for waterproofing and moisture-proofing.

[0029] 5. The setting of the groove makes the epoxy resin and the TVS tube bite each other, and the bonding is tighter and firmer; the setting of the slot is conducive to the heat dissipation of the BT resin PCB board, and the heat is conducted and dissipated to ensure the stable performance of the entire package; the overall structural size of the small-size package composed of the BT resin PCB board, TVS tube and epoxy resin is 1.0mm×0.5mm×0.6mm, and the size variation range is allowed to be ±0.5mm, in order to reduce the volume of the single chip and ensure the single chip arrangement density. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the assembly side structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the back structure of the BT resin PCB board of the present invention;

[0032] Figure 3 For the present invention Figure 1 Enlarged structural diagram at A in the middle.

[0033] In the figure: 1. BT resin PCB board; 2. TVS tube; 3. Epoxy resin; 4. Matching groove; 5. Flange lip; 6. Groove; 7. Waterproof pad; 8. Slot; 9. Solid crystal glue. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1-3The present invention provides a technical solution: a PCB type TVS diode package and a preparation process thereof, comprising a BT resin PCB board 1 and an epoxy resin 3, a TVS tube 2 is arranged on the outer surface of the BT resin PCB board 1, the epoxy resin 3 is arranged on the upper surface of the TVS tube 2, a matching groove 4 is provided on the left end surface of the epoxy resin 3, and a flange lip 5 is fixed on the right end surface of the epoxy resin 3, a groove 6 is provided on the surface where the TVS tube 2 and the epoxy resin 3 are bonded, and a waterproof pad 7 is adhered to the bottom surface of the TVS tube 2, grooves 8 are provided on the upper and lower side surfaces of the BT resin PCB board 1, and a solid crystal glue 9 is coated on the connection end surface of the BT resin PCB board 1, the connection end surface of the TVS tube 2, between the epoxy resin 3 and the TVS tube 2, and between the TVS tube 2 and the BT resin PCB board 1.

[0036] The specific process steps of the preparation process of the PCB type TVS diode package are as follows:

[0037] a. Prepare raw materials: Use BT resin substrate as the base material, design the pad position according to the TVS size, and make a complete lead circuit;

[0038] b. Bonding: Attach the TVS to the front of the PCB through bonding adhesive;

[0039] c. Baking: Fix the chip on the PCB substrate by baking;

[0040] d. Wire bonding: The positive and negative electrodes of the chip are fixed to the PCB board through wire bonding to form a path;

[0041] e. Molding: Use encapsulation glue and mold it on the PCB through a mold;

[0042] f. Baking: curing the encapsulation glue by baking;

[0043] g. Cutting: Cut the product into designed size;

[0044] h. Testing;

[0045] i. Taping;

[0046] j. Storage.

[0047] The overall structural size of the small-size package composed of the BT resin PCB board 1, the TVS tube 2 and the epoxy resin 3 is 1.0mm×0.5mm×0.6mm, and the allowable size variation range is ±0.5mm.

[0048] BT resin substrates are mainly composed of bismaleimide (BMI) and triazine.

[0049] During the raw material preparation stage, etching circuits are used for conduction on both the positive and negative sides of the PCB using BT resin as the substrate.

[0050] The packaging glue should be Epoxy or Silicone.

[0051] The positions of the matching grooves 4 and the flange lips 5 correspond one to one, and the sizes of the matching grooves 4 and the flange lips 5 match each other, and every two epoxy resins 3 are connected by matching grooves 4 and flange lips 5 .

[0052] The grooves 6 are evenly arranged along the horizontal direction of the upper surface of the TVS tube 2 , and the cross-sectional shape of the grooves 6 is trapezoidal, and the depths of the grooves 6 are all equal.

[0053] The slots 8 are equidistantly arranged along the horizontal direction of the upper and lower surfaces of the BT resin PCB board 1 , and the slots 8 on the upper surface of the BT resin PCB board 1 correspond to the slots 8 on the lower surface of the BT resin PCB board 1 .

[0054] The left and right outer surfaces of the BT resin PCB board 1 are in contact with the left and right inner surfaces of the TVS tube 2 , and the bottom area of ​​the TVS tube 2 is equal to the surface area of ​​the waterproof pad 7 .

[0055] The advantages of the present invention are: the bonding between BT resin and the external sealing glue (epoxy resin) during compression molding is very high, which is much higher than the bonding with the metal frame, thereby making the product more airtight. At the same time, because both are resin materials, the expansion coefficients when expanded by heat are also similar, and there will be smaller internal stress, thereby avoiding the circuit breaking problem that occurs when the metal frame is welded on the client side, and the reliability and quality of the product are higher; at the same time, the manufacturing process of the substrate will increase the single-chip arrangement density of the substrate, which can reach 6000~8000pcs per single chip, which is much larger than the 50~200pcs / single chip of the metal frame, and the efficiency in packaging production will be very high.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A PCB type TVS diode package, comprising a BT resin PCB board (1) and an epoxy resin (3), characterized in that: The outer surface of the BT resin PCB (1) is provided with a TVS tube (2), the epoxy resin (3) is placed on the upper surface of the TVS tube (2), a matching groove (4) is provided on the left end surface of the epoxy resin (3), and a flange lip (5) is fixed on the right end surface of the epoxy resin (3), a groove (6) is provided on the surface where the TVS tube (2) and the epoxy resin (3) are bonded, and a waterproof pad (7) is bonded to the bottom surface of the TVS tube (2), the upper and lower side surfaces of the BT resin PCB (1) are both provided with grooves (8), the connection end surface of the BT resin PCB (1), the connection end surface of the TVS tube (2), between the epoxy resin (3) and the TVS tube (2), and between the TVS tube (2) and the BT resin PCB (1) are all coated with a die-bonding adhesive (9), and the BT resin PCB (1) has bismaleimide (BMI) and triazine as main resin components.

2. The preparation process of a PCB type TVS diode package according to claim 1, characterized in that: The specific process steps of the preparation process of the PCB type TVS diode package are as follows: a. Prepare raw materials: Use BT resin substrate as the base material, design the pad position according to the TVS size, and make a complete lead circuit; b. Bonding: Attach the TVS to the front of the PCB through bonding adhesive; c. Baking: Fix the chip on the PCB substrate by baking; d. Wire bonding: The positive and negative electrodes of the chip are fixed to the PCB board through wire bonding to form a path; e. Molding: Use encapsulation glue and mold it on the PCB through a mold; f. Baking: curing the encapsulation glue by baking; g. Cutting: Cut the product into designed size; h. Testing; i. Taping; j. Storage.

3. The PCB type TVS diode package according to claim 1, characterized in that: The overall structural dimensions of the small-size package formed by the BT resin PCB board (1), the TVS tube (2) and the epoxy resin (3) are 1.0 mm×0.5 mm×0.6 mm, and the allowable dimensional variation range is ±0.5 mm.

4. The PCB type TVS diode package according to claim 2, characterized in that: In the raw material preparation stage, etching circuits are used for conduction on both the positive and negative sides of the PCB using BT resin as a substrate.

5. The PCB type TVS diode package according to claim 2, characterized in that: The packaging glue is selected from Epoxy or Silicone.

6. The PCB type TVS diode package according to claim 1, characterized in that: The positions of the matching grooves (4) and the flange lips (5) correspond one to one, and the sizes of the matching grooves (4) and the flange lips (5) match each other, and every two epoxy resins (3) are connected by matching with the flange lips (5) through the matching grooves (4).

7. The PCB type TVS diode package according to claim 1, characterized in that: The grooves (6) are evenly arranged in the horizontal direction of the upper surface of the TVS tube (2), the cross-sectional shape of the grooves (6) is trapezoidal, and the depths of the grooves (6) are all equal.

8. The PCB type TVS diode package according to claim 1, characterized in that: The slots (8) are arranged equidistantly in the horizontal direction along the upper and lower surfaces of the BT resin PCB board (1), and the slots (8) on the upper surface of the BT resin PCB board (1) correspond to the slots (8) on the lower surface of the BT resin PCB board (1) in one-to-one position.

9. The PCB type TVS diode package according to claim 1, characterized in that: The outer surfaces at both left and right ends of the BT resin PCB board (1) are mutually fitted with the inner surfaces at both left and right sides of the TVS tube (2), and the bottom surface area of ​​the TVS tube (2) is equal to the surface area of ​​the waterproof pad (7).

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